Design of a Bi-Directional Multi-Port Dc-Dc Converter for Hybrid Energy Storage in Electric Vehicles

Usage of Electric Vehicles (EVs) in wide scale reduces the increasing consumption of fossil fuels in the transportation system. EVs consists of three major units namely, battery pack, power electronic converter (PEC) and electric motor. The PEC incorporates two or more DC-DC converters, each with a specific purpose like charging the battery, powering the motor and supplying ancillary loads. EVs utilize battery as its major source of energy along with other sources like PV or fuel cell. In order to effectively utilize the EVs, the conventional PECs can be replaced with a central power converter which reduces the cost and improves the functionality. This work introduces a multi-port Bi-directional DC-DC converter with a charge controller to automate battery charging and discharging processes allowing hybridization of available energy sources for effective power management. The proposed converter can be operated in regenerative braking mode improving efficiency. Based on the variations in load demand and availability of energy sources, the proposed converter setup was tested in battery charging, discharging and regeneration modes using MATLAB/Simulink and an efficiency of 90 % was achieved.