Fault Diagnosis of Induction Machines in Transient Regime Using Current Sensors with an Optimized Slepian Window

The aim of this paper is to introduce a new methodology for the fault diagnosis of induction 15 machines working in transient regime, when time-frequency analysis tools are used. The proposed 16 method relies on the use of the optimized Slepian window for performing the short time Fourier 17 transform (STFT) of the stator current signal. It is shown that for a given sequence length of finite 18 duration the Slepian window has the maximum concentration of energy, greater than can be reached 19 with a gated Gaussian window, which is usually used as analysis window. In this paper the use 20 and optimization of the Slepian window for fault diagnosis of induction machines is theoretically 21 introduced and experimentally validated through the test of a 3.15 MW induction motor with broken 22 bars during the start-up transient. The theoretical analysis and the experimental results show that the 23 use of the Slepian window can highlight the fault components in the current’s spectrogram with a 24 significant reduction of the required computational resources. 25