A New Improved Methodology to Identify an Interturn Fault Location in Transformer Winding Based on Fault Location Factor

The identification of interturn faults in power transformers at an early stage is crucial to prevent extensive damage to the windings. To address the said issue, an interturn fault localization approach based on the fault location factor (FLF) is introduced in this article. The value of FLF during the prefault condition for all possible fault locations is stored as FLFcal in a lookup table. During the fault event in a transformer, the value of FLF (FLFmeas) is computed using the measured winding impedance at a reference frequency. By comparing the values of FLFmeas and FLFcal, the precise fault location in the transformer is determined. The effectiveness of this approach is assessed through a comprehensive simulation study to ensure its reliability. In addition, two different laboratory-developed winding models of the transformer, each with distinct winding configurations, and 3-phase field transformer of 400 kVA are utilized to validate the proposed approach. Finally, a comparative analysis is conducted between the proposed approach and several existing methods, highlighting its dominance in localizing interturn faults.