摘要
研究了变频器在长线传输时产生的过电压问题,理论分析表明,电动机端过电压与PWM变 频器采用的开关器件上升时间和PWM变频器与电动机之间的电缆长度密切相关:上升时间越短, 电缆长度越长,电压反射现象越显著,过电压也越高。为消除PWM变频器长线传输时在电动机端产 生的过电压等负面效应,提出了一种逆变器输出无源滤波器。实验研究验证了该滤波器能够将变频 器输出的PWM电压滤成近似正弦波,从而有效地抑制电动机端的过电压。这种滤波器还可以有效 降低共模电压。文中分析了这种滤波器的共模结构及其可以降低共模电压的原因,实验验证了设计 思想的正确性。同一种结构的滤波器能够同时消除差模dv／dt和共模电压,减小了滤波器的体积和成 本,结构简单,是一种消除逆变器输出负面效应的有效手段。
Over-voltage at motor terminals when long cables are connected between the PWM (Pulse-Width Modulation) inverter and the motor is investigated. Analysis shows that the over-voltage is dependent on the PWM rise-time of switching devices and cable length: shorter rise-time, longer cable, and higher over-voltage. For reducing over-voltage at motor terminals, an inverter output passive filter is proposed. Experiments show its validity. The common-mode configuration of the proposed filter is also analyzed and identified through experiments. A filter, which can not only eliminate over-voltage but also suppress common-mode voltage, is achieved, the differential-mode dv/dt and common-mode voltage can be solved synchronously, thus reducing the bulk and cost of the filter, and so it is an effective method for reducing adverse effects of the inverter.
出处
《电机与控制学报》
EI
CSCD
北大核心
2005年第1期5-10,共6页
Electric Machines and Control
基金
国家自然科学基金项目(50377008)
