Calculation and Analysis of Temperature Field Characteristics of Power Transformers in Oil During Short Circuit Processes

The current increases rapidly under the condition of short-circuit, leading to a rise in the winding temperature. Currently, the standard formulas in IEC 60076–5 are commonly used to calculate the temperature rise, but there is limited analysis of the temperature variation process and local hotspots during the short circuit fault. To address this issue, this paper performs a fluid and temperature dependent field simulation of the transformer through simulation software FLUENT. First, a static temperature dependent field simulation is conducted under rated conditions. Then, in the static simulation, the temperature and oil flow distribution characteristics during the 2-s short circuit process are simulated. Finally, the simulation results are compared with the results obtained from national standard calculations to validate the accuracy of the simulation method. And mechanical performance tests on copper conductors at different temperatures is conducted.