Study On High-frequency Induction Heating Power Supply

Induction heating has many advantages such as heating speed, high heatingefficiency, heating uniformity and easily automated etc.. For these reasons, inductionheating has been widely used in casting melting, forging blank heating, surface heattreatment and welding industry. Moreover, induction heating is also widely used inhome appliance products such as the electromagnetic oven and electromagneticwater heater etc.. With the development of the theory of induction heating and powerelectronic devices, the performance of induction heating power supply become moreand more excellent, and its application fields are also expanding, increasingly widerange of applications. Therefore, the study of induction heating power supply has avery broad application prospects. And there is a very important positive effect forindustrial production and daily life.This dissertation describes the basic principle, and introduces developmenttrend, and analyses the common topology of induction heating power supply. Andstudy the commonly used power induction heating power control modes. Thecharacteristics of the common signal sensor were explored. And the equivalentcircuit model of MOSFET and the driving characteristics were summarized.The commonly technology and topology structure were investigated andunderstood. On this basis, a method for phase tracking was proposed, which usedphase-shifted full-bridge topology. The phase signal was sent to the capture moduleof TMS320F2812by voltage and current signals processing circuit which weredesigned in the paper. The system used PFM technology and fuzzy control algorithmfor phase tracking, and used PSM technology and fuzzy control algorithm tocomplete the power regulation.This dissertation adopted TMS320F2812digital signal processor of TI as thecore control system, and the hardware design and the software design werecompleted. Designed hardware circuits include main power circuit, isolation drive circuit, and signal detection processing circuit etc.. This paper presented the selectionbasis of key components and the principles of important circuits, and the signalprocessing circuit was designed and simulated by ORCAD software. The proposedmethod of phase tracking was simulated by MATLAB/Simulink. The software designwas completed by referencing simulation data. And the feasibility of the proposedmethod was verified.Finally, experimental platform was built. The experimental data shows that theload phase controlling has good dynamic and static performance when the inductionheating power supply ran, and the power controlling of the power supply has goodstability. The experimental results verify the feasibility of the proposed phasetracking method.