The oil-immersed transformer is a crucial piece of equipment in the power system. Operating at the specified temperature is necessary to ensure the normal operation of the transformer. The insulation paper on the winding surface has a significant impact on the actual temperature of the transformers, which is often overlooked by researchers. The one-dimensional steady-state heat conduction model of the transformer is established by analyzing the heat diffusion process of winding to transformer oil. Atomic force microscope was used to observe the microsurface structure of insulation paper and copper. According to the experiment, the heat transfer resistance in the series process of heat transfer at 70∘C is 0.0138 m² K/W. Space thermal circuit model of transformer is established by thermoelectricity analogy method, and the simulation circuit is optimized according to the boundary conditions set up in the actual environment. The results show that the error of the hot spot temperature is closer to the measured temperature and decreases by 2.5% when considering the thermal resistance of insulation paper.

中文翻译：

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绝缘纸对油浸式变压器绕组热点温度的影响

油浸式变压器是电力系统中的重要设备。在规定的温度下运行是保证变压器正常运行的必要条件。绕组表面的绝缘纸对变压器的实际温度影响很大，而这一点往往被研究人员所忽视。通过分析绕组向变压器油的热扩散过程，建立了变压器的一维稳态热传导模型。用原子力显微镜观察绝缘纸和铜的微观表面结构。根据实验，串联传热过程中的传热阻力为70∘C 为 0.0138 m ² K/W。采用热电类比法建立变压器空间热路模型，根据实际环境中设置的边界条件对仿真电路进行优化。结果表明，考虑绝缘纸的热阻，热点温度的误差更接近实测温度，降低了2.5%。