Implementation Of Solid State Relays For Power System Protection

ABSTRACT This paper provides the implementation of solid state relays for enhancement of power system protection. Relays are an essential part of the power systems and are responsible for the control of any overload voltage or current and protection of the devices from these parameters. The main function of the relay is to constantly monitor the parameter to be controlled and if it exceeds the percentage range set by the controller then it sends a signal to the circuit breaker to break the connection and isolate the faulty part. Solid state relays are preferred over mechanical relays and in this paper relay functioning is done with the help of opto-coupler. Controlling of opto- coupler is done with the help of microcontroller. Circuit operates through Zero Voltage Switching leading to reduction in harmonics. The implementation of relay circuit offers minimal delay time which enables better time response for protection.