A Variable Magnetic Flux Motor Suitable for Vehicle Applications

摘要

Permanent magnet motors are widely used in hybrid electric vehicles (HEVs) and electric vehicles (EVs) because they have high efficiency and small volume. However, the electric current for weakening the magnetic field control has to be increased because the induced electromotive force is increased in proportion to the revolution speed. Therefore, the motor efficiency decreases at highrevolution speeds. In this study, we developed a variable magnetic flux motor (VFM), which has a control method for mechanically weakening a magnetic field to improve the motor efficiency at highrevolution speeds. Compared to a conventional motor, the variable magnetic flux motor has a wider driving region. Additionally, its high-efficiency region expands to the high-revolution speed region.