Alocação ótima de dispositivos de proteção em rede de distribuição considerando a incerteza das cargas elétricas

Abstract

The purpose of this work is to allocate protection devices in a 134-bus electrical distribution network to optimize grid reliability in the event of faults. The objective is to minimize the sum of the costs of Unsupplied Energy (ENS) due to permanent faults, the costs due to temporary faults, and the costs of protection devices. An index of reliability of the distribution network is the ENS calculated during a fault in the grid; the lower this index, the more reliable the protection. The ENS is the cost of the interruption of electrical power to the energy provider due to faults in the electrical grid. The protection is allocated in the grid for a one-year horizon, with the protection devices being sized for the electrical load of the last year. The uncertainty of the loads in the grid is given by the normal distribution curve whose average value is the average active power consumed in a given bar. Selectivity is guaranteed by the fuses allocated in the branches of the main feeder (secondary feeders), therefore, permanent faults are interrupted by the device closest to the upstream of the fault. Only automatic reclosers are allocated to the main feeder and a fuse is mandatory allocated at the beginning of the secondary branches. The project considers temporary and permanent faults. In the case of temporary faults, a penalty or cost is considered to penalize the (transient) reconnection of electrical loads located after the recloser and justify the allocation of reclosers, in addition to the one located at the power substation, since temporary faults are the vast majority in the network. The studies in this work will help the local electric power utility in the optimized allocation of protection devices with reliability and cost reduction.