Integration of Fast Charger with the Powertrain of a Battery Electric Vehicle

Abstract

The transition toward sustainable transportation and the increasing adoption of electric vehicles (EVs) are driving the need for more efficient and compact fast-charging systems. This thesis investigates the integration of a fast charger with the powertrain of a battery electric vehicle by reusing existing traction components such as the inverter and electrical machine stator. The work focuses on the experimental evaluation of integrated charging topologies, with particular attention to system efficiency, electrical behaviour, and power loss mechanisms under different operating conditions. The proposed system is based on interleaved boost converter configurations integrated with the vehicle powertrain, enabling reduced component count, lower system volume, and improved power density. An experimental test bench was developed including electrical machines, inverter hardware, measurement systems, and embedded control system. Both simulation and laboratory measurements were used to analyze switching losses, conduction losses, current ripple, and efficiency trends for different switching frequencies and phase-shift operating conditions. The experimental results demonstrate the feasibility of integrated fast-charging systems for future electric vehicles and provide insights into the trade-offs between the studied topologies, quantifying efficiencies, losses, and ripple suppression, thereby establishing a technical baseline for full-scale systems. The results show a peak system efficiency of 94.4% for the three-phase interleaved boost topology (T1) and 93.9% for the two-phase configuration (T2). Rotor inclusion reduces the phase current ripple and does not exhibits vibrations or acoustic noise; however, it maintains similar system efficiency to T2.