i-PCGRID Workshop 2016
April 1st 2016
San Francisco, CA
Liang Min*
Eddy Banks, Brian Kelley, Mert
Korkali, Yining Qin, Steve Smith,
Philip Top, and Carol Woodward
*min2@llnl.gov, 925-422-1187
LDRD 13-ERD-043
LLNL-PRES-673302
This work was performed under the auspices of the U.S. Department
of Energy by Lawrence Livermore National Laboratory under contract
DE-AC52-07NA27344. Lawrence Livermore National Security, LLC
California power grid
consists of 6000
transmission
substations…
and 10,000 distribution
circuits….
serving about 15
million customers.
Lawrence Livermore National Laboratory
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Decoupled transmission and distribution
simulations are insufficient for complex smart
grid systems
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We have built a HPC architecture to couple T&D
simulation to address pending complex smart
grid systems
The grid simulation assumption was made that
the time-scales on the distribution network do
not impact the transmission system.
f, g and h are all functions of V1, V2,
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, and
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• We have built our own transmission simulator, GridDyn. It is written
in C++ and use SUNDIALS/IDA and KINSOL as the solvers.
Software components are independent, reusable, and replaceable.
• Distribution simulator (GridLab-D) was modified and enhanced for
HPC.
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GridDyn Architecture
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Test Case – Coupled Transmission and
Distribution System Model
PG&E Feeder Model
WECC Transmission Model (180 buses)
•
•
•
IEEE 13 Feeder Model
Lawrence Livermore National Laboratory
Assigned one distribution feeder simulation to one
core, the whole transmission simulation to one core.
Increased load on Bus 140 by connecting more
distribution feeders to that transmission bus and
monitored what happens to the bus voltage.
Goal is to run larger distribution problem in same
amount of time
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Test Case – Using scaled-up demand response
at the distribution level to offset the need for
load shedding to avoid voltage collapse
2% DR was called to
offset the need of load
shedding to avoid
voltage collapse
Background:
•
As CAISO studied, after the SONGS retirement,
voltage stability collapse became the limiting
constraint in LA basin.
1 T+ 63Gridlab-D
•
The urgency to scale-up demand response is high
to maintain a reliable electric system, particularly
in Southern California, in the absence of the San
Onofre Nuclear Generating Station (SONGS).
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1 T+ 511Gridlab-D
1 T+ 1GridLab-D
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Validation Study with PG&E - CYME and
GridLab-D simulation results comparison
on the PG&E Feeder
CYME vs Gridlab-D
Voltage Profile Error
10
0
CYME
-10
-20
Voltage Profile
V
7600
-30
7400
7200
-40
7000
-50
6800
V
GLD
6600
A
B
C
-60
6400
6200
5800
•
•
•
-70
A
B
C
6000
0
0.5
1
1.5
Distance from source (ft)
2
x 10
0
0.5
1
Distance from source (ft)
1.5
2
x 10
4
Both CYME and GridLab-D results indicate a strong imbalance in the load
The errors in voltage are less than 1%.
Errors are caused by the impedances mismatch when translating between the two models
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 Smart grid = Electricity infrastructure + “Intelligence” infrastructure.
 We need a power systems and
communication co-simulation to
answer very important questions:

What will happen to the electric grid:
- If data is dropped or delayed?
- If data is modified in transit?
-…
 With this capability, we can help
utilities better design their widearea control schemes and
ensure system security and
reliability.
NIST Smart Grid Reference Diagram
The interdependencies of communication and power
systems are becoming increasingly important
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 Small toolkit for coupling
continuous and discrete
time simulations
 Provides
• Time control for advancing
state of federated
simulators
• Communication between
objects in federated
simulatorsfor HPC
 Designed
• Asynchronous API design
• MPI used as communication layer
• Parallel conservative granted time window
synchronization algorithm
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22-23
22-21
22
21-22
21-16
r
21
23-24
r
23
r
r
21-22
21-16
r
28-29
19
r
27-17
r
r
24-23
28
19-16
r
23
17-16
r
17
16-19
16-21
18-17
16-17
r
15
24-16
26
26-28
18
r
16-15
r
26-29
26-25
16-21
25-26
r
15-14
16-19
29-26
r
26-27
16
16-24
25
18-3
25-2
4-5
r
13-14
4-14
14
13
13-10
14-13
r
r
r
14-15
2-3
2
14-4
r
3-4
3-2
2-1
10
5-4
1-39
5-8
5
5-6
11-10
8-5
r
r
r
11-6
6-11
6
r
r
8-7
8
11
Point-to-Point Link (propagation delay
15-14 to transmission line reactance)
proportional
39-9
r
9-39
r
6-7
9-8
7
7-6
Original Single Line Diagram
IEEE 39-bus System
16-17
39-1
39
8-9
9
6-5
16
r
CSMA Link (5µs
delay)
16-15
15 propagation
1
r
10-11
15-16
1-2
3-18
10-13
r
16-24
2-25
4-3
4
3
17
r
r
r
24-16
17
24
29
27
17-27
r
29-28
r
27-26
17-18
24
15-16
24-23
28-26
21
23-24
17-18
17-16
22-21
22
23-22
19
r
23-22
22-23
19-16
7-8
Resultant Communication
System Model
N
Substation LAN
for bus N
13-14
r
A-B
13-10
4-14
Gateway Router
ns-3 Smart
13
relay) for
B
r
4-5
r
4-3
14
4
Grid Application
(protection
end A of transmission line A to
14-13
14-15
14-4
r
Total has about 100 communication nodes3-4
10-13
10
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10-11
r
5-4
5-8
5
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Ad-hoc (peer to peer) protection relay systems scenario:
Bus fault at Bus 4 at t=0.2s and clear the fault at t=0.25s
Supervisory (master agent) wide area control scenario:
fault at Bus 4 at t=0.2s and clear the fault at t=0.35s
We could vary the line latency and the
throughput to assess different control
schemes. As the WAN latency
increases, trip times increase, which
affects system voltage recovery.
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Delayed Voltage
Recovery due to
long fault clear time
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Tech transfer activities
 The integrated T&D simulator will be used as the
validation platform by Eaton/PG&E for their ARPA-E
project.
 The GridDyn will be used on LBNL’s SuNLaMP project
“A Cyber-physical co-simulation platform for Distributed
Energy Resources in Smart Grids”.
 Parallel distribution modeling has been proposed to
support California distribution resource planning
activities – partnering with LBNL/SLAC through GMLC.
 GMLC has proposed to continue the integrated T&D&C
research direction.
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Q&A
Thank You