Page 39 - IJEEE-2023-Vol19-ISSUE-1

Basim T. Kadhem
a) Without controller.
b) With full order controller for 29th
c) With reduce order controller to 3rd.
d) With reduce order controller to 14th.
Fig. 14: (1). Rotor angle oscillations, (2). Terminal voltage
generator, (3). Level compensation, and (4). SVC susceptance.
At three phase short circuit.
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This 14th reduced order LQG/LTR controller is capable of
efficiently dampening all SSR modes at varying amounts of
series compensation, ranging from 30% to 90%. Rotor angle
oscillations, level compensation, and SVC susceptibility were
presented in Fig. 15 for three different levels of level
compensation.
2
1.8
1.6 Dg(2) Dg(3)
1.4
1.2 Dg(1)
1
Level compensation(3)
0.8 Level compensation(2)
0.6
0.4 Level compensation(1)
0.2 SVC susceptance (3) SVC susceptance (2)
0
-0.2 SVC susceptance (1) 10
0 2.5 5 7.5
Fig.15: System response for three phase short circuit 0.1sec at
time t=1sec, with reduce order controller to 14th. Rotor angle
oscillations, level compensation, and SVC susceptance for
three cases according the following
1-for level compensation = 50%
2- for level compensation = 60%
3- for level compensation = 70%
VII. CONCLUSION
In order to dampen subsynchronous resonance
oscillations, this study outlines a design process for LQG
control of VSC, TCSC, and excitation system. One feedback
signal (angular speed deviation) and three control signals, each
of which is capable of dampening all undesired oscillations,
are used to create a robust control utilizing LQG. This setup
uses a quantity that can be measured, making it both easy to
use and practical. The 14th order version of the full-order
robust controller displayed the same high performance.
APPENDIX I
Generator data
Xd=1.869, Xq=1.869, Xs=0.194, X'd=0.3016, X''d=0.2337,
X'q=0.2337, Ra=0.0022, Rr=904e-6, R1d=3.688e-3,
R1q=0.00108,
Transformer data
Rt=0.005, Xt=0.12.
Excitation system data
Kou=-15, K1u=-7.2, Tou=0.09, T1u=0.039, Tp=0.07,
Transmission line data
RL=0.025, XL=0.5
SVC data
Kour=-15, K1ur=-10, Tour=0.09, T1ur=0.39, Tpr=0.001,
BLo=-0.01, BLmax=-0.0001, BLmin=-0.25;