Abstract:Parameter identification is the key technology in measurement - based load modeling. An improved particle swarm optimization ( PSO) algorithm is proposed to identify the parameters for the aggregate load model based on Sichuan PMU system. The new algorithm combines the PSO with the difference multiple curves fitting. It takes the advantages of the global search ability of PSO and the local search ability of the difference multiple curves fitting,which is a more powerful search technique. Based on the simulation data of Sichuan PMU system,the numerical results show that the hybrid learning algorithm can improve the accuracy and reduce the computation time for the parameter identification of load model.