Research On High Power Factor And Soft-Switching Monocrystal Furnace Heating Power

The fast development of PV industry makes the demand of monocrystalline silicon increased dramatically which promote the development of monocrystal furnace heating power. It is a DC power with high power, and the output provide heat source for monocrystal furnace through directly heat the graphite resistance. The stability of the heat source directly determine the quality of monocrystalline silicon. So the stability and output precision must be improved for products with high quality. The traditional thyristor power supply hinder the improvement of quality because of low efficiency,low power factor and low accuracy. This paper will apply power factor correction(PFC)and soft switching to the design of power supply in order to improve the power factor and reduce the switch loss.A Boost circuit is increased for PFC after rectifier. The average current control method which include inner current loop and outer voltage loop is applied to make the current phase change as voltage phase so as to provide the power factor.At the same time IGBT can achieve soft switching. The traditional hard switch full bridge converter is threw out in DC/DC transform link. The working process of PS-ZVS-PWM,PS-ZCS-PWM andPS-ZVZCS-PWM full bridge converter are analied detailed. The PS-ZVZCS-PWM full bridge converter is chosen based on their advantages and disadvantages.And the soft switch conditions of advanced and lag bridge arm are analied in this paper. Introduce a new method of high frequency transformer's designing.In order to meet the needs of modern production, the power supply realize digital control by using DSP.A stable output is achieved through PI control algorithm.The simulation software MATLAB and PSPICE are used for PFC link and PS-ZVZCS- PWM full bridge converter link and the whole system.A model machine with 150KW/50KHz is designed based on TMS320F2812. The experimental results and simulation waveform are given in this paper.