Design Of A 6 kW Multiple-Input Bi-directional DC-DC Converter With Decoupled Current Sharing Control For Hybrid Energy Storage Elements

A Triple Half Bridge (THB) Bidirectional DC-DC converter was proposed recently to combine different power energy storage elements/sources through a multi-winding transformer. The THB converter can be utilized in different applications including electric vehicle and distributed energy generation system. This paper presents the dynamic analysis and associated control design of this THB converter. An equivalent circuit based small signal model was developed. Bode plots of the control-output transfer functions were derived and interference between two input ports was analyzed. A double loop control system with current sharing strategy was implemented and a decoupling network was designed to obtain better control performance. Finally, a 6 kW prototype was built in the laboratory to verify the theoretical design. The experiment results show decoupling and good dynamic response as expected.