A novel second-order model of induction motor loads

In power system dynamic studies, it is necessary to represent induction motor loads with a standard reduced order model in order to reduce computational requirements. A third-order model, neglecting the stator transients, is often used. In this paper, the third-order model is further simplified into two second-order models, called as slip-flux-magnitude and slip-flux-angle models. The model derivations are given in detail. The dynamic responses of both models are compared with the higher third-order model for the cases of small and large horse power induction motor loads. The study results show that the slip-flux-angle model gives better approximation of the third-order model.