精选优质文档-倾情为你奉上外文文献 1. INTRODUCTION Electric Drive Technology Development 1.1 Current Situation 30 Over the years, the DC motor drive has undergone significant changes. First of all, replacing a rectifier, thyristor rectifier device to replace the conventional long-standing group of DC motors and generators of mercury rectifier DC electric drive device to complete a big leap forward. At the same time, control circuit has achieved a high level of integration and miniaturization, h
