Método de localización de fallas basado en impedancia aparente para sistemas de distribución con generación distribuida/Impedance-based fault location method for power distribution system considering distributed generation

This work aims to solve the problem of fault location considering distributed generation (DG). As one of most relevant characteristics of this proposed method, the fault current is estimated using the measurements of voltage and current obtained at the power substation and at the node where the DG is placed. These last measurements avoid the effort of using an electrical model to consider the impact of the distributed generator and it also makes possible to take into account their variations in fault state and pre-fault state. This methodology is based on the estimation of the fault impedance, which considers the effect of distributed generation and the variation of load current. The proposal is validated under the IEEE 34-nodes test system, which is modified to connect one generator in the longest radial. Tests are performed considering single phase, phase to phase and three phase faults, and resistances between 0 and 40 ohms and distributed generation contribution between 5% and 50%. The results obtained are performance surfaces, which show errors bellow 2% at the estimation of the fault distance.