Research And Design Based On Soft Switch Of Phase-Shifted Full Bridge Power System

With the rapid development of the national economy, the rapid spread of various electrical and electronic equipment. How to reduce the volume of power supply, reduce the power loss and improve the efficiency and stability of the power supply, has become an important topic in modern power technology research. The reduction of power volume is bound to increase the switching frequency, and the concept of soft switching is presented for the reduction of the switching loss. Soft switching technology can effectively reduce the switch loss, improve power efficiency. Which phase shifted full bridge topology, large output power, simple hardware structure, widely used, but in different load cases, soft switching conditions are difficult to maintain, easily detached soft switching state. The power consumption is increased, the power efficiency is reduced, and even the burned switch device is burned.This thesis introduced and analyzed the view of the problems in traditional power system, phase shifted full bridge topology ZVS soft switching technology based on the proposed solutions to a power supply system, real-time monitoring of the ZVS soft switching state, and had carried on the optimization in the standby power and stability. Finally, power supply system of modified were simulation and experiment, to verify the feasibility and effectiveness of the scheme.This thesis is Based on the soft switching technology. Firstly, it analyzes the control principle of the basic phase shifted full bridge DC-DC converter circuit, and the necessary condition to realize the soft switching phase-shift full bridge converter is studied, and introduced the device parameter selection method. In this paper, a phase shifted full bridge ZVS DC stabilized voltage power supply system is designed, which is based on high efficiency and safety.. In the control mode, the STM32 series microcontroller is adopted to realize the distribution control of the power source working pulse, and the control algorithm is improved by the digital PID algorithm.. And the soft switch state of the system for real-time monitoring, in mutational load in the power system has the advantages of high stability, and is provided with a sleep mode, can automatically monitor the situation of the load, and automatically enters sleep mode to save energy.According to the design scheme in the end, we discussed in this paper phase-shift full bridge ZVS soft switching power supply prototype experiments were conducted which is proved to effectively realize soft switching and in a certain extent to improve the power transmission efficiency and stability.1 he scheme has the advantages of simple structure, low cost, high flexibility, easy to control, automatic system output voltage, output current, micro temperature controller, phase angle monitoring and control, to further improve the efficiency and safety of power system. The power supply system has wide applicability and has good application prospect.