Quad-Active-Bridge DC-DC Converter based on-board Power Electronic Interface for Electric Vehicle

Driven by concerns of climate change and depletion of fossil fuels, there is an increasing trend to migrate to electric vehicles (EV) from conventional Internal Combustion Engines (ICE). Aided by the support of various governments, the era of all-electric-vehicles is becoming a reality. However, the commercialization of EV is hampered to some extent due to the drawbacks of EVs such as limited driving range, sluggish response and shorter operational life of on-board battery. A hybrid energy storage system (HESS), comprising a battery and ultra-capacitor (UC) can overcome some drawbacks of an EV with battery as the only energy storage. The power electronic architecture that integrates the HESS is one of the most important aspects to be considered in designing the drive-train of the EV. This paper uses a Quad-Active-Bridge (QAB) DC-DC converter as the on-board interface for the HESS. The system inherits several desirable features like high power density, soft-switching and higher efficiency from active-bridge topologies. The technical design of the proposed system along with structure of digital controller is included in this paper. Simulation and experimental results to substantiate the performance merit of the system are also included.