A New Five-Phase Brushless Permanent Magnet Motor for Vehicle Application 2002-01-1877

In this paper, a new five-phase brushless permanent magnet motor is proposed. The proposed motor has concentrated windings such that the produced back-emf is trapezoidal. The motor is supplied with sinusoidal or combined sinusoidal and third harmonic currents. For presenting the superior performance of the proposed five-phase motor, its three-phase counterpart is also analyzed. By changing the number of turns and slot width, the amount of copper and iron are kept constant in the two motors such that the copper and core losses are almost the same. Non-linear finite element method is used for studying the tooth flux density and calculating the developed static torque. Also, the developed torque is obtained using mathematical model in dq frame. In all the cases, the back-emf and supplied current are maintained in phase, so that the maximum torque is obtained. Average torque, torque ripple and tooth flux density of all cases are compared. It is shown that lower torque ripple and higher average torque can be achieved by proper combinations of slots/pole ratio of the machine