Determining the optimal location for UFLS to increase the adaptability to the scenarios

In this paper, a new method for optimizing the location and amount of multistage Under Frequency Load Shedding (UFLS) based on real power system simulation is presented. The optimization is based on the worst case event of the system and the proposed UFLS scheme is executed for a large number of events on the system. The system frequency response for the occurrence of different events in four modes is compared: optimal UFLS, optimal UFLS with the forced distribution, concentrated and distributed Load Shedding(LS). The simulation results show that the optimal location is very important issue for the UFLS, because of its great effect on the system frequency response after disturbance. Optimization for the worst event also has a positive effect on other events. The results also show that the LS distribution over several points makes the UFLS program more adaptable to the large number of possible scenarios. However, optimization of LS locations for the worst event has better results in terms of adaptability to different event scenarios and improvement ofpower quality indices

Keywords:

Under Frequency Load Shedding , Frequency recovery , multi-stage UFLS , static load shedding , Optimization