Underfrequency Load Shedding approach for islanding of industrial co-generation System

This paper presents frequency stability analysis and enhancement of an isolated system using Under Frequency Load Shedding (UFLS). Reliability and security operation of large power systems has always been a primary goal for system operators. When a power system disruption occurs, it causes power mismatch. In any isolated system, this generation load imbalance causes severe disturbance and the system frequency begin to change and can lead to complete blackout. To ensure system stability and availability during disturbances, generation trip, transmission and distribution equipment failure, generally utilize some type of load shedding scheme. In this paper under frequency rely is used to detect abnormal frequency operation and disconnect loads to maintain stable operation of the system. The system frequency response for deferent generation-load scenarios is also determined. A power distribution system of a large Oil Storage Terminal is simulated on ETAP software and the transient stability is analyzed for islanded condition.