2025 Volume 41 Pages 80-84
While we work to develop environmentally conscious products, we must also work to improve product value that is unique to Mazda to create products chosen by customers. One of the most important values is quietness. By reducing motor noise, an EV-specific unpleasant noise, we aim to create a high-quality interior space in which occupants can enjoy music and conversation. Under such circumstances, we have been working on developing the technology to predict motor noise to improve development efficiency. However, to predict the electromagnetic force that is the excitation source of motor noise, it is necessary to reproduce not only the fundamental wave of the three-phase AC input to the motor, but also the harmonic components. Therefore, by taking into account the inductance of the motor coil, which changes from moment to moment due to interaction with the motor back electromagnetic force and constructing a coupled model in which the current and magnetic flux mutually affect each other, it is possible to predict currents that include harmonic components, thereby improving the accuracy of motor noise predictions. This report explains the efforts on our achievement.
