变频技术与电动机调速

Frequency Conversion Technology and Motor Speed-Adjustment

目前,我国电动机总装机容量达4.5亿千瓦,电动机总装机容量占目前总用电量的70%以上,其中近70%的电机拖动的负载是风机、泵类、压缩机等,而其中又有近70%的电机适合进行调速,即有约两亿千瓦的电机处在浪费运行的状态。因此如何实现电动机节能就显得非常重要。文章根据目前应用比较广泛的交流电动机,简单地介绍它的特点,结合以往的调速方式以及各自调速方式的优劣性,分析为什么要采用变频调速,而且如何实现变频调速,以及采用变频调速以后节能的效果。

Currently, China＇s total capacity of motor reached 450 million kW, which consumes 70% of total generated energy of China. About 70% of motors drive fan, pump, and compressor.70% of them are suit for speed-adjust, that is, about 200million of motors are in waste running situation. So, the energy conservation of mo- tor becomes very iraportant. Two methods are discussed in this paper, one is to increase the efficiency of motor to reach a long time high efficiency working, which is mainly used in constant speed machine ,the other is to increase the accuracy of the control of motor＇s speed, making motor runs in a most energy conservation speed situation.