变压器露点温度的多参数耦合模型与试验研究

A Multi-Parameter Coupling Model for Transformer Dew Point Temperature and Its Experimental Validation

摘要: 为精准揭示油浸式变压器油箱内部露点温度的变化规律，解决真空干燥工序中的绝缘受潮控制难题，本文基于饱和水汽压理论、湿空气物理特性及真空环境气体分压定律，通过理论推导与多参数耦合拟合，建立了露点温度与温度、相对湿度、油箱绝对真空度的统一显式计算模型。搭建110 kV变压器油箱真空试验系统，完成10组典型工况试验与3组交叉验证。结果表明：模型计算值与实测值的平均绝对误差为0.44℃，决定系数R² = 0.998，显示出良好的计算精度与工程可靠性。与已有定性认识不同，本文实现了三项因素对露点影响程度的定量分离与比较。该模型形式简洁、计算高效，可为变压器真空干燥工艺优化及绝缘状态监测提供理论依据与实用工具。

Abstract: To accurately characterize the variation of dew point temperature inside oil-immersed transformer tanks and address the challenge of insulation moisture control during the vacuum drying process, this paper establishes a unified explicit calculation model correlating dew point temperature with temperature, relative humidity, and absolute vacuum pressure. The model is derived based on saturated water vapor pressure theory, physical properties of moist air, and the law of partial pressures in vacuum environments, combined with multi-parameter nonlinear fitting. A 110 kV transformer tank vacuum test system was built, and 10 sets of typical operating conditions along with 3 sets of cross-validation tests were conducted. Results show that the average absolute error between the calculated and measured dew point values is 0.44˚C, with a coefficient of determination (R²) of 0.998, demonstrating good calculation accuracy and engineering reliability. Unlike existing qualitative understandings, this study achieves, for the first time, a quantitative separation and comparison of the effects of temperature, humidity, and vacuum pressure on dew point. The proposed model is concise in form and computationally efficient, providing a theoretical basis and a practical tool for optimizing transformer vacuum drying processes and monitoring insulation conditions.