Volume 12 INSTRUCTION MANUAL FOR DC ELECTRIC POWER …

Instruction Manual For DC Electric Power System Evaluation Methodology 8/1/2013 Page 1 of 257

Volume 12

INSTRUCTION MANUAL

FOR

DC ELECTRIC POWER SYSTEM

EVALUATION

METHODOLOGY

Richard A. Uher RAIL SYSTEMS CENTER

2013 Country Club Drive Mount Vernon, PA 15135-3040

[email protected]

TOM Version 3.4.2 Edition

August 1, 2013


Preface

This document is part of a series of instruction manuals, which can be used as guidelines for applying the Train Operations Model (TOM) to rail systems throughout the world. In this connotation, rail system definition includes main line railroads, heavy and light rail, trolleybuses, high-speed rail and MAGLEV and people movers. There are several manuals in the series: Volume 1 – An Introduction to the Instruction Manual for Applying the TOM Volume 2 – Instruction Manual for Applying the TOM to Transit Systems DC Electric – English Units Volume 3 – Instruction Manual for Applying the TOM to Transit Systems DC Electric – Metric Units Volume 4 – Instruction Manual for Applying the TOM to Transit Systems AC Electric – English Units Volume 5 – Instruction Manual for Applying the TOM to Transit Systems AC Electric – Metric Units Volume 6 – Instruction Manual for Applying the TOM to Railroads Fueled – English Units Volume 7 – Instruction Manual for Applying the TOM to Railroads Fueled – Metric Units Volume 8 – Instruction Manual for Applying the TOM to Rail Systems; Technology Aspects Volume 9 – Instruction Manual for Procedures and Shortcuts in the TOM Volume 10 – Instruction Manual for Including the Return Circuit in Electric Rail Systems Volume 11 - Instruction Manual Exercising the AC Drive Model Volume 12 – Instruction Manual For DC Electric Power System Evaluation Methodology Volume 13 – Instruction Manual For AC Electric Power System Evaluation Methodology Volumes 2-13 cover nearly all transit systems and railroads in the world. This instruction manual is Volume 12. These volumes are unprotected. Thus the user is free to make notes or rewrite sections according to his preferences. The primary purpose for using the TOM is evaluation. The evaluation generally takes the form of a study, with certain objectives, which may or may not be well defined. As the study is conducted, new objectives may result, because of unanticipated results. Within the framework of evaluation, designs may be modified and further evaluated, so that in this sense, the TOM may be considered a design tool. The TOM is used together with other standard software, such as Microsoft Office (in particular, WORD, EXCEL and POWERPOINT). This combined package is most effective in assembling client data as well as presenting results. In some instances, the TOM interacts directly with these office programs, while in other cases; the user handles the office packages directly.


Table of Contents 1 INTRODUCTION........................................................................................................ 8 2 DESCRIPTION OF DCEM RAIL SYSTEM ............................................................ 11

2.1 TRAIN .............................................................................................................. 11 2.1.1 Train Consists ....................................................................................................................... 11

2.1.1.1 Types of Cars in Fleet ................................................................................................. 11 2.1.1.2 Train Types ................................................................................................................. 12

2.1.2 Train Resistance Information ............................................................................................... 12 2.1.3 Car Physical Characteristics ................................................................................................. 13 2.1.4 Car Propulsion Systems........................................................................................................ 13

2.1.4.1 CAM Car Propulsion................................................................................................... 13 2.1.4.2 ACD Car Propulsion ................................................................................................... 14

2.2 RIGHT OF WAY.............................................................................................. 14 2.2.1 Track Layout......................................................................................................................... 14 2.2.2 Passenger Stations ................................................................................................................ 15

2.3 ELECTRIC DISTRIBUTION SYSTEM.......................................................... 16 2.3.1 Overview .............................................................................................................................. 16 2.3.2 Nodal Diagram ..................................................................................................................... 16

2.3.2.1 Primary Circuit............................................................................................................ 17 2.3.2.2 Return Circuits ............................................................................................................ 19

2.3.2.2.1 Return Circuit Without Bonds ........................................................ 19 2.3.2.2.2 Return Circuit With Bonds ............................................................. 20

2.3.3 Substations............................................................................................................................ 21 2.3.4 Wayside Electrical Components........................................................................................... 21

2.3.4.1 Primary & Return Circuit (Inclusion of Return Circuit Method) ................................ 21 2.3.4.2 Primary Circuit (Loop Method) .................................................................................. 22

2.4 OPERATIONAL TIMETABLE....................................................................... 23 2.5 BASIC SYSTEM.............................................................................................. 23

3 TOM INITIAL SIMULATION ................................................................................. 24 3.1 TPS INPUT FILES ........................................................................................... 24

3.1.1 Control.................................................................................................................................. 24 3.1.2 Train ..................................................................................................................................... 25

3.1.2.1 CAM Train.................................................................................................................. 25 3.1.2.2 ACD Train................................................................................................................... 32

3.1.3 Station................................................................................................................................... 38 3.1.4 Right of Way ........................................................................................................................ 40

3.1.4.1 Grade File.................................................................................................................... 40 3.1.4.2 Curve File.................................................................................................................... 42 3.1.4.3 Speed Restriction File ................................................................................................. 43 3.1.4.4 Route Files .................................................................................................................. 45

3.1.5 TPS File of Filenames .......................................................................................................... 49 3.1.5.1 Rock Garden to Noel End ........................................................................................... 49 3.1.5.2 Noel End to Rock Garden ........................................................................................... 50 3.1.5.3 Rock Garden to Fenton Harbor ................................................................................... 51 3.1.5.4 Fenton Harbor to Rock Garden ................................................................................... 52 3.1.5.5 Listing of All TPS Input Files ..................................................................................... 53

3.2 TPS RESULTS ................................................................................................. 54 3.3 ENS INPUT FILES........................................................................................... 54

3.3.1 Circuit Files .......................................................................................................................... 55 3.3.1.1 Primary Circuit (Return Circuit Method).................................................................... 56 3.3.1.2 Primary Circuit (Loop Method) .................................................................................. 57 3.3.1.3 Return Circuit (Without Rail Bonds) .......................................................................... 58 3.3.1.4 Return Circuit (With Rail Bonds) ............................................................................... 59


3.3.2 Return Circuit Impedance Files ............................................................................................ 60 3.3.2.1 Return Circuit (Without Bonds).................................................................................. 60 3.3.2.2 Return Circuit (With Bonds) ....................................................................................... 62

3.3.3 Network Files ....................................................................................................................... 64 3.3.3.1 Network Files (Circuit Files Method) ......................................................................... 64 3.3.3.2 Network Files (Original Method)................................................................................ 67

3.3.4 Operating Time File.............................................................................................................. 67 3.3.5 Train Location Files.............................................................................................................. 68 3.3.6 Current Measurement Input File........................................................................................... 70 3.3.7 ENS Files of Filenames ........................................................................................................ 71

3.3.7.1 Return Circuit with Bonds .......................................................................................... 71 3.3.7.2 Loop ............................................................................................................................ 73 3.3.7.3 Return Circuit Without Bonds..................................................................................... 74 3.3.7.4 Original ....................................................................................................................... 75 3.3.7.5 Original Double Track ................................................................................................ 76 3.3.7.6 Listing of All ENS Input Files .................................................................................... 77

3.4 ENS RESULTS................................................................................................. 78 3.4.1 Adjustment of Train Location File ....................................................................................... 78 3.4.2 ENS Run Summaries ............................................................................................................ 81

4 POWER SYSTEM DESIGN EVALUATION .......................................................... 82 4.1 ENERGY CONSUMPTION ............................................................................ 82 4.2 GHOST TRAIN APPROACH.......................................................................... 84

4.2.1 Ghost Train Listings ............................................................................................................. 84 4.2.2 TPS for Ghost Trains............................................................................................................ 84

4.2.2.1 Input Files for TPS...................................................................................................... 85 4.2.2.2 TPS Results ................................................................................................................. 97

4.2.3 ENS for Ghost Trains ........................................................................................................... 97 4.2.3.1 ENS Input Files ........................................................................................................... 97 4.2.3.2 ENS Results ................................................................................................................ 98

4.3 TRAIN VOLTAGES ........................................................................................ 99 4.3.1 Voltage Graphs – Normal Train Operation .......................................................................... 99

4.3.1.1 CAM Rtn Cct w/o Bnds Nom Volt ............................................................................. 99 4.3.1.1.1 Inclusion of the Return Circuit Method .......................................... 99 4.3.1.1.2 Loop Method................................................................................. 100 4.3.1.1.3 Original Method Single Track Impedance.................................... 101

4.3.1.2 CAM Rtn Cct w Bnds Nom Volt .............................................................................. 102 4.3.1.2.1 Inclusion of Return Circuit Method.............................................. 102 4.3.1.2.2 Original Method Double Track Impedance .................................. 103

4.3.1.3 CAM Rtn Cct w/o Bnds Ave Volt ............................................................................ 104 4.3.1.3.1 Inclusion of Return Circuit Method.............................................. 104 4.3.1.3.2 Loop Method................................................................................. 105 4.3.1.3.3 Original Method............................................................................ 106

4.3.1.4 CAM Rtn Cct w Bnds Ave Volt................................................................................ 107 4.3.1.4.1 Inclusion of Return Circuit Method.............................................. 107 4.3.1.4.2 Original Method Double Track Impedance .................................. 108

4.3.2 Minimum Train Voltage – Normal Train Operation .......................................................... 109 4.3.2.1 No Regeneration ....................................................................................................... 116 4.3.2.2 Regeneration ............................................................................................................. 117

4.3.3 Voltage Graphs – Ghost Train Operation ........................................................................... 119 4.3.3.1 Nominal Voltage ....................................................................................................... 119

4.3.3.1.1 Rock Garden to Noel End ............................................................. 119 4.3.3.1.2 Noel End to Rock Garden ............................................................. 121


4.3.3.1.3 Rock Garden to Fenton Harbor..................................................... 123 4.3.3.1.4 Fenton Harbor to Rock Garden..................................................... 125

4.3.3.2 Average Voltage ....................................................................................................... 127 4.3.3.2.1 Rock Garden to Noel End ............................................................. 127 4.3.3.2.2 Noel End to Rock Garden ............................................................. 129 4.3.3.2.3 Rock Garden to Fenton Harbor..................................................... 131 4.3.3.2.4 Fenton Harbor to Rock Garden..................................................... 133

4.3.4 Minimum Train Voltage – Ghost Train Operation ............................................................. 135 4.3.4.1 Nominal Voltage ....................................................................................................... 135 4.3.4.2 Average Voltage ....................................................................................................... 135

4.4 TRAIN CURRENTS ...................................................................................... 136 4.4.1 Current Graphs ................................................................................................................... 136

