Analysis of arc channel characteristics of high voltage pulse discharge in transformer oil

Abstract

Transformers are susceptible to explosions under internal short-circuit faults, posing a significant threat to the safety and stability of power systems. Investigating the shock wave characteristics induced by pulsed arc discharges in transformer oil, which simulate real internal short-circuit fault scenarios, holds considerable theoretical and engineering significance for enhancing transformer damage resistance. In this study, a comprehensive experimental platform was developed to analyze pulsed discharges in transformer oil, which measures voltage, current, and shock wave signals, and visualize the arc channel and shock waves. To capture the complex coupling between electrical and fluid dynamic processes, a liquid–electric coupled shock wave model was constructed based on an improved arc impedance channel. This model incorporates the effects of channel radius, temperature, and time-varying conductivity. By leveraging the experimentally measured data, the model's parameters and initial conditions were iteratively calibrated to ensure computational accuracy. The arc channel properties and shock wave pressures predicted by the model were then compared with experimental results, demonstrating good agreement and validating the model's reliability. Overall, the proposed coupled model offers a critical engineering framework for improving the shock resistance and anti-explosion performance of transformer oil under fault conditions.