0 引言电子技术的发展、电子器件制造水平的不断提高,电力电子器件在容量、耐压、特性和类型等方面得到了迅速发展。特别是近年来,电子器件向着大容量、高效率、高响应、低损耗的方向发展。而变频器作为现代电子器件与计算机技术有机结合的产物,随着产品的开发创新和推广使用,使得交流异步电动机调速领域发生了一场巨大的技术革命,直流传动的控制特性、精度、调速范围等控制要求,以现有的变频器技 0 Introduction The development of electronic technology, the continuous improvement of the manufacturing level of electronic devices, power electronic devices in the capacity, pressure resistance, characteristics and type has been rapid development. In recent years, in particular, electronic devices have been developed toward large capacity, high efficiency, high response and low loss. The inverter as a modern electronic devices and computer technology, the product of organic integration, with the product development and innovation and promotion of use, making AC induction motor speed field occurred a huge technological revolution, the DC drive control features, precision, Speed ​​range and other control requirements, with the existing inverter technology