变频器供电异步电动机绝缘系统概述

Summarization of Insulation System of Induction Motor Fed by Frequency Inverter

变频器供电异步电动机通常指变频调速电动机(以下简称电动机)。大多变频器输出PWM脉宽调制波形,含有大量谐波,将增加附加损耗。变频器输出电压的峰值较高,对电动机的绝缘造成严重的威胁,产生的高次谐波会导致电动机绝缘被击穿。由于变频电源的特殊性,以及系统对高速或低速运转、转速动态响应的需求,对作为动力主体的电动机,提出苛刻的要求,尤其是电动机绝缘系统。为更好地消除因变频器供电对电动机绝缘系统产生的不利影响,对电磁线槽绝缘、相间绝缘、浸渍漆、浸漆工艺予以概述。

The induction motor fed by frequency inverter usually refers to variable-frequency adjustment-speed induction motor （ hereafter referred to as motor）. Most of the frequency inverters output PWM （pulse width modulation） waveform, contain a lot of harmonics and will increase the additional loss. Because of the higher peak value of output voltage of frequency inverter, the insulation system of motor will be threatened seriously. The motor insulation system will get breakdown by the produced higher-order harmonic. Due to particularity of the variable-frequency power supply as well as the demands of system for high-speed operation, low-speed operation or dynamic response speed, the stringent requirements are proposed to the motor （ main body of power） , especially for that of insulation system. In order to preferably eliminate the adverse effects of motor insulation system caused by frequency inverter power supply, this paper briefly describes the solutions used for magnetic wire, slot insulation, phase-to-phase insulation and impregnating varnish and the technologies of impregnating varnish.