4.4.1.1 CAM Rtn Cct w/o Bnds Nom Volt ........................................................................... 136 4.4.1.1.1 Inclusion of the Return Circuit Method ........................................ 136 4.4.1.1.2 Loop Method................................................................................. 137 4.4.1.1.3 Original Method Single Track Impedance.................................... 138

4.4.1.2 CAM Rtn Cct w Bnds Nom Volt .............................................................................. 139 4.4.1.2.1 Inclusion of the Return Circuit Method ........................................ 139 4.4.1.2.2 Original Method Double Track Impedance .................................. 140

4.4.1.3 CAM Rtn Cct w/o Bnds Ave Volt ............................................................................ 141 4.4.1.3.1 Inclusion of the Return Circuit Method ........................................ 141 4.4.1.3.2 Loop Method................................................................................. 142 4.4.1.3.3 Original Method Single Track Impedance.................................... 143

4.4.1.4 CAM Rtn Cct w Bnds Ave Volt................................................................................ 144 4.4.1.4.1 Inclusion of the Return Circuit Method ........................................ 144 4.4.1.4.2 Original Method Double Track Impedance .................................. 145

4.4.2 Maximum Current Comparisons ........................................................................................ 146 4.4.2.1 No Regeneration ....................................................................................................... 149 4.4.2.2 Regeneration ............................................................................................................. 149

4.4.3 Ghost Train Current Graphs ............................................................................................... 150 4.4.3.1 Nominal Voltage ....................................................................................................... 150

4.4.3.1.1 Rock Garden to Noel End ............................................................. 150 4.4.3.1.2 Noel End to Rock Garden ............................................................. 152 4.4.3.1.3 Rock Garden to Fenton Harbor..................................................... 154 4.4.3.1.4 Fenton Harbor to Rock Garden..................................................... 156

4.4.3.2 Average Voltage ....................................................................................................... 158 4.4.3.2.1 Rock Garden to Noel End ............................................................. 158 4.4.3.2.2 Noel End to Rock Garden ............................................................. 160 4.4.3.2.3 Rock Garden to Fenton Harbor..................................................... 162 4.4.3.2.4 Fenton Harbor to Rock Garden..................................................... 164

4.5 SUBSTATION LOADING ............................................................................ 166 4.5.1 Application of the TOM ..................................................................................................... 166 4.5.2 Nominal Voltage Results.................................................................................................... 172 4.5.3 Average Voltage Results .................................................................................................... 175

4.6 DISTRIBUTION SYSTEM CURRENTS AND RMS LOADING................ 178 4.6.1 Current Analyzer of the FMM............................................................................................ 178 4.6.2 Distribution System Currents ............................................................................................. 184

4.6.2.1 Heating Currents ....................................................................................................... 188 4.6.2.1.1 Substation Connections................................................................. 188 4.6.2.1.2 Track Bond Lines.......................................................................... 189


4.6.2.1.3 Track Lines on Track 1 ................................................................. 190 4.6.2.1.4 Track Lines on Track 2 ................................................................. 191

4.6.2.2 Real Currents............................................................................................................. 192 4.6.2.2.1 Track Bond Lines at Substations .................................................. 192 4.6.2.2.2 Track bond Lines Between Substations........................................ 193

4.6.3 RMS Loading ..................................................................................................................... 194 4.6.3.1 File Viewer Display Method..................................................................................... 194 4.6.3.2 Current Analyzer Screen Method.............................................................................. 197

5 CONTINGENCY ANALYSES ............................................................................... 205 5.1 SUBSTATIONS OUT OF SERVICE ............................................................ 205

5.1.1 Removing a Substation from Service ................................................................................. 205 5.1.1.1 Original Method........................................................................................................ 205 5.1.1.2 Inclusion of Return Circuit Method or Loop Method ............................................... 210

5.1.2 Determination of Minimum Voltage .................................................................................. 213 5.1.3 Normal Train Operation ..................................................................................................... 221

5.1.3.1 Results with Original Method ................................................................................... 221 5.1.3.1.1 Nominal Voltage........................................................................... 221 5.1.3.1.2 Average Voltage ........................................................................... 222

5.1.3.2 Results with Inclusion of Return Circuit Method Without Rail Bonds..................... 222 5.1.3.2.1 Nominal Voltage........................................................................... 223 5.1.3.2.2 Average Voltage ........................................................................... 223

5.1.3.3 Results for Original Method – Double Track Impedance ......................................... 223 5.1.3.3.1 Nominal Voltage........................................................................... 224 5.1.3.3.2 Average Voltage ........................................................................... 224

5.1.3.4 Results for Inclusion of Return Circuit Method with Rail Bonds ............................. 225 5.1.3.4.1 Nominal Voltage........................................................................... 225 5.1.3.4.2 Average Voltage ........................................................................... 225

5.1.4 Ghost Train Operation ........................................................................................................ 226 5.1.4.1 Results with Original Method Single Track Resistance............................................ 226

5.1.4.1.1 Nominal Voltage........................................................................... 226 5.1.4.1.1.1 Fenton Harbor – Rock Garden............................................... 226 5.1.4.1.1.2 Noel End - Rock Garden...................................................... 226 5.1.4.1.1.3 Rock Garden - Fenton Harbor.............................................. 227 5.1.4.1.1.4 Rock Garden - Noel End...................................................... 227

5.1.4.1.2 Average Voltage ........................................................................... 228 5.1.4.1.2.1 Fenton Harbor – Rock Garden............................................... 228 5.1.4.1.2.2 Noel End - Rock Garden...................................................... 228 5.1.4.1.2.3 Rock Garden - Fenton Harbor.............................................. 228 5.1.4.1.2.4 Rock Garden - Noel End...................................................... 228

5.1.4.2 Results with Inclusion of Return Circuit Method Without Bonds ............................ 229 5.1.4.2.1 Nominal Voltage........................................................................... 229

5.1.4.2.1.1 Fenton Harbor – Rock Garden............................................... 229 5.1.4.2.1.2 Noel End - Rock Garden...................................................... 229 5.1.4.2.1.3 Rock Garden - Fenton Harbor.............................................. 229 5.1.4.2.1.4 Rock Garden - Noel End...................................................... 229

5.1.4.2.2 Average Voltage ........................................................................... 230 5.1.4.2.2.1 Fenton Harbor – Rock Garden............................................... 230 5.1.4.2.2.2 Noel End - Rock Garden...................................................... 230 5.1.4.2.2.3 Rock Garden - Fenton Harbor.............................................. 230


5.1.4.2.2.4 Rock Garden - Noel End...................................................... 230 5.2 RESTARTING TRAINS ................................................................................ 231

5.2.1 Original Method with Single Track Impedance.................................................................. 233 5.2.1.1 Nominal Voltage ....................................................................................................... 233 5.2.1.2 Average Voltage ....................................................................................................... 233

5.2.2 Inclusion of Return Circuit Method without Rail Bonds.................................................... 233 5.2.2.1 Nominal Voltage ....................................................................................................... 233 5.2.2.2 Average Voltage ....................................................................................................... 234

5.2.3 Original Method with Double Track Impedance ................................................................ 234 5.2.3.1 Nominal Voltage ....................................................................................................... 234 5.2.3.2 Average Voltage ....................................................................................................... 234

5.2.4 Inclusion of Return Circuit Method with Rail Bonds ......................................................... 234 5.2.4.1 Nominal Voltage ....................................................................................................... 234 5.2.4.2 Average Voltage ....................................................................................................... 235

5.2.5 Position and Time Sensitivity ............................................................................................. 236 5.2.5.1 Time Delay................................................................................................................ 236 5.2.5.2 Start Point Shift ......................................................................................................... 237

6 SELF-CONSISTENT AVERAGE VOLTAGE....................................................... 239 6.1 ORIGINAL METHOD SINGLE TRACK IMPEDANCE............................. 247 6.2 INCLUSION OF RETURN CIRCUIT METHOD WITHOUT BONDS....... 248 6.3 LOOP METHOD............................................................................................ 248 6.4 ORIGINAL METHOD DOUBLE TRACK IMPEDANCE........................... 249 6.5 INCLUSION OF RETURN CIRCUIT METHOD WITH BONDS............... 249 6.6 COMPARISON SELF-CONSISTENT TO TRACTION STANDARDS AVERAGE VOLTAGE .............................................................................................. 249

6.6.1 Normal Train Operation ..................................................................................................... 250 6.6.1.1 Train Minimum Voltage ........................................................................................... 250 6.6.1.2 Train Maximum Current ........................................................................................... 250 6.6.1.3 Substation Loading ................................................................................................... 251 6.6.1.4 Distribution System Currents .................................................................................... 252

6.6.2 Contingency Operation – Substation Out of Service .......................................................... 255 6.6.3 Contingency Operation – Train Restart .............................................................................. 255

6.7 CONCLUSIONS............................................................................................. 256 7 SUMMARY ............................................................................................................. 256


1 INTRODUCTION The purpose of this manual is to provide a guideline for application of the TOM to DC Power Distribution in Rail Transit Systems. Generally, heavy and light rail systems fall into this category. Three phase AC power is provided to DC Transformer-Rectifier substations, which in turn distribute this power via a third rail, catenary or trolley to trains, which pick up the power and use it for propulsion and on-board auxiliaries. It is important to understand what the TOM “ is and is not “ in order to properly apply it. The TOM is not a design model for any of its applications. As quoted on the web page located at http://www.railsystemscenter.com/: “The Train Operations Model (TOM) contains all of the computer tools to simulate the operation of a rail transit system or mainline railroad on a computer.” The TOM is a tool for evaluation. Traction Power Engineering consultants use the TOM as an evaluation tool. The design of the power system is laid out, evaluated by the TOM and things are adjusted based on TOM evaluation. This is done until an “adequate” design is achieved. The TOM is neither a liberal nor conservative tool. It is the engineering process that generates inputs to the TOM that are either liberal or conservative. The TOM can do no more than those inputs. If liberal input then liberal output. If conservative input then conservative output. The decision of “adequate” is made by the experienced engineer using the TOM. The terms liberal and conservative are used here to measure the strength of the power distribution system. Liberal applies to a weak power system and conservative applies to a strong power system. From time to time within this guideline, these terms will be used to describe method of evaluation. This guideline is based on the IEEE Standard: P1653.3 Guide for Rail Transit Traction Power Systems Modeling The first question to be answered in terms of this standard is what the TOM can and cannot do as an evaluation tool.

http://www.railsystemscenter.com/�


The TOM can:

Determine energy consumption Estimate train voltages at every position Estimate train currents at every position and currents through all lines feeding the

train as functions of time. Provide information on substation loading. Develop Root-Mean-Square (RMS) current in all lines feeding the trains. Simulate contingency conditions

The TOM cannot:

Perform fault modeling Harmonic analysis of the power circuit Estimate rail to ground voltages (except under special circumstances)

The last “cannot;” namely “Estimate rail to ground voltages” should be qualified. The TOM has a Rail Voltage Model, which has the capability of estimating, rail-to-ground voltage with a single train running on a two track network. With this configuration, only one train is between substations at any given time. With two trains between substations, the rail-to-ground voltage will be lower because of cancellation effects of the current through the rails between the trains and substations. However, this is no longer true for three trains between substations. So the Rail Voltage Model is of limited usefulness and could be used as a starting point for a more sophisticated model. This guideline uses a base rail transit system in order to provide instruction to the reader. This base system has all of the characteristics of real world transit systems. The first step is to provide a description of the rail system appropriate for determining input data to the TOM. This is actually the first step that anyone uses for any model. More specifically that step is a preliminary step to conversion of “ the raw rail system data” into files which are readable by the simulators. Any user of the TOM should take the time to produce such a description before producing input files to the TOM. The description then becomes a working document, which is updated as new information is obtained, which subsequently require changing TOM input. Section 2 is such a document. This document will use metric units. Since the TOM has both English and Metric unit capability, the document can be converted to English units if desired. After the system description document is written, the next step is to complete the initial simulations using the TOM. This is usually accomplished by considering the most taxing conditions, but with normal operation. For example, the minimum headway operation with crush loaded trains is such a case. This condition is referred as initial operation.


