The Design Of An Unattended System Power Supply

In recent years,the power supply of unattended system is more and more widely used in military radar.In order to ensure the safe,efficient and reliable operation of radar,an unattended AC/DC system power supply was designed for radar system.The research status and development trend of unattended power supply are introduced firstly,and introduces the practical use circuit of several module power supply in detail.Through the detailed analysis of the design index,the overall design scheme of the power supply of unattended system is given.Then,the advantages and disadvantages of several common soft start circuits and the scope of use are introduced and analyzed in detail.The working process and calculation method of the soft start circuit designed in this paper are given.Then,through the comparative analysis of active PFC and passive PFC,the design adopts the design Passive PFC circuit is used to realize power factor correction,and the calculation method of PFC inductance is given.Then,the full bridge phase shifting technology in the main power circuit is introduced and analyzed in detail.The calculation methods of main power tube,resonance sense,transformer and whole current bridge in phase shifting full bridge circuit are given.Then,starting from the small signal model of buck circuit,ZVS PWM is derived The small signal model and its open-loop transfer function of the converter are simulated by using PSIM software.The voltage feedback loop based on ucc3895 is designed to make the system more stable.Then,the paper gives several auxiliary source circuits and main function program flow chart which is realized by software.Finally,the test results verify the feasibility of the design scheme.Finally,the prototype is made,and the detailed index test is carried out.Through the comparison of the index requirements and test data,the functions proposed in the index are basically realized,and some unsatisfactory indicators are also given the follow-up improvement methods,the feasibility and correctness of the system power supply design scheme has been proved.