Design And Implementation Of A Wide Input Voltage DC/DC Power Supply

Power supply is the core of all power electronic equipment,which provides basic energy and power for the equipment.With the increasing requirements of weapon equipment reliability and environmental adaptability,especially the airborne power supply system,it is necessary for the power supply to have a wide range of input voltage and good step response to meet the wide range of input voltage fluctuation caused by the change of engine speed.Therefore,in order to improve the redundancy and reliability of the power supply system,the wide input range DC / DC power supply is of great significance in airborne and vehicle applications with large input voltage variation range.In recent years,a wide input power supply with digital analog hybrid control and full digital control has been introduced,which has high efficiency,high power density,and rich functions such as enabling parallel current sharing.Domestic similar power supply mostly adopts analog control scheme,which has a large gap in electric parameters and output functions,so it is unable to replace the imported power supply.Based on a horizontal project design,this paper studies the basic principles of wide input switching power supply topology and control mode according to the development requirements of wide input power supply.According to the development goal,the key parameters and functions of the power supply are designed and simulated.Finally,a wide input voltage DC / DC power supply is designed which reaches the same technical level of similar imported products.The input voltage range of the power supply is 16v-40 v,the output voltage is 12 V,the output power is 120 W,the ripple is as low as 25 mV,and the efficiency is 87% in full load.The research contents of this paper are as follows:1.The current situation and development trend of switching power supply are introduced,and puts forward the significance and research contents of this topic according to the research background of low-voltage wide input voltage power supply.2.Compared with the common switching power supply topology scheme and its advantages and disadvantages,this paper focuses on the detailed analysis of the two-level topology cascade mode and feeding mode.According to the characteristics of the power supply parameters,a two-stage topology of current fed buck + interleaved forward is designed.Then the main structure of the power supply is simulated,and the stability of the main power circuit and the control measures are analyzed.3.According to the development goal of power supply,the key functions and characteristics of auxiliary power supply,magnetic components,drive,external synchronization,parallel current sharing,low ripple output are designed,and the unit circuit simulation is completed.Then,from the perspective of engineering application,reliability design of power supply such as derating design and thermal design is carried out,which verifies the feasibility of the design scheme.4.According to the development plan of the power supply,the manufacture of the wide input voltage power supply prototype is completed,and the key characteristics and parameters of the power supply prototype are tested and analyzed in detail,and the test results meet the predetermined requirements.