The Research Of 500kW IGBT Parallel Resonant Induction Heating Power Supply Device

This thesis is a research project cooperated with Shaanxi Mei Tai Electrical Company. Interiorly, intermediate frequency and high frequency high-power induction heating has done many researches, but there has few ripe manufacture and industrial background. In conclusion, induction heating power supply in China is inferior to external manufacture at all points.In this thesis, parallel resonant induction heating power supply is mainly discussed. IGBT was adopted in main circuit. The theory of induction heating and the characteristic of parallel resonant load were analyzed. The difference between direct current power regulation and inversion power regulation were compared. The power regulation of Three-Phase Full-Bridge Controlled Rectifier was selected finally. Meanwhile, the significance of superposition time was described. In this thesis, the close loop simulink model of 10kHz/500kW parallel resonant induction heating power supply system was established and the waveform of direct current power regulation, PPL and inverter startup were analyzed. Based on these theories, the controller of induction heating power supply is designed based on DSP TMS320F2812. The full digital control of the close loop system of power regulation, PLL system, superposition time and inverter startup were studied primarily. Over-voltage protective circuit, over-current protective circuit, sampling circuit and detecting circuit was designed. Especially, the suppressant circuit has given and done some simulation. This simulation can prove its correctness and feasibility, so power supply and IGBT can operate reliably. Finally, controller had been adjusted with main circuit established by company. It can prove that these control schemes are correct and feasible.