Research On Asymmetrical Half Bridge Flyback Converter With ZVS

Asymmetrical half-bridge flyback converter combines the advantage of asymmetricalhalf-bridge converter and flyback converter, and the structure is simple, the cost is low, theperformance is high. This converter is an ideal switch mode power supply. Some keyquestions in the forming principle and equipment design theory has been studied on baseof the other’s conclusions in the paper. In this thesis, the main researching contentsincludes:This text deeply analyzes the working principle of the Asymmetrical half-bridgeflyback converter; a mathematical model was established which is based on the steadymode of operation; a Small-signal model of main circuit was established on base of theaverage state-space equations; equivalent circuit model of the converter is establishedthough using peak current control mode.Based on the PSIM software, Asymmetrical half-bridge flyback converter wassimulated and analyzed the main circuit of the open-loop and closed-loop structures. Thecorrectness and accuracy of the mathematical model is verified by simulation. Meanwhilethe choice of the mainly circuit parameter is based on the simulation data.The asymmetrical half-bridge flyback converter was studied in this paper, andproduced a 120W experimental prototype, and relevant experimental study was carried out.The experimental results proved that the accuracy of the theoretical analysis andsimulation model.The experimental data proves that: Asymmetrical half-bridge flyback converter canrealize the ZVS operation and be controlled for the power MOSFET, the circuit structureis better for switching loss and electromagnetic interference, reaching the Expected goal.The highest effective of the converter utilization rate is up to 97%.