Optimal load shedding based on line voltage stability index using harmony search algorithm

Modern power systems have been operated close to their limits for reasons of economic viability. Consequently, a small increase in the load may lead to the Maximum Loading Point (MLP) of the system resulting in voltage collapse. Under such circumstances, the buses for load-shed have been selected based on line voltage stability index and its sensitivities at the operating point. This avoids voltage collapse and improves the system stability. Computational algorithms for minimum load-shed have been developed using the heuristic technique, Harmony search (HS) algorithm. The algorithm proposed in the present paper is implemented on the standard IEEE 14-bus and 25-bus test systems to obtain the optimal load shedding at the selected buses when the systems are operated at their MLP. The effectiveness and efficiency of the proposed method are established by improvements in the line voltage stability index and the bus voltages