高性能永久磁石モータの技術動向と応用

Abstract

Permanent magnet motor technology keeps improving because of the progress of the permanent magnet, the semiconductor device and the motor control technology. This article describes the technology trend of high performance permanent magnet motors and their applications. Remarkably compact, light-weight and high performance permanent magnet motors were obtained by using a Nd-Fe-B permanent magnet. The performance of permanent magnet motor is correlated closely with the property of permanent magnet. The high density winding technique and the cooling method of molding with a heat-conductive resin are effective for down-sizing of motor. However, the high energy permanent magnet increases the cogging torque of motor. A magnetic field analysis is effective in reducing the cogging torque. The ultra-small-sized motors and the large torque motors are the recent topics. Permanent magnet motors are widely used instead of induction motors or hydraulically-operated system. The inverter driven permanent magnet motors have enable industry facilities to realize higher performance and energy saving. The compact and flat-shaped permanent magnet motor removed a machine room from the elevators. The electric injection molding machines have brought about improving an energy conservation and a working environment. The industrial robots have flexible solutions for industrial automation, for practically all manufacturing and material handling requirement. The improvement of the property, the quality and the reliability of the permanent magnet is expected for the permanent magnet motor.