基于介电模量检测的油纸绝缘老化评估方法研究

老化是影响油纸绝缘设备绝缘强度的重要原因之一。在试验和理论分析的基础上,文中将一个新的参量——介电模量引入油纸绝缘老化状态评估,并针对不同老化程度油浸纸板试样开展宽频范围内介电模量谱测量;与频域介电谱相比较,介电模量对于油纸绝缘系统绝缘结构老化/劣化的微观机理的表征具有新的特征,其介电模量谱在低频范围内出现了明显的弛豫峰,并深入分析了水分含量与弛豫峰的相应关系及产生原因。为消除现场测量中现场环境温度可能引起的影响,通过试验和拟合表明温度对介电模量的影响规律符合Arrhenius方程,可通过计算予以校正。通过文中的研究结论,介电模量可以作为现场评估油纸绝缘系统老化程度的有效方法。

Evaluation Study of Aging Condition of Oil-paper Insulation Based on Dielectric Modulus Measurement

Aging has a profound influence on device's insulating condition.Based on theoretical analysis and experiment,a new kind of parameter--dielectric modulus is introduced to evaluate oil-paper system's insulating condition in this thesis.The dielectric modulus spectrum of oil-immersed paper samples are obtained under different aging degree.Compared with conventional parameter dielectric constant,dielectric modulus shows its unique features in characterizing dielectric sample's internal insulation defect,at1observable relaxation peak appears in low-frequency area of dielectric modulus spectrum.Relation between oil-paper samples'aging condition and relaxation peaks is concluded as well.Temperature's influence on the test process is also studied and the regularity is according with Arrhenius function by fitting results.Through the work in this thesis,dielectric modulus can be treated as a useful tool and a new method to analyze oil-paper insulation system's aging degree.