Investigation on Dynamic Sensing and Real‐Time Evaluation Method for Short‐Circuit Strength of Power Transformer Windings

ABSTRACT

The short‑circuit withstand capability of transformer windings is critical to the safe and stable operation of modern power systems. Conventional static calculation approaches commonly suffer from insufficient assessment accuracy, whereas traditional full destructive short‐circuit tests involve substantial economic costs and irreversible equipment damage in practical engineering. To address these technical limitations, this paper proposes a Dynamic Sensing and Real‐time Evaluation (DSRE) method for quantitative assessment of winding short‐circuit strength. Through dynamic monitoring of the evolution of short‐circuit impedance and vibration signal under successive short‐circuit tests, a real‐time quantitative evaluation framework that accounts for cumulative plastic damage is constructed. The typical impedance deterioration observed under low‑magnitude short‑circuit current reflects the technical advantages of the dynamic DSRE strategy over conventional static analysis. Combined with finite‑element calculations of internal electromagnetic force distributions, the proposed method enables reliable identification and early warning of the critical instability state of transformer windings. Systematic tests on a 110 kV three‐phase three‐winding transformer demonstrate that the integration of the sensing module and software evaluation platform improves the accuracy of short‐circuit strength verification and the reliability of winding condition assessment. This work provides a potential approach for the real‐time assessment of 110 kV transformer winding short‐circuit withstand capacity.