Transient current suppression scheme for bi-directional DC-DC converters in 42 V automotive power systems

42 V electrical power systems are on their way to replacing the present 14 V systems in automobiles and 42 V/14 V dual voltage systems have been proposed to provide backward compatibility with the existing components for the 14 V system. The synchronous buck/boost converter is an attractive topology for 42 V/14 V dual voltage systems since it offers bi-directional operation without additional components. In this paper, transient currents generated during converter startup or changes in operation modes between buck and boost are analyzed and a cost effective solution to remove the transient currents is proposed. The validity of the proposed control strategy is investigated through simulations and experiments