PLC的通讯功能在异步电机变频调速中的应用

Application for Variable-Frequency Driving of Asynchronous Motor Based on Communication Function of PLC

运用PLC的通讯控制功能,设计了异步电机的变频调速控制系统。首先将PLC设为主站,变频器设为从站;其次配置变频器工作在通讯模式;然后根据变频器通讯协议参数定义,通过MODBUS通讯功能指令控制异步电机变频调速;最后分析了变频器的频率给定精度。实验证明,该系统运行稳定,电气接线简单,与传统的异步电机变频调速方法相比,频率给定没有转换误差。

The variable-frequency drive of asynchronous motor is designed by using the communication function of PLC. PLC is set to master station,inverter is set to slave station.According to communication protocol parameter definition,using communication function code to control the variable-frequency drive of asynchronous motor.At the last, Frequency accuracy of inverter is analyzed in this paper.