Multi-input bidirectional DC-DC converter is quite vital for a single system to interface multiple sources and allow energy exchange between sources and loads. In this paper

a general multi-input DC-DC converter topology and its control strategy are proposed for hybrid energy storage system. This converter can connect any number of power sources and make any ports controllable bidirectionally. To interface <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$ power sources

only <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N+1$ controllable power switches are needed

which makes converter more compact with largely reduced power devices and driving circuits. Without loss of generality

a case with two sources <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(N=2)$ is utilized as a typical study case for experimental verification. Experimental results show this converter can interface two individual power sources simultaneously and ensure flexible power flow control with all ports bi-directionally. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N=2$ converter structure can be developed as an integrated converter module

which is able to combine with traditional bidirectional buck/boost DC-DC converter (BBDC) to construct series-connected or parallel connected integrated converters for multi-source applications.