Digital Control Of Induction Heating Power Supply And Its Intelligent Control Method Research

In this thesis, the series resonant induction heating power supply was mainly discussed. By analyzing its load characteristics and power regulation scheme, an induction heating power supply structure with uncontrolled rectifier and phase-shift PWM power regulation strategy was selected, in which the inductive phase-shift PWM power regulation method and it's application in MOSFET power supply was particularly studied. The characteristics of phase-shift PWM control method and its full bridge soft switch realization was lucubrated. In the meantime, aiming at the complicated time-variant parameter and non-linear structure of the induction heating power supply, Fuzzy-PI power controller was designed basing on the discussion of Fuzzy control, and simulation results show that the Fuzzy-PI control method have better effect than tranditional control method. The close loop simulink model of phase-shift PWM induction heating power supply was established under MATALB/Simulink environment, and the system simulation research was implemented with the established model.On the basis of theoretic analysis, the main circuit and control circuit of 100 kHz/1kW inductive phase shift induction heating power supply was designed. The digital control of the phase-shift PWM induction heating power supply was studied primarily. A new close loop software PLL and phase shift power regulation strategy was proposed to realize the digital control of the power supply, and the whole digital close loop control system was designed based on DSP TMS320F240. Subsequently, 100 kHz/1kW power supply exiperiment platform was constructed, and the system close loop control was completed on the platform. Finally, the experiment results demonstrate the validity of theoritics analysis and the feasibility of digital control strategy.