Elimination of Field Winding Induced EMF in Stator Electrically-Excited Synchronous Machine Using Open-Winding Inverter

In this paper, the elimination of field winding induced EMF ripple using open-winding inverter for stator electrically-excited synchronous machines (stator-EESMs) is presented. Due to the doubly salient topology, the induced EMF ripple exists in the field winding of stator electrically-excited synchronous machines. Although the induced EMF ripple can be reduced to an acceptable level by certain methods, the average torque is inevitably reduced as well. With the open-winding inverter, the DC-biased phase current can be generated and therefore the original field winding is removed. The results show that, by using open-winding inverter, the field winding induced EMF ripple is eliminated whilst the torque performances are effectively improved.