大温差极低温环境下瓷悬式绝缘子机电性能试验分析

Test and Analysis of Porcelain Suspension Insulators with Large Temperature Difference in Extremely Low Temperature Environment

通过开展常规温差(-35~40℃)、大温差极低温(-55~40℃)环境运行后瓷悬式绝缘子残余机电强度试验,以及模拟常规温差、大温差极低温冻融循环条件下水泥胶合剂体积变化率试验,研究了大温差极低温冻融循环对瓷绝缘子运行性能的影响。试验结果表明,大温差极低温环境较常规温差环境下运行更易造成瓷绝缘子瓷件缺陷;水泥胶合剂经极低温作用后孔隙率增大、体积膨胀率变大,是瓷绝缘子在大温差极低温环境下机电强度加速下降的重要原因。这种劣化是一种"微缺陷"不断发展的过程,在较长时间内无法通过测试其绝缘电阻发现。

In this paper,the residual electromechanical strength test of porcelain suspension insulators after its operation in normal temperature difference(-35~40℃)and large temperature difference with extremely low temperature(-55~40℃)environment operation,and test the volume change rate of cement adhesive under the simulated conditions of normal temperature difference and large temperature difference with extremely low temperature freeze-thaw cycle were carried out,the effect of large temperature difference and extremely low temperature freeze-thaw cycle on the running performance of porcelain insulators was studied.The results showed that,operating in large temperature difference and extremely low temperature environment was more likely to cause defects in porcelain insulators than in normal temperature difference environment.The increase of porosity and volume expansion ratio of cement adhesive after extremely low temperature was an important factor for the accelerated decline of electromechanical strength of porcelain insulators in large temperature difference and extremely low temperature environment,which could not be found by testing its insulation resistance for a long time,and it was a evolving process of microdefect.