Modelling of Ageing Distribution Cable for Replacement Planning

The paper proposes a new reliability model of ageing distribution cable and simulation methodology for prioritization of cable replacement. The proposed reliability model combines IEC cable thermal model, Arrhenius aging model and Weibull probability distribution. Here, Weibull scale parameter is defined through the Arrhenius aging model, in which conductor temperature is governed by the cable thermal model. A novel estimation method for the calculation of Arrhenius model parameters is proposed. The cable reliability model is then incorporated into the developed sequential Monte Carlo simulation procedure and reliability indicators and loss-of-lives are calculated. An industry based cable ranking scheme is further proposed to prioritize individual cable due for replacement. The whole methodology is tested on several medium voltage distribution networks.