January 9, 2013

BAL-001-TRE-1 Primary Frequency Response

Update for Texas RE RSC

2

SAR-003 Standard Drafting Team

BAL-001-TRE-1 RSC January 9, 2013

Name Company

Sydney Niemeyer (Chair) NRG Energy

Ananth Palani (Vice-Chair) Optim Energy

Pamela Zdenek Infigen Energy

Vann Weldon ERCOT

Brenda Hampton Luminant

Sandip Sharma ERCOT (Non-voting SME)

3

BAL-001-TRE-1 RSC January 9, 2013

Submittal for RSC Approval

● Drafting Team has finished the standard and related documents. Each active team member approved all documents.

● Request RSC to approve standard for Posting, Review and Balloting.

4

Requirements Overview

● Applies to BA, GO and GOP function● Provides requirements for:

Identifying Frequency Measureable Events (FME) Calculating the Primary Frequency Response (PFR) of each

resource in the Region Calculating the Interconnection minimum Frequency Response Monitoring the actual Frequency Response of the Interconnection Setting Governor deadband and droop parameters Providing Primary Frequency Response performance requirements.

● Importantly, the standard narrows the governor deadband and requires the droop curve to begin at the edge of the deadband with no step function.

BAL-001-TRE-1 RSC January 9, 2013

5

Generator PFR Performance Measures

● Under this standard, two Primary Frequency Response performance measures are calculated: “initial” and “sustained.”

The initial PFR performance (R9) measures the actual response compared to the expected response in the period from 20 to 52 seconds after an FME starts.

The sustained PFR performance (R10) measures the best actual response from t(46) to t(60), compared to the expected response at t(46).

BAL-001-TRE-1 RSC January 9, 2013

6

BAL-001-TRE-1 RSC January 9, 2013

Increased Maintenance & Operating Costs?

● Generator Owners had concerns with smaller dead-bands increasing costs.

● Data from before dead-band and droop curve implementation compared to latest data indicates a significant cost savings.

● Significant increase in grid reliability.

7

BAL-001-TRE-1 RSC January 9, 2013

ERCOT Frequency Profile from 2008

ERCOT Frequency Profile Comparison

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

On

e M

inu

te O

ccu

ran

ces

2008

439,200 One Minute Periods in the Ten Months of Data January through October

Prior to Nov 2008 nearly all generators implemented a +/- 0.036 Hz dead-band governor, many with a step-response at the dead-band. The frequency profile reflected this dead-band setting.

8

BAL-001-TRE-1 RSC January 9, 2013

ERCOT Frequency Profile from 2012

ERCOT Frequency Profile Comparison

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

On

e M

inu

te O

ccu

ran

ces

2012

439,200 One Minute Periods in the Ten Months of Data January through October

By the end of October 2012 more than 20% of ERCOT generators had implemented the smaller +/- 0.017 Hz dead-band.

9

BAL-001-TRE-1 RSC January 9, 2013

How Does This Impact Generator Movement?

Jan thru Oct 2008 and 2012

0

20000

40000

60000

80000

100000

120000

140000

160000

MW

2008 MW Response of 0.036 db 2012 MW Response of 0.0166 db

591324.0

364610.0 MW Response of 0.0166 db

MW Response of 0.036 db

38.34% Decrease in MW movement with lower deadband.

MW Movement of a Typical 600 MW Generator Exposed to ERCOT Frequency during Time PeriodDue to Primary Frequency Response Only

With the lower dead-band setting a similar size generator saw a 38% decrease in movement between 2008 and 2012.

10

BAL-001-TRE-1 RSC January 9, 2013

Not All Improvement Due to Dead-Band & Droop

● Approximately 20% of ERCOT Generators now meet R6 of this Standard.

● Other Changes Impacted Frequency Control Change in Market from Zonal to Nodal Dispatch. Many generators previously not providing PFR

correctly are now working correctly but at the larger dead-band.

Wind Generators are now required to have PFR and governors in service.

