Comparison of different winding schemes reference to their application on speed sensorless control of induction machines

Control of induction machines without mechanical sensors has gained more and more interest in the past years. Different methods for sensorless control have been proposed in literature recently. To guarantee a stable operation in the whole fundamental frequency range including zero fundamental stator frequency, it is not enough to consider only the fundamental wave behaviour of the machine. All these methods have also to take into account side effects which are denoted as parasitic effects in normal operation of the machine but which are of high importance on the performance of control if the mechanical sensor is omitted. Their influence on the transient electrical behaviour of the machine is usually utilised by the mentioned schemes. To apply a sensorless control method on an induction motor drive it is thus necessary to know the coherence of machine design parameters and the signals obtained by the method. In this paper the influence of different types of stator winding schemes on the transient electrical behaviour of the machines is investigated reference to the use in sensorless control. The measurements were made on induction machines with different types of stator windings by applying the INFORM method. In addition, results gained by measuring the transient behaviour with measurement coils at different spots in the machine give a further insight into the mentioned coherence.