Research On DC Power Supply Of Low Input Current Pulsating Under Pulsed Load

Recently,pulsed power loads like spacecraft,radar are more and more.The DC input bus will produce a great current ripple,resulting in large radiation emission when working under pulsed load.The current ripple will not only cause a great voltage drop in the energy storage device hence the life of which reduced,but also make a higher requirement on the stability of the bus.In this dissertation,two kinds of DC power supply are designed,achieving low input current ripple in the DC bus at the same time small variation in the supply output voltage.Aiming at the problem that large input current ripple in the DC bus when the power supply working under the pulsed load,in this dissertation,selecting capacitor as the intermediate energy buffer unit,the non-isolated hybrid energy storage system composed of Boost converter and Buck converter is designed.The Boost converter is directly controlled by the input current closed loop,in which the current reference is calculated though the average power required of the pulsed load.The method automatically adjust ing the input current reference though using the digital potentiometer is proposed,in case that the closed-loop control may fail when the average power of the power supply system drifts.In order to achieve the isolation of input and output,the isolated hybrid energy storage system composed of the double-tube forward converter and Buck converter is designed.The voltage-type control introducing the input current low-frequency disturbance is proposed in the double-tube forward converter,in which the closed-loop control parameters are designed with reference to the back current gain transfer function and the output impedance tra nsfer function,so that the output capacitor can provide pulsating power as much as possible,and the DC bus provides the average power.In the two DC active hybrid systems designed,post-stage Buck converter both use traditional voltage closed-loop control,realizing small variation in the output voltage and fast dynamic response when the pulsed load changes.Time domain simulation in the Saber software and hardware circuit are built to verify the superiority of two DC power supply structures and the contr ol methods in the dissertation,which can realize the input current ripple is smaller than ?10% of the average,as well as the small ripple of the output voltage.