This paper proposes a methodology for optimal cable replacement based on utility financial benefits that are calculated by considering the entire network in the planning period. The overall problem is set within a sequential Monte Carlo simulation framework and uses novel reliability modelling of ageing distribution cable using the ‘IEC-Arrhenius-Weibull’ model. Optimal cable replacement schemes are developed by considering the connection of new wind sources and network reconfiguration to reduce cable ageing and defer its replacement. The core concepts of the proposed methodology are two new mixed-integer non-linear optimization models. The first optimizes the connection of new wind sources by minimizing the connection and reinforcement costs, as well as minimizing the cost of the cable thermal-loss-of-lives in the planning period. In the operations stage, the network is optimally reconfigured to minimize the cost of losses, the thermal-loss-of-life of cable, and reliability. Both optimization models are applicable to radially operated medium voltage networks that are backfed from several normally open points. The final outputs are proposed cable ranking lists for replacement and reliability and cost metrics.
- Replacement planning, ageing cable, IEC-Arrhenius-Weibull reliability model, optimal wind connection, optimal reconfiguration, thermal loss-of-life.