A High Power-Factor And Soft-switching Power Supply

In power system, the power electronic equipments are used more and more at present. This brings on power factor falling and harmonic damage. For ensuring that the power system regularity works, adopts now, way sometimes is to restrict the capacities switching in the power system commutation equipment. The use of high DC power supply is limited. Therefore, the high power factor high-power Switching-Mode power supply becomes the major topic of discussion studying.There exist two problems in the high-power Switching-Mode power supply realizing the high power factor mainly: First, with the power increasing by, the switching losses also may follow that to increase by, how to come to reduce the switching losses; What topology, secondly, adopt to realize power factor adjustment coming structure.Be to resolve the first problems, A novel ZVZCS-PWM converter is proposed which uses a coupled output inductor. A simple auxiliary circuit that consists of neither lossy component nor active switching is used. The voltage stress of the secondary rectifier diode is kept as small as that of hard-switching converter. The current to charge clamping capacitance is self-adjusted in accordance with the load at light condition, which guarantees high efficiency over wide load range. Diode D_c of auxiliary circuit is softly commutated and it's of reverse recovery is minimized.A kind of method brought forward for power factor correction tries to correct the circuit that the front had been mentioned. A single-stage power factor correction circuit that combines a Two-Switch power factor correction circuit the new model ZVZCS-PWM converter is presented in this paper. The circuit turns not to append the switch component, not increasing the voltage strain that the switch is in charge of in H-bridge.The paper has analyzed the operating principle being a circuit's turn, has given out main parametric reckoning. The Pspice9.2, a kind of circuit special emulator, has been applied to analyzing the converter characteristic on the base of open loop control. The paper has analyzed an impact of every parameter over converter function, has got optimization parameters of every main component.The simulation result proves: Used this converter's topology structure, the envelope curve of import electric current follows entering voltage change. And power factor correction has been realized. At the same time, the zero electric current cutoff in the advance bridge arm and the zero voltage cutoff in the lagging bridge arm are able to realize above fixed load in 15%. The converter has high efficiency within loads very broad range. This has the prospect applying broadly in the equipment which uses IGBT.