College of Engineering and Architecture
Specifications for the
Power Grid Simulator
Anjan Bose
Washington State University
Pullman, WA
CMU Conference on Testbeds
Pittsburgh, PA
April 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

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Electromagnetic (<msecs)
Electromechanical (>msecs)
Uniform frequency (secs)
Economic Dispatch (min)
Unit Commitment (hours-days-weeks)
Hydro Coordination (seasonal)
Planning (years)
0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
1.05
1.15
1.25
1.35
1.45
1.55
1.65
1.75
1.85
1.95
2.05
2.15
2.25
2.35
2.45
2.55
2.65
2.75
2.85
2.95
3.05
3.15
3.25
3.35
3.45
3.55
3.65
3.75
3.85
3.95
4.05
4.15
4.25
4.35
4.45
4.55
4.65
4.75
4.85
4.95
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
5
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.5
1
1.5
2
2.5
3
Time Step of 0.5(s)
Time Step of 0.1(s)
3.5
4
4.5
5
5.5
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Time Step of 0.1(s)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
College of Engineering and Architecture
What is Real Time?
• Is the computation time faster than the time step?
• What affects the computation time
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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 harder
Many 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 logic
Also
 PMUs
 Communications
 Computation
Handling 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 Analytics
Programmable PMU
C37.118
PI Interface
PI Server
OPAL-RT
11
Real Time Digital Simulator and Other Devices
The test bed consists of –
a)
b)
c)
d)
e)
f)
Real Time Digital Simulator
Master Computer
Substation Automation Computer
5 Nos. of PMUs
Software & Hardware PDCs
Synchrophasor Vector Processor
(SVP)
g) Real Time Automation Controller
(RTAC)
h) GPS Clocks (2 Nos.)
i) Ethernet Hub
j) Amplifiers
k) Different Softwares.
http://www.eecs.wsu.edu/~asrivast/SGDRIL/index.html
12
Cyber-Power System Modeling
Application Layer
Layer
Application
RT-VSM
Control
Center
OpenPDC
NS 3, GridStat,
or Deternet
Communication
Layer
Subsystem
Sensor and
Actuator Layer
Database
PDC
PMU
Hardware Interface/Ethernet Internet
Power
System Layer
Real Time Power System Simulator
GridSim: High Level Diagram
Transient Stability Simulator
Simulator
Power Topology
User Defined Model
RT Timekeeping
Output Streamer
Control Listener
Measurement Generator
Topology Mapper
Control Center SE
Running at 5Hz
Substation 2
Timestamp Generator
C37.118 Output
Timing
Implementation
& Design
Substation 1
Data Receiver &
Control Forwarder
Timing
Design
…
GridStat
Control Center Oscillation
Monitor
Running at 30Hz
Substation N
Closed Loop Controller
Running at 30Hz
14
…
…
Substation N
SubstationSE
SubstationGW
…
GridStat
Control Actions
SubstationGW
Visualization
Computation
Time Alignment
Substation 2
Computation
SubstationSE
Visualization
Computation
Time Alignment
GridStat Subscriber
GridStat Publisher
…
GridStat Subscriber
Time Alignment
C37.118 Output
Topology Mapper
Timestamp Generator
Format Parser
SubstationGW
Time Alignment
Timing
Design
Substation 1
GridStat Subscriber
Timing
Implementation
& Design
SubstationSE
GridStat Publisher
Control Listener
Measurement Generator
GridStat Publisher
Output Streamer
Time Alignment
RT Timekeeping
Data Receiver &
Control Forwarder
Transient Stability Simulator
Time Alignment
User Defined Model
Simulation Engine
Power Topology
GridSim: Full Architectural Diagram
Control Center SE
(5Hz)
Control Center Oscillation
Monitor (30 Hz)
Controller
(30Hz)
15
Adaptation for GridCloud Architecture
COL2
Client Handler
…
PMUN-1
COLN-1
PMUN
COLN
Re-played Data Files
Of C37.118 Data
Replay Process 2
PMU2
…
COL1
COL2
Client Handler
…
PMUN-1
COLN-1
PMUN
COLN
Re-played Data Files
Of C37.118 Data
Replay Process 3
PMU2
…
COL1
COL2
…
Client Handler
PMUN-1
COLN-1
PMUN
Time-Synchronized Data Sources
291 Substations
SubstationSEM
P
Control Center SE
Running at 5Hz
SubstationSE1
P
GridStat
291 Substations
SubstationSEM
S
P
GridCloud Replica 3
4632 Streams
PMU1
P
GridCloud Replica 2
4632 Streams
PMU1
SubstationSE1
Visualization
COL1
Results
4632 Streams
Computation
PMU2
…
GridCloud Replica 1
Time
Alignment
Re-played Data Files
Of C37.118 Data
Replay Process 1
PMU1
COLN
Internet
SubstationSE1
P
291 Substations
SubstationSEM
P
GridCloud running on Amazon Elastic Compute Cloud
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 sets
This is difficult to design. Maybe a few testbeds
can cover the whole range