Research On ZVZCS Converter With Passive Clamp Network

Full-bridge topology of soft-switching converter is used widely in switching power supply area because of its low voltage and current stresses. Because IGBT is used in full-bridge DC-DC converter, how to avoid the trailing current has attracted people more attention. There are many ZVZCS DC-DC converter topologies to solve this problem. But these topologies are too complex or make much power loss. There is not a famous effective topology until now. This paper put forward a new topology of ZVZCS converter with passive clamp netwok.It's difficult to establish a mathematic modeling on complicated DC-DC converter such as full bridge topology. It is because that there are many modes in this converter. The operation course is complex. This paper puts forward a new modeling method with PWM equivalent switching modeling. This modeling can be established without solving high order nonlinear equation system. So it makes the modeling course greatly simple. After making a model, the frequency characteristic can be analyzed. Also the effect of system parameters is analyzed.A 100kHz 96W DC-DC converter with passive clamp netwok is designed based on this topology. And this design makes DSP TMS320F2812 be control chip. This method improves switching frequency and control precision. It can achieve Full Digital control. And this paper designs control circuit, driving circuit and protection circuit. This paper uses PSPICE of ORCAD to simulate the operation of main circuit. System parameters are confirmed farther. The prototype converter is implemented to verify. Main waveforms and performance indexes are tested. By analyzing the experimental results our theoretical analysis is confirmed. The converter has many virtues such as simple topology, high efficiency and low peak voltage of secondary side.