Design Of A Digital Switching Power Supply Based On ZVS-MR

The environment pollution,the energy shortage and the greenhouse effect are more and more serious.In order to solve these problems,the government has spent a lot of manpower and material resources.A lot of Chinese cities have shut down the heavy pollution enterprises,and executed the traffic control.All of these indicate that we should save the energy and have a low-carbon life.With the people's living standards have been improved rapidly,and cars have become a necessity thing in our life.At the same time,cars consume a lot of oil,causing harm to the environment and energy.Reducing the energy consumption and environmental pollution of vehicles has become an urgent matter.As a clean energy,electric energy will become one of the clean energy developed by the country for a long time in the future.Replacing fuel vehicles with electric vehicles is an important way to reduce environmental pollution,and it will also be an important trend in the future.For a long time,due to the limitations of battery technology and other factors,the electric vehicle has short mileage and long charging time.In recent years,Tesla company designs an electric vehicle mileage up to 500 km with excellent battery management system.Electric cars will enter a period of rapid development.With the development of electric vehicle industry,the number of electric vehicle charging power will also increase rapidly.Therefore,the design of an efficient electric vehicle charging power has great significance to our society.Based on the above situation,a digital switching power supply which has high efficiency based on multi resonant circuit topology is designed in this paper.In this paper,the non-isolated topology such as Buck and Boost is abandoned,considering the power safety of the load,the disintegration of the ground,and the reduction of mutual interference.Soft switching technology can improve the efficiency of the power supply and reduce the interference generated.So the traditional hard circuit topology is abandoned.In addition,the working principle of the phase-shifting full bridge soft switching topology is studied in this paper.But it has some problems,such as the loss of side duty ratio,loss of soft switching and poor reliability.Finally,the zero voltage soft switching multi resonant topology is selected.In this paper,we introduce the main characteristics of the multi resonant topology,and analyze the working process and DC characteristic of the multi resonant zero voltage soft switching topology.These characteristic not only can obtain the maximum power efficiency,but also greatly reduced the difficulty of the design of electromagnetic compatibility.Then based on multi resonant zero voltage soft switching topology,we design a power supply's parameter of the circuit apology that the output voltage is from 400 to 500VDC,and the maximum output current is 20A.Secondly,based on the master chip TMS320F2808,we design the main control circuit.In order to form a complete power supply system,the design of auxiliary circuits,such as input and output monitoring circuit,start-up delay circuit and auxiliary power supply,are also carried out in this paper.Finally,the structure of the power system is designed and made in kind.In the design of PCB,the main power line is the "U" type circuit design,and its structure design adopts the classic tunnel wind cooling structure.This not only reduces the interference of the circuit to the outside world,but also makes the power have good heat dissipation effect.The actual testing of the physical power supply is also carried out in this paper.We have achieved the design expectation,and the design of the power supply module has been used in Linyi city and other areas.