The friction between rotor and stator of a rotating machine is the common fault, as well as a huge problem to be studied and solved. Acoustic emission (AE) technology provides a new solution to friction detection. However, due to that AE signals cause waveform distortion during transmission in complex structure of a rotating machine, and they are interfered by strong noises of operating environ...

In this paper the faults diagnosis of induction machines based on the discrete wavelet transform (DWT) is detailed. The wavelet decomposition is used to extract the information from a signal over a wide range of frequencies. This analysis is performed in both time and frequency domains. The Daubechies wavelet is selected for the analysis of the stator current. Wavelet components appear to be us...

The out-of-step operation conditions of a synchronous machine may occur as a result of a power system three-phase fault. The mostly used methods of identification of loss of synchronism are not secure enough. In the paper a new method using highresolution spectrum estimation method is presented. In the case of asynchronous operation of a synchronous machine the current waveform in the stator wi...

Results of a comparative experimental investigation of various media for noninvasive diagnosis of rotor faults in induction motors are presented. Stator voltages and currents in an induction motor were measured, recorded, and employed for computation of the partial and total input powers and of the estimated torque. Waveforms of the current, partial powers and , total power, and estimated torqu...