Research On High Frequency Induction Heating Power Supplies Based On PWM Chopping Power Modulation

Induction heater is applied widely in industry, such as refining, casting, forging, sintering, thermolize, brazing and crystal-growth and so on. At present, the crystal growth equipment is equipped with vacuum tube high frequency induction heating power supply imported from overseas or produced in China. While this kind of power supply has many disadvantages, such as low reliability, short longevity of vacuum tube, operational safety and low transfer efficiency, existing huge capacity solid induction heating power supply cannot replace them to meet industrial needs.This paper briefly introduced the basic knowledge and the development of high-frequency series resonant induction heating power supply. Analyze and affirm the blue print of the power composing, the method of power regulation. It can be concluded that power regulating in the commutate side in favor of enhancing the frequency and power of high-frequency induction heating power supply. And a novel zero-voltage zero-current transition (ZVZCT) soft-switching cell is presented. Based on the proposed soft-switching cell, novel Buck ZVZCT PWM converter are built. The operation principle of Buck ZVZCT PWM converter is given in detail and zero-voltage zero-current switching is realized main switch , zero-current turn on and zero-voltage zero-current turn off is achieved in auxiliary switch , zero-current zero-voltage turn off and zero-voltage turn on is implemented in freewheeling diode at the same time. In addition, the proposed ZVZCT soft-switching cell is not only suitable for DC-DC converter, both in pulse width modulation (PWM) control.Then, a main circuit of 5KW/100KHz high-frequency induction heating power with MOSFET switch device is designed. After a study of the basic requirements and normal drive method of drive circuit, a MOSFET's drive circuit with IXDD414CI core device is designed. After a study of all kinds of control circuit, a chopper regulating circuit with PWM integrated circuit is designed.The validity and feasibility of the design are approved by the simulation.