College of Engineering and Architecture

Specifications for the Power Grid Simulator

Anjan BoseWashington State University

Pullman, WA

CMU Conference on TestbedsPittsburgh, PAApril 1, 2015

College of Engineering and Architecture

What is Simulation?

• Testbed?• Analytical Tools?• Apps?• Simulation maybe a part of an analytical tool• Analytical tool or app requires Input – static vs time variable Output – characterizes the app

• Simulation is a mathematical description of behavior

College of Engineering and Architecture

What is simulation?

• Is power flow a simulation?• Power flow ‘simulates’ an instant• Simulation usually implies behavior over time Electromagnetic (<msecs) Electromechanical (>msecs) Uniform frequency (secs) Economic Dispatch (min) Unit Commitment (hours-days-weeks) Hydro Coordination (seasonal) Planning (years)

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0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5Time Step of 0.5(s)

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Time Step of 0.1(s)

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Time Step of 0.1(s)

College of Engineering and Architecture

What is Real Time?

• Is the computation time faster than the time step?• What affects the computation time Size of the grid Complexity of the models (equations) Nonlinearities, particularly discontinuities Computer architecture Algorithm

Are there any real time simulators?

College of Engineering and Architecture

Simulator Characteristics

• Models Algebraic equations (power flow) Differential equations Logic (control, protection)

• Main concern is the speed of dynamic behavior• Faster behaviors are harderMany simulators are possible.Can they be seamlessly connected?

College of Engineering and Architecture

Transmission vs Distribution

• Mostly simulated separately• Distribution models usually smaller• Do we have to model distribution in our

transmission simulation?• Distributed generation, dynamic load control• How much detail?

College of Engineering and Architecture

Why New Simulation Testbeds?

• Faster sensing (PMU)• Faster communication• Faster computers• Faster controllers (FACTS)

Can we operate the grid more efficiently and reliably?Need better tools to design and test new operational procedures and controls.

College of Engineering and Architecture

Simulation Challenges

• What is missing in the existing simulators? New measurements New power electronics equipment New controls logicAlso PMUs Communications ComputationHandling of the feedback loop of streaming measurements, control logic and control signals

College of Engineering and Architecture

Real Time Simulation

• Does the simulation have to be real time?Issues• Synchronizing the simulation of different parts Power grid Communications Computation Control/protection logic

Don’t know how to do time simulation of communication and computation

SGDRIL Test Bed at WSU

PI SYSTEM

PI Interface PI Server

PI Analytics

C37.118

OPAL-RT

Programmable PMU

11

Real Time Digital Simulator and Other Devices

The test bed consists of –a) Real Time Digital Simulator b) Master Computerc) Substation Automation Computerd) 5 Nos. of PMUs e) Software & Hardware PDCs f) Synchrophasor Vector Processor

(SVP)g) Real Time Automation Controller

(RTAC)h) GPS Clocks (2 Nos.)i) Ethernet Hubj) Amplifiersk) Different Softwares.

http://www.eecs.wsu.edu/~asrivast/SGDRIL/index.html 12

Hardware Interface/Ethernet Internet

PMUPDCDatabase

Subsystem

NS 3, GridStat, or Deternet

Control Center

OpenPDC

RT-VSMApplication LayerApplication Layer

Communication Layer

Sensor and Actuator Layer

Power System Layer

Cyber-Power System Modeling

Real Time Power System Simulator

GridSim: High Level Diagram

GridStat

Transient Stability Simulator Substation 1Control Center SE

Running at 5Hz

Control Center Oscillation Monitor

Running at 30Hz

Pow

er T

opol

ogy

Sim

ulat

or

User Defined Model

RT Timekeeping

Output Streamer

Control ListenerTimestamp Generator

Topology Mapper

C37.118 Output

Closed Loop ControllerRunning at 30Hz

Substation 2

Substation N

…

Data Receiver & Control Forwarder

Measurement Generator

TimingImplementation

& Design

TimingDesign

14

GridSim: Full Architectural Diagram

GridStat

Transient Stability Simulator Substation 1

SubstationSE

SubstationGW

Control Center SE(5Hz)

Tim

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ignm

ent

Com

puta

tion

Visu

aliza

tion

Grid

Stat

Pub

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r

Grid

Stat

Sub

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er

… Tim

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ent

Control Center Oscillation Monitor (30 Hz)

Tim

e Al

ignm

ent

Com

puta

tion

Visu

aliza

tion

Grid

Stat

Sub

scrib

er

Pow

er T

opol

ogy

Sim

ulat

ion

Engi

ne

Use

r Def

ined

Mod

el

RT Timekeeping

Output Streamer

Control Listener

Measurement Generator

Form

at P

arse

r

Tim

esta

mp

Gene

rato

r

Topo

logy

Map

per

C37.

118

Out

put

Data

Rec

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Cont

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Substation 2

SubstationSE

SubstationGW

Grid

Stat

Pub

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… Tim

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Substation N

SubstationSE

SubstationGW

Grid

Stat

Pub

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… Tim

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…

Controller(30Hz)

Tim

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Com

puta

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Cont

rol A

ctio

ns

Grid

Stat

Sub

scrib

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TimingImplementation

& Design

TimingDesign

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Adaptation for GridCloud Architecture

GridStat

Replay Process 2

Re-

play

ed D

ata

File

sO

f C37

.118

Dat

a

PMUN

PMUN-1

PMU1

…PMU2

GridCloud Replica 1

COLN

COLN-1

COL1

…COL2

SubstationSE1 P

SubstationSEM

Control Center SERunning at 5Hz

Tim

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ignm

ent

S

Com

puta

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Resu

lts

Visu

aliza

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GridCloud Replica 2

COLN

COLN-1

COL1

…COL2

SubstationSE1

SubstationSEM

GridCloud Replica 3

COLN

COLN-1

COL1

…COL2

SubstationSE1

SubstationSEM

Client Handler

291 Substations

291 Substations

291 Substations

Replay Process 1

Re-p

laye

d Da

ta F

iles

Of C

37.1

18 D

ata

PMUN

PMUN-1

PMU1

…PMU2

Client Handler

Replay Process 3

Re-

play

ed D

ata

File

sO

f C37

.118

Dat

a

PMUN

PMUN-1

PMU1

…PMU2

Client Handler

4632 Streams

Time-Synchronized Data Sources Internet GridCloud running on Amazon Elastic Compute Cloud

P

P

P

P

P

4632 Streams

4632 Streams

16

College of Engineering and Architecture

Testbed Challenge• What are we testing? A scenario A widget (sensor, relay, controller) A control process or protection scheme

• Inputs Streaming measurements (real time data) System data (static data)

• What simulation to use• Output Must include performance metrics

College of Engineering and Architecture

Testbed Challenge

• Many testbeds?• Or one very flexible testbed Changeable, flexible simulations Different system data sets Different scenarios (measurement data) Different output setsThis is difficult to design. Maybe a few testbedscan cover the whole range