Section 3 illustrates the use of the TOM in this simulation. It includes setting up the trains and right of way conditions for the TPS (Train Performance Simulator). This is then followed by inputting the parameters and conditions for running the ENS (Electric Network Simulator) and the running it for initial operation. Section 4 shows the methodology for analyzing the power system design. This methodology uses the output of both the TPS and ENS to effect these analyses. The topics of Energy Consumption, the Ghost Train, Train Voltages, Train Currents, Substation Loading and Distribution System Currents and RMS Currents are discussed in this section. Section 5 describes power system contingency analysis. Conditions such as substations out of service and restarting stopped trains are considered here. Section Error! Reference source not found., labeled Power System Design Re-Evaluation re-visits the design and develops discussion of other options which should be considered Finally, Section Error! Reference source not found. summarizes the instruction manual and summarily reiterates the items covered.


2 DESCRIPTION OF DCEM RAIL SYSTEM Certain kinds of data are required to describe a rail transit system for TOM application. These data are divided into five general categories:

o Train o Right of Way o Electrical Distribution o Operational Timetable o Basic System

Each of these is described for the DCEM Rail System in the following sections. 2.1 TRAIN The group Train is further divided to include:

o Train Consists o Train Resistance Information o Car Physical Characteristics o Car Propulsion Characteristics

This kind of information is used to create the train files, which are input files to the TPS.

2.1.1 Train Consists The Train Consists are described by the types of cars in the fleet, which are used for service and how these cars are used in trains. A train is a group of one or more cars coupled together. For a power system evaluation, it is proper to take the longest train consist for the evaluation. This will be a six car train.

2.1.1.1 Types of Cars in Fleet There will be two types of cars used for the analysis:

Type 1 - Self-propelled using DC Series motors with Cam Control (Switched Resistor)(CAM Cars). These cars have no regeneration capability Type 2 - Self-propelled using AC Induction motors with Inverter Control (ACD Cars). These cars have regeneration capability.


2.1.1.2 Train Types Two train types will be used for power system evaluation.

1. A fleet of six-car trains using CAM Cars. These will not regenerate. 2. A fleet of six-car trains using ACD Cars. These will regenerate.

Most of the work will be completed using the CAM fleet, since these are expected to be hardest on the power system.

2.1.2 Train Resistance Information The Davis formula is used for train resistance.

9/11/2002 TOM Training Section 3/RAUher 39

Train Resistance

Davis Formula:TRR = 1.3 (6.37) * W + 29 (129) * n + f * W * v

TRA = [CA + CS *(C-1)] * A * v2

where in English (Metric) units:

W: weight of train(tons)(tonnes) n: number of axles/trainv: Speed of train(mph)(kph) f: flange coefficient(lbs/ton/mph)(nts/tonne/kph)C: Number of cars/train A: frontal area(ft2)(m2)

TRR : Train Rolling Resistance(lbs)(nts)

Aerodynamic coefficientsCA : Front car(lbs/ft2 /mph2 )(nts/m2/kph2) CS : Trail cars (lbs/ft2 /mph2 )(nts/m2/kph2)

TRA : Train Aerodynamic Resistance(lbs)(nts)


2.1.3 Car Physical Characteristics The car physical characteristics are outline below for each type car:

All power system evaluation runs will be made at crush load (AW4).

2.1.4 Car Propulsion Systems Two propulsion systems will be discussed one for the CAM cars and the other for the ACD cars.

2.1.4.1 CAM Car Propulsion


A FULL DESCRIPTION OF THE COMPUTATIONAL METHOD IS EXPLAINED IN THE PROGRAM MANUAL.

2.1.4.2 ACD Car Propulsion

A description of and values for the ACDR equipment parameters is contained in EXERCISING THE AC DRIVE PROPULSION MODEL INSTRUCTION MANUAL Volume 11. The methodology for computing the performance of the propulsion system is contained in the Program Manual. 2.2 RIGHT OF WAY

2.2.1 Track Layout The rail system layout is shown below:


2.2.2 Passenger Stations The dwell time is 30 seconds at Vernor Ave. The remaining stations have dwell times of 20 seconds. Train loading is AW4 or 100% load factor everywhere for the purpose of power system evaluation.


2.3 ELECTRIC DISTRIBUTION SYSTEM

2.3.1 Overview There are two way to evaluate the power system. One is called the old or original way, which the TOM did before the development of TOM Version 3.4. The second way that the power system will be evaluated is with the TOM Version 3.4. Comparisons will be made between the two methods. The user must decide if the additional insight into evaluation obtained by using the new method is worth the additional effort, since it will be more difficult to evaluate the power system using TOM Version 3.4. With the development of TOM Version 3.4, the TOM now has the capability of including the return circuit in a more meaningful way in power system evaluation. Thus some definitions are in order before proceeding. The Inclusion of the Return Circuit method will be used to exercise the full capability of Version 3.4. This method is more fully described in Volume 10 – Instruction Manual for Including the Return Circuit in Electric Rail Systems

2.3.2 Nodal Diagram The Nodal Diagram for the DCEM Rail System for this exercise is shown next.


2.3.2.1 Primary Circuit In this rail system, the Primary Circuit is the positive circuit. One Primary Circuit is considered.



2.3.2.2 Return Circuits Two Return Circuits are considered in the analysis. The first is without bonds and the second is with bonds.

2.3.2.2.1 Return Circuit Without Bonds This Return Circuit has no bonds. It is shown next.

This circuit looks exactly like the Primary Circuit previously discussed. There are bonds at the substation. Without bonds means there are no bonds between substations. The substation bonds in the return circuit and ties in the primary circuit can have a lower resistance than the normal rail bond or tie between substation. In this exercise it will not.


2.3.2.2.2 Return Circuit With Bonds The second Return Circuit under consideration is one with rail bonds every 0.25 km. This circuit is shown next.


2.3.3 Substations All transformer-rectifier units are 12-pulse with a commutating to total reactance of 0.045. The open circuit AC voltage is 13.2 kV and the open circuit DC voltage is 750 v. The other data on the substations follow:

2.3.4 Wayside Electrical Components The handling of impedances is different, depending on whether the Inclusion of the Return Circuit Method or the Loop Method is used for the ENS.

2.3.4.1 Primary & Return Circuit (Inclusion of Return Circuit Method) The impedances uses for this method are listed.


2.3.4.2 Primary Circuit (Loop Method) The impedances are listed in the next table.

These impedances are used for the old method of analysis, prior to TOM Version 3.4.


2.4 OPERATIONAL TIMETABLE The operational timetable will be based on the desired minimum headway for the system. This is six minutes for each line. Thus the minimum headway for trains between Rock Garden and Noel End will be six minutes and the minimum headway for trains between Rock Garden and Fenton Harbor will be six minutes. Thus, the average minimum headway for trains on the part of the line between Rock Garden and Lazy Junction will be 3 minutes, while the headway on the Lazy Junction to Noel End and Lazy Junction to Fenton Harbor branches will be six minutes. On the Rock Garden to Lazy Junction portion of the line the minimum headways will be staggered so that they average 3 minutes. It can be expressed by the formula:

HW(Average) = [HW(ne) + HW(fh)]/2 = 3 Thus trains leaving Rock Garden are spaced 3 minutes apart with alternate destinations (Fenton Harbor or Noel End). The offset of trains leaving Fenton Harbor and Noel End are adjusted so that the average headway of the returning trains to Rock Garden are as close to three minutes apart as is practical, within the constraints of clearing the interlocking at Lazy Junction. Thus returning trains could alternate up to 2 and 4 minutes and still allow junction clearance and schedule spacing. Junction clearance is set at 30 seconds, so that no two trains can proceed through the junction within 30 seconds of each other. The timetable satisfying all of these requirements is shown in Section 3.3.5 The actual operational schedule can only be worked out after the constraints have been met. Any of the solutions will have an effect on the power system. 2.5 BASIC SYSTEM The basic system parameters are listed next.


3 TOM INITIAL SIMULATION 3.1 TPS INPUT FILES

3.1.1 Control The File Construction Module – Control File Input – Main Screen for trains running in the increasing kilometer-post direction is shown.

A similar file exists for the decreasing kilometer-post direction.


3.1.2 Train Four initial train files will be built to cover the two types of trains, CAM and ACD. In each case, a train file will be built at nominal voltage, which is set at 750v, and at average voltage. In the latter case, the average voltage selection causes the voltage to vary inversely with the power drawn. In the power mode, maximum power draw implies minimum voltage and minimum power drawn implies nominal voltage. In the electric brake mode, maximum power output to the line implies maximum voltage and minimum power output means nominal voltage. In the case of average voltage, the maximum and minimum voltage are arbitrarily set at traction standards. Maximum = 1.1 x Open Circuit and Minimum = 0.75 * Open Circuit. Thus Maximum Voltage = 825 v and Minimum Voltage = 562.5 v. It should be stated at this point that this selection of the average voltage limits is not self-consistent with the distribution network. Choice of the limits of Maximum and Minimum should be tailored to the network. The Voltage Averager is a tool of the File Construction Module in TOM Version 3.4.2 and higher, which can accommodate self-consistency. The process for determining a self-consistent average voltage is discussed in Section Error! Reference source not found. The reason to create two files for each type train is to apply two levels of conservatism in the power system evaluation. In the first case, selection of nominal voltage entails a higher train performance level than in the second case, which mimics the trains actual drop in voltage with power drawn. In the second case, the train will have lower performance level resulting in both higher inter-station run times and lower energy consumption. Thus, the second case will result in lower currents and lower voltage drops.

