直驱永磁牵引电机振动原因分析

Cause Analysis of Direct-drive Permanent Magnet Traction Motor Vibration

目的:与传统的异步电机相比,直驱永磁传动可省掉齿轮传动装置,提高传动效率,减小传动机构维护工作量,并提高传动系统整体效能。为解决直驱永磁牵引电机低速运行时振动加剧的问题,提高直驱永磁牵引电机服役寿命及安全性与舒适性,特开展本研究。方法:针对直驱永磁牵引电机在90~105 r/min转速范围内出现的振动加剧问题,根据永磁电机振动机理通过解析法分析了直驱永磁牵引电机极槽配合与电机径向电磁力之间的数值关系;使用SKF-AX型数据采集器对直驱永磁牵引电机传动端与非传动端及不同方向进行振动加速度检测,并对振动结果进行频谱分析,找到引起振动的频段;通过有限元方法对直驱永磁牵引电机进行径向力分析,对定子铁心模态进行分析,得到径向力的幅值、频率以及定子铁心自振频率。结果及结论:结合解析法、振动检测试验及有限元仿真分析证明该电机在90~105 r/min转速范围内发生共振是引起振动加剧的根本原因;并基于以上分析对该电机的极槽配合进行了改进,将电机14极114槽更改为14极126槽。通过有限元仿真分析及振动检测试验可知,已有效解决了电机在90~105 r/min出现的共振问题,提高了直驱永磁电力机车的安全性与舒适性。

Objective:Compared to conventional asynchronous motors,the DPM(direct-drive permanent magnet)transmission eliminates the need for gear transmission device,improving transmission efficiency,reducing maintenance workload on transmission mechanisms,and enhancing the overall efficiency of the transmission system.To address the issue of increased vibration during low-speed operation of DPM traction motors,it is aimed to improve the service life,safety,and comfort of these motors from conducting this specific research.Method:Focusing on the intensified vibrations observed in the 90 to 105 r/min rotation speed range of DPM traction motors,according to the vibration mechanism of permanent magnetic motors,an analytical approach is employed to investigate the numerical relationship between slot matching in the motor poles and the motor radial electromagnetic force of the DPM traction motor.The SKF-AX data collector is utilized to measure vibration acceleration at the transmission and non-transmission ends of the DPM traction motor and in different directions.Spectral analysis is conducted on the vibration results to identify the frequency range causing the vibration.Finite element analysis is employed to analyze the radial force in the DPM traction motor and assess the modal characteristics of the stator core,obtaining the amplitude,frequency,and natural frequency of the stator core.Result&Conclusion:The combined use of analytical method,vibration detection tests,and finite element simulation analysis demonstrates that resonance in the 90 to 105 r/min rotation speed range is the root cause of the intensified vibration.Based on this analyses,the motor pole matching is improved by changing the configuration from 14-pole,114-slot to 14-pole,126-slot.Finite element simulation analysis and vibration detection tests confirm the effective resolution of resonance issue in the 90 to 105 r/m speed range,thereby enhancing the safety and comfort of DPM electric locomotives.