Electrical Motor Applied by Low Iron Loss Magnetic Material

Abstract

To reduce core loss of an electrical motor, I select lower iron loss magnetic material than conventional electrical steel as NO (Non-Oriented) steel, and GO (Grain-Oriented) steel, amorphous steel and nanocrystal material. They are applied to the electrical motor of IPM-SM (interior permanent magnet synchronous motor) and manufactured as GO motor, amorphous motor, and nanocrystal motor. In GO motor, due to the strong magnetic anisotropy, GO steel is divided into some pieces, and they are arranged so as that the main magnetic flux follows the easy magnetization direction of GO steel. The motor core loss is measured in the drag force test where stator core is excited by the permanent magnet of the rotor. The core loss reduces in order of NO motor, GO motor, amorphous motor, and nanocrystal motor. The measured core loss is in good agreement with the calculated core loss of finite element method. Since the core loss includes the stator loss as well as rotor loss and permanent magnet loss of sintered NdFeB, the calculation data show that the stator loss of the nanocrystal motor is about one-twentieth smaller than the one of NO motor.