Supersonic-Frequency Induction Heating Power Research And Design Based On DSP

With the advantages of great heating speed, high efficiency, precisely control ability, environment-friendliness, long life-span of usage of heating, electromagnetic induction heating is becoming the main stream of the modern heating method gradually. It has a bright prospect in the application of the industrial production. The application object of this thesis is the heat treatment of the petroleum drill collars, and the equipment used to heat the drill collars is based on electromagnetic induction heating technology.This research uses TMS320F2812, the DSP chip made by TI Company, as the main controller, which makes the frequency tracking and power control of the induction heating power supply possible. This controller has some advantages of higher integration, stronger data processing ability, etc. over the previous single chip control. DSP adopts fuzzy control on the control algorithm to put the power adjustment of the electromagnetic induction heating power supply into effect and make the load changing the output power value in accordance with the temperature. Compared with the previous PID control, the fuzzy control does not depend on the precise mathematical model of the controlled object and has an ability of good robustness and overshoot restraint. In addition, it has advantages of shorter adjustable power transition, slighter voltage overshoot and higher steady-state accuracy, etc. The use of the redundant resources in chip of EMS320F2812 on the phase-locked control realizes the DPLL control and the automatic tracing of output frequency to load frequency. DPLL is featured with high accuracy, strong anti-jamming capability, and good stability. It could increase the output efficiency of electromagnetic induction heating power supply to ensure the inverter working at the state of soft switching.This thesis introduces the fundamental principles of electromagnetic induction heating at first, and then analyzes the two normal topological structures and power adjustment methods of electromagnetic induction heating power supply. The scheme design of system hardware circuit and control circuit is completed on the base of theoretical analysis. The hardware circuit includes main circuit, MOSFET driving circuit, conditioning circuit, protection circuit and power supply model, etc. The control circuit includes the control chip and peripheral circuit, etc. For the reason that the equipment will be intervened by strong electromagnetic when the electromagnetic induction heating power supply working in the condition of high voltage and heavy current, this thesis introduces the method and design of anti-jamming in four aspects to avoid the electromagnetic interference influencing the output power value. In the end, this research will emulate and debug the whole system design and work out the emulation waveform and test result.