Application of a new method in detecting a mechanical failure associated with series capacitance change in a power transformer winding

The Frequency Response Analysis (FRA) based method is expected as an efficient one in diagnosis of mechanical failures in windings of power transformers, especially in cases other testing methods cannot provide any indication for the diagnostic. However, the current FRA assessment which is based on the relevant Chinese standard and other draft international standards is not sensitive enough in detecting such failures in all cases.