基于对数正态分布的电缆状态评估方法研究

Research on cable state evaluation method based on logarithmic normal distribution

为了了解电缆在长时间使用后的健康状况,通过对数正态分布和Weibull分布两种分布函数来进行电缆状态的评估。先假定电缆的介电损耗与局部放电数据符合两种分布,借助于Matlab数值模拟软件对某供电公司近几年通过振荡波试验检测积累的老化数据进行了拟合,并对两种拟合结果进行了对比分析。结果证明,对数正态分布更符合电缆老化参数的分布。设定了电缆状态的三个级别,通过建立状态评估模型,并使用该模型完成对某供电公司10 k V电缆的状态评估。研究成果有助于及时了解电缆在运行过程中的状态变化,并提出对应的检修计划。

In order to know the health condition of the cable after prolonged use, the cable state is evaluated by logarithmic normal distribution and Weibull distribution. The distribution of the dielectric loss and partial discharge of the cable is assumed to conform to two different distributions. With the help of Matlab numerical simulation software, the aging data accumulated by a power supply company through oscillatory wave test in recent years is fitted. The comparison between the two fitting results shows that the logarithmic normal distribution is more accordant with the distribution of aging parameters of cables. Three levels of cable status are set, and a state assessment model is established and used to evaluate the state of 10 k V cable in a power company. The research results will help to understand the changes in the state of the cable during the operation and put forward the corresponding maintenance plan.