说明：  从感应电机变频调速控制器设计和实现的角度出发，主要研究和探讨交流变频器模块化硬件设计和各种控制原理两部分 内容
(From the induction motor speed controller design and implementation point of view, the main research and explore AC Inverter modular hardware design and a variety of control theory of two parts)