Stator winding turn fault detection for induction machines

Stator winding failures are a serious problem of induction machines. In the case of bearing failures or rotor faults, fault-specific signatures increase slowly. An induction machine with such failures still can be operated for a certain time without taking strict precautions. Stator faults may occur much faster due to insulation breakdown or overload and are therefore more critical with respect to time. This paper presents measurement results of an accidentally arising stator winding fault, which was recorded during the investigation of stator asymmetries. Furthermore, an on-line fault detection technique as well as some measurement data applied to this technique, are presented. The used technique is based on extracting a so called injected negative sequence current.