Multiobjective Multiscenario Under-Frequency Load Shedding in a Standalone Power System

A load shedding scheme is important in a power system, especially in a microgrid or an offshore standalone power system, in which spinning reserves may be small and renewable power generation is uncertain. This paper presents a novel method for determining the shed load and delay time at each stage for under-frequency load shedding (UFLS) relays in an offshore power system near Taiwan. The Taguchi method is used to design orthogonal experiments related to different scenarios. The shed loads and delay times in a scenario are obtained by particle swarm optimization-based multiobjective programming. In the studied power system, the proposed UFLS scheme ensures less load shedding and a faster frequency response than the traditional UFLS scheme.