| There are more and more loads with pulsation characteristics in spacecraft such as satellites.When the converter drives the load with pulsation characteristics,the input current will also produce large pulsation,which will lead to large fluctuations in the voltage of the supply DC bus,affecting the normal operation of other power-using equipment and reducing the conversion efficiency and service life of the satellite power system.In this paper,a twostage low-frequency pulsation power suppression converter is designed to suppress the input current pulsation while powering the electrical equipment.This paper firstly proposes a pulsating power suppression converter based on a two-stage structure.The mid-bus capacitor works in a large ripple state,periodically absorbing and releasing the pulsating energy to achieve the effect of pulsating power suppression.The front stage converter can effectively suppress the input current pulsation,while the back stage converter can stabilize the output voltage.The mechanism and propagation path of input current pulsation are analyzed from the perspective of the closed-loop impedance of the converter,and a pulsating power suppression method and control circuit of voltage compensator with low pass filter are proposed to suppress the pulsation of the converter input current.The above control method significantly reduces the closed-loop bandwidth of the front stage converter when suppressing input current pulsation.The smaller the closed-loop bandwidth of the system is,the stronger the ability of the converter to suppress input current pulsation,but the worse its dynamic performance is.To solve this problem,a fast dynamic response method based on loop switching is further proposed in this paper.When the bus voltage is within the target range,the converter works in the pulsation power suppression mode;when the bus voltage is outside the target range,the converter works in the fast dynamic response mode to accelerate the adjustment speed of the intermediate bus voltage of the converter when the load changes abruptly.Finally,a theoretical prototype with an average power of 500 W and output pulse frequency of 100-300 Hz was built in the laboratory for experimental verification.The experimental results verify the feasibility and effectiveness of the proposed control method. |
