Master Plans for the Development of MV Electricity Distribution Networks

The development of the public electricity transmission and distribution network represents a major investment, and the equipment built has a very long lifespan of around 40 years. It is therefore imperative that a coherent, economically optimized and robust approach be taken to the necessary upgrades. Each network operator, whether transmission or distribution, is therefore required to develop a forward-looking vision of the evolution of its network. Obviously, these visions must be coordinated within a given territory. These forward-looking visions enable us to design the future network with a view to the future, integrating new technologies and new user expectations at an early stage. This is the logic of a master plan. This master plan will then serve as a reference for all the work that will be decided upon as new users arrive, in response to increased consumption, to improve quality or to compensate for the obsolescence of the network's oldest components.

All electricity companies are developing a similar approach, which enables us to understand how the long-term vision fits in with short-term decisions. This article illustrates the approach adopted in France by the incumbent distributor Enedis.

The master plan is drawn up in accordance with the distribution company's policies and technical rules, and consists mainly of a long-term target and the best strategy (successive operations to move from one network situation to another) for developing distribution facilities leading to this target. The structures concerned by the master plan are source substations and MV networks; LV networks are excluded from these studies.

The existence of the master plan makes it possible to :

• guarantee the efficiency of investments, by integrating both the time dimension (long-term optimization) and the diversity of their purposes (connection of loads and decentralized generation, reinforcement, renewal, quality of supply, etc.);

• forecast and evaluate the investments to be made over a 10-year period (creation of source substations and MV feeders, renewal and reinforcement of existing structures, etc.);

• estimate quality-of-supply levels for different timeframes, based on allocated investment volumes;

• check the evolution of power supply security in the event of exceptional events;

• streamline investment decision-making by reducing the number of solutions to be studied, while ensuring long-term consistency;

• facilitate dialogue with all parties involved in the construction, operation and management of MV distribution facilities;

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