2020 年 28 巻 4 号 p. 306-312
In order to develop a high-efficiency, low-loss, small, high-power, high-speed rotating motor, it is necessary to accurately measure the magnetic properties of electrical steel sheets under PWM excitation. A shunt resistor is generally used for measuring magnetic characteristics, but non-contact current measurement is required. However, iron cores are used in commercially available current measurement sensors, and it is necessary to consider the effects of core characteristics on high-frequency currents. The authors are focusing on Rogowski coils and developing small current / magnetic field sensors specialized for motor and electrical steel sheet evaluation. In this paper, we make a prototype of Rogowski coil, and report on the evaluation of basic electrical characteristics and the results of application to the measurement of magnetic characteristics of electrical steel sheets under sinusoidal excitation and PWM excitation.
