G. Elsaady et al., FUZZY ADAPTIVE MODEL-REFERENCE APPROACH-BASED POWER-SYSTEM STATIC VARSTABILIZER, Electric power systems research, 45(1), 1998, pp. 1-11
This paper presents a power system Static VAR stabilizer based on the
fuzzy adaptive model reference approach. The Static VAR Compensator SV
C (thyristor controlled reactor-fixed capacitor (TCRFC) type) is used
for voltage regulation and to improve power system stability. The prop
osed control system consists of a feedback fuzzy controller using the
speed state deviation and its derivative as input signals. Moreover, a
model reference with a fuzzy adaptive mechanism is built to make the
power system speed deviation response follow a certain track. The refe
rence model transfer function of second order is chosen which has desi
red performance specifications. The input signal to reference model is
the speed state deviation response. While the error between model ref
erence output response and the power system speed deviation response i
s an input signal to fuzzy adaptive mechanism, the other fuzzy adaptiv
e mechanism signal is the derivative of the above mentioned error sign
al. The control signal to the SVC stabilizer comprises the sum of the
feedback fuzzy controller output and the fuzzy adaptive mechanism outp
ut signals. The proposed control system is proved by digital simulatio
n power system speed and torque angle states response due to various d
isturbances. Furthermore, the effect of the additional signal comes fr
om the fuzzy adaptive mechanism for enhancing the power system stabili
ty. A comparison between power system response using the proposed SVC
stabilizer and without adding the control signal of fuzzy adaptive mec
hanism is presented. The results show the effectiveness and power of t
he presented SVC. (C) 1998 Elsevier Science S.A. All rights reserved.