A multi-port DC-DC converter topology with simultaneous buck and boost outputs

Multi-port DC-DC converter topologies can be used to generate multiple DC outputs from a single DC input source — the voltage gains can be step-up and/or step-down type. Compared to dedicated converters, these integrated topologies have higher efficiencies, lesser Bill-of-Material, as well as lesser coordination communication requirements. This paper proposes a multi-port DC-DC converter topology which generates two outputs — step-up as well as step-down, from a single DC input. The converter architecture is realized by replacing the controlled switch of a boost converter with a half bridge network and a low pass filter. Compared to traditional buck converters, the proposed converter has higher reliability, due to its inherent shoot-through protection and has a wider range of step-down outputs. In contrast to two separate buck and boost converters, this proposed topology performs the same function with lesser number of switches. Operating modes and steady state behavior of the proposed converter has been studied in this paper. A suitable control scheme to control both outputs has been described. The behavior of the proposed converter has been verified using a 150 W laboratory prototype, which produces a step-up voltage of 18 V and a step-down voltage of 6 V from a single 12 V input.