Design And Research Of Low-voltage And High-current Dc Switching Power Supply

The DC switching power supply is the largest one in the range of applications and market of all kinds of power, including the "Switch Mode Rectifier" which AC input into DC output and the "DC-DC converter" which DC input into DC output. After several years of development, DC Switching Power that has been applied a number of high-tech, intelligent technology, surface mount technology, has formed the modern DC switching power supply which characterized by high-frequency, high efficiency, high power density, high reliability.Based on the design requirements of engineering prototype, the DC switching power supply adopts a full-bridge converter topology, and the operating principle and circuit characteristics of the full-bridge converter are analyzed in this paper. In this paper, Power-MOSFET is used as diode on some states for reverse current, therefore the problem of reverse-recovery follow. Base on the analysis of diode reverse-recovery, the paper change the operational condition of Power-MOSFET to soft the reverse-recovery process. Base on the analysis of glitch voltage translation, the paper propose a new snubbed circuit.According to the request of the subject, the main voltage transformer, output filter inductance and saturation inductance have been designed.By AP method, the output filter inductance and high frequency transformer have been designed. And the input and output filter capacitor and the main power devices have been designed.The simulation and experiments are made on a prototype of DC switching power supply, the simulation and experiments results are in positive to the analysis showing the feasibility of the proposed methods.