Influence of end winding leakage in permanent magnet excited synchronous machines with asymmetrical rotor design

The authors describe the influence of the stator end winding coils on an asymmetrical rotor. Experimental investigations have shown, that the expected dynamic behaviour and torque output reduces enormously, when the motor length becomes shorter. These effects are pointed out with a rotor with interior radial buried magnets and short motor length by 3D field calculations. A current control method is applied to use the reluctancy of this rotor and to reach minimal current consumption. Due to the saturation, 3D- finite elements field calculations are compared with the 2D- finite element field calculation. Methods for torque estimation are discussed. Different rotor lengths are taken into account and a difference of rotor length to stator length is examined. To regard the effect of saturation, different current levels are calculated