Modelling of Ageing Distribution Cablefor Replacement Planning

Cable Replacement Considering Optimal Wind Integration and Network Reconfiguration

“…Consideration of system aspects in replacement planning was first done for ageing transformers, which are arguably the most important components. Hence, the ageing and replacement of cables and transformers was reviewed and classified into four categories: a) Ageing processes in cable [3][4][5][6][7][8][9][10] and transformers [11][12][13][14][15][16]; b) Power system analyses with ageing components [17][18][19][20][21][22][23][24]; c) Replacement of individual/ populations of cable [2,[25][26][27] and transformers [28]- [31]; and d) Cable and transformer replacement based on power system analyses [32][33][34].…”

“…On the other hand, investigation of asset replacement based on whole-system studies is very limited [32][33][34]. A network reliability simulation methodology that makes use of the exponential hazard rate model was used in [32] to assess the economic benefits of proactive cable replacement.…”

“…Its main disadvantage is the use of a continuity reliability method [52] that does not consider asset and operation constraints, nor network control actions. The authors of paper [33] have proposed the 'IEC-Arrhenius-Weibull' reliability model for ageing cable to include cable properties and future operating conditions, and used it in a simplified network simulation software to prioritize cable replacement. Finally, prioritization of transformers for replacement based on non-sequential reliability analysis was proposed in [34] in which a single year 3 with only load variation is studied.…”

“…This was considered the best approach to model various types of uncertainty and chronological phenomena. The proposed methodology makes use of the recently developed 'IEC-Arrhenius-Weibull' model, used to sample up-times of ageing cable [33]. The focal points of the methodology are optimal connection of the prespecified set of new wind units and optimal network reconfiguration whose common objective is to minimize the total cost including cable loss-of-lives.…”

“…Compared to the probabilistic simulation methodology [32], the proposed methodology contains many additional features, such as 'IEC-Arrhenius-Weibull' model [33], real-time thermal ratings of assets, wind modelling with a stochastic process, optimal wind integration and network control actions, and novel cable prioritization for replacement. Compared to the authors' previous work [33], additional features include the development of a three-stage SMCS procedure as opposed to two-stage SMCS [33], modelling of two cable thermal models [55,56] in the 'IEC-Arrhenius-Weibull' model, development of optimal wind integration and network reconfiguration models, and a novel cable ranking criterion.  Reduction in cable ageing and replacement deferral are realized by optimal wind integration and optimal network reconfiguration.…”