3.1.2.1 CAM Train The File Construction Module – Train File Input – Main Screen is shown for the nominal voltage case.


With the exception of the File Name and File Caption, this screen will be the same for the average voltage case. Clicking the Train Makeup Input checkbox, will expose the File Construction Module – Train File Input – Train Makeup Input screen, which is shown completed. This screen is the same for all four train files.


On the Main Screen, clicking the Propulsion Input checkbox, will expose the File Construction Module – Train File Input – Propulsion Input screen, which is shown completed. This screen is the same for both CAM train files.


Clicking the Compute from Model checkbox, exposes the File Construction Module – Train File Input – Electric Propulsion Model Input screen, which is shown completed. This screen is the for the CAM train file whose performance characteristics are set at the nominal voltage of 750v.


The screen for the second file, done at average voltage is shown next.



A comparison can be made between the Tractive Effort vs. Speed Curve at nominal voltage and at average voltage. This comparison is shown next.

The tractive effort for nominal voltage is larger than that for average voltage, indicating a higher performance train.


The power efficiency curves are shown next.

Thus, efficiencies are different for nominal vs average voltage, thus output power at the line is different because of both performance and efficiency.

3.1.2.2 ACD Train The File Construction Module – Train File Input – Main Screen is shown for the nominal voltage case.


On the Main Screen, clicking the Propulsion Input checkbox, will expose the File Construction Module – Train File Input – Propulsion Input screen, which is shown completed. This screen is the same for both ACD train files.


Clicking the Compute from Model checkbox, exposes the File Construction Module – Train File Input – Electric Propulsion Model Input screen, which is shown completed. This screen is the for the ACD train file whose performance characteristics are set at the nominal voltage of 750v. The screen for the second file, done at average voltage is shown next.


A comparison of the Tractive Effort vs. Speed Curve for nominal and average voltage is shown next.


The Electrical Braking Effort vs Speed Curves are shown next.



3.1.3 Station Four station files are required. All of these files will have a 100% load factor, which means that the analysis is conducted with crush loaded trains. Two examples of station files are shown by producing their main screen. The File Construction Module – Station File Input screen for the train run from Rock Garden to Noel End is shown next.

The File Construction Module – Station File Input screen for the train run from Rock Garden to Fenton Harbor is shown next.



3.1.4 Right of Way

3.1.4.1 Grade File The File Construction Module – Grade File Input screen for the train run from Rock Garden to Noel End is shown next.


The File Construction Module – Grade File Input screen for the train run from Rock Garden to Fenton Harbor is shown next.


3.1.4.2 Curve File The File Construction Module – Curve File Input screen for all train runs.

This is an input file for tangent track. The curvature is everywhere zero.


3.1.4.3 Speed Restriction File The File Construction Module – Speed Restriction File Input screen for the train runs in both directions from Rock Garden to Noel End is shown next.


The File Construction Module – Speed Restriction File Input screen for the train runs in both directions from Rock Garden to Fenton Garden is shown next.


3.1.4.4 Route Files The File Construction Module – Route File Input screen for the train run from Rock Garden to Noel Garden on track 1 is shown next.


The File Construction Module – Route File Input screen for the train run from Noel Garden to Rock Garden on track 2 is shown next.


The File Construction Module – Route File Input screen for the train run from Rock Garden to Fenton Harbor on track 1 switching to track 3 at 4.00 km is shown next.


The File Construction Module – Route File Input screen for the train run from Fenton Harbor to Rock Garden on track 4 switching to track 2 at 4.00 km is shown next.


3.1.5 TPS File of Filenames The File of Filenames files will be produced for all of the TPS runs initially considered. Sample screens will be shown for the CAM train at nominal voltage on all four train runs. This will be followed by a listing of all TPS Files to be considered initially in this evaluation.

3.1.5.1 Rock Garden to Noel End


3.1.5.2 Noel End to Rock Garden


3.1.5.3 Rock Garden to Fenton Harbor


3.1.5.4 Fenton Harbor to Rock Garden


3.1.5.5 Listing of All TPS Input Files


3.2 TPS RESULTS The TPS results are shown next.

3.3 ENS INPUT FILES There are two way to analyze the power system. One is called the old or original way, which was conducted using the TOM before the development of TOM Version 3.4. The second way that the power system will be evaluated is with the TOM Version 3.4. Comparisons will be made between the two methods. The user must decide if the additional insight into evaluation obtained by using the new method is worth the additional effort, since it will be more difficult to evaluate the power system using TOM Version 3.4 methods. With the development of TOM Version 3.4, the TOM now has the capability of including the return circuit in a more meaningful way in power system evaluation. More detail on the return methodology and loop methodology is discussed in Volume 10 – Instruction Manual for Including the Return Circuit in Electric Rail Systems. Circuit files must be constructed first, which are then inputs to the Network file.


3.3.1 Circuit Files Four circuit files will be constructed. The first of these is a primary circuit for use with a return circuit using the return circuit method. The second is a primary circuit which is intended to be used with the loop method. This means that the impedances of the return circuit lines are put in series with the primary circuit lines. The loop method is very close to the original method (before TOM Version 3.4) in power system evaluation. Finally, two return circuits are constructed, one circuit has rail bonds only at the substations, while the other has rail bonds ever 0.25 km. The first is designated as without rail bonds, while the second is designated as with rail bonds. All circuit construction will be accomplished using the graphical procedure and only the final graph screen will be shown under each circuit. More detail on the construction procedure is discussed in Volume 10 – Instruction Manual for Including the Return Circuit in Electric Rail Systems.


3.3.1.1 Primary Circuit (Return Circuit Method)


3.3.1.2 Primary Circuit (Loop Method)

This circuit is the same as the previous primary circuit with the exception that the track lines and the substation lines have impedances which include the series impedance of the primary circuit and the return circuit.


3.3.1.3 Return Circuit (Without Rail Bonds)


3.3.1.4 Return Circuit (With Rail Bonds)


3.3.2 Return Circuit Impedance Files The return circuit impedance files provide tables of dynamic impedance of the return circuit for each point of the line. Two are required for the two return circuits.

3.3.2.1 Return Circuit (Without Bonds) Top of Table


Middle of Table

Bottom of Table


3.3.2.2 Return Circuit (With Bonds) Top of Table

Middle of Table


End of Table


3.3.3 Network Files The networks to be used in this evaluation are listed.

1. Network for the Primary Circuit with the Return Circuit without bonds, to be used in the Inclusion of Return Circuit Method.

2. Network for the Primary Circuit with the Return Circuit with bonds, to be used in the Inclusion of Return Circuit Method.

3. Network for the Primary Circuit, to be used in the Loop Method. 4. Network constructed by the original method (before TOM Version 3.4) to

approximate 2.). 5. Network constructed by the original method (before TOM Version 3.4) to

approximate 3.).

3.3.3.1 Network Files (Circuit Files Method) The circuit files method of creating the Network file applies to items 1-3 in the listing. One example; namely, 1.) Network for the Primary Circuit with the Return circuit without bonds. The File construction Module – Network File Input – Main Screen is shown with the Include Return Circuit checkbox checked.


Clicking the Generate Network command button exposes the File Construction Module – Network File – Network Generator Input screen, which has been completed by selecting a file from each of the file list boxes as shown.

Clicking the Generate Network command button generates the network and returns to the main screen.



3.3.3.2 Network Files (Original Method) The nodal diagram for the original method is next.

3.3.4 Operating Time File The cycle time of the system will be 6 minutes, since the headway for each of the two lines is 6 minutes. The simulation time will be set at 8:00 – 8:06 am. The File Construction Module – Operating Time File Input screen is shown next.


3.3.5 Train Location Files There are constraints on the Train Location files for the trains as outlined in Section 2.4. To satisfy all of the constraints, it will be necessary to do it by trial and error. So the initial timetable is chosen as simply as possible, and then modified to satisfy the constraints. These constraints are

1. The average headway on the Rock Garden to Lazy Junction portion of the line is to be 3 minutes, with the trains on this portion of the line not being separated by less than 2 minutes and by more than 4 minutes.

2. Clearance of the interlocking at Lazy Junction to be at least 30 seconds.


The first timetable is developed by assuming the Noel End trains leave Rock Garden every six minutes on the hour and the Fenton Harbor trains leave Rock Garden every six minutes beginning at 3 minutes after the hour. In the reverse direction, it is assumed that the trains leave Noel End for Rock Garden every six minutes on the hour and the trains leave Fenton Harbor for Rock Garden every six minutes on the hour. The File Construction Module – Train Location File Input screen is shown next for CAM trains with no offset.

All trains in this timetable have no offset.


3.3.6 Current Measurement Input File The current measurement file is built to measure all currents out of every substation. The File Construction Module – Current Measurement Input File screen is shown next.


3.3.7 ENS Files of Filenames Initially, there will be 20 initial ENS runs. For each of the trains, CAM and ACD, and for nominal and average voltage, the following five runs will be made:

1. Return circuit with bonds. 2. Loop. 3. Return circuit without bonds. 4. Original. 5. Original Double Track.

ENS File of Filenames screens from each of the five runs will be shown for the CAM train at nominal voltage in the following five subsections. A better description of each of these runs will be provided in each subsection. The sixth subsection provides a listing of all ENS input files to be used initially.

3.3.7.1 Return Circuit with Bonds


This run is made with CAM trains, whose performance was calculated at the nominal voltage of 690 v. The run uses the Inclusion of Return Circuit Method with a return circuit that has bonds between the two tracks every 0.25 km.


3.3.7.2 Loop

This run is made with CAM trains, whose performance was calculated at the nominal voltage of 690 v. The run uses the Loop Method. This means that only a primary circuit is used where the track return impedance is placed in series with the primary impedance.


3.3.7.3 Return Circuit Without Bonds

This run is made with CAM trains, whose performance was calculated at the nominal voltage of 690 v. The run uses the Inclusion of Return Circuit Method with a return circuit that does not have bonds between the two tracks, except at the substation connection.


3.3.7.4 Original

This run is made with CAM trains, whose performance was calculated at the nominal voltage of 690 v. The run uses the Original Method. The original method is pre-TOM Version 3.4 and is similar to the Loop Method, except that the substation feeds and bonds are not included. See the nodal diagram of Section 3.3.3.2


3.3.7.5 Original Double Track

This run is made with CAM trains, whose performance was calculated at the nominal voltage of 690 v. The run uses the Original Method. The original method is pre-TOM Version 3.4 and is similar to the Loop Method, except that the substation feeds and bonds are not included. See the nodal diagram of Section 3.3.3.2. In this case, in contrast to the previous case, the return circuit uses a double track return rather than a single track return. It is added in series with the primary circuit impedance. This is meant to simulate rail bonds between substations.


3.3.7.6 Listing of All ENS Input Files


3.4 ENS RESULTS

3.4.1 Adjustment of Train Location File Before the ENS can be run, it will be necessary to adjust the timetable (Train Location File) to accommodate the constraints mentioned in Section 2.4. This adjustment will be accomplished using the CAM trains, nominal voltage, Original Method run, in order to obtain a train graph. From this graph, it can be determined how to set the timetable offset. The initial run will have no offset.

