Design And Implementation Of High-temperature DC Switching Power Supply Based On SiC Devices

The switching power supply shows some special advantages,such as small volume,high efficiency and environmental protection,relying on its principle of energy transmission with high frequency.After decades of development,the switching power supply has been widely used in power transmission,military,industry,daily life,and many other fields.At present,the power devices that is core of switching power supply,are mainly made by silicon material.The power devices' highest working temperature,in theory,are less than 150 degrees Celsius and can't present a good feature at the highest working voltage,conduction resistance and highest switching frequency,limited by physical properties of silicon itself.Therefore,Industrial-grade DC-DC switching power supply working temperature is limited to 85 degrees Celsius,and even military rank,can't more than 125 degrees Celsius.At the same time,more and more high temperature and high power fields,such as aerospace,oil exploration,photovoltaic power generation and new energy vehicles,are explored.There power supply system,especially their power devices,fever seriously,leading to the conventional switching power supply can't directly use.To ensure the reliability of the system by achieving the temperature indicators,the ways of active cooling system or replacing components repeatedly have to be used,leading to increase the size and cost of the whole system greatly,which can't be acceptable because the power field is sensitive to space and price.Silicon carbide is a new third generation of semiconductor materials.Power devices based on silicon carbide materials have the excellent characteristics of high junction temperature,high switching frequency,low on-resistance,high reverse breakdown voltage and free from electromagnetic radiation compared with traditional power devices.Using the power devices based on silicon carbide as the core devices of high temperature switch power supply,the junction temperature of power devices are 175 degrees Celsius above and other active and passive components also can bear high temperature above 200 degrees.Therefore,this project,high temperature switching power supply,can greatly reduce or even eliminate the active cooling system on the promise of ensuring the reliability,which saving the cost of the system,reducing the whole system weight and expanding the space utilization,which have vital significance in the fields of aerospace,oil exploration,new energy vehicles and so on.The mainly working in this article dividing into four parts:(1)Fist of all,researching the present situation of the development of switch power supply and the application prospects of silicon carbide in switching power supply device in detail.Then,on the viewpoint of material science,analyzing the advantages of silicon carbide SBD,MOSFET,JFET and BJT respectively in theory.(2)Analyzing the difficulties and design methods of high temperature switching power supply by comparing the influence of high temperature to different solutions of different modules in switching power supply on the background of high temperature DC switching power supply for antenna array surface.(3)Splitting the high temperature DC switching power supply into different modules based on the traditional theory of switching power supply and describing the design schemes of the different modules in high temperature switching power supply.(4)Completing the project of design and implement of high temperature DC switching power supply step by step,in the order of simulation,normal temperature and high temperature,starting from verifying the principle of switching power by simulation to system testing of high temperature DC switching power supply.