The Research Of Power System Composite Load Modeling Method

To studying on modern electric power systems, the digital simulation has became the main tool of the planning, operating, control and analysis of power system. Load model has played the most important role on the precision and credibility of simulation result, the specialist all over the world are devoting their mind to its modeling work Owing to the characteristics of random time variance, complex composition, discontinuousness and nonlinearity, the accurate mathematics model of composite toad have still not build up. The measurement-based load modeling method is used in this paper.At first, the paper discuss briefly choice of load model and research of parameters identification method by studying basic theory of the measurement-based load modeling method, describe mechanism of the load model structures of third- order induction motor and parameters identification method based on improved genetic algorithm in detail.Secondly, In the area of identification theory of artificial nerve network ,aiming at the multi-dimensional nonlinearity characteristics of the composite load modeling, the paper propose a load modeling method based on GRNN neural networks which compares with other two kinds of the improved BP-algorithm. The exemplification of emulation proves that the new algorithm has quick convergence rate, few computing time, higher precision and stronger non-linear characteristic description ability.The most difficulty of load model's Practical application is the time-variation character of the load. Researches during the recent years show that the classification and synthesis for load characteristics is the effectual way of solving the time-variation problem. Based on systematical studies on the classification and synthesis of load dynamic characteristics, and with results of predecessor's research this paper propose the comprehensive methods of induction motor's Parameter Clustering center. The results proved that some kind of load composite model parameters obtained by the new method was able to well descript all samples in this kind of load, as the same time this method also has the excellences of clear physical significance and practical convenience.