Multiport isolated bidirectional DC-DC converter interfacing battery and supercapacitor for hybrid energy storage application

This paper focuses on the hybrid energy storage system (HESS) utilizing and interfacing multiple energy storage system. The topology of the proposed multiport isolated bidirectional dc-dc converter (BDC) is the triple active full bridge (TAB) topology that interfaces battery as primary energy storage and supercapacitor as auxillary energy storage. Battery is the most matured technology in energy storage system (ESS) which has high energy density. On the other hand its dynamic response is slow which makes it unsuitable to satisfy the requirements of sudden changes on load or power. Meanwhile supercapacitor has short charging and discharging time and high power density. Interfacing of battery and supercapacitor mainly leads to stress reduction of battery that acts as main source. The proposed topology has the advantage of inherent bidirectional power flow, minimal number of conversion steps, high efficiency and centralized control can be implemented. Control strategy proposed for this converter is based on phase shift control (PS). In addition a control scheme employing a PI regulator is employed. The simulation results for different operating modes are carried out using MATLAB / Simulink 2014 environment to verify the efficacy of the proposed converter.