BANG-BANG CONTROL FOR IMPROVEMENT OF TRANSIENT STABILITY OF POWER SYSTEM

Abstract

The use of time optimum control theory to the problem of improving the transient stability of power system is relatively a new idea. According to one of this method the stability limit is improved by removing the system's transients in dead-beat non-oscillatory manner in minimum possible time. The first method which was first developed accord-ing to this theory is bang-bang control of excitation, which suffers from the drawback that the transient removal is in oscillatory manner for single intermediate switching.The another method of tie line reactance control seems to be better, but the expected over-voltages involved in switching operations are high. The method presented in this work is another approach for transient removal in dead-beat non-oscillat-ory manner using the same ti m optimal theory.. The control process is implemented with a phase shifter, capable of shifting the phase in either direction. The logic presented for the method has been illus-trated on a power system model consisting of two tie lines interconnecting a power station to .,.n infinite- bus system.