Abstract The importance of the distribution network is not overlooked by anyone. The transformer is one of the key equipment in this network. Therefore, great care and attention are needed in its design, maintenance and operation. Most of the oil-immersed distribution transformers are operated under solar radiation conditions. However, increasing the oil temperature due to solar radiation is not considered in their design. This increases the oil temperature above the design temperature value and thus reduces the life of the transformer. In this paper, due to the lack of specified equations for solar energy absorption by the fins and tank of the transformer, a novel method and equation are proposed for the calculation of the transformer solar radiation absorption amount. As well as, the effect of orientation on the corrugated tank distribution transformers oil temperature is investigated using the Electro-Thermal Resistance Model (E-TRM). For this purpose, two identical transformers with different orientations are tested experimentally and the results are compared and verified with the numerical results. The transformer tank color is one of the effective factors of solar radiation absorption. Depending on the absorption and emission rates, the effect of the different colors of the transformer tank on the oil temperature in different loading is investigated in this paper. The results show that the use of bright colors in comparison with dark colors can lower the oil temperature by about 3 °C on the rated loading of the transformer. In order to consider the effect of solar radiation on the transformer, the modified ambient temperature is introduced for the design of the transformer. Finally, the effect of transformer operation under solar radiation and with different colors is investigated and transformer loading de-rating is proposed by a novel equation.

中文翻译：

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基于E-TRM方法的配电变压器安装方向和颜色效应的热行为研究及其对负载的影响

摘要 配电网的重要性是不容忽视的。变压器是该网络中的关键设备之一。因此，在其设计、维护和操作中需要非常小心和注意。大多数油浸式配电变压器是在太阳辐射条件下运行的。然而，在他们的设计中没有考虑由于太阳辐射而增加油温。这会使油温升高到设计温度值以上，从而缩短变压器的寿命。本文针对变压器翅片和槽体对太阳能的吸收缺乏具体的公式，提出了一种计算变压器太阳辐射吸收量的新方法和公式。也，使用电热电阻模型 (E-TRM) 研究了方向对波纹槽配电变压器油温的影响。为此，对两个具有不同方向的相同变压器进行了实验测试，并将结果与​​数值结果进行了比较和验证。变压器油箱颜色是吸收太阳辐射的有效因素之一。根据吸收率和排放率，本文研究了不同颜色的变压器油箱在不同负载下对油温的影响。结果表明，在变压器额定负载下，与深色相比，使用亮色可使油温降低约 3°C。为了考虑太阳辐射对变压器的影响，在变压器的设计中引入了修改后的环境温度。最后，研究了变压器在太阳辐射和不同颜色下运行的影响，并通过一个新的方程提出了变压器负载降额。