● However, only the decrease in the dead-band can significantly improve the frequency profile inside the +/-0.036 Hz deviation range.

11

BAL-001-TRE-1 RSC January 9, 2013

Impact on ERCOT CPS1 Performance

ERCOT CPS1

100

110

120

130

140

150

160

170

CP

S1

Av

era

ge

100

110

120

130

140

150

160

170

Monthly Average 12 Month Rolling Average

Oct 2008 12 month avg. CPS1 = 122.03

Oct 2012 12 month avg. CPS1 = 160.17

12

BAL-001-TRE-1 RSC January 9, 2013

With All the Improvement Why BAL-001-TRE

● Fair and accurate measure of PFR. 12 month rolling average or minimum 8 event avg. Allows for event exclusion due to equipment limits. Accounts for generator ramping before the event. Adjusts expected performance due to known

generator delivery limitations. Accounts for non-frequency responsive capacity

like duct burner operation and other augmentation.

● Equal expectations for all generators. Wider dead-band governors benefiting from

generators with smaller dead-band. With the standard all generators will move less and

operate closer to their economic target.

13

BAL-001-TRE-1 RSC January 9, 2013

Field Trial Results

● 28 generating units were evaluated in the trial, which included 7 coal, 4 gas, 2 simple cycle combustion turbine, 5 wind, and 10 combined cycle units.

● Based on 35 events from June 2011 to June 2012.

● No high-frequency events were evaluated.● 8-event average was not possible with some

units.● These results use NEW R10 calculation.

14

BAL-001-TRE-1 RSC January 9, 2013

Field Trial Results – Coal Units

Coal Plant R9 R10 Comments

Generator 1 0.5841 0.6460 Generator 2 0.4643 0.3706 Participation in less than 8

events Generator 3 1.1892 1.2609 Generator 4 0.8872 0.9909 Generator 5 0.2530 0.4113 Participation in less than 8

events Generator 6 0.6092 0.8444 Generator 7 1.1987 1.3827

15

BAL-001-TRE-1 RSC January 9, 2013

Field Trial – Gas Units

Gas Plant R9 R10 Comments

Generator 1 0.7712 1.1068 Generator 2 0.4716 0.7218 huge data latency Generator 3 1.3608 1.3778 Participation in less than 8

events Generator 4 1.3415 1.7862 Participation in less than 8

events

Simple cycle combustion turbine R9 R10 Comments

Generator 1 0.1001 0.0178 Participation in less than 8 events

Generator 2 0.7409 0.8621

16

BAL-001-TRE-1 RSC January 9, 2013

Field Trial – Wind Units

Wind Generation R9 R10 Comments

Generator 1 1.3824 1.3737 Participation in less than 8 events

Generator 2 No Evaluation No Evaluation No Participation Generator 3 No Evaluation No Evaluation No Participation Generator 4 0.6259 1.0435 Participation in less than 8

events Generator 5 0.8189 0.7211 Participation in less than 8

events

17

BAL-001-TRE-1 RSC January 9, 2013

Field Trial – Combined Cycle Units

Combined Cycle R9 R10 Comments

Generator 1 0.2712 0.2360 Generator 2 1.5976 1.7676 Participation in less than 8

events Generator 3 0.7664 0.7863 Generator 4 0.5668 0.6246 Generator 5 0.9181 1.2397 Generator 6 1.1232 1.4586 Generator 7 0.6946 0.9575 Generator 8 0.5710 0.8235 Generator 9 0.3705 0.7409

Generator 10 0.7794 1.1074

18

BAL-001-TRE-1 RSC January 9, 2013

Changes Made after Field Trial and Comments

● Changed Sustained Measure (R10) from average over several minutes to instantaneous at t(46). Too much happens during former averaging window.

● Added 5 MW limit to the 2% exception criteria.● Moved examples of “legitimate operating conditions

that may support exclusion” from Measures to Requirements (R9 and R10).

● M7 re-written to focus on notice from GO to GOP of change in Governor status. Avoids concern about 24/7 proof issue.

