Series resonant converter for discharge of batteries space vehicles power systems

Authors: Osipov V. A., Shkolnyy V. N., Shinyakov Yu. A., Yaroslavtsev E. V., Shemolin I. S.

Annotation: The article deals with the resonant bridge converter of the module of the charge-discharge device for power supply systems for space vehicles constructed on the DAB (Dual Active Bridge) topology with pulse-width modulation and frequency tuning. It is established that the load powering mode (the mode of limiting the output power or limiting the discharge current) determines the energetically efficient converter control strategy, which ensures the minimum values of the operating currents, the mass of the converter, and improves its efficiency. When limiting the output power, inverter regulation is recommended, and when the discharge current is limited, rectifier regulation is recommended. It is shown that in order to ensure a soft switching on of the transistors, a frequency tuning that forms the necessary current direction that opens the reverse diodes of the ZVT (Zero Voltage Transition) transistors is needed. In this case, switching processes occurring in the inverter and rectifier of the resonant converter and the conditions for providing ZVT for them are different. The characteristics of the converter at low loads are determined, as well as an increase in the frequency tuning with decreasing load power. Control strategy for the converter at a limited fixed frequency is proposed. The experimental verification of the results is made, conclusions are drawn, and the results are discussed.

Keywords: power supply system, resonant converter, soft switching