Under Voltage Load Shedding for Contingency Analysis to Optimize Power Loss and Voltage Stability Margin

Power system contingency is a condition of operation which may be caused due to line outage in a system and could lead to entire system voltage instability. This may further result in voltage collapse leading to total blackout of the system. Therefore, voltage collapse prediction and estimating voltage stability margin is an important task in power system operation and planning. In this paper Line Stability Index Lij utilizing the concept of power flow in a single line is adopted to determine the condition of voltage instability. The purpose of Lij is to determine the point of voltage instability, the weakest bus in the system and the critical line referred to a bus. Analytical approach based technique for load shedding has been developed as a solution for secured operation of power system under various contingency conditions to optimize the power flow in order to minimize the system losses within acceptable limit. To validate the effectiveness of the proposed method simulation has been carried out on IEEE 14 bus system.