Leakage Inductance Characteristics of Power Transformer Winding Fault Based on ANSOFT

Abstract

The development momentum of the power industry is pushed by the increasing demands and continuous progress in allsections of the economy. The improvement of the voltage grade of transmission lines is imminent, and the capacity of a singletransformer continuously increases, thereby resulting in the serious problem of magnetic leakage, which that can aggravatethe stray loss of transformers and the degree of winding deformation. The simulation model of leakage inductance under thedifferent fault states of transformer winding was proposed on the basis of finite element method to reduce the threat to thesafe and stable operation of power grids caused by the winding insulation damage from magnetic leakage. ANSOFT softwarewas used to establish the physical model of 800kVA and 10kV true distribution transformers, and the leakage inductancevalues of transformer winding with a three-phase grounding short circuit, a turn-to-turn fault, and an inter-turn fault wereanalyzed. Finally, the accuracy of the model was verified through the finite element simulation. Results indicate that theleakage inductance of transformer increases by 30% in a three-phase short circuit, the leakage inductance is negativelycorrelated with the number of fault turns in a turn-to-turn fault, and the leakage inductance has a nonlinear positive correlationwith the number of fault turns in an inter-turn fault. The proposed method provides references for the detection and evaluationof transformer operation fault.