Multi‐Layered Simulation using the SGRS Simulator; Interaction of TE and Flywheel Controlled Dynamic System
Kevin Bachovchin, Martin Wagner, Marija Ilic
kbachovc@andrew.cmu.edu, mwagner1@andrew.cmu.edu, milic@andrew.cmu.edu
10th CMU Electricity Conference
Pre-conference Workshop
March 30, 2015
Outline
 Link multi‐time scale simulations  Adaptive load management (ALM): slow time‐scale
 Fast dynamics with flywheel control: fast time‐scale
 Market needs to specify reactive power set point
 Reactive power set point is critical to whether there is an equilibrium
 Depending on the reactive power set points, sometimes dynamics cannot be stabilized  Demonstrate stable and unstable responses on Smart Grid in a Room Simulator
2
Interactive Communication
 Communication for multi time‐scale simulation with ALM and fast dynamics for generators
Source: M. R. Wagner, K. D. Bachovchin, M. D. Ilić, "Computer Architecture and Multi
Time-Scale Implementations for Smart Grid in a Room Simulator," EESG Working
Paper No. R-WP-1-2014, March 2015.
3
Importance of Reactive Power
 Typically the market only specifies the active power set point
 However the reactive power is critically important to the equilibria and stability of the system
Power Factor PF = 0.99 (Without Shunt Capacitor)
Power Factor PF=0.2 (Without Shunt Capacitor)
3
3
2
2
[0.9615, -0.18 rad]
1
 2 (rad)
1
2 (rad)
Manifold of Active Power Balancing Eqn at Bus 2
Manifold of Active Power Balancing Eqn at Bus 2
Manifold of Reactive Power Balancing Eqn at Bus 2
0
0
-1
-1
[0.182, -1.27 rad]
-2
-2
-3
-3
0
0.5
1
1.5
2
2.5
3
Voltage V2 (pu)
3.5
4
4.5
5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Voltage V2 (pu)
Source: X. Miao, K. D. Bachovchin, M. D. Ilić, "Effect of Load Type and Unmodeled
Dynamics in Load on the Equilibria and Stability of Electric Power System," EESG
Working Paper No. R-WP-1-2014, March 2015.
4
5
Flores Island – Market Control
 Based on prices, market computes active power set points P* from each component
5
Flores Island – Dynamics Control
 Since currently the market does not specify reactive power set points Q*, data for Q* is randomly created
 Place a voltage source inverter and the variable speed drive on the hydro and diesel generator buses
 Control the sum of the power out of the hydro and diesel generators to match the active and reactive power set points
6
Flores Island – Variable Speed Drive Control
 Determine the variable speed drive set points based on the set points from the market
 Controllable inputs for the variable speed drive are
u k  g k xk , yck 1 , yk ref


T
u k  u1d u1q u2 d u2 q 
T
x k  i1d i1q qC1 iS 2 d iS 2 q iR 2   
T
y ck 1   vd vq 
y k ref  2 ref i1d ref i1q ref 
T
 Set points for the variable speed drive are
y k ref  h k  yck 2 , rk ref

T
y ck 2  iGd iGq 
T
r ref   PG * QG * 
PG *  Vd  i1d ref  iGd   Vq  i1q ref  iGq 
QG *  Vq  i1d ref  iGd   Vd  i1q ref  iGq 

Solve for i1d ref and i1q ref
7
Simulation Results – Hydro/Diesel Generator Bus
Total Power out of Hydro Generator Bus
Total Power out of Diesel Generator Bus
0.2
P
P*
power(pu)
power(pu)
0.2
0.1
0
0
20
40
60
80
0.1
P
P*
0
100
0
20
40
0.02
0.01
Q
Q*
power(pu)
power(pu)
80
0
20
40
60
t(sec)
80
100
Q
Q*
0
-0.02
0
100
t(sec)
t(sec)
-0.01
60
0
20
40
60
80
100
t(sec)
8
Simulation Results – Wind Generator Bus
Stable Case:
Unstable Case:
Reactive Power Load Consumption
10
5
0
0
20
40
60
80
100
power(pu)
power(pu)
Reactive Power Load Consumption
10
5
0
0
20
40
80
100
t(min)
t(min)
Wind Generator Bus Voltages
Wind Generator Bus Voltages
1.2
1.2
1
1
0.8
vB2d
vB2q
0.6
0.4
voltage(V)
voltage(pu)
60
0.8
vB2d
0.6
vB2q
0.4
0.2
0
0.2
-0.2
0
-0.2
-0.4
0
20
40
60
t(min)
80
100
-0.6
0
20
40
60
t(min)
80
9
100
Conclusions
 Demonstrated multi time‐scale simulation with feedforward market controller and feedback flywheel controller
 Showed that with a high reactive power load, the system may not reach a stable equilibrium
Future Work
 Market level controller specify the reactive power set point  Design fast dynamic control, so that we don’t need voltage source inverter at each bus
 Combine with other time‐scale simulations (AGC)
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