By viewing this train graph, two facts become obvious.

1. The trains running in opposite directions are required to clear the junction at kp 4.0 in about 12 seconds.

2. Trains running in the reverse direction are very close to 2 and 4 minutes apart, respectively. Thus the reverse running headway can be adjusted to get the trains closer to 3 minutes apart.


These two problems can be remedied by offsetting the Fenton Harbor to Rock Garden trains by 2 minutes and the Noel End to Rock Garden trains by 1 minute. These offsets can be accomplished easily by using the Shift command on the File Construction Module - Train Location Input File screen.

The ENS can be quickly rerun with this new timetable to verify.


Clearances at the junction are now greater than 1 minute and the reverse running trains are 3.2 and 2.8 minutes apart. All ENS will be done using this timetable.


3.4.2 ENS Run Summaries

The next three sections will concentrate on the runs with CAM Trains. For accuracy comparisons, regarding the method used, comparisons should be made among o – original, l – loop and n – inclusion of return circuit methodologies. The following table shows this comparison for the CAM trains.


4 POWER SYSTEM DESIGN EVALUATION Power system design evaluation involves the following topics, which the TOM can handle.

1. Energy Consumption 2. Train Voltages 3. Train Currents 4. Substation Loading 5. RMS Loads 6. Rail Voltage Estimates

These are discussed in the next six sections. 4.1 ENERGY CONSUMPTION In most cases, energy consumption will require more information than is present in this manual. Evaluation of the power system normally involves conditions that are not encountered in normal operation and in most cases in contingency operation. However, energy consumption is computed under conditions of normal operation. Energy consumption has a broad meaning. The context in which energy consumption is most often used is energy cost. The factors that determine electricity cost in rail transit are related to variables of system design and operating practices (referred to as the energy use pattern), and the power rate structure of the electric utilities that serve the system. The energy use pattern is controllable within limits by transit management. The power rate structure, which sets the schedule of charges for electricity for energy use, power demand, and facilities is a matter of negotiations between the transit authority and the electric utilities subject to rate making jurisdiction of the public utility commissions. The cost of electricity on rail transit systems is made up of facilities, power demand and energy use components. The facilities charges are generally fixed and may partially be funded by the transit systems' contributions-in-aid of construction. The energy consumption and power demand components result from operating the transit system. Energy consumption is the actual use of power integrated over time. Electric meters measure energy use in units of kilowatt-hours (kWh). Power demand represents the generation, transmission and distribution facilities shared by transit with other customers or groups of customers of the electric utility serving the transit system. Electric meters also measure and record power demand as energy per unit


demand time interval. The actual billing power demand generally results from complex mathematical formula, which is usually different for every rail transit system. Power demand has units of kilowatts (kW). The formula used by the electric utilities to compute the billing power demand component of the electric bill for rail transit systems in North America can be generalized to a few basic elements.

1. Specification of a demand consolidation, which is a way to combine the recordings of several meters for computing demand. Maximum demand is determined coincidentally, when in a given customer class and/or jurisdiction1, it is the maximum of the sum of the average energy use recorded on all electric meters in the same demand interval; and, non-coincidentally, when it is the sum of the maximum average powers recorded on all electric meters in any demand interval.

2. Computation of a monthly demand, which is the maximum demand as determined by using the demand consolidation method in a monthly billing period.

3. A ratchet demand, simply called a ratchet, calculated by a predetermined formula, and which represents a minimum demand level for billing purposes.

4. Computation of the billing demand which is the maximum of the monthly demand and the ratchet.

Energy consumption will not be discussed here. It is covered in Volume 2 – Instruction Manual for Applying the TOM to Transit Systems DC Electric – English Units Volume 3 – Instruction Manual for Applying the TOM to Transit Systems DC Electric – Metric Units These manuals provide the necessary data which allows the computation of energy cost with specific examples which show how to use the TOM to accomplish these computations.

1 The jurisdiction is the area over which the regulatory body (usually the public utility commission) governs the setting of rates by the electric utility. The customer class is a category used by the utility to classify the customer according to his energy use pattern. For example, residential and industrial users are in different customer classes.


4.2 GHOST TRAIN APPROACH The Ghost Train is a train which moves through the system between terminals and carries only an auxiliary load, which is the peak load the normal train would impose on the system. Thus, through this approach, the peak load is placed at every point of the system and the resulting voltages, currents and powers are calculated. The Ghost Train approach consists of running a TPS for each of the ghost trains to be considered followed by an ENS using the power profile previously calculated by this TPS. The resultant Current Measurement Output file (AO-*.*) is then used to determine train voltage and current profiles and substation loading. The first task is to determine the number and nature of the ghost train profiles to run. Once this is established, the next task is to set up the TPS Input files followed by running of the TPS to obtain the ghost train power profiles. After this is completed, the third task is to set up the ENS Input files followed by running the ENS to obtain the Current Measurement Output files. These output files are then used to present ghost train voltage, current and substation loading profiles.

4.2.1 Ghost Train Listings There will be two classes of ghosts trains; one for trains using the average voltage and the other for trains using nominal voltage. Only CAM trains are considered in this exercise. For each class, there will be four trains, each of which will run between terminal to terminal on the different routes. Thus, a total of eight TPS are required. In addition, each of the resulting TPS Power Profiles will be used for two ENS runs, one run using the original method and the other using the return circuit method. Thus a total of sixteen ENS runs will be made. The input files for both the TPS runs and ENS runs are discussed in the next two sections.

4.2.2 TPS for Ghost Trains The idea of the ghost train approach is to have the peak load experienced by the system placed at every position along the right of way for all routes. This is accomplished by modifying the train file so that the auxiliary loads on the ghost train add up to the peak load and a minimum of propulsion load is placed on the system as the ghost train moves along its route.


4.2.2.1 Input Files for TPS Proceed first by determining what the peak load is for each of the two classes considered; namely, trains using average voltage and trains using nominal voltage. To determine this peak load, graph the Power vs Position for each of the previous TPS runs with CAM V=Nom and CAM V=Ave (See Section 3.2). The procedure for one of these graphs is given as an example. The Graphic Utility - Main Screen is shown next.

Click the Train Run Results check box to produce the next screen.


Click the Power vs Position check box and the TPS Run File TPScnfr.dcm to choose the file for the TPS run labeled CAM V=Nom Fenton Harbor to Rock Garden (See Section 3.2).


Click the Complete Graph command button to produce the graph.


It is easily observed that the peak power for this run is 7.54 MW. Running through all eight TPS runs in this manner, shows that the peak power for CAM V=Nom is 7.54 MW and for CAM V=Ave is 5.76 MW. The next step is to set up two train files, which have the following properties.

1. The auxiliary loads on each of the cars sums to the peak power. 2. The train resistance is as close to zero as possible (No speed dependent terms) 3. The weights of the cars is 1 tonne. 4. Cars have zero length.

Since the auxiliary load per car is limited to 999 kW (input limitation of TOM), the ghost train will have as many cars as is necessary to make up the peak power. Choose each car to carry an auxiliary load of 999 kW, with the first car to carry the fraction so that all cars sum to the peak load.


Thus for 7.54 MW, there will be 7 cars with 999 kW and one car with 547 kW and for 5.30 MW, there will be 5 cars with 999 kW and one car with 765 kW. The car physical parameters are shown next.

The train resistance parameters for ghost trains are shown next.

The Tractive Effort vs Speed curves can remain the same and the Traction Efficiency can be set to 1.


Two train files will be required for the ghost trains. The File Construction Module – Train File Input – Main Screen is shown for both of them. First, the CAM V=Nom case.

And then, the CAM V=Ave case.


The File Construction Module – Train File Input – Train Makeup Input screen is also shown for both cases. First, the CAM V=Nom case.


And then, the CAM V=Ave case.


The following input files shall also be used for the TPS runs.

• The Grade file will be that of level track. • The Curve file will be that of tangent track. • The Speed Restriction file will be set to 10 kph everywhere. • The Station files for each of the four routes will only contain two stations;

namely the terminal stations. • The Route files will remain the same for each of the four routes. • The Control files will remain the same.

Examples of TPS Files of Filenames are shown for two cases out of the eight runs. First, the TPS File of Filenames, for CAM V=Nom Rock Garden to Noel End Ghost Train.


And then, for CAM V=Ave Fenton Harbor to Rock Garden Ghost Train.


A complete listing of all of the files used for the TPS Ghost Trains is shown in the next table.



4.2.2.2 TPS Results Results for ghost train TPS are shown next.

4.2.3 ENS for Ghost Trains The important output from ENS will be the Current Measurement Output file, which will be used later in determining voltage and current profiles.

4.2.3.1 ENS Input Files Sixteen ENS runs are carried out; four runs at nominal voltage and four runs at average voltage for both the original method network and the return circuit without bonds network.. In each of these runs, there is only one train on the line at a time. Trains which run between Rock Garden and Noel End will require and Operating Time file which extends 40.25 minutes and trains which run between Rock Garden and Fenton Harbor will require and Operating Time file which extend 36.65 minutes. This is determined by reviewing the TPS results of Section 4.2.2.2. Thus two Operating Time files will be required. Because the trains are identified by their terminal stations (RN, NR, RF and FR), four train ids will be required and since nominal voltage trains have 9 cars, while average voltage trains have 6 cars, eight Train Location files will be required to cover all conditions (4 id conditions x 2 number of cars conditions). With the exception of the Power Profiles (P-*.dcm) , which are labeled with the same designation as the TPS File of Filenames, from which they were created, the input files for the ghost train runs are shown next.


4.2.3.2 ENS Results A summary of the ENS runs for the ghost trains are listed below.

The summaries do not have any meaning. It is the Current Measurement Output files from these runs which will be used later.


4.3 TRAIN VOLTAGES The TOM has the capability to provide train voltage graphs, which show the voltage profile of the train. Four conditions will be shown with one of the conditions in each of the following subsections. For each of the conditions, two or three graphs will be shown, one for inclusion of the return circuit method, one for the loop method (if appropriate and one for the original method.

4.3.1 Voltage Graphs – Normal Train Operation

4.3.1.1 CAM Rtn Cct w/o Bnds Nom Volt

4.3.1.1.1 Inclusion of the Return Circuit Method


4.3.1.1.2 Loop Method


4.3.1.1.3 Original Method Single Track Impedance


4.3.1.2 CAM Rtn Cct w Bnds Nom Volt

4.3.1.2.1 Inclusion of Return Circuit Method


4.3.1.2.2 Original Method Double Track Impedance


4.3.1.3 CAM Rtn Cct w/o Bnds Ave Volt In this case, the voltage used for train performance is allowed to vary with the power drawn by the train. This is a better simulation of what actually happens in practice. In lieu of performing a simulation where train performance is put into the iteration loop, this configuration is a first approximation to that process, in the sense that it makes the assumption that the voltage drop is mostly determined by the power drawn by the train itself, rather than other trains on the system. It also avoids extremely long computational times.





