基于PLC的模糊变频无级调速系统

Development of Fuzzy-frequency conversion timing system based on PLC

设计了一种基于松下系列PLC、变频器及组态软件实现对三相异步电机变频无级调速的控制系统,通过上位机组态界面输入框给定电机转速,加入旋转编码器作为电机转速反馈信号[1],使电机能够在给定转速下稳定运行;采用模糊控制调节方式控制PLC的输出脉冲,进而控制变频器的输出频率;通过PLC与上位机的连接,运用组态软件实现对电机运行状态的监控,并可通过控制按钮实时地控制电机的运行状态。实验结果显示,采用了模糊控制的监控曲线比采用PID调节的监控曲线有了明显的改善,测量值和变频器输出曲线已经没有明显的超调现象,且曲线趋于稳定的时间也明显缩短,可广泛应用于电机变频调速系统中。

This control system was designed based on the PLC of the Panasonic series,inverter and configuration software to regulate the frequency speed of Three-phase asynchronous motor steplessly.The control system rotates motors with the input box of PC software,it takes Rotary Encoder as the feedback of speed of the motors,and the control system could make motors operate smoothly by the given speed.The Fuzzy-Control was adopted to control the output pulse of the PLC,and then,to control the output pulse of the inverter,with the connection of the PLC and the PC,it makes the supervision of the configuration software to the running state of the motors come true,and it even could control the running state of the motors at all times with the controlling button.The experimental results illustrate that,it was an obvious improvement to use the control curve of the Fuzzy-Control than to use the curve of the PID.It also shows that there isn＇t any clear overshoot of the measurements,and this shortens the time obviously of the curve tending to stability.This system can be widely used to the speed regulating system of the motors.