Investigation of the working mechanism and characteristics of dual-mode doubly salient starter generator with variable winding

A starter generator is a core technology of the more-electric aircraft and all-electric aircraft. The traditional switched reluctance machine (SRM) requires a high accuracy position sensor and high-speed processor while generating power. Therefore, the cost of the controller is high and the maximum speed of the machine is limited. A dual-mode doubly salient starter/generator is proposed in the study. In the process of starting and generating power, the machine operates based on the SRM principle and the doubly salient electromagnetic machine principle, respectively. In order to realise the transformation of the operating principle, the machine uses a winding switching device, and half of the windings are replaced as field winding that provide DC excitation in the generator mode. A suitable power converter is proposed based on introducing the structure and working principle of the machine. A winding switching device is designed, and the conversion process is explained in detail. A finite-element method is simultaneously used to analyse the motor-driven performance and the power-generation performance of the machine. A 12/8-pole prototype machine is developed. Additionally, the effectiveness of the starting, generating, and dual-mode conversion is verified by experiments.