温度及老化程度对变压器绝缘纸板复弹性模量的影响

The complex elastic modulus of pressboard in power transformer is closely related to the temperature and degradation, the research on it can make great contribution to get the dynamic characteristics of power transformer windings and the method to detect the winding mechanical condition based on vibration signal. Based on the viscoelastic theory of materials, this paper makes an accelerated aging experiment on pressboard, and then the characteristics of storage modulus and mechanical loss angle of degraded pressboard under different temperature are studied through dynamic mechanical analyzer. Besides that,the relationship between complex elastic modulus, temperature and degradation are analyzed combining with the test on degree of polymerization(DP)of pressboard. The results show that the complex elastic modulus of pressboard decreases with the increase of degradation and temperature, the tangent of mechanical loss angle is below 0.055 and remains unchanged under the influence of temperature and degradation. The influence coefficient of complex elastic modulus decreases with the increase of degradation degree. The results of this paper have great guiding significance for evaluating degradation and mechanical condition of power transformer based on vibration signals.