PWM驱动系统中感应电动机共模模型的研究

PWM逆变器在应用中会产生共模电压.共模电压在IGBT的高速开关期间产生高频充放电电流.这个电流通过电机内部的寄生电容产生流入地线的漏电流.漏电流过大将对电源产生电磁干扰;感应的轴电压过高还会使电机轴承过早毁坏,从而影响系统运行的可靠性.为研究共模电压的危害及方便分析相应的抑制策略的效果,建立了高频感应电机的共模模型,仿真和实验结果证明了模型的正确性和实用性.

RESEARCH ON INDUCTION MOTOR COMMON-MODE MODEL IN A PWM DRIVE SYSTEM

Pulse width modulated (PWM) inverter can generate common-mode voltage. Common-mode voltage can produce charge-discharge current at the distant of every insulated gate bipolar transistor (IGBT) high-speed switching. This current creates ground current escaping to earth through stray capacitors inside motors. The large ground current can create electromagnetic interference to the source and shorten the life of motor bearings by induced high shaft voltage, effect reliability of the whole system. To research the adverse effects of common-mode voltage and analyze the reducing effects expediently, common-mode induction motor model is founded based on analysis. Simulation and experiment results are presented to indicate the proposed model validity and practicability.