Comparison of Weibull Distribution and Crow-AMSAA Model Used in Cable Failure Analysis

Power cables are always subject to electrical, thermal, mechanical, and environmental stresses when in service. These stresses together with poor workmanship during installation and maintenance, lead to insulation degradation and defects, such as excessive sheath circulating current, partial discharge activity and increasing dielectric loss, which can result in premature cable failure causing unplanned outages. The unplanned outages will bring inconvenient in people´s life and huge economic loss. Two kinds of statistical models are discussed in the paper. The Weibull and Crow-AMSAA model which are widely used in reliability analysis have been compared and used in the paper to analysis the cable failure data in order to obtain the failure model of cable and the prediction of failures in the future. The result of which can be further used in making optimum decisions on cable maintenance and replacement. The comparison of Weibull and Crow-AMSAA models shows that the result of Weibull model is more believable when the population is small.