Affiliations: [a] College of Electrical Engineering, Zhejiang University, Hangzhou, China | [b] School of Electrical and Information Engineering, Tianjin University, Tianjin, China | [c] School of Electrical Engineering and Automation, Tianjin Polytechnic University, Tianjin, China
Correspondence:
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Corresponding author: Tingna Shi, College of Electrical Engineering, Zhejiang University, No. 38, Zheda Road, West Lake District, Hangzhou, 310027, China. Tel.: +86 0571 87951655; Fax: +86 0571 87951655; E-mail: tnshi@tju.edu.cn
Abstract: Interior permanent magnet machine has been widely used in electric vehicles due to its high-power density and good flux weakening performance. This paper firstly introduces the principle of flux-weakening control, which are the foundation to describe the effect of d-axis inductance and q-axis inductance on the speed range of motor. Secondly, regarding an interior permanent magnet synchronous motor with V -type permanent magnet structure as the research object, an improved rotor structure has been proposed which concludes asymmetric segmentations of permanent magnets and protuberances from centers of every magnetic poles toward airgap. Furthermore, the Taguchi method is utilized to optimize the proposed improved structure. Finally, the optimized rotor structure which meet the requirement of d-axis inductance, q-axis inductance and electromagnetic torque has been obtained. Compared with the initial structure, the optimized rotor structure can increase d-axis inductance effectively, and hence broaden the speed range with constant power operation.
