The Research Of The Induction Heating Power Supply Based On FPGA

At present, analog control is used for most of the induction heating power supply, this type of control system is poor at reliability, required highly on component technology and difficult to modify the parameters, all of these greatly influenced the application of the induction heating equipment. In this kind of situation, the digital control system is deeply studied, through the research on frequency tracking, power control, and FSM, induction heating power supply control system is designed based on FPGA. The most prominent feature of this control system is that digital control is realized with higher precision and easer to modify the parameters, and the whole control system integrated on the chip of FPGA. In this paper, the main work is as follows:the designation of the digital phase-lock loop circuit, power control circuit and the finite state machine of the inverter circuit.The mainly working content is as follows:A, the designation of digital phase-lock loop circuitPhase-lock loop is widly used in frequency tracking of the induction heating power supply. In this paper, the74297which embedded at the bottom of FPGA is used, the phase-lock loop designed mainly including counter, register, frequency divider.B, the designation of the power control circuitThis paper adopts DC chopper circuit, trough voltage control to solve the power control of induction heating power supply. The designation of the power control circuit is divided into DC chopper circuit, error amplifier circuit and PWM pulse control circuit. Through the feedback of the error amplification circuit and PWM pulse control circuit, power output can do adjustment by itself, so as to ensure the stability of the power output.C, the designation of FSMThe FSM designed mainly controls normal start-up, operation, turn off of the inverter circuit. In this state machine, seven states were designed, the realization of the state conversion is according to the jump conditions. From top to bottom, the inverter system parts together formed a SOC system, and simulated in Quartus II environment.The simulation results showed that the designation of the induction heating power supply’s FPGA control system is feasible.