变频电路 meaning in English

frequency changing circuit
frequency converting circuit

A novel pwm dc converter with snubber cell
一种新的带有缓冲单元的脉宽调制式直流变频电路
The main work includes : the main circuit and control software and hardware of the actuator are analyzed and designed in brief . the main circuit is designed and developed in detail , mainly including ac to ac transducer circuit and its protect circuit . the control circuit is designed and developed in detail mainly including the control of transducer , the design of interface between human and machine , the realization of location measurement circuit and the development of serial port communication
这些工作主要包括：对电动执行机构的主电路和控制软硬件进行系统分析和总体设计，为后续开发工作做好铺垫；对电动执行机构主电路进行设计和开发，主要是实现交-交变频的电力电子电路及与之相关的保护电路；对电动执行机构的控制电路进行设计和开发，主要包括对变频电路的控制，人机界面的设计，执行机构位置测量电路的实现，串口通信的实现等；在工业以太网方面，本文介绍了工业以太网技术和国内外几种典型的工业以太网协议，并着重介绍了用于工业过程控制的epa协议，并对其进行了分析。