4.3.1.3.3 Original Method


4.3.1.4 CAM Rtn Cct w Bnds Ave Volt





4.3.2 Minimum Train Voltage – Normal Train Operation To make an adequate comparison among minimum train voltages for the different cases considered here, it is best to use the File Manipulation Module – Minimum Train Voltage Finder, which is available in TOM Version 3.4.2 and later versions. This tool has the ability to extract the minimum train voltages, their locations (position and track number) and the ID of the affected train, from the Current Measurement Output File (AO-*.dcm). The extraction is in EXCEL tabular format, so that it may be pasted directly into an EXCEL Spreadsheet table, which is a compilation of these voltages for the various cases considered here. One example of a table entry is presented here for instructional purposes. Begin with the File Manipulation Module – Main Screen, shown next.


Click the Minimum Train Voltage Finder command button.


Choose a Current Measurement Output file (AO-cab.dcm) by double-clicking on it in the file list box.


Choose the number of minima desired. The first is the lowest voltage, the second is the next higher voltage, the third is the next higher voltage and so on. Choose 8.


Click the Create File command button.


Click the OK command button to produce the next screen.


The first entry in the table is the minimum train voltage in the system. It was pasted on the Clipboard as follows: ENScab.dcm CAM Rtn Cct w Bnds Ave Volt 665.2 0.402 1 R1RF This information is in EXCEL format, with tabs between the entries, so that it may be pasted into a row of an EXCEL Spreadsheet table. After this process is completed for all cases of interest, the full table is shown next for the cases with no regeneration.


4.3.2.1 No Regeneration

The process just covered is a quick way to construct a table of this sort. The table contains information which may be used to compare ENS methodology among the Inclusion of Return Circuit, Loop and Original ways of simulation as far as minimum train voltage is concerned. Rearranging the table makes things easier to see.

The table is divided into two parts, average voltage and nominal voltage. Each of these parts is further subdivided into single track rail return and double track rail return.


In the single track rail return subdivision, all ENS methodologies represent the same estimate. Only a different methodology is used for each of the three cases. In the double track rail return subdivision, the comparison is not equivalent. In the first case, double track return = bonds every 0.25 km linking the two tracks together, while in the second case, there are so many bonds that effectively the two tracks are the parallel combination of a single track.

4.3.2.2 Regeneration

The table contains information which may be used to compare ENS methodology among the Inclusion of Return Circuit, Loop and Original ways of simulation as far as minimum train voltage is concerned. Rearranging the table makes things easier to see.


The table is divided into two parts, average voltage and nominal voltage. Each of these parts is further subdivided into single track rail return and double track rail return. In the single track rail return subdivision, all ENS methodologies represent the same estimate. Only a different methodology is used for each of the three cases. In the double track rail return subdivision, the comparison is not equivalent. In the first case, double track return = bonds every 0.25 km linking the two tracks together, while in the second case, there are so many bonds that effectively the two tracks are the parallel combination of a single track.


4.3.3 Voltage Graphs – Ghost Train Operation Voltage graphs for the ghost trains present a clear voltage profile given a peak power at all points on the line. There will be sixteen of these graphs, divided first by Nominal Voltage and Average Voltage; then by line and direction (four graphs) and finally; by method of simulation Return Circuit and Original. All substations as well as all stations associated with the particular line are also shown on the graph.

4.3.3.1 Nominal Voltage

4.3.3.1.1 Rock Garden to Noel End



4.3.3.1.2 Noel End to Rock Garden



4.3.3.1.3 Rock Garden to Fenton Harbor



4.3.3.1.4 Fenton Harbor to Rock Garden



4.3.3.2 Average Voltage













4.3.4 Minimum Train Voltage – Ghost Train Operation Finding of minimum train voltage is possible for the ghost trains as well as the normal trains described in Section 4.3.2. Tables are presented in the next two sections for the nominal and average voltage representations of the ghost trains. These presentations include both the original method with single track return resistance and the inclusion of return circuit method without rail bonds. The cases of the original method with double track return resistance and the inclusion of return circuit method with rail bonds were not considered since they will result in higher minimum voltages.




4.4 TRAIN CURRENTS

4.4.1 Current Graphs

4.4.1.1 CAM Rtn Cct w/o Bnds Nom Volt







4.4.1.2 CAM Rtn Cct w Bnds Nom Volt





4.4.1.3 CAM Rtn Cct w/o Bnds Ave Volt







4.4.1.4 CAM Rtn Cct w Bnds Ave Volt





4.4.2 Maximum Current Comparisons To make an adequate comparison among minimum train voltages for the different cases considered here, it is best to use the File Manipulation Module – Maximum Train Current Finder, which is available in TOM Version 3.4.2 and later versions. This tool has the ability to extract the minimum train voltages, their locations (position and track number) and the ID of the affected train, from the Current Measurement Output File (AO-*.dcm). The extraction is in EXCEL tabular format, so that it may be pasted directly into an EXCEL Spreadsheet table, which is a compilation of these voltages for the various cases considered here. A process very similar to this process was carried out for the minimum voltage case in the previous section and will not be completely repeated here. Two screens are shown for instructional purposes. Begin with the File Manipulation Module – Main Screen, shown next.


Click the Maximum Train Current Finder command button.


The remainder of the process is exactly the same as was shown for minimum voltage in Section 4.3.2, The tabular results are presented for both regeneration and no regeneration.


4.4.2.1 No Regeneration

4.4.2.2 Regeneration


4.4.3 Ghost Train Current Graphs Current graphs for the ghost trains present a clear current profile given a peak power at all points on the line. There will be sixteen of these graphs, divided first by Nominal Voltage and Average Voltage; then by line and direction (four graphs) and finally; by method of simulation Return Circuit and Original. All substations as well as all stations associated with the particular line are also shown on the graph.



























4.5 SUBSTATION LOADING Substation loading is concerned with the current passing through the substation transformer-rectifiers (converter) at any given time. There are several currents of interest.

• Maximum converter current and the time at which maximum current occurs. • Average converter current over the simulation time interval. • RMS converter current over the simulation time interval.

4.5.1 Application of the TOM TOM Version 3.4.2 and higher can quickly summarize these currents of interest. The technique is illustrated here. Begin with the File Manipulation Model – Current Analyzer screen.


Click the Converters command button on the screen.

Select the Current Measurement Output file (AO-*.dcm) which is to be used to calculate the currents of interest. This is accomplished by double clicking on the filename or by clicking on the filename followed by clicking on the Select One command button. The advantage to the latter method is that once the file is clicked, the file caption appears in the mouse tool tip.




Click the OK command button to review the file. Information on the converter currents is now on the Clipboard. The next screen now appears.


For each converter on the system, the maximum and minimum currents are displayed as well as the time of occurrence in the simulation. The average and RMS currents are also shown. Note that only the magnitude (not the direction) of the current is displayed. This procedure can be applied to all of the AO – files of interest and summaries are presented in the next two sections, one section for nominal voltage and one section for average voltage. In both sections, there are five summaries produced

1. Inclusion of return circuit method with bonds. 2. Original method with double track return impedance. 3. Inclusion of return circuit method without bonds. 4. Original method with single track return impedance. 5. Loop method (with single track return impedance).


Information on the Clipboard is as follows: Y0 - 00 4911.8 8:05:22 116.7 8:05:57 1841.1 2383.6 Y1 - 01 3564.9 8:00:15 272.5 8:05:57 1405.4 1591.4 Y2 - 02 4194.2 8:01:31 216.8 8:04:59 1479.9 1810 Y3 - 03 3020.4 8:01:09 75.1 8:04:59 572.4 792.7 Y4 - 04 4176.6 8:02:48 37.2 8:04:59 994.5 1508.1 Y5 - 05 4400.3 8:04:42 126.7 8:05:57 1631.9 1985.7 Y6 - 06 7130.1 8:04:27 189.2 8:03:44 1141.6 1746.9 Y7 - 07 3604 8:01:08 27.6 8:04:59 277.2 490.4 Y8 - 08 6321.4 8:01:30 97.4 8:04:59 1267.2 1757.1 Y9 - 09 5778.6 8:00:16 84.9 8:04:12 1295.5 1924.4 Y10 - 010 2466 8:01:08 18.7 8:04:59 187.6 333.9 Y11 - 011 5613.5 8:05:46 18.9 8:04:59 717.3 1329.3 This information can be pasted directly into the EXCEL table formats.


4.5.2 Nominal Voltage Results




4.5.3 Average Voltage Results




4.6 DISTRIBUTION SYSTEM CURRENTS AND RMS LOADING TOM Version 3.4.2 and later allows for the computation distribution system currents through all of the lines both in the primary and return circuits. These currents may be graphed as a function of time or summarized in terms of RMS currents. They may also be summarized in tables in particular EXCEL Spreadsheet table formats. This section is not meant to be exhaustive, since the number of currents through lines of the circuits is large, rather is meant to be a demonstration of many things which can be done using Version 3.4.2 of the TOM.

4.6.1 Current Analyzer of the FMM The Current Analyzer program of the FMM is used to obtain distribution system currents and RMS loading of the lines. A brief description of the FMM is presented here, but more detail is presented in the reference Volume 10 – Instruction Manual for Including the Return Circuit in Electric Rail Systems. Begin with the FMM Main Screen.


Click the Current Analyzer command button, which opens the Current Analyzer screen.


Choose a Current Measurement Output file by double clicking on it or by clicking on it and clicking on the Select command button.


Click the Choose Circuit combo box.


In this case there are two circuits to choose from, because the network input to the ENS run, which produced the Current Measurement Output file had a return circuit. The Primary Circuit file is PC-n.dcm and the Return Circuit file is RC-n.dcm. Choose the Return Circuit file.


The Return Circuit Current Analysis Output file could now be created, by clicking the Create File command button. However, since it was already created as it exists Current Analysis Output file list box, it can be viewed here, by clicking on it and then clicking on it and then clicking on the View One command button.


A detailed explanation of this file appears in the Program Manual and is not discussed here. A brief explanation appears in the next section.

4.6.2 Distribution System Currents Distribution system currents will involve graphs of various types of currents as a function of time. The currents by type are Current values may be real, reactive, magnitude and heating. o Real – This current shows both direction and magnitude. Direction is indicated as positive for the increasing milepost or track number direction or as negative for the decreasing milepost or track number direction. o Reactive - This current is appropriate for AC distribution systems (It is zero for DC distribution systems.) and shows both direction and magnitude. Direction is indicated as positive for the increasing milepost or track number direction or as negative for the decreasing milepost or track number direction. o Magnitude - This current is appropriate for AC and DC distribution systems. In the case of AC or DC distribution, this current is the complex absolute value of real and reactive current, given by the formula: Square Root[Real*Real + Reactive*Reactive].


