Fault Diagnostic in the Transformer Winding by Sweep Frequency Response Analysis

Abstract

High voltage transformer, an expensive element of transmission and distribution networks, works under different mechanical, electrical and environmental conditions. As its performance in the network directly affects the reliability of the network, temporary/permanent outage results in interruption of power to the customers along with a loss of revenue. In order to avoid the said problem, this paper presents Sweep Frequency Response Analysis (SFRA) based technique that detects turn to turn shorts in the winding of the high voltage transformer. Unlike graphical analysis based conventional technique which needs expertise and experience of different people for fault diagnostic, the proposed technique is capable to detect and locate fault using statistical parameters that do not require expert advice. The simulation results as well as results obtained from the laboratory prototype of the transformer clearly indicate the effectiveness of the suggested technique in detecting and locating series and parallel faults in the winding of the high voltage transformer.