Identification Method of the Load Component Proportion based on the Dynamic Response under Large Disturbance

Abstract

In the traditional load model, motor and static loads are used to represent electrical equipment. However, since the electrical equipment using power electronic interface has accounted for a large proportion at present, the load components should be divided into motor, static load and power-electronic-interfaced load. The composition of the electric load is time-varying, and mastering the proportion of different load components is the key to establish an accurate load model. The existing load component proportion identification method identifies the key parameters of the load model and motor proportion parameters under large disturbances. However, the accuracy of this method is affected by the accuracy of load model parameters; moreover, it cannot identify the proportion of three types of load components. To this end, based on the analysis of different response characteristics of motor, static load and power-electronic-interfaced load under large disturbance, this paper proposes a load component proportion identification method based on dynamic response under large disturbance. This method first determines the proportion of static load according to the drop value of active power of load during the duration of large disturbance; then, the proportion of power-electronic-interfaced load is determined according to the separation results of motor response and the highest fitting accuracy; finally, the proportion of motor load can be calculated. The case study shows that the method does not depend on other parameters in the load model and has high identification accuracy.