Investigation of the Influence of Transformer Oil Duct Size on Winding Temperature Distribution Using a Thermal Hydraulic Network Model

• Main Authors: Gao, Meng, Tang, Zhenfu, Wang, Yuan, Shi, Chaoqun, Ning, Yichen, Fu, Mingli, Zhuo, Ran, Zhang, Xiaojing
• Format: Conference Proceeding
• Language: English
• Subjects: Accuracy; Ducts; hotspot temperature; Hydraulic systems; Oils; power transformer; Temperature distribution; Thermal engineering; thermal hydraulic network model; Windings
• ISSN: 2474-3852
• DOI: 10.1109/ICHVE61955.2024.10676166

In this study, based on the temperature calculation and heat-run test results of a 40 / 53 / 66- MVA, 225/26.4-kV transformer modeled according to the CIGRE technical brochure 659, different convergence conditions of hydraulic and thermal networks were set up to study their effects on the accuracy of the THNM calculation results. Based on this model structure, the sizes of vertical and horizontal oil ducts were changed and THNM was used to calculate the temperature distribution and hotspot temperature location of the windings and analyze the influence of the oil duct structure on the temperature distribution of the windings. Reducing the horizontal oil duct size significantly lowers the winding temperature by 10{ }^{\circ} \mathrm{C} for 1 mm reduction, and increasing the vertical oil duct size on the inlet side can also lower the temperature but not obvious. However, reducing the duct size must satisfy the electrical insulation requirements. This study approximately proved the feasibility of THNM in rapidly calculating the transformer winding temperature, and the relationship between the oil duct structure and the temperature distribution provides a reference for transformer design.