The insulation performance of oil paper insulation is significantly affected by moisture such that monitoring moisture content is important. However, it is difficult to obtain the moisture content accurately due to its dynamic change under multi physical fields. Studying the moisture transportation in oil paper insulation under multi physical fields becomes a vital method in solving the problem. A multi physical model describing moisture migration was proposed, which considered the effects of temperature on moisture in different existing states in oil-immersed paper (OIP). The temperature distribution formed a vapour pressure gradient to drive moisture migration and affected migration speed. Then, experiments and simulations of moisture migration were performed, which showed that the experiments were in good agreement with simulation. The results revealed that the temperature gradient caused uneven moisture distribution and the increased temperature reduced OIP moisture content. The established model could fully characterise moisture migration under temperature gradient, which provided a theoretical reference for predicting the risk of partial dampness and evaluating insulation performance.

中文翻译：

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变压器油纸绝缘中的水分传输模型：理论与实验

油纸绝缘的绝缘性能受水分影响很大，因此监测水分含量非常重要。然而，由于水分含量在多物理场下动态变化，因此很难准确获取水分含量。研究多物理场下油纸绝缘材料的水分传输成为解决这一问题的重要方法。提出了描述水分迁移的多物理模型，该模型考虑了温度对油浸纸（OIP）中不同存在状态的水分的影响。温度分布形成蒸气压梯度，驱动水分迁移并影响迁移速度。然后对水分迁移进行了实验和模拟，结果表明实验与模拟吻合良好。结果表明，温度梯度导致水分分布不均匀，温度升高降低了 OIP 水分含量。建立的模型能够充分表征温度梯度下的水分迁移，为预测局部受潮风险和评估绝缘性能提供理论参考。