An Efficient Method for Undervoltage Load Shedding

This paper analyses the Thevenin equivalent characteristics of voltage instability by the P-V curve at the load buses. The situation and the time for load shedding are determined by identifying the weakest bus in the network by means of a voltage instability proximity index (VIPI). The index is defined by estimating Thevenin equivalent parameters using the online power flow technique. Load shedding amount is determined based on the load control of demand side management (DSM). The proposed algorithm of the efficient UVLS scheme is tested to show its effectiveness by an actual power network in China.