Diagnosis and identification of transformer faults from frequency response data

Identification of transformer faults using matched amplitude and phase response characteristics is presented. In frequency response analysis, fault diagnosis is done by detecting changes in frequency response tests. The vast amount of data up to 2 MHz needs to be quantified and characterized for the classification of faults. By a matched fitting with higher order transfer function up to 40, poles, zeros and their relative damping were determined in the frequency plane. Each set of data corresponding to faults is used to train a backpropagation ANN network. Out of 12 faults, the processing technique is able to identify the changes and classify the type of fault for on-line analysis. The location of fault and the severity of faults in the form of more sensitivity are brought out using this signal processing technique.