Analysis of temperature characteristics of power transformer withstand short circuit shock for two seconds

Abstract

The occurrence of a short-circuit fault in a transformer results in a rapid increase in the short-circuit current, and the temperature of the transformer winding rises rapidly. At present, many scholars use analytical formulas to solve for the average temperature of transformer short-circuit for two seconds, but the transient change of the temperature of transformer short-circuit for two seconds is less considered. In order to counter this phenomenon, this paper establishes a two-dimensional planar power transformer model, simulates its fluid-temperature coupling field, and obtains its temperature distribution results. In this thesis, the steady-state fluid-temperature field of 40000 kVA/110 kV oil-immersed power transformers under rated working condition is analyzed. Secondly, on the basis of static analysis, the temperature characteristics after two seconds of short circuit is analyzed numerically. Finally, by comparing the simulated value with the formula calculation value, the calculation results were verified.

Keywords

• Oil-immersed transformer
• Numerical analysis
• Temperature characteristics
• Fluid-temperature field