电缆参数对变频驱动电机轴电压和轴电流的影响  

The Influence of Cable Parameters on the Bearing Voltage and Bearing Current of the Variable Frequency Drive Motor

作　　者：陈立珂 刘瑞芳[1] 李知浩 张亮亮 李伟力[1] Chen Like;Liu Ruifang;Li Zhihao;Zhang Liangliang;Li Weili(School of Electrical Engineering Beijing Jiaotong University,Beijing 100044 China;Jing-Jin Electric Technologies Co.Ltd,Beijing 100015 China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]精进电动科技股份有限公司,北京100015

出　　处：《电工技术学报》2024年第15期4755-4766,4793,共13页Transactions of China Electrotechnical Society

基　　金：中央高校基本科研业务费专项项目(2022YJS158);北京市自然科学基金(3222055);2021年高功率高效电驱动总成系统开发及产业化项目(TC210H02Q)资助。

摘　　要：变频驱动系统中变频器共模电压会引起电机轴电压继而造成轴承电腐蚀,带来巨大的危害。变频器与电机之间连接电缆的寄生参数对电机轴电压和轴电流影响的机理仍有待确定。该文提出了电缆-电机系统的轴电流模型,分别给出电机及电缆参数的提取方法,研究了电缆类型及长度变化对系统阻抗曲线的影响规律,对系统阻抗特性进行了仿真及实验验证。建立变频器-电缆-感应电机轴电流系统仿真模型,并搭建轴电流实验台进行测试,测试结果验证了模型的正确性。研究结果表明,电缆的电容参数是影响电机轴电压的关键因素,采用屏蔽电缆或增加电缆长度会增大电缆寄生电容,增加定子接地电流、降低电机容性轴电压;采用屏蔽电缆电机轴两端电压高于非屏蔽电缆。The common-mode voltage output by the inverter drive motor system,through the coupling of the motor capacitances,induces bearing voltage,which causes electrical corrosion of the bearing and endangers the operation of the motors.In the frequency conversion drive system,the frequency converter and the motor are generally connected by cables.There are different types of cables,such as shielded and unshielded cables.The type and length of cables affect their equivalent electrical parameters.The influence of cable parameters on the bearing voltage is currently unclear,and the key parameters of the cable that affect the motor bearing voltage are still uncertain.This paper analyzes the influence of the cable type and length on bearing voltage,providing a basis for the design and selection of the cable of the frequency conversion system to suppress the bearing current and bearing voltage.Firstly,the mechanism of high-frequency bearing current generation of the motor in the variable frequency drive system is analyzed,and the common-mode equivalent model of the motor and cable system is established.Secondly,taking a 5.5 kW induction motor as an example,the electrical model parameters of the cable and motor are extracted through the impedance test curve.The impedance characteristics of the cable and motor composition system are verified.An unshielded cable with 3 m,a shielded cable with 3 m,and a shielded cable with 10 m are compared.The influence of the cable type and length on motor bearing voltage and bearing current is studied through circuit simulation.Finally,a bearing current test platform is built,and the accuracy of the model and the correctness of the simulation analysis are verified.The corresponding suppression scheme is given for the motor bearing voltage and bearing current problems of the frequency conversion drive system.According to the simulation results,compared with the 3 m unshielded cable,the stator ground current of the 3 m shielded cable increases by nearly 25%,and the bearing voltage and bearing cur

关 键 词：变频驱动 屏蔽电缆 轴电压 轴电流 接地电流 

分 类 号：TM34[电气工程—电机]