Detection of induction machines anomalies using stand-still tests

The main topic of this paper is to examine the feasibility of detecting the rotor defaults of induction motors by performing stand-still tests. We show that feeding the machine with special excitation signals (discrete interval binary sequence (DIBS) and multisine), it is possible to excite with low frequency resolution the faulty modes by analyzing the current spectrum and the dispersion flux captured by a flux sensor. The method presented is general and may be applied to the induction machine whilst in rotation or at standstill. It is based on broadband excitation signals which are able to excite the faulty modes of devices under tests. Experimental measurements are made both on healthy and faulty machines and the comparison gives a difference in the flux and current machine signatures which is basically the most commonly used method of fault detection.