摘要
变压器油纸绝缘的水分与老化状态将直接影响到变压器的电气性能和运行寿命。为了研究水分含量和老化对油纸绝缘频域介电特性的影响规律,从而更准确地评估变压器油纸绝缘的含水量与老化状态,在实验室内制备了不同水分含量与不同老化状态的油纸绝缘样品并测试了其复电容(C*)频域谱,提出了一种利用复电容虚部(C″)评估油纸绝缘含水量与老化状态的新方法并提取了评估纸板水分含量与老化状态的频域介电特征量,初步建立了纸板水分含量及聚合度分别与频域介电特征量的量化关系。最后,通过引入"FDS曲线频率平移"方法消除温度对老化油纸绝缘样品C*频域谱的影响。结果表明:提取的频域介电特征量对纸板含水量以及老化状态变化比较敏感;通过"FDS曲线频率平移"方法得到的C*主曲线可以消除温度对C*频域谱的影响。
The electrical properties and service life of power transformers are directly affected by the moisture and aging of oil-paper insulation. To investigate the influences of moisture and aging on frequency domain spectroscopy(FDS) for accurately evaluating the moisture content and aging state in transformers, some experimental pressboards with different moisture contents and aging states were firstly prepared, and then the complex capacitance spectroscopy(C*) was measured. After that, a new method which can assess the moisture content and aging state by using the imaginary part of complex capacitance(C″) was proposed. The frequency domain dielectric characteristics(FDDC) utilized as the evaluation of moisture content and aging state of pressboards were also extracted, and the quantitative relations between FDDC and moisture content & degree of polymerization(DP) were proposed. Finally, the temperature influence on C* was eliminated by introducing 'frequency shift of FDS'. Results show that the FDDC proposed in this paper are very sensitive to moisture content and aging state. The master curve of C* obtained by 'frequency shift of FDS' could eliminate the temperature influence on C*.
出处
《电工技术学报》
EI
CSCD
北大核心
2015年第6期247-254,共8页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(51277187)
关键词
变压器
油纸绝缘
状态评估
频域介电谱
频域特征量
Power transformer,oil-paper insulation,condition assessment,frequency domain spectroscopy(FDS),frequency domain dielectric chara
