Comparative Research on Four-Phase Dual Armature-Winding Wound-Field Doubly Salient Generator with Distributed Field Magnetomotive Forces for High-Reliability Application

In this article, a four-phase dual armature-winding wound-field doubly salient machine with distributed field magnetomotive forces (DAW-WFDSM-DF) and corresponding double-redundant rectifier circuit are proposed to improve the electromagnetic performance of the traditional WFDSM in terms of the output voltage ripple, fault-tolerant capability and output capability. Firstly, due to the uniformly distributed field magnetomotive forces of the proposed machine, the more feasible stator/rotor pole combinations of the four-phase machine can be obtained and the influence of stator/rotor-pole combination on electromagnetic performance is investigated, especially for the fault-tolerant capability. Based on a multi-objective evaluation function including output capability, fault-tolerant capability and unbalanced magnetic forces, the 4N-stator-pole/3N-rotor-pole (4N/3N) and 4N/5N combinations are recommended. Then, considering that the fault-tolerant capability of 8/6-pole machine is poorer than that of 12/9-pole one, the 12/9-pole and 8/10-pole DAW-WFDSM-DFs are comparatively researched for taking as the representatives of 4N/3N and 4N/5N, including no-load and on-load characteristics and fault-tolerance performance under single winding open-circuit condition. Finally, as the 8/10-pole DAW-WFDSM-DF exhibits remarkably higher efficiency and stronger fault-tolerant capability than the 12/9-pole one, an 8/10-pole prototype is manufactured and tested to verify the analytical results.