An expert system for voltage control in a power system network

This paper presents a prototype of an expert system for alleviation of voltage violations in the day-to-day operation of large power networks. Voltage control for varying load and generation conditions can be achieved by co-ordinated control of switchable shunt VAr compensating (SVC) devices and on-load transformer taps (OLTC), while generator excitations are used in the dynamic control of voltage profile. This paper deals with the development of an expert system for voltage corrections for base case and contingency conditions using switchable shunt reactive compensation and transformer tap settings. The performance of the expert system is compared with the conventional optimization technique of voltage control and concurrent results have been obtained. The proposed expert system has been tested with simulated conditions of a few practical power systems. Results obtained for a 24 bus EHV Indian power network have been included for illustration purpose. The expert system is found to be suitable for online application in energy control centers as the solution is obtained very quickly.