High power and low voltage power supply for low frequency pulsed load

摘要

The output of low frequency pulsed power supply (PPS) consists of vivid low frequency components. To prevent the low frequency pulsating power from propagating to the input of PPS, it is necessary to add storage unit to compensate the pulsating power. Compared with passive components, like inductor, capacitor, or combination of them, taking bidirectional converter as the storage unit can sharply cut down the volume and weight of whole system. In this paper, a bidirectional buck/boost converter is employed as a bidirectional converter to provide this fluctuating power. At the same time, a load current feed-forward scheme is proposed for the bidirectional buck/boost converter to improve the tracking accuracy of the inductor current. To improve the dynamic performance when load is on and off, two rapid voltage loops are introduced to limit the maximum and minimum voltage of the storage capacitors respectively, and peak voltage control is used to regulate the voltage across the storage capacitors simultaneously. Finally, a prototype with peak output power of 2kW, average output power of 300W and the pulsed frequency of 150Hz∼300Hz has been fabricated and tested in the lab. The experimental results are presented to verify the validity of theoretical analysis.