However for DC distribution, the reactive current is zero. This type of current is always positive. o Heating – This current represents the heating effect in a line in which trains run. It differs from the Magnitude type current in that it captures the heating effect of the train presence on the line. The RMS (Root-Mean-Square) current used for calculating heating effects. The difference between Heating and Magnitude type currents is explained below, by considering a line with three nodes, one of which is a train ( T ).

Thus, the Heating current takes into account the passage of the trains through the network. The real, reactive and magnitude of current doesn’t have any meaning for lines (tracks) with trains on them. A more detailed explanation of types of currents is presented in the Current Analyzer section of the Program Manual. The Current Analyzer is a program in the File Manipulation Module. Heating current in bonds, ties, feeders and substation connection is the same as current magnitude since no trains run on these lines. Thus, in the following sections, which are based on nominal voltage heating currents will be plotted for bonds, substation connections, and lines, while real currents are plotted just for bonds. Only the return circuit with bonds will be considered, although plots of this sort can be produced for all circuits, both primary and return. Only two substations will be included Y1-01 at kilometerpost (kp) 1.00 and Y5-05 at kp 2.00.


The substation connections are lines 800 at Y1-01 and 805 at Y5-05. There are track bond lines here as well, which connect tracks 1 and 2. These are track bond lines 812 at Y1-01 and 8112 at Y5-05. The rail bonds between substations Y1-01 and Y5-05 are track bond lines 819 at kp 1.25, 8110 at kp 1.5 and 8111 at kp 1.75. The track lines are as follows:

1. Between kp 1.00 and 1.25 A7 on track 1 and B7 on track 2. 2. Between kp 1.25 and 1.50 A1 on track 1 and B0 on track 2. 3. Between kp 1.50 and 1.75 A9 on track 1 and B9 on track 2. 4. Between kp 1.75 and 2.00 A10 on track 1 and B10 on track 2.


The region selected for current analysis is illustrated next.


4.6.2.1 Heating Currents The results for instantaneous currents are shown in the graphs in the next four sections.

4.6.2.1.1 Substation Connections


4.6.2.1.2 Track Bond Lines


4.6.2.1.3 Track Lines on Track 1


4.6.2.1.4 Track Lines on Track 2


4.6.2.2 Real Currents Track bond lines are the only lines where real current makes any sense. Two cases are considered: Track bond lines at substations and track bond lines between substations.

4.6.2.2.1 Track Bond Lines at Substations


4.6.2.2.2 Track bond Lines Between Substations


4.6.3 RMS Loading RMS currents in all of the lines of both the primary and return circuits can be determined by two methods in TOM Version 3.4.2. The first method is to use the File Viewer display of the Current Analysis Output file to show these currents and the second method involves the Current Analyzer screen itself.

4.6.3.1 File Viewer Display Method Thus if the file is displayed:

Clicking the View RMS Currents command button will automatically scroll to the RMS current display.


All of the RMS currents are displayed here. If a report format is desired, with a table pre-formatted in an EXCEL Spreadsheet, click the EXCEL Ready command button to paste the information on the Clipboard. The result is the next screen.

Click the OK command button.


The information pasted on the Clipboard looks as follows: A0 A1 A0 1 1822.1 B1 B0 B2 2 531.6 A2 A3 A4 1 823.5 B2 B3 B4 2 1707.3 C3 C3 C1 3 365.7 D3 D3 D1 4 1264 C2 C2 C4 3 1171 C4 C4 C3 3 1284.6 D2 D2 D4 4 691.4 D4 D4 D3 4 1094 A4 A5 A6 1 237 …etc. This information can then be pasted into a pre-formatted EXCEL table. Only part of the table is shown since it is very large.

The table continues… This table can actually be viewed in the companion EXCEL WorkBook: TOMInstructionManualDCElectricPowerSystemMethodology.xls


4.6.3.2 Current Analyzer Screen Method This is a second method for obtaining RMS currents. This method will also display the maximum and minimum currents and time of occurrence and the average current. It begins with the File Manipulation Module – Current Analyzer Screen.

Clicking the Line Current command button displays the next screen, which is the Line Current Analyzer.


Choosing the type circuit (primary or return), produces the next screen.


Double clicking on the Current Analysis Output file results in the next screen.


Click the Create File command button to produce the next screen.


Line names are translated from the TOM Line Name to the Translated Line Name using the FMM – Line Name Translator. This is explained in the Program Manual. Click the Yes command button on the inquiry.


The opportunity will be presented to paste Clipboard information into an EXCEL table formatted for the purpose. Click the OK command button and the next screen appears.


In addition to the RMS currents, the maximum and minimum value of current and their time of occurrence and the average current is displayed for each line in the circuit. All of this refers to the heating current. The Clipboard contains the information, which can be pasted into an EXCEL formatted table. Only part of the table is shown because it is large.


The results in tabular form are too large to show properly in this document. All of the results can be viewed in the companion EXCEL WorkBook: TOMInstructionManualDCElectricPowerSystemMethodology.xls The book opens to an index page, which has various sections. The results here can be seen in the index entries:

Clicking one of the underlined entries in the workbook, will jump to the results.


5 CONTINGENCY ANALYSES Two types of contingency analyses classes are considered here. The first will take a substation out of service for maintenance purposes while the second will restart stopped trains, which have stopped and lie one stopping distance apart. Only three trains are used in this analysis. 5.1 SUBSTATIONS OUT OF SERVICE The first task is to determine the consequences of removing a substation from service for either preventive or corrective maintenance. After the substation is removed from service, the minimum voltage is determined. Results will be presented for normal train operation (both nominal and average voltage) and ghost train operation.

5.1.1 Removing a Substation from Service Begin with zipping the directory c:\rom\tomda\dcm and storing the zip file (e.g. PWREVALBasic.zip). This action will allow the user to use the original files minimizing the creation of new files. Since all substation removal, one at a time, must be accommodated, extracting the original Network file each time, will speed up the process.

5.1.1.1 Original Method It is much easier to remove a substation from service using the original method ENS, so this will be done now, showing as an example, the methodology for the first substation Y0 – 00. Begin with the File Construction Module – Network File Input – Main Screen.


Import the file N-o.dcm into the screen by double clicking on the filename.


Click on the AC Part of Nodal Diagram check box.


Click on Z0 in the Line Input grid, followed by a click on the Delete Row command button.


Click the Yes command button to remove the substation.


The action taken was to open the secondary breakers of the substation leaving the tie breakers closed.

5.1.1.2 Inclusion of Return Circuit Method or Loop Method Taking a substation out of service with the Inclusion of Return Circuit Method is a little more difficult than with the Original Method just demonstrated. The procedure is accomplished in four steps:

1. Removing the substation connection line from the Return Circuit. 2. Removing the substation connection line from the Primary Circuit. 3. Recalculating the Return Circuit Dynamic Impedance. 4. Recreating the Network file.


The first step of removing the substation connection line from the return circuit is demonstrated here. Step 2 is just a repeat with the primary circuit instead of the return circuit. Steps 3 & 4 were shown previously in Sections 3.3.2 and 3.3.3. Begin with the File Construction Module – Return Circuit File Input – Return Circuit By Graphics screen.

The removal of the substation at position 0.0 is demonstrated in detail. With the right mouse button , click on the line to be removed. This action produces the following screen.


The substation connection line to be removed is 809. Click the Remove menu item.


Create the file with the line removed to finish the Step 1 process. Removal of the substation connection line from the Primary Circuit is accomplished in the same manner. The next two steps are

5.1.2 Determination of Minimum Voltage The next two steps for all of the methods is to run the ENS and then the FMM – Minimum Voltage Finder to determine the minimum voltage. The methodology was discussed in Sections 4.3.2 and is partially repeated here.


To view the effects on minimum voltage, open the FMM.


Click the Minimum Train Voltage Finder command button (TOM Version 3.4.2 and later).


Select the appropriate Current Measurement Output file, just created by the ENS run.


Choose the Number of Minima (10) desired.




The Clipboard contents are: ENScno.dcm CAM Original Sng Trk Nom Volt 567.7 0.47 1 R1RN Click the OK command button to view the results.


The minimum voltage can now be compared with the case with all substations operational.


5.1.3 Normal Train Operation

5.1.3.1 Results with Original Method The results using nominal voltage with the original ENS method are shown.

The minimum voltage and train position and track number are displayed together with the minimum voltage difference compared with all substations operational.

5.1.3.1.1 Nominal Voltage With a 750 v open circuit and nominal voltage, there are three cases of substation removal where the minimum voltage drops below the traction standard of 562.5 v (-25%). These are displayed next.


5.1.3.1.2 Average Voltage

In this case, only substations Y9-09 and Y11-011 are lower than traction standards. In anticipation of correcting the low voltage problems, the ENS is now run for several cases with the three substations out of service. The results of these runs for the Inclusion of Return Circuit Method are shown next.

5.1.3.2 Results with Inclusion of Return Circuit Method Without Rail Bonds

The results using nominal voltage with the Inclusion of Return Circuit Method are shown, where the return circuit has rail bonds only at substations (without rail bonds). Only Substations Y6 – 06, Y9 – 09 and Y11 – 011 are taken out of service, one at a time.


The results for the return circuit without rail bonds are shown next.

5.1.3.2.1 Nominal Voltage

In this case, with either Substations Y6 – 06, Y9 – 09 or Y11 – 011 out of service all three minimum voltages are below traction standards.


In this case, only Substation Y9 – 09 out of service results in a minimum voltage below traction standards, although Substation Y11 – 011 is on the borderline.

5.1.3.3 Results for Original Method – Double Track Impedance The original method with double track impedance in the return circuit simulates a circuit with a large number of rail bonds, but again assumes the primary and return circuits are in series. Both nominal and average voltage cases are demonstrated.


5.1.3.3.1 Nominal Voltage The minimum voltage with the critical substations out of service one at a time is shown next.

In this case, only Substation Y9 – 09 out of service results in a minimum voltage below traction standards.


All substations are above traction minimum standards.


5.1.3.4 Results for Inclusion of Return Circuit Method with Rail Bonds The results for the return circuit with rail bonds are shown next.


Again, all substation outages result in minimum voltages below traction standards.


All substation outages result in minimum voltages higher than traction standards.


5.1.4 Ghost Train Operation

5.1.4.1 Results with Original Method Single Track Resistance


5.1.4.1.1.1 Fenton Harbor – Rock Garden

Because of low voltage problems, removal of substations Y9 – 09 and Y11 – 011 from service result in non-convergence of the ENS.

5.1.4.1.1.2 Noel End - Rock Garden

Because of low voltage problems, removal of substations Y9 – 09 from service result in non-convergence of the ENS. Since this ghost train runs on track 2, the removal of Y11 – 011 has little influence here.


