A Novel Winding Switching Control Strategy for AC/DC Hybrid-Excited Wind Power Generator

In this article, a novel winding switching strategy is proposed to improve the flux-weakening capability of a hybrid-excited reluctance machine (HERM). The key is that in low-speed operation, the primary and the secondary windings are connected in series and serve as armature winding to maximize output voltage while in high-speed operation, the secondary winding is switched to dc excitation winding to realize variable speed constant voltage output. The machine configuration, operation principle with dual excitation sources, winding switching concept, and manipulation circuit are illustrated in detail. Then the electromagnetic characteristics of HERM in different operation status are investigated. Finally, the variable speed constant voltage output of wind power generation system resorting to winding switching as well as dc excitation regulation is verified with Maxwell/Simplorer cosimulation.