An Online Diagnosis Method for EMU Traction Transformer Winding Faults based on Short-Circuit Impedance Identification

To enhance the safety and reliability of traction transformers in high-speed train operations, this paper presents a novel online monitoring and diagnostic method for detecting the inter-turn short fault in traction transformers based on short-circuit impedance identification. The equation formed by ∑i (the sum of input and output currents) and ∆u (the difference between input and output voltages) in a traction transformer has been mathematically proven to be an ellipse using trigonometric formulas. And the effectiveness of the proposed online monitoring and diagnostic method for the inter-turn short fault (ITSC) is validated using a finite element joint simulation model. The variation characteristics of the short-circuit impedance under fault conditions are analyzed. The simulation results demonstrate that the proposed fault diagnostic method is capable of effectively and sensitively detecting the inter-turn short fault in traction transformers.