Tokyo-based Mitsubishi Electric Corp has developed a prototype electric vehicle (EV) motor drive system with a built-in silicon-carbide (SiC) inverter.
Reckoned to be the smallest of its kind, the EV motor drive system is intended to enable manufacturers to develop EVs offering more passenger space and greater energy efficiency.
Global demand for EVs and hybrid EVs (HEVs) has been growing in recent years, reflecting increasingly strict regulations for fuel efficiency and growing public interest in saving energy resources and reducing carbon dioxide emissions, notes Mitsubishi Electric. As EVs and HEVs require relatively large spaces to accommodate their robust battery systems, there is a strong need to reduce the size and weight of motor systems and other equipment to ensure sufficient passenger space, the firm adds.
Mitsubishi Electric says that, with an integrated all-SiC inverter, its new prototype EV motor drive system has been downsized further (to 14.1L, for 60kW) due to having a smaller motor, resulting from improved thermal resistance between the motor drive system and cooling system. The system is equal to existing EV motors in power and volume, enabling replacement.
Mitsubishi Electric also highlights improved motor cooling performance, since the cooling system for both the motor and inverter are integrated due to the cylindrical shape of the power module accommodating parallel cooling ducts for motor and inverter. This ensures stable cooling with even a low-power pump.
Mitsubishi Electric plans to commercialize its new EV motor system after finalizing technologies for motor/inverter cooling, as well as downsizing the dimensions further and increasing efficiency.
