Transient performance of self-excited wind-turbine induction generator under induction motor load

Abstract

Self-excited induction generators (SEIG) are increasingly employed in remote areas for electricity production from wind energy. Analyzing of a stand-alone SEIG dynamic performance is largely limited to static load. This paper presents dynamic simulation of small SEIG feeding induction motor (IM) load. Mathematical models of SEIG, IM, and wind turbine are at first clearly implemented into Matlab/Simulink environment. The IM load coupled with constant and speed-squared mechanical torque are mainly considered under sudden connection to the SEIG. The study results reveal that the IM load with particular constant torque mostly causes a greatest fall of SEIG voltage during the sudden connection or decreasing of wind speed. The constant toque load also results in deepest and longest duration of SEIG voltage sag when the IM load is initially connected to the SEIG due to insufficient reactive power from the excitation capacitor. By applying an extra starting capacitor, the sufficient reactive power support can be obtained for successful startup of the IM load to the SEIG.