Lightning protection system design for distribution networks based on System Average Interruption Frequency minimization

The effects of lightning are the main cause of interruptions in electrical networks (distribution feeders), imposing a crucial impact on power quality and reliability. An exhaustive review of the state of the art shows that avant-garde solutions have not yet presented explicit mathematical models that relate the interdependence of these two phenomena. This paper presents a novel mixed integer linear programming (MILP) model to be utilized in the design of lightning protection systems (LPS) and which aims at minimizing sustained and momentary interruptions in distribution networks while leveraging investment costs. The proposed model considers a selection of different shielding structures and grounding systems. The constraints of the optimization model include technical and economic aspects of LPS implementation. A case study considering a real distribution feeder with 81 buses is presented. Test results highlight the generality of the proposed model and illustrate the potential for real-life application. It is worth pointing out that the proposed optimization model is currently used by a distribution utility as a reliability-oriented tool for LPS design.