Operation aspects of an isolated wind driven induction generator regulated by a shunt voltage source inverter

This paper deals with an isolated wind power generator based on a squirrel-cage induction machine, regulated by a voltage source inverter (VSI) with a battery bank. Since the VSI allows bidirectional flow of active and reactive power, it regulates, without any special controls, the voltage and frequency of the generated power. On the other hand, operated as a terminal impedance controller, it can vary the equivalent load seen by the induction machine, thus varying electronically the wind turbine speed for maximum efficiency with regulated output voltage. Some operation aspects and the load regulation limits are discussed considering a reduced rating VSI for lowering costs.