Modeling and Simulation of Under -Frequency Relay for Generator Protection

Abstract

Power systems are undergoing structural changes induced by the combination of the operation of microgrids and distributed generation units. This transfiguration has impersonated new challenges in well-established power system practices, coordination of protection systems and especially on the design. Same time, technological improvements in protective equipment have set up the basis for the development of digital frequency relays which enable an alternate approach to standard protection schemes. It is necessary for the power system to operates, regulates and manages ancillary services more efficiently to maintain the reliability of the system. The power system is continually laying unexpected contingencies which cause inequality between load demand and generated power. Such uncertainties cause the disturbance in the power system frequency. The only way to maintain power system frequency by balancing load and generation. In this paper, we have designed the under frequency relay model in Matlab simulink. We have noticed that when the load on the system is increased, the designed model shed the extra load and are modeled through under frequency relay by comparing the frequency responses of the power system.

Keywords

• synchronous machine; under- frequency relay; relay setting; critical load