In view of the growing decarbonization of the electricity system, an abrupt fall in the prices of renewable and storage distributed energy resources (DERs) is being observed and expected to continue. This trend together with most sophisticated communication s and control strategies allow distribution companies to improve the performance of the electricity distribution network, for instance improving voltage control, congestion management or reliability. The latter will be the subject of this paper. The problem analyzed in this paper is improving the reliability of radial distribution networks in rural areas where traditional reinforcements cannot be carried out because they are located in hard-to-reach environments or naturally protected areas where the permits to build new lines are difficult to obtain. Currently, when a contingency occurs in such a feeder, it is isolated, and there is a loss of supply for all customers located downstream for the duration of the fault until the service is restored. In some cases, autonomous diesel generators are used to mitigate the problem, but they create noise and environmental pollution. This paper proposes a novel methodology to optimally locate and size a set of renewable DERs in terms of reliability and investment. With the proposed solution, in the event of a contingency and once the fault is isolated, the downstream customers can maintain their supply through a set of several micro-grids (MGs) while the fault is being repaired. The methodology presented is verified and put into practice in a case study of an actual rural feeder with problems in the continuity of supply in which traditional reinforcements are not an option due to the difficulty of obtaining permits.
Keywords: Micro-grids, continuity of supply, power distribution, power system, planning
Registration date: 2020-04-17