Multi-Input Isolated Power Converter for Electric Vehicles with Hybrid Energy Storage

Abstract

The existing converter relies on a non-isolated transformer and lacks bidirectional support in the case of multiple and regenerative inputs. The proposed work focuses on an isolated multiport bidirectional DC-DC converter topology featuring a battery and a supercapacitor for an electric vehicle (EV) of 2 kW. The proposed topology can provide uninterrupted power to the EV’s electric motor and recover braking energy, allowing bidirectional power flow. As a result, the battery discharge time can increase due to the additional source, such as a supercapacitor and regenerative action. The system integrates two single H-bridge converters at the input and a single H-bridge converter at the output, with an existing switch. The converter enables the reduction of the rated voltages of the battery and supercapacitor packs. Additionally, a power-flow management scheme and its corresponding control scheme are proposed. The performance test has been conducted on traditional and PI control methods under different operating conditions with a switching frequency of 50 kHz, such as switching power from the battery or supercapacitor to the load during driving and from the load back to the source during energy generation. Power flow capabilities and efficiency values validate the viability and effectiveness of the proposed system of 2 kW.