Study on the Detection of Transformer Oil Temperature

Kehui Zhou,Yuanliang Huang,Tengyu Sun,Hongqi Li

doi:10.1051/matecconf/20167501005

Abstract

Based on the influence of the ambient temperature, wind speed and other factors on the transformer monitoring system, the hot spot temperature model of the transformer outer wall is established by using thermoelectric analogy theory and lumped parameter model. Through the analysis of experimental data, mathematical model of influence of ambient temperature and wind speed on temperature of transformer is built, and the correction values on the temperature of the transformer are obtained under the different ambient temperature and wind speed. The correction values make the transformer hot-spot temperature more objective and more authentic, which has significant influence on the running of the transformer safely and efficiently.

Highlights

As the demand for electrical energy increasing, the security of corresponding devices has a higher demand
When the power system is developing to EHV, power grid, high-capacity and automated direction, the reliability of the transformer to the safe operation of power system is increasing [1]
Because the internal structure of the transformer is complex and the transformer hot spots are usually in the position of the high potential, it is difficult for the transformer to monitor constantly by sensor and we need to use temperature calculation method to estimate the temperature distribution within the transformer and forecast the maximum temperature

Summary

Introduction

As the demand for electrical energy increasing, the security of corresponding devices has a higher demand. In this paper, with the ambient temperature and wind speed as the input variable, the hot spot temperature model was established based on the transformer wall temperature. The winding and the core dissipate the heat to the transformer oil, causing the temperature of the transformer oil rise, and the transformer oil dissipate the heat to the air by cooling device. National standard GB1094.2-1996 stipulates that the transformer oil tank and structural surface temperature rising limit is 80K. In the literature [2] model, the transformer hot spot temperature model is modeling to the heat transfer process within the transformer wall, without considering the influence of the air and the transformer oil tank wall (outer) surface heat transfer resistance. To further study the correlation of the inner wall surface temperature and ambient temperature and wind speed, the paper carried out the following experiment.

C C T T Fe

Improved transformer hot spot temperature model

Summary