用逐步升压法和Weibull参数估计油纸绝缘寿命

为评估油纸绝缘老化寿命 ,采用逐步升压法加速电老化油纸绝缘模型 ,利用Weibull概率分布对同一电压等级下多次试验得到的击穿寿命统计分析 ,利用反幂函数和指数函数拟合试验数据 ,求得两个模型中的电压耐受系数 ,用以评估油纸绝缘的电老化寿命。同时用恒定电压法试验作对比分析 ,结果表明 ,两种加压方法计算结果吻合 ,而逐步升压法简单 ,数据分散性小

Estimating Lifetime of Oil-paper Insulation Under Electrical Aging Conditions Using Step-stress Tests and Weibull Parameters

OIL PAPER MATERIAL IS A MAJOR KIND OF INSULATION USED IN HIGH VOLTAGE OIL IMMERSED EQUIPMENT. IT IS SIGNIFICANT TO EVALUATE OIL PAPER LIFETIME SUFFERED FROM ELECTRICAL AGING, WHICH CAN IMPROVE THE RELIABILITY OF HIGH VOLTAGE EQUIPMENT. IN THIS PAPER, A STEP STRESS TEST METHOD IS USED IN ACCELERATED LIFE TESTS AND WEIBULL MODEL IS USED TO STATISTIC ANALYSIS FOR THE MEAN LIFETIME OF SEVERAL SAMPLES UNDER THE SAME VOLTAGE VALUE. THIS PAPER USES INVERSE POWER AND EXPONENTIAL MODEL TO FIT TEST DATA AND CALCULATE VOLTAGE ENDURANCE COEFFICIENTS. CONSTANT STRESS TEST DATA IS ALSO USED AS THE COUNTERPART OF THAT MEASURED BY THE STEP STRESS TEST. IT IS INDICATED THAT THE TWO METHODS CAN LEAD TO THE SAME ANALYSIS RESULTS. FURTHERMORE, THE TEST VOLTAGES OF STEP STRESS TEST ARE MORE EASILY SELECTED THAN THAT OF CONSTANT TESTS AND THE DATA OF THE FORMER IS LESS SCATTERED.