基于加速性能退化数据的XLPE绝缘可靠性评估

XLPE Insulation Reliability Assessment Based on Accelerated Performance Degradation Data

传统的基于失效寿命数据的固体电介质绝缘可靠性评估方法,试验时间长、失效数据少且难以获取。针对这一问题,本文研究了基于加速性能退化试验数据的可靠性评估方法。首先,采用平均电荷密度作为性能退化特征量,分别在140、160、180 kV/mm场强条件下进行加速性能退化试验,获取性能退化数据。其次,计算得出各场强条件下交联聚乙烯(XLPE)绝缘材料的伪失效寿命并确定其统计分布。最后,结合虚拟增广理论对伪失效寿命数据进行扩充,利用统计分析方法对扩充后的数据进行分析。结果表明:采用加速性能退化试验方法进行XLPE绝缘可靠性评估,经理论计算得到样本可靠度、失效分布密度函数、平均寿命等性能可靠性指标。结合加速寿命模型理论推导出20 kV/mm稳定场强条件下该XLPE绝缘材料的预期寿命为15.3年,且到达预期寿命时可靠度为0.4451。

The traditional insulation reliability evaluation method based on failure life data for solid dielectric need long test time,and the failure data is little and difficult to obtain.In view of this issue,a reliability assessment method based on the test data of accelerated performance degradation was studied in this paper.Firstly,the average charge density was used as the characteristic parameter of performance degradation,and accelerated performance degradation tests were conducted to obtain performance degradation data under 140 kV/mm,160 kV/mm,and 180 kV/mm of field strength,respectively.Secondly,the pseudo-failure life of XLPE insulation material under different field strengths was calculated,and its statistical distribution was determined.Finally,the pseudo-failure life data was expanded in combination with the virtual augmentation theory,and the expanded data was analyzed by statistical analysis methods.The results show that the performance reliability indicators such as sample reliability,failure distribution density function,and average life can be obtained through using accelerated performance degradation test method to assess the reliability of XLPE insulation.In combination with the accelerated life model theory,the life expectancy of the XLPE insulating material is 15.3 years under 20 kV/mm of stable field strength,and the reliability when reaching the expected life is 0.4451.