The Influence of Inverter Feeding on the Apparent Stray Inductance of Asynchronous Machines

The stray inductance is an important parameter for the design of inverters feeding asynchronous machines. Measurements are proposed which are relevant for determining the apparent stray inductance of an inverter-fed asynchronous machine. These measurements show that the apparent stray inductance is considerably smaller than the one obtained with classical sinusoidal methods. This amounts to smaller commutating capacitors in current source inverter (CSI) motor drives. A theoretical explanation for this phenomenon is presented and confirmed by calculation.