Load Modeling Of Power Systems Considering Distribution Networks

A new synthesis load model is proposed by CEPRI (CEPRI-model), in which the distribution network has been considered. A virtual bus is introduced in this load model, with which several branches are connected, including equivalent static load, equivalent induction motor, and equivalent compensating capacitor. Between the virtual bus and the 110kV bus there is equivalent impedance of distribution network. Compared to the traditional load model, the structure of this new model is more complete, and will be more fit for the practical power system. But how to work out the parameters of this new model needs more research.In this paper, the research work is based on this new load model. The following issues are investigated:1. A combinative method for working out all parameters of the CEPRI-model is presented. In detail, the impedance of distribution network can be obtained by theoretic equivalence method or component-based method, the parameters of induction motor and static load can be obtained by measurement-based method.2. The emphasis of this paper is to work out the parameters of induction motor and static load by measurement-based method, assuming the impedance of distribution network is given. An improvement is proposed in load parameter identification: load parameters are divided into important parameters and unimportant parameters, only the important parameters are necessary to be estimated while the unimportant parameters can be substituted with their representative values in programs. The important parameters include stator reactance, initial slip and the proportion of the induction motor.