An economic centralised combinational load shedding scheme to protect power system in case cascade and major disturbances occur

Abstract

This paper introduces an economic centralised combinational load shedding scheme for self-healing of the power system against cascading significant disturbances. The proposed method utilises the voltage stability risk index (VSRI) to maintain the power system's voltage and frequency stability margin. In this algorithm, the protection against cascading disturbances when the spinning reserve of the system cannot recover has been considered. Moreover, it considered the voltage and economic cost of loads to find the proper location of load shedding and minimised the number of customers being turned off to increase social welfare. Furthermore, a voltage stability index based on the maximum power limit of the transmission lines (L index) and frequency steps is used to offset issues associated with VSRI. According to the simulation results that have been performed over the 39-bus New England system, the proposed scheme has a better performance than the previous methods.