2020
Volume 20, Number 4, pp. 131-136
Noncontact iron loss measurement of motor stator core using radiation thermometer in the atmosphere
D. Wakabayashi,1 T. Nishimura,1 M. Oka2 and M. Enokizono3
1 Nippon Bunri University, 1727 Ichigi Oita-city, Oita 870-0397, Japan
2 National Institute of Technology, Oita College, 1666 Maki Oita-city, Oita 870-0152, Japan
3 Vector Magnetic Characteristic Technical Laboratory, 533 Joi Usa-city, Oita 879-0442, Japan
Electric motors are widely used in electric vehicles, drones, robots, etc., and are expected to power electric aircraft in the future. Therefore, it is important to develop a high-efficiency motor. Electrical steel sheets are generally used for the motor cores. Although it is necessary to process the steel sheets in the motor manufacturing process, the stress due to the processing affects the magnetic characteristics. For this reason, motor iron loss evaluation during manufacturing is required. In order to introduce it to the manufacturing site, it is necessary to build a low-cost system for iron loss evaluation in various manufacturing processes in the atmosphere for a short time, without contact, and with easy operation. For the above purpose, we introduced a low-cost noncontact radiation thermometer (thermography camera) and constructed a motor iron loss distribution visualization system. Using this system, it was verified whether iron loss can be accurately evaluated in the atmospheric environment, despite the low resolution of the thermographic camera. A relative evaluation of thermal iron loss can be achieved by reexamining the excitation method. Furthermore, we showed the possibility of performing an absolute evaluation by bringing the sensor closer to the object and increasing the resolution.
Keywords: electrical steel sheet, magnetic power loss, motor core, thermography camera