Field Oriented Control of Permanent Magnet Brushless Hub Motor in Four-Wheel Drive Electric Vehicle

The back electromotive force (EMF) waveform of permanent magnet (PM) brushless hub motor is usually nearly sinusoidal, which is suitable for sinusoidal current control. The field oriented control based on hall-effect sensors is applied to minimize the torque ripple in this paper. The estimated rotor position through the interpolation method is calculated by the signals of the hall-effect sensors. A feed forward controller is developed to eliminate the instantaneous great torque change of the motor to reduce the torque ripple. The results show that the field oriented control with feed forward control eliminates the vehicle irregularity.