A Method to Suppress Second Harmonic Order Radial Force by Teeth Flux Density Control in Multi-phase MATRIX motor

In recent years, multi-phase inverter-fed motors that realize additional advantages have been actively studied because of developments of power semiconductor switching devices. The authors also have proposed a MATRIX motor driven by H-bride inverters connected with each phase winding individually for the purpose of realizing electric motors with high functionalities. In addition, since motors are being applied to various applications that is close to people, further quietness of motor is required. In this paper, a method is proposed that 2^nd order radial direction electromagnetic force can be suppressed by teeth flux density control in the MATRIX motor. By utilizing high degree of freedom of current control owe to multi-phase drive and local flux density observation capability of the MATRIX motor, the 2^nd order radial force on each tooth and vibration are suppressed. The effectiveness of the proposed method was clarified by simulation results.