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This paper presents an innovative method for fault location in distribution networks based on classical circuit analyses. Two synchronized and few nonsynchronized pre- and during-fault voltages are required at few buses along with the impedancematrix. A new impedance matrix manipulation procedure is proposed so that the distribution system is investigated in partitions across multiple subsystems. This procedure allows the fault location process to be performed by solving systems of determined equations, making the method more technically accessible. The fault is located by analyzing the voltage sag at the terminal-bus of each subsystem separately. The proposed method is validated on the IEEE 33-bus, 12.66 kV distribution system with/without distributed generation (DG). Simulation results show the robustness and accuracy of the method under several pre- and during-fault scenarios and measurements errors. [ABSTRACT FROM AUTHOR]

The zero-sequence electromagnetic suppressor (ZSES) refers to a well-established alternative during the zero-sequence current mitigation in industrial systems. Its arrangement consists of a zero-sequence electromagnetic filter (ZSEF) and a zero-sequence electromagnetic blocker (ZSEB). Since the ZSEB also plays an important role in the ZSES performance, this paper presents an extensive analysis showing the impacts that can be caused when the ZSEB operates under non-ideal condition. To circumvent such impacts, this paper proposes an innovative method for dimensioning and designing the ZSEB, allowing the ZSES performance to be conveniently adjusted. The proposed technique allows the user to know the current unbalance factor that will result in the supply system. Applying the proposed method, it is verified in the PSIM software that the ZSEB presents exactly the performance as adjusted. [ABSTRACT FROM AUTHOR]

This paper proposes an innovative method for dimensioning and designing the zero-sequence electromagnetic filter applied to three-phase four-wire distribution power systems. As premises, the optimum ratio between zero-sequence and positive-sequence impedances of the filter must be established in order to potentiate the filtering percentage of zero-sequence currents and ensure the quality of the supply system displacement power factor. The calculations are based on the sequential harmonic transmittances of the equivalent circuit reduced to the coupling point of the electromagnetic filter. To validate the proposed method, the results obtained with the application of the electromagnetic filter designed in a test system using the MATLAB software are compared to the results of the system modeled in the PSIM software. [ABSTRACT FROM AUTHOR]