The Design Of The High-power Switching Power Supply Based On The Phase Shifting Full Bridge Soft Switch Technology

At present, the Switching power supply with its unique advantage is gradually replacing the linear power. However, it also put forward higher requirements for components with the increase of voltage and current levels. In the high power occasion, the general switch tube is difficult to satisfy the requirement of the voltage and current stress. So people tend to reduce stress by choosing appropriate topology circuit. Tologies commonly used in high-power include push-pull, half-bridge and full-bridge. In this paper, the author’s chooses is a full-bridge topology. In order to obtain higher conversion efficiency, we also need to adopt soft switch technology. By the analysis on full bridge topology of different control methods and different soft switch methods, the author selectes the phase-shift full bridge zero voltage soft switch technology finally.In this paper, the phase shifting full bridge zero voltage switching power supply is analyzed, and its steady-state dc model and the small signal ac model are established. According to the steady-state dc model, this paper presents a method for calculating the resonant inductance, and the method can lead to a reasonable duty ratio loss and has no effect on ZVS. In addition, this article also workes out the design and selection to main circuit components. This article uses ac small signal model to set up the power unit’s transfer function expression, and obtained the power unit’s transfer function according to the main circuit design parameters. On the basis of the above the author completes the loop compensation design, it make the system have enough stability margin and good dynamic performance.Finally, according to the design parameters above, the author make out of a sample and got the sample’s waveform. Experiments show that the power supply has reached the expected goal.