Short-circuit fault detection in power transformer using frequency response analysis bipolar signature of inductive inter-winding measurement

Abstract

The short circuit fault detection practices of power-transformer winding are important to ensure its unfailing and proper operation. In this regard, Frequency response analysis (FRA) is a favourable tool that can be used to detect a such fault. The FRA method has four measurement configurations called: end-to-end, open circuit test, short circuit test, and inductive inter-winding test, capacitive inter-winding test. However, a method of detecting the short circuit fault using FRA end-to-end measurement is investigated. This paper aims on investigating the inductive inter-winding of short circuit faults by showing a bipolar signature. The FRA inductive inter-winding measurement has been obtained from 11/0.415 kV, 500kVA distribution transformer to interpret the characteristics of resonances indicating a bipolar signature. There is a different level of short circuit fault artificially applied to the transformer winding. The inductive inter-winding measurements show that the resonances showing the bipolar signature at the mid-frequency range can be employed to determine the short circuit fault in the transformer winding. Based on this finding, a process of identifying the short circuit fault of a transformer winding is proposed. The data of short circuit fault and normal data of FRA measurement are compared. The proposed method can add to improving the purpose of using the FRA method to detect short-circuit faults in power transformers.