Fuse cutout allocation in radial distribution system considering the effect of hidden failures

Among the several components of distribution systems, protection devices present a fundamental importance, since they aim at keeping the physical integrity not only of the system equipment, but also of the electricians team and the population in general. One of the protective devices playing a vital role in overhead distribution lines is fused cutout. At the era of privatized utilities, the protection devices should be allocated and coordinated optimally to reduce capital investments and the system outage costs. Amid this situation, the mentioned type of the protection device (fuse cutout) has not been studied for economical allocation up to now. In this paper, responding to this need, an accurate reliability model of fuse cutout containing hidden failures is figured out in the shape of a new Markov model. This model is used for economical allocation of the fuse cutouts. On the basis of the proposed model, a methodology for economic allocation of fuse cutouts is presented. This methodology involves the worth of energy not supplied (ENS) of the network and makes a balance between the cost of fuse cutout installation and the benefit of ENS decrease because of the minimizing the faulty zone by using more fuse cutouts. The methodology is tested on a sample distribution network as well as on IEEE 6-bus distribution test system (RBTS). Moreover, its capability on decision making about the fuse cutout placement and its simplicity for implementing on MV overhead lines are displayed.

► Accurate reliability model of fuse cutout containing hidden failures is figured out.
► The proposed reliability model is in the shape of a new Markov model.
► The proposed Markov model is used to allocate fuse cutouts in MV overhead lines.
► The allocation methodology uses the reliability index of energy not supplied (ENS).
► An economic analysis is used to investigate cost-saving benefits of the proposed model.