Yoshitake Kamijo, Toshiba Corporation
Recent traction motors are operated with the traction inverter to ensure the high efficient drive and variable drive speed. In such the application, electromagnetic harmonics noise by the carrier frequency from traction inverters occur the sound noise which are radiated from the motor surface. In the conventional method to reduce the noise by the carrier frequency, sometimes the career frequency distribution has been used to reduce the electromagnetic noise. Since the relationship between structural characteristics and electromagnetic noise are not clear, the noise reduction is limited by the career frequency distribution. To make it clear the relationship between the mechanical motor characteristics and career frequency characteristics, this presentation reports the results and consideration based on the investigation for the relationship between the electromagnetic-force modes in career frequency and the natural vibration modes.