Short-Time Failure Mode Considerations Associated With Power Transformer Overloading

Recent Trends in the Condition Monitoring of Transformers

“…The shape of recovery voltage measured for an aged transformer is shown in Fig. 1.16 [39]. It has been reported that the initial slope of the recovery voltage is determined by dc conductivity [40].…”

“…Cross-wavelet transform may be considered as an extension of wavelet-based analysis [39,40]. The mathematical operation for cross-wavelet transform is similar to the computation of CWT.…”

“…The mathematical operation for cross-wavelet transform is similar to the computation of CWT, as stated earlier. Mathematically, the cross-wavelet transform of two signals, x(t) and y(t) is defined as [31,[39][40][41][42][43]:…”

“…Cross-wavelet transform has already been applied successfully in geosciences [40,41] and biomedical signal processing [39]. Very recently it has also been proposed for transient analysis [31,42,44].…”

Risk assessment for transformer loading

“…Gassing produces a potential risk to the dielectric strength of the transformer. The test results in [24] indicate that there is a gradually increasing probability of dielectric failure whenever normal operating temperatures are exceeded, and the probability of failure is significantly increased at temperatures above 150 C.…”