The Research Of The Control System Of High Frequency Power Supply For Induction Heating Based On DSP

In the running of the series resonant induction heating power supply, the operation of the inverter is closely related to the breadth of the dead time. The inverter control must perform the functions of load frequency following and dead time regulating in time. At the same time, the control circuit must realize power regulating of the rectifying circuit and the inverter circuit and keep some parameters impervious to the interferer.This paper has researched high frequency solid induction heating power supply. In the first chapter, it has introduced the history and basic knowledge of induction heating and the control problems on inducting power supply.The basic principals of the resonant tank and the two main topologies are analyzed in detail. This paper select the series-resonant inverter because it is more suited to high frequency power supply and it will be easy to enhance power capacity and enable the power supply to work on higher frequency if power is regulated in the rectifier. So uncontrolled rectifier and Buck chopper constitute DC circuit is selected as rectifier circuit.In the realization of the inverter control circuit, the frequency self-following system with optimal dead time based on DSP is researched. The core instrument for frequency-following is the PLL. The DSP is used to realize the regulating of the dead time on-line. The hardware control system based on TMS320LF2407A is designed, which includes sampling circuit, protective circuit, phase-compensated circuit, driving circuit and so on. The program of system is compiled. The strategies of the closed loop control of high frequency induction heating power supply and the fuzzy control is introduced to the powercontrol. The hardware and software realization scheme is given. In the end of this paper, much of wave and the experiment results are provided.