Studies On Dynamic Load Characteristics Synthesis Methods And The Development Of Composite Load Modeling Platform

Electric power system simulation is the base of the planning, operating, control and decision-making of power system. However, for the composite load has the characteristics of complex composition, random time variance and spread over different area, its exact mathematics model is still not built up.The measurement-based load modeling method is used in this paper. The parameters identifying modeling of three dynamic load model structures of third-order mechanical-electrical transient induction motor paralleled with constant impedance, first-order mechanical transient induction motor paralleled with constant impedance and first-order voltage transient induction motor paralleled with constant impedance are realized. And by the load modeling practice, it is showed that the third-order induction motor paralleled with constant impedance load model can describe the active power character and reactive power character of actual composite load well, so it is a good composite load model.The most difficulty of composite load modeling is the time-variation character of the load. Researches for near years have showed that the classification and synthesis for load characteristics is the effective way of settling the time-variation problem. In this paper, based on the systematic researches of the dynamic load characteristics synthesis problem and the synthesis methods, a new dynamic load characteristics synthesis method that directly synthesizes the field measured load characteristics is presented. This method uses the center of gravity method to obtain the clustering centers of load classifications and their equivalent samples, and by identifying each clustering center equivalent sample, the synthetic load model of each classification is gained. With the dynamic load characteristics data collected from a substation, it is showed that the synthetic model built up from this method can describe different dynamic load characteristics samples in a classification well, and this method has the advantages of clear physical meaning and small computing.The development of load modeling theory cannot separate from the modeling practice in actual project. In order to use the load characteristics data collected from a substation to build up the load model of this substation by measurement-based load modeling method, a load modeling software platform is developed in this paper. This platform realizes a series of computing for measurement-based load modeling method,...