Improved Flux-Weakening Method With Excitation Current Distribution for Hybridly Excited Asymmetric Stator Pole Doubly Salient Machine Based on Electrical Vehicle

The hybridly excited asymmetric stator pole doubly salient machine (HEASPDSM) has demonstrated great attraction to electrical vehicle (EV) for its strong robustness, while it suffers poor torque capability during the high-speed operation range. In order to solve such a problem, an improved flux-weakening method with excitation current distribution is proposed for the HEASPDSM in this article. First, the machine topology and the operating principle are briefly introduced. Second, the mathematical model is established, and the flux-weakening analysis is given out. Third, an excitation current distribution method has been put forward to the whole speed range along with the maximum torque per ampere (MTPA), the current and voltage limit (CVL), and the maximum torque per voltage (MTPV) from low to high operation automatically, which can widen the speed range and strengthen the torque capability. Finally, the feasibility of the proposed algorithm has been fully validated by both simulation and experimental results.