T. Wolbank, K.A Loparo, R. Wöhrnschimmel:
"Modeling and on-line detect.of stator winding faults in inverter fed induct. motors utilizing inverter statistics";
Talk: IEEE International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives SD, Oviedo, Spanien; 09-01-1999 - 09-03-1999; in: "Proceedings of the IEEE Int.Symp.on Dignostics for Electrical Machines,Power Electronics and Drives", Vol.1 (1999), 113 - 118.

A simulation model is presented to analyse the influence of asymmetrical stator windings in induction machines fed by an inverter. Based on this model the influence of a stator winding breakdown caused by an interturn isolation failure on the behaviour of the machine as well as on the inverter control is investigated. A new on-line method to detect such asymmetries in stator windings is presented and investigated reference to its range of operation. This method utilises the influence of stator asymmetries on the inverter current control scheme. By evaluating the statistical distribution of the different inverter switching states asymmetries in the stator can be detected and located. The measurement inputs needed to implement this method are already available in modern inverter fed drives thus no additional sensors are necessary. The fault detection algorithm is very simple and therefore easy to implement on a microprocessor. Practical measurements made on a test stand verify the applicability of the proposed on-line method to detect stator faults