CAJ | 학술논문

为探讨初始水分含量对变压器油纸绝缘老化过程的影响机制,设计了绝缘纸初始水分质量分数分别为1%、3%、5%的矿物油-纸绝缘试品在90°C下的加速热老化试验,定期取样测量了绝缘纸聚合度、油纸绝缘水分质量分数、油中糠醛质量浓度、油中酸值等特征参量。然后,在分子模拟软件内建立了不同含水量的矿物油分子、糠醛分子、水合氢离子模型,通过分子动力学模拟技术计算了糠醛分子及水合氢离子与不同水分含量油分子模型之间的扩散系数、相互作用能、径向分布函数。实验结果表明：绝缘纸和矿物油中水分含量在老化过程中均是波动的,油中糠醛和酸值在老化过程中的变化趋势未与绝缘纸聚合度的下降规律相对应,受系统水分含量的影响较大。分子模拟结果表明：水分的增加显著降低了糠醛及小分子酸的扩散能力,并与糠醛及小分子酸形成稳定的氢键;同时,水分与糠醛及小分子酸的极性作用改变了彼此的相互作用能。实验数据与分子模拟结果相互验证,为深入研究油纸绝缘的老化机理及诊断提供了理论参考。
위탐토초시수분함량대변압기유지절연노화과정적영향궤제,설계료절연지초시수분질량분수분별위1%、3%、5%적광물유-지절연시품재90°C하적가속열노화시험,정기취양측량료절연지취합도、유지절연수분질량분수、유중강철질량농도、유중산치등특정삼량。연후,재분자모의연건내건립료불동함수량적광물유분자、강철분자、수합경리자모형,통과분자동역학모의기술계산료강철분자급수합경리자여불동수분함량유분자모형지간적확산계수、상호작용능、경향분포함수。실험결과표명：절연지화광물유중수분함량재노화과정중균시파동적,유중강철화산치재노화과정중적변화추세미여절연지취합도적하강규률상대응,수계통수분함량적영향교대。분자모의결과표명：수분적증가현저강저료강철급소분자산적확산능력,병여강철급소분자산형성은정적경건;동시,수분여강철급소분자산적겁성작용개변료피차적상호작용능。실험수거여분자모의결과상호험증,위심입연구유지절연적노화궤리급진단제공료이론삼고。
The mineral oil-paper samples with different initial moisture contents （ 1 %, 3 %, and 5 % ） were thermally aged under 90%C in order to study the influence of the mechanism of initial moisture on thermal degradation process of oil-paper insulation. All the samples were periodically sampled and the degree of polymerization （DP） of insulation paper, the moisture content of oil-paper samples, furfural, acid in oil, and so on were measured during the aging process. Moreover, by using a material simulation software, oil molecule with different moisture contents, furfural molecules and hydroniumions were modeled, respectively. Then, diffusion coefficients, interaction energies, and radial distribution function among furfural molecule, hydroniumion and oil molecules with different moisture contents were calculated based on dynamic molecular simulation technology. The obtained results show that moisture in both oil and paper is fluetuant during the aging process. Additionally, furfural and acid in oil, which do not correspond with the decrease of DP, are markedly influenced by the moisture of oil-paper system. Molecular simulation results reveal that the increased moisture can not only reduce the diffusion capability of furfural and hydroniumions, but also result in more stable hydrogen bonds between moisture and furfural ＆ hydroniumion. Meanwhile, the interaction energies between moisture and furfural ＆ hydroniumion have been changed due to the mutual polar effect of moisture and furfural % hydroniumion. The experimental results and molecular simulation results agree with each other, and the relevant results can provide theoretical reference for in-depth study on the aging mechanism and diagnosis of oil-paper insulation.