Improved group search optimization method for optimal power flow problem considering valve-point loading effects

Optimal power flow (OPF) is an important tool for smart grid optimal dispatch. In this paper, an improved group search optimization (IGSO) method is proposed to solve the OPF problem with the valve-point loading effects, which is an optimization problem with many local optima. In the IGSO algorithm, the search space of the scroungers is enlarged to give a more sufficient exploitation around the producer and to help the scroungers explore other areas to avoid falling into a local optimum. A strategy is also introduced to help scroungers to learn from other members to improve the global searching ability. Moreover, scroungers and rangers update their positions only when better positions are found. Good performances of the IGSO algorithm on the OPF problem with the valve-point loading effects are verified by tests on a 26-bus system, and the IEEE 30-bus and IEEE 118-bus systems.