Search

The traditional service restoration methods are experiencing a significant challenge because the performance of such methods is often dominated by very large processing time. Therefore, it is important to develop a fast and an accurate method to solve a complex non-linear optimization problem representing the service restoration problem in a distribution system. In this paper, due to a binary nature of the service restoration problem, the Binary Water Cycle Algorithm (BWCA) is proposed to reduce out-of-service loads and system losses considering operational constraints, the radial topology of the distribution systems, and the influence of the presence of distributed generations (DGs) on the service restoration problem. The proposed method is a modified form of the Water Cycle Algorithm (WCA) that is mainly used for discrete and continuous optimization problems. The effectiveness of the proposed method is validated by comparing with other well-known meta-heuristic algorithms using a modified IEEE 33-node radial distribution system. The simulation results demonstrate the robustness of this method to provide a precise decision with short convergence time for solving service restoration problems. [ABSTRACT FROM AUTHOR]

Most of the fault-location methods developed in the past employed measurements obtained from a limited number of meters installed in a power system. Optimal meter placement in power systems is to make the best use of a limited number of meters available to keep the entire network observable. This article presents the fault-location observability analysis for distribution systems and proposes a novel optimal meter placement algorithm to keep the system observable in terms of fault-location determination. First, the observability of fault location in power systems is defined. Then analysis of the whole system is performed to determine the fewest number of meters needed and the best locations to place those meters to achieve fault-location observability. Case studies based on a 16-bus distribution system have been carried out to illustrate the proposed algorithms. [ABSTRACT FROM AUTHOR]

This article presents novel fault-location algorithms for distribution systems by utilizing voltage and current measurements at the local substation. The methods extend from previously published algorithms by explicitly modeling feeder shunt capacitances so that the methods will be applicable to distribution feeders with significant capacitances, such as underground cables. The bus impedance matrix technique is harnessed to develop the relationship between the substation voltage and current and the fault location and fault resistances, based on which the fault location can be derived. To accommodate inherent unbalances in distribution systems, the methods are developed in the phase domain instead of the symmetrical component domain. The distribution network parameters and topology are assumed to be known for constructing the bus impedance matrix. Simulation studies have demonstrated that the methods can achieve very accurate results. [ABSTRACT FROM AUTHOR]

This article describes a novel and accurate algorithm to determine the fault location on power transmission lines without requiring line parameters. Voltage and current measurements at the two ends of the transmission line during the fault are utilized for fault location, and no pre-fault data are needed. In the past, a two-terminal method has been proposed based on a simplified transmission line model with no shunt capacitances. This article presents a new and accurate method considering line shunt capacitances for unbalanced faults. In deriving the unknown fault location, the line parameters, including series impedance and shunt capacitance, are treated as unknown variables as well. Approaches based on both synchronized and unsynchronized measurements are described. Since there is not enough information in three-phase balanced fault cases, shunt capacitances are not considered for balanced faults; however, the method for balanced faults still proves to be quite accurate. The chief merit of the algorithm is that only voltage and current measurements during the fault are required, and there is no need to worry about line parameters in order to pinpoint the fault location. Evaluation studies based on simulated data have indicated that the new approaches yield quite accurate results. [ABSTRACT FROM AUTHOR]

This article presents a transmission line fault location algorithm based on distributed parameter line model by utilizing unsynchronized voltage and current measurements from two terminals of the line. The new solution fully considers the impacts of the shunt capacitance of the line and is virtually independent of fault resistance and source impedance. Evaluation studies based on simulation studies for verifying the accuracy of the algorithm are reported, and quite promising results have been achieved. [ABSTRACT FROM AUTHOR]

Diverse transmission line fault location methods have been proposed utilizing voltages and currents as inputs. This article develops several algorithms utilizing only the voltages, dispensing with current transformers and thus eliminating the errors caused by saturation of current transformers. The algorithms are applicable to line to ground faults, line to line faults, and line to line to ground faults. The algorithms utilize unsynchronized fault voltage measurements from two ends of a line and do not require pre-fault data. Shunt capacitances of the line are fully considered. Encouraging results have been obtained by simulation studies. [ABSTRACT FROM AUTHOR]