Basic technical principles for the distribution network
Electricity distribution networks

In France, distribution networks are subject to certain general rules.

– Networks are tree-like, not meshed. This means that any point served is only supplied at any given time by one electrical path, coming from a source substation, passing successively through a MV network, a MV/LV substation and then a LV network. This path may also include production facilities connected at MV or LV.

– Source substations generally have two power supplies and a back-up transformer to cope with the failure of one of the supply elements. This is known as the N-1 principle, which stipulates that users must continue to receive normal service in the event of the failure of a network element.

– The HTA network is loopable when it is built underground or in high-density areas, so that users can be re-supplied in the event of failure of one of the normal supply sections. The choice of MV voltage level...