Integrated On-Board Battery Charger for Electric Aircraft Based on Multiphase SPM Synchronous Machine

The transition to electric aircraft has gained worldwide attention as initiatives and legislations are presented in support of zero-emission aviation industry. Due to the high-power and high reliability requirements for electric aircraft propulsion, multiphase electric machines become attractive in such applications, which enables the possibility of having integrated on-board battery charger (IOBC). IOBCs fully leverage the existing powertrain propulsion elements, i.e., the multiphase machine and power inverter, into the charging process, requiring no additional hardware for fast charging. Moreover, zero average torque production and unity power factor operation at the grid side can be simultaneously achieved. Thus, this paper proposes an IOBC concept for electric aircraft, utilizing a multiphase surface-mounted permanent magnet (SPM) synchronous machine. First, an asymmetrical six-phase 36-slot/34-pole SPM machine design is presented based on the magnetic equivalent circuit (MEC) model. Thereafter, the machine is optimized using a multi-objective genetic algorithm (MOGA) optimization approach. Finally, finite element (FE) simulations have been carried out to verify the theoretical findings.