Effects of induction machines dynamics on power system stability

Analysis of stability is essential for power system planning and stable operation. The results of transient and steady-state stability studies depend on the appropriate choice of load models. This study investigates modeling issues of the induction motors that are used as a dynamic part of load models. Due to its superiority, we propose the application of the rotor speed frame based model of induction motors instead of a system frequency frame based model in power system stability simulations. A comparative study of steady-state stability of a power system is performed with different induction motor models. The implementation of lower-order models gives more optimistic results. A larger proportion of induction motor load degrades the stability of power systems. It is shown that a third-order model implemented in a rotor speed frame based system is most suitable for stability studies.