Research And Design Of The Series Resonant Medium Frequency Induction Heating Power Supply

Compared with the traditional heating technology, induction heating technology has the advantages of high efficiency, energy saving, environmental protection and safety.Therefore, it is widely applied to heat treatment industry such as metal heat treatment,diathermy, smelting, welding etc, and has penetrated into many areas including industrial,civil and commercial. The key point of induction heating technology is the manufacturing of the induction heating power supply. The output frequency of medium frequency induction heating power supply is 1KHz~20KHz, and for the resonant induction heating power supply, it is using the RLC load characteristics to make the circuit working in the resonant state.This paper has compared and analyzed the two topologies of main circuit in the induction heating power supply. Its main point is to discuss the select series resonant inverter, and analyze the variety of power adjustment mode of induct heating power supply.It has the conclusion of choosing the inductive phase shift PWM Power Control Method.This paper has deep discussion about theory on the Load characteristics series resonant inverter power adjustment and phase shifting. With the application of the MATLAB /Simulink environment, building simulation models for the series resonant induction heating power, which can made simulation research on induction heating power supply system.Based on the theoretical analysis, this paper has designed the main circuit and control circuit of induction heating power supply of 20KHz/200 W. In the main circuit, it has made detailed introduction about the parameter selection for device on rectifier circuit, inverter circuit and load circuit. In the control circuit, with the application of frequency tracking technology and control strategy of phase-shift PWM power, by using phase-locked loop CD4046 and phase-shift resonant controller UC3875 design hardware control circuit,which effectively improve the system's stability. Meaning time, a experimental prototype is built, and the tests and experiments has been implemented, with the experimental result that verify the feasibility and correctness of the control scheme.