Dynamic Load Model in Power System Based on Physical Structure and Measured Data

Abstract

It is well known that adequate dynamic load model is essential for evaluating power system stability. For representing the behavior of actual load, this paper presents a concept of dynamic load model, that is, a variable conductance behind a constant reactance, and also presents a method for determining the reactance from observation point to internal load by using measured data. In all of measured 64 data in major disturbances, the conductance shows much higher value instantaneously after the recovery of voltage sag. The tendency is well explained by the presented concept, but cannot be represented by the traditional static load model. As to the numerical simulation, the behavior of existing loads after instantaneous voltage sag is well represented by a parallel composite of a constant admittance and an induction motor behind a series constant reactance on the CRIEPI-Y-method, which is a typical simulation tool for power system analysis.