A Fuzzy Logic Based Load Shedding Technique for Operation of DG in Islanding Mode

A varying load affects the frequency when a power system is running in islanding mode on a distributed generator. Load shedding techniques are implemented in the system to avoid the loss of generation due to overloading. Under frequency load shedding technique is the most popular technique used for load shedding in a power system. Conventional methods for load shedding are not much efficient for the modern and complex power systems and also for the power systems running in islanding mode. This paper explains the design of a fuzzy logic controller for implementing UFLS in a power system operating on a single generator in islanding mode. The proposed method of load shedding is based on the priorities given to the loads, operating frequency of the system and rate of change of frequency. For this purpose a MATLAB/ Simulink model is designed and tested on a real time simulator OP-4510 (designed by OPAL-RT). The real time simulation of fuzzy logic based load shedding controller has given accurate load shedding and restored the frequency quickly.