Simulation of temperature rise in low voltage winding of natural oil circulation transformer and analysis of oil flow heat dissipation

Abstract

Abstract The heat dissipation performance of an oil-immersed transformer is the key to its stable operation. Winding loss is a crucial part of transformer heat loss, and winding heat dissipation greatly influences the rise in transformer temperature. In this paper, depending on the finite element method, the magnetic field distribution of a 66 MVA (225/26.4 kV) natural oil circulation transformer is analyzed, and the DC and eddy current losses of the low voltage winding are calculated. Based on the finite volume method, the temperature field distribution of the low-voltage winding is calculated, and the heat flux distribution of the contact surface between the disc insulation paper and the oil flow is obtained. It is found that there are transition points and extreme points between the upper and lower surface of the disc and the inner and outer surface of the disc, and the heat flux on the upper and lower surface of the disc conductor has obvious alternating oscillation. This study provides direction for further analysis and understanding of the heat dissipation mechanism and structural design of natural oil circulation transformers.