变频电机杂散电容精确计算与轴电压抑制槽口设计

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Stray capacitance calculation and slot opening design for bearing voltage suppression in variable frequency drive motors

LIU Ruifang'， ZHANG Wenjiao²， ZHANG Tianhe1， CHEN Like¹， ZHONG Hui³ （1.School ofElectricalEngineering，Beijing Jiaotong University，Beijing10o44，China;2.SchoolofElectricalEnginering， Xi'an Jiaotong University，Xi'an 710049，China;3.Suzhou Inovance Automotive Co.，Ltd.，Suzhou215104，China）

Abstract： With the development of electric vehicle drive systems towards high-voltage and high-frequency directions，the motor bearing electric corrosion caused by inverter-output common-mode voltage through stray capacitance coupling has become a bottleneck in EV development. Accurate calculation of motor stray capacitance and subsequent motor design optimization to suppress bearing voltage offers a cost-effective and reliable solution to address this issue.Analytical calculations of stray capacitance were performed in a permanent magnet synchronous motor by reasonably partitioning the end-winding region and establishing an analytical calculation model，with verification through experimental tests.From the perspective of motor design optimization， various slot opening configurations including narrow slots，skewed slots ， zigzag slots，and combined narrow-skewed slots were investigated. The results demonstrate that narrow skewed slots and zigzag slot openings can effectively reduce the bearing voltage ratio （BVR）. Furthermore， motor performance analysis reveals that the narrow skewed slot configuration reduces cogging torque and decreases air gap magnetic field distortion rate compared to the original design，which contributes to mitigating motor vibration and noise.

Keywords ： permanent magnet synchronous motor ; bearing voltage; stray capacitance; bearing voltage ratio ；motor design

0引言

变频驱动系统在国民经济中有着广泛应用，变频器作为此系统的核心部件，常采用脉宽调制技术进行控制[1-2]。（剩余13674字）