Research On Control Technique Of Series Resonant IGBT Induction Heating Power Supply

With the advancement of power electronics, the induction heating theory and the induction heating devices have developed greatly. As the social energy is short supply, the induction heating reflects the growing importance, induction heating power supply is widely used in industrial applications and daily life for its unique advantages.This paper firstly introduces the induction heating power supply's basic principles, characteristics and development status at home and abroad, etc. Secondly, the power modulation methods of series resonant inverter are studyed. and the results show that the inverter circuit is always working in inductive state when selecting inductive phase-shift PWM modulation, and it's easy to achieve soft switching, then reduces the switching losses and improves the overall efficiency of the inverter circuit, and the control circuit is simpler and power modulation is faster, the mathematical relationship between output power and phase-shift angle is also derived.Thirdly, a inverter frequency tracking circuit for fixed-angle-control is designed, the control strategy is simulated by Matlab/Simulink and tested by a induction heating power supply prototype .The results show that this method is feasible. This circuit plays a vital role in achieving series resonant inverter's safe, stable and efficient operation.At the end, a drive circuit of IGBT is designed in this paper, it not only meets the drive requirements of high-power IGBT, but also realizes the over-current protection of devices, the detection and protection of pulse loss, device damage and power instability. the design of schematic and PCB is completed based on Protel 99SE, and the experiment results show that the circuit is correct.