Frequency Response Analysis (FRA) is popular technique which has been used since the last decade as a diagnostic method for transformers. However, accurate interpretation of FRA measurements is still challenging. Recent studies reveal that apart from winding deformation, FRA data can also be influenced by moisture variation in transformer paper insulation. Hence, a specific transformer’s model ...

Synchronous generator (SG) plays a vital and critical role in the power system by supplying electric to consumers. Various faults SGs can cause some catastrophic events such as disruption or blackout. These be classified into two electrical mechanical faults. Short circuit stator windings field winding are fault while bearing, static/dynamic eccentricity, broken damper bars one. Unlike inductio...

In this paper, a fault diagnosis method is developed for a particular class of nonlinear systems described by a polytopic Linear Parameter Varying (LPV) formulation. The main contribution consists in the synthesis of an accurate Fault Detection and Isolation (FDI) filter and also a sensor fault magnitude estimation with a quality factor. This quality factor of the filter underlines if the fault...

When insulation fault occurs in the ignition coil partial secondary winding discharges. Random pulses with various amplitudes appear in primary current and secondary voltage waveforms simultaneously. Moreover the secondary voltage may distort if the fault is serious. Traditional methods are difficult to identify the discharge pulses. This paper examines a measure to overcome the shortages of tr...

This paper presents an intelligent fault detection based on adaptive continuous wavelet transform of broken rotor bars for Induction Motor (IM). Broken rotor bars, bearing decay, eccentricity, as motor faults appears as different frequencies in the stator current signals. The stator current and speed signals at deferent operation conditions obtained from the winding function are analysed throug...

Abstract Considering the nonlinear and non-stationary characteristics of transformer vibration acceleration signal obtained from surface tank, variational mode decomposition (VMD) theory is introduced. Simulation analysis shows that VMD has obvious advantages over EMD when needle frequency similar to signal. It effectively avoids two types modal aliasing over-decomposition, accurately reflects ...

A running transformer frequently experiences interturn faults; they are typically difficult to detect in their early stages but eventually progress short circuits, which cause damage the transformer. Therefore, finding out fault mechanism of full process can provide a theoretical basis for detection. In this paper, an electromagnetic-solid mechanics coupled finite element model consistent with ...