The Research On Identification Strategy Of Power System Aggregate Load Model And The Development Of Composite Load Modeling Platform

The problem of power system aggregate load modeling is one of the basic research subjects in the field of power system analysis. Nowadays people have gradually realized the importance of load modeling, and a new upsurge of research and practice of load modeling has been raised both at home and broad. This article, based on the actual conditions of the electric network in some area, attempts to do some research work on load model practical application. This article emphasizes on two aspects. One is about the research and improvement of mechanism dynamic load model, and how to raise its parameter precision, how to identify efficiency and stability is the inevitable request of model practical application. The other is about the development and improvement of power system aggregate load modeling platform that faces the project.The induction motor model of the aggregate load has been widely applied in the power system transient simulation process. This article first elaborates the third-order induction paralleled with constant impedance model, and then from that, it infers that there exists the first-order mechanical transient induction model and the first-order voltage transient induction model on its foundation. Through the identification of the mechanism dynamic model parameter and the analysis of scattered questions, the article suggests we use the strategy which combines the wide range search with the partial fine search to solve the overall optimizing question. The actual load characteristic sample modeling showed that the third-order induction motor paralleled with constant impedance model can describe the active power character and reactive power dynamic character of actual load much better.This article proposes to use The Simple-point Optimum Identification Strategy, in order to solve the problem that the performance of induction motor model is not sufficient to the transition process of aggregate load actual response. Based on the third-order induction motor dynamic model, it uses the difference between the actual measured response and the same time basic induction model response as the internal feedback added to the model output, and forms a generalized induction motor model of the aggregate load on the basis of simple-point optimum identification. Large numbers of modeling practice on actual load data indicate that the characteristic of the improved model is better than the basic model, especially when the voltage disturbance is very small its expression ability performs well. All this shows the improved model can draw the essential characteristic of synthesis load well. The simple-point Optimum Improvement Model put forward by this article is an original and effective development to the induction motor mechanism model class, and has the important project significance to the load modeling practical application.The development of load modeling theory can't be separated from the support of project practice. Combined with the actual research topic of the local electrical network, this article describes the power system aggregate load modeling platform from the aspects of its development necessity, design mentality, realization technology and functional description and so on. The platform includes three big modules respectively based on measured modeling, component modeling and database management. It uses relations database SQL Server and the object-oriented programming language VC++ as development environment, and uses many kinds of modules conformity and the connection technology to realize the functions of load modeling, classification, as well as load characteristic data and model parameter management and so on. The platform's design should take the raise of the entire work automation level and the operating efficiency as a principle, takes the face to the project practice as a goal. It is expected to play a vital role in the course of pushing the power system load modeling to the practical use. Key Words: Power system; Aggregate load; Load model; Parameter identification;...