● Changed deadband setting from 0.01666 to 0.017 Hz.● Reformatted R2 to break into sub-requirements.● Added non-frequency responsive augmented capacity

exclusion.

19

BAL-001-TRE-1 RSC January 9, 2013

Benefits of the Field Trial

● Presentations prepared and delivered to each participant. One presentation for each generator with one

graph for each event evaluated (generator on line during the event). Potentially 980 graphs total. Included Performance summary and critique.

● Reviewed performance with each participant through web conferences.

● Participants became familiar with the standard, proper PFR expectations and could easily see shortcomings in performance.

20

BAL-001-TRE-1 RSC January 9, 2013

Example of New R10 Measure

540.0

550.0

560.0

570.0

580.0

590.0

600.0

610.0

59.66

59.68

59.7

59.72

59.74

59.76

59.78

59.8

59.82

59.84

59.86

59.88

59.9

59.92

59.94

59.96

59.98

60

60.02

60.04

60.06

13:15:43 13:15:53 13:16:03 13:16:13 13:16:23 13:16:33 13:16:43 13:16:53 13:17:03 13:17:13 13:17:23 13:17:33 13:17:43

Freq

uenc

y -H

z

Unit:Sample Generator

Hz Average Frequency MW Average MW Initial EPFR(Final) EPFR(Final@T(+46))

592.65

59.844

564.70

1.178 Initial P.U. Performance

MW

Thursday, December 15, 20111.434 Sustained P.U. Performance

60.005

1) Frequency @ t(+46) sets the expected performance.

2) Based on Frequency @ t(+46) expected performance is calculated.

3) Generator performance is based on “best” performance between t(+46) through t(+60).

21

BAL-001-TRE-1 RSC January 9, 2013

Primary Frequency Response Reference Document

● This Primary Frequency Response Reference Document is not considered to be a part of the regional standard.

● This document will be maintained by Texas RE and will be subject to modification as approved by the Texas RE Board of Directors, without being required to go through the formal Standard Development Process. This arrangement provides Regional flexibility in

adjusting the technical details of the performance metric calculations.

The PFR Reference Document includes flowcharts that detail the calculations

22

BAL-001-TRE-1 RSC January 9, 2013

PFR Reference Document Revision Process

● A Revision Request may be submitted to the Texas RE Reliability Standards Manager

● The Reliability Standards Committee (RSC) will consider the request The revision request will be posted in accordance with RSC

procedures The RSC shall discuss the revision request in a public meeting,

and will accept and consider verbal and written comments pertaining to the request

The RSC will make a recommendation to the Texas RE Board of Directors

● The Board may adopt the revision request, reject it, or adopt it with modifications Any approved revision to the Primary Frequency Response

Reference Document shall be filed with NERC and FERC for informational purposes

23

Implementation Plan

● 12 months after Effective Date The BA must be compliant with Requirement R1 At least 50% of the GO’s generating units/generating facilities must

be compliant with Requirement R6 (if >1 unit/facility) At least 50% of the GO’s generating units/generating facilities must

be compliant with Requirement R7 (if >1 unit/facility) The GOP must be compliant with Requirement R8

● 18 months after Effective Date The BA must be compliant with Requirements R2, R3, R4, and R5 100% of the GO’s generating units/generating facilities must be

compliant with Requirement R6 100% of the GO’s generating units/generating facilities must be

compliant with Requirement R7

BAL-001-TRE-1 RSC January 9, 2013

24

Implementation Plan

● 24 months after Effective Date At least 50% of the GO’s generating units/generating facilities must

be compliant with Requirement R9 (if >1 unit/facility) At least 50% of the GO’s generating units/generating facilities must

be compliant with Requirement R10 (if >1 unit/facility)

● 30 months after Effective Date 100% of the GO’s generating units/generating facilities must be

compliant with Requirement R9 100% of the GO’s generating units/generating facilities must be

compliant with Requirement R10

BAL-001-TRE-1 RSC January 9, 2013