Study On Novel Soft Switching Power Factor Correction Converter

Due to its advantages of small size, high efficiency and high power density, switch power enjoys an enormous development. As high frequency switch power usually needs AC/DC conversion, the current waveform of input AC utility distorts, and generates plenty of harmonic, thus the generation of harmonic interference among adjacent devices and the whole grid. As the result, the power supply quality of grid is influenced. In order to restrain the harmonic pollution, improve grid quality, power factor correction (PFC) has already become an important research direction. Because of its advantages of small input current distortion and high efficiency, Boost converter is usually used in the pre-regulator of two-stage PFC, to realize high power factor. APFC circuit of middle and high power generally works under CCM, which exists a serious problem in diode reverse recovery. Among all kinds of measures are used to solve this problem, the utilization of soft switching topology is an important one, which can not only solve the problem of diode reverse recovery, but also efficiently reduce switching loss and noise of the switch, thus circuit switching efficiency be greatly improved and circuit EMI effectively reduced. Along with the constant promoting of circuit power and frequency, the importance of soft switching circuit has been promoting day by day.This paper made a research on a novel designed single-phase soft-switching Boost PFC circuit. First of all, the operating principle of this circuit was analyzed, and all kinds of work modes as well as work waveforms are provided. Secondly, research on the circuit specification is implemented, then the design condition of circuit resonance parameter is confirmed, and the duty ratio of the circuit discussed, loss calculation formula analyzed, and so on. After that, small models of the main circuit and control circuit were established and analyzed, thus the transfer function of inductive current–switch duty ratio, Gi d( s ), as well as transfer function of output voltage–voltage loop compensator output, Gv c( s ), confirmed. Then control structures of current loop and voltage loop, as well as transfer function, were analyzed. Fourthly, the parameters of main circuit and control circuit were designed, and then the parameter of main circuit, including the main switch, output capacitance and auxiliary network parameter, was chosen, control circuit parameters, including the setup of multiplier, voltage loop and current loop, confirmed.In the end of the paper, the system simulation was completed by Saber software, and the converter efficiency and input current harmonic distortion rate were analyzed in detail. And a low power experiment was given. The correctness of theoretical analysis of novel single-phase soft-switching Boost PFC converter was improved by simulation and experiment.