Research And Design Of High Power High Frequency Induction Heating Power Supply

The basic theory and the development situation of high-frequency series resonant induction heating power supply were described and analyzed in depth in this thesis. The temperature control issue was also analyzed and discussed. The system and block circuit structure of the power supply were designed. After analysis and discussion on the differences between the series resonant inverter and parallel resonant inverter, the series resonant inverter was chosen as power supply. The output frequency of inverter power supply was modulated by DSP techniques together with phase-locked loop based on dead zone theory. Compared the advantages and disadvantage of adjusting methods, it is found that the rectifier side tuning work is beneficial to the improvement on high frequency induction heating power supply frequency and power. The non-controlled rectifier and chopper tuning work as selected as the control way in this system.The series resonant inverter was compared with the parallel resonant inverter, and the operating states of the inverter circuit were analyzed. The voltage and the current of inverter at resonance were comparatively low. Therefore,the power dissipation of high frequency power supply was lowest switched at resonance. The inverter control circuit and its modules were designed, and the control and power circuits with the best dead band frequency tracking control system and non-controlled rectifier and chopper power control were analyzed and researched in detail. The phase-locked loop was used as the core of frequency tracking device, the online adjustment of the dead area was realized according to the dead zone theory, using DSP. The hardware control platform with the TMS320LF2407 A, as the control core, was designed, including sampling circuit, protect circuit, drive and other peripheral circuit, and introduces the PID control of induction heating power supply power regulation. The inverter power supply and Buck chopper were simulated, the main parameters of the system was represented in this thesis.