PWM变频器用于异步电动机时存在的问题分析

Analysis of problems on Induction Motor with PWM Frequency Converter

PWM 变频器正在得到越来越广泛的应用,使异步电动机在节能、改善控制性能及扩大其使用范围等方面收益非浅。然而,电动机使用 PWM 变频器与使用一般工频电网电源相比存在着许多问题。例如,变频器到电动机的电缆长度对电动机瞬时电压的影响,电动机发热增加等。本文主要分析了异步电动机使用 PWM 变频器时存在的一些特有的问题及其原因,提出了在实际应用中正确使用 PWM 变频器的一些方法。

The PWM frequency conventer are being widely used on the induction motors be- cause they can benefit the induction motors in saving energy,improving control performance and widening application range.However,There exist some problems when the motor uses PWM fre- quency converter as its power supply irstead of ordinary power supply,such as the effect of the ca- ble length from the conventer to the motor on the transient voltage of the motor,increment of the heat production of the motor etc.. This paper mainly analyzes some special problems and the causes on induction motor with PWM frequency converter,and also presents some practical methods of using the converter.