Optimal-Third-Harmonic-Injection-Based Control for a Five-Phase Dual Stator-Winding Induction Generator DC Generating System

This paper presents a third-harmonic optimization method for a five-phase dual stator-winding induction generator (FPDWIG). In this generator, a cage-type rotor is used, and there are two sets of five-phase stator windings. Based on the principle of nonsinusoidal power supply, the third harmonic is injected and optimized. By minimizing the cost function of the oscillation of flat level of air-gap flux density, the optimal ratio of the third harmonic is determined to make the waveform of the air-gap flux density flat-topped for better core utilization. The corresponding implementation based on the control-winding flux-oriented control with the consideration of different load conditions is given, as well. The simulation and experimental results verify the correctness and validity of the proposed optimization method, and by using this method, the desired air-gap flux density can be obtained, and the output power of the FPDWIG can be increased.