Selection of stator yoke height of traction switched reluctance motor

Results of computational investigation of influence of the stator yoke height on traction characteristics of 250 kW SRM-250-850 switched reluctance motor at nominal speed of 850 min−1 are presented. The computational studies used a mathematical model of electromagnetic processes in the SRM-250-850, taking into account saturation of steel and unevenness of the magnetic field distribution in the tooth area of the motor. The adequacy of the model is proved by comparison with the results obtained using the Finite Element Method. It is shown that saturation of the stator yoke decreases magnetizing force applied to the teeth area and leads to occurrence of the mutual induction magnetic flux. That, in turn, causes weakening of tracking torque and creates braking torque, and thus, decreases the electromagnetic starting torque and acceleration of the vehicle. Recommendations on choice of stator yoke height for power inductor motor, taking into account its structural performance in the housing or without housing are developed.