5.1.4.1.1.3 Rock Garden - Fenton Harbor

Because of low voltage problems, removal of substations Y9 – 09 and Y11 – 011 from service result in non-convergence of the ENS.

5.1.4.1.1.4 Rock Garden - Noel End

Because of low voltage problems, removal of substations Y9 – 09 from service result in non-convergence of the ENS. Since this ghost train runs on track 1, the removal of Y11 – 011 has little influence here.


5.1.4.1.2 Average Voltage Voltage drops are expected to be smaller here. Thus, only three substation removals are considered here and for the remainder of this exercise. The substations are Y6 – 06, Y9 – 09 and Y11 – 011.






5.1.4.2 Results with Inclusion of Return Circuit Method Without Bonds

5.1.4.2.1 Nominal Voltage By viewing the next four subsections, it is seen that the same low voltage non-convergence problems are experienced using the Inclusion of Return Circuit Method as with the Original Method.












5.2 RESTARTING TRAINS Two weak points were discovered in the power system. The first weak point was between substations Y9 – 09 (0.0) and Y0 – 00 (1.0) on tracks 1 and 2. The second weak point was between substations Y4 – 04 (5.7) and Y11 – 011 (6.6) on tracks 3 and 4. In the first case, the weak points are between the passenger stations Rock Garden (0.3) and Marion Place (1.4). Trains accelerating out of Rock Garden on Track 1 (+dir) and out of Marion Place on Track 2 (-dir) would be affected. Four assumptions for the exercise:

1. When trains are stopped, they are spaced at least the stopping distance from each other so that the front end of one train is the safe stopping distance from the back end of the train ahead. The stopping distance is based on 100 kph speed.

2. Three trains are stopped and are to be restarted. More than three trains between passenger stations is not practical because of distances involved.

3. Initially, the first and second trains are between passenger stations and the third is at the passenger station.

4. All trains restart simultaneously. An illustration of the assumptions of train restart is shown next. The trains are shown in green.


Assumptions 3 & 4 are only initial assumptions. Later, shifting the initial positions of the stopped trains as well as delaying the restart of each subsequent train is discussed. The operating assumptions on train spacing are listed below.

Trains D, E and F begin at Fenton Harbor and travel to Rock Garden. Trains G, H and I begin at Noel End and Travel to Rock Garden. Trains A, B and C begin at Rock Garden and travel either to Noel End or Fenton Harbor. The remainder of the schedule is the same. To understand how the TOM is used to simulate this operation, the following steps are made explicit.

1. For each of the four cases, three new Station files must be built, where the first station in the file is replaced by the Start Position. The Station File ID should be different for each of the files in a group. It must also be different from the normal running trains.

2. For each of the four cases, three new TPS File of Filenames files are built each containing the new Station file and new output filenames.

3. TPS is run for all cases. 4. For each of the four cases, a new Train Location file must be built, which adds

the stopped trains and eliminates the normal train they replaced. For example, if the normal train leaves Rock Garden at 08:00:00 and is replaced by the three stopped trains, the stopped trains must restart from their Restart Positions at 08:00:00 and the normal train (leaving at 08:00:00) is removed from the timetable.

5. For each of the four cases, a new ENS File of Filenames file is built, which includes the new Train Location files, new output filenames and the new power profiles (P-files), which represent the stopped trains.

6. ENS is run for all four cases.


7. Finally, the Minimum Voltage Finder of the FMM is used to find the minimum voltage and its position from the appropriate Current Measurement Output file (AO-).

The train re-start exercise was conducted for the Original Method with Single Track Impedance, the Inclusion of Return Circuit Method without Rail Bonds, the Original Method with Double Track Impedance and Inclusion of Return Circuit Method with Rail Bonds. In each of these cases, both Nominal and Average Voltage were considered.

5.2.1 Original Method with Single Track Impedance


In this case, all minimum voltages are below that of the traction standard of 562.5.


All minimum voltages are above the traction standard.

5.2.2 Inclusion of Return Circuit Method without Rail Bonds




5.2.3 Original Method with Double Track Impedance



5.2.4 Inclusion of Return Circuit Method with Rail Bonds





5.2.5 Position and Time Sensitivity Two additional perturbations can be done on the assumptions to determine the effect on minimum voltage.

1. Allow the trains to restart in successive order each delayed by n-seconds. 2. Shift the stop points slightly on the restarting trains.

5.2.5.1 Time Delay The results are shown next.

With the exception of the NE-RG stopped trains, the minimum voltage occurs as stated in the assumptions; namely, last departing train in the station and simultaneous starts. In the case of the NE-RG stopped trains, the minimum voltage of 540.3 v occurs with a 2-second delay on restarting successive trains.


5.2.5.2 Start Point Shift The shift distance is 0.025 km and 0.050 km. The following tables incorporate the shift distance into the new start point.

The results are shown next.


Similar to the Offset in Time case, with the exception of the NE-RG stopped trains, the minimum voltage occurs as stated in the assumptions; namely, last departing train in the station and simultaneous starts. In the case of the NE-RG stopped trains, the minimum voltage of 540.5 v occurs when the last train is 0.025 km from the station.


6 SELF-CONSISTENT AVERAGE VOLTAGE The Power System Evaluation just completed has revealed some weak points in the system. These weak points were discovered using Nominal Voltage performance. Average Voltage performance would not show these weak points, however the movement of trains is slightly slower, which may or may not have acceptable consequences on train schedules. The nominal voltage was assumed to be 750 v, the open circuit voltage. This is not consistent with power system delivery. The average voltage, which varies between the open circuit voltage (750 v) and minimum voltage (562.5 v) depending on the train power. (In regeneration, the average voltage approach varies the voltage between open circuit voltage (750 v) and maximum voltage (825 v) depending on power regenerated, minimum power open circuit voltage and maximum power maximum voltage.) This process is discussed further in Volume 11 - Instruction Manual Exercising the AC Drive Model. A self-consistent average voltage approach accounts for the power distribution system under which the trains operate. The assumption is made that the voltage seen by a train is due to the power of that train alone. The TOM does not have the capability of using an iterative method between multiple train performance and electric network simulation. The Voltage Averager is a tool of the File Construction Module in TOM Version 3.4.2 and higher, which can accommodate self-consistency. The process for determining a self-consistent average voltage is discussed in the following section. Once this has been completed, a second assessment could be conducted of the design. A second point to be made here is that the use of Nominal Voltage will always be a more conservative approach to power system evaluation. It is up to the evaluation engineer to make that judgment. To determine a self-consistent average voltage, one in which the minimum train voltage is the same as the minimum train voltage on the network, the Voltage Averager of the File Manipulation Module is used. A full description of the Voltage Averager process is in the Program Manual. A quick demonstration of the process is conducted here. Begin with the File Manipulation Module - Main Screen.


Click the Voltage Averager command button.


The choice is made to use the Original Method Average Voltage ENS File of Filenames (ENScao.dcm). Double-click on the filename to obtain the next screen.


The process writes over files, so that it gives a warning that files can be saved, if so desired. Assuming the files have been saved, click the Yes command button and the following screen appears.


Three options are available, Process, Auto Process and Quit Process. Click the Process command button.


This is the end of the 0’th iteration. With the exception of the Train Minimum Voltage, the other parameters of the Train file; namely, Nominal and Minimum Voltage are the same as the Average Voltage using Traction Standards. In other words, the Self-Consistent Average Voltage process at this point is the same as the Average Voltage used in this instruction manual up to this point. Click the Continue Process command button until the Train Minimum Voltage of the iteration is the same as the Train File Minimum Voltage.


At this stage, the iteration process has converged and the Average Voltage Train file is the self-consistent one; namely, the Train Minimum Voltage achieved during the ENS run is the same as the Train File Minimum Voltage used for the inputs into the run. This state of affairs will be referred as the Self-Consistent Average Voltage case. Clicking the Quit Process command button produces the next screen.



Click the OK command button and the result is: 0 750 562 750 616 1 750 616 750 649 2 750 649 750 643 3 750 643 750 646 4 750 646 750 644 5 750 644 750 645 6 750 645 750 645 7 750 645 750 645 pasted on the Clipboard. This information can be pasted into an EXCEL spreadsheet table similar to the one next displayed, for report purposes. 6.1 Original Method Single Track Impedance


6.2 Inclusion of Return Circuit Method Without Bonds

6.3 Loop Method


6.4 Original Method Double Track Impedance

6.5 Inclusion of Return Circuit Method With Bonds

6.6 Comparison Self-Consistent to Traction Standards Average

Voltage A comparison is made between the Self-Consistent Average Voltage approach as determined in the Voltage Averager process and the Traction Standards Average Voltage approach as determined using the Traction Standards in Train file Electric-Model construction. Please note that the latter approach is just the 0’th iteration step of the former. This comparison is conducted with the Inclusion of Return Circuit Method Without Bonds. It is completed for both Normal Train Operation and Contingency Operation.


In the comparison, the following topics are addressed.

• Train Minimum Voltage • Train Maximum Current • Substation Loading • Distribution System Currents

6.6.1 Normal Train Operation

6.6.1.1 Train Minimum Voltage Train minimum voltage will be the same as minimum voltage in the Train file. The next table compares the two situations.

6.6.1.2 Train Maximum Current


6.6.1.3 Substation Loading


6.6.1.4 Distribution System Currents




6.6.2 Contingency Operation – Substation Out of Service

6.6.3 Contingency Operation – Train Restart


6.7 Conclusions The results presented in Sections 6.1, 6.2 and 6.3 cluster around the same position with minimum voltages between 640 and 645 v. This is expected. Likewise, the results in Section 6.4 Original Method Double Track Impedance are slightly higher than those of Section 6.5 Inclusion of Return Circuit Method With Bonds as is expected, since double track impedances has a larger conductivity than tracks with rail bonds. Comparisons of Traction Standards vs Self-Consistent Average Voltages show minimal differences as far as Train Minimum Voltage is concerned. Spot checks of Substation Loading and Train and Line Currents show similar minimal differences. 7 SUMMARY Three method of ENS are used in this manual. These are termed Original, Loop and Inclusion of Return Circuit. Whether or not to use all three is up to the evaluator. The most meaningful and most time consuming is the Inclusion of Return Circuit. It allows for analysis of both primary and return circuit. It takes the return circuit into account as a separate system. It also allows for analysis of the currents in these circuit. The other two methods, Original and Loop, assume that the return circuit is in series with the primary circuit. These methods are less accurate, but for ballpark answers, they are very quick. Using the Nominal Voltage approach leads to a conservative evaluation of power system design, especially if the nominal voltage is take to be the open circuit voltage. Using Average Voltage based on Traction Standards or on Self-Consistency is a less conservative and more realistic approach. The purpose of this manual is instruction on how to apply the TOM to the evaluation of Power System Design. Thus no conclusions are drawn concerning this evaluation.


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