Design Of Constant Power Output Control System Of Induction Heating Power Supply Based On PLC

With the outstanding feature of high-effencicy, energy-saving and pollution free, induction heating is extensively applied in industrial production. This paper focuses on the medium frequency induction heating power supply to realize the constant power output control of heating power supply so as to meet needs of special process. The existing induction heating supply, mostly controlled by potentiometer, and the way to adjust the output power fails to meet automatic production line and needs of special process. Based on the analysis of medium frequency induction heating power supply and related control system, this paper studies the control mode to realize control method and control mode of constant power output control by adopting PLC and touch panel. This paper put forwards the constant power control strategy of adopting PID close-loop control after analyzing the constant power control system of induction heating power supply. This paper finally adopts CPU224 of Siemens S7-200 as the main controller and Siemens EM23 as analog module. This paper collects output voltage and current data by CPU224 and EM23 and thereafter calculates the actual output. After inputting the given magnitude of power through MCGS touch panel, the difference of the given and actual magnitude of power can be got, and therefore the constant power output can be got after the PID calculation inner PLC and closed-loop control on the output power. This paper establishes the simulation mode by MATLAB and conducts setting on PID parameter. The experiment shows that this control system can realize well power control on medium frequency induction heating power supply output and the system, featured by swift response and high precision, can be used and promoted.