PERMORMANCE CHARACTERISTICS OF MICROPROCESSOR BASED NUMERICAL RELAY

Abstract

Present power system is a complex network comprising of various power plants interconnected through transmission lines in a grid meeting the growing need of power. With the complexity in network and power distribution, the power system is subjected to constant disturbances created by random load changes, by faults created by random load changes, by faults created by natural causes, and sometimes as a result of equipment or operator failure. to overcome such faults and to isolate faulty equipment we go for power system protecting relaying. The function of a power system relaying is to cause the prompt removal from service, of any element of power system, when it is subjected to short circuit or it starts to operate in any abnormal manner that might cause damage or otherwise interfere with the effective operation of the rest of the system. Over current and earth fault relays are one of the most widely used relays in power system.. The working of typical over current and earth fault...