Search

This paper presents a fault detection and faulty area identification algorithm in double-circuit transmission lines (DCTLs) compensated by the generalized unified power flow controller (GUPFC) for the first time. The topology of the GUPFC-compensated DCTL is threatened by three types of faults: single-circuit faults, inter-circuit faults, and grounded double-circuit cross-country faults. In the first step, the suggested scheme can determine the time of fault in this type of topology using a very fast method that is based on the analysis of a current index called the current jump index. In the second step, the fault type and area are identified with the help of two other indices, i.e., voltage difference index and current difference index. The test network presented in this paper, which includes a DCTL and a GUPFC, along with the proposed algorithm, is implemented in the MATLAB software package. The results of the simulation and sensitivity analysis of the algorithm confirm the correct performance of the algorithm. [ABSTRACT FROM AUTHOR]

This paper presents an effective technique for tracking and finding the direction of switched capacitor banks in distribution system generating switching transient when certain number of power quality meters exist. The proposed method is comprised of two independent algorithms. Algorithm utilizing the steady-state power quality data based on changes of the phase-angle difference between voltage and current and algorithm utilizing the transient state power quality data based on branch voltage and current changes immediately before and after the capacitor switching instant. This technique uses modal current and voltage signals that can be constructed by combining three-phase current and three-phase voltage. Wavelet transform is used to detect the exact instant of switching transient. The efficiency of proposed method was validated using IEEE 34-bus distribution system, modeled in PSCAD. [ABSTRACT FROM AUTHOR]

A new traveling-wave-based algorithm is proposed in this paper for the protection of transmission lines. In the proposed algorithm, Teager energy operator is used to extract traveling waves. Teager energy operator has a high computational efficiency and extracts traveling waves with high resolution. The amplitude of the first detected traveling wave as well as that of the traveling waves which are detected in 2 L / v and 2( L − x )/ v seconds (“ L ” is the line length, x is an initial guess about the fault location, and “ v ” is the traveling wave propagation speed) after the first one are used to discriminate internal and external faults. Then the traveling wave propagation speed and the time difference between the first and the second traveling waves are used to find the fault location. This process can also be used for the internal fault identification. Finally, two decision trees and the amplitude of initial current traveling waves in different modes are used for the fault type classification and faulted phase selection. The feasibility of the proposed algorithm is investigated by test signals which are simulated in PSCAD/EMTDC, and the algorithm is implemented in MATLAB. [ABSTRACT FROM AUTHOR]

This paper provides an algorithm of fault resistance compensation for digital ground distance relay considering the voltage and current transformer effects. Performance of the conventional ground distance relaying manner is adversely affected by different ground faults and also typical type, called a simultaneous open conductor and ground fault. The proposed scheme by using local-end data only, has shown satisfactory performances under wide variations in fault location, with different values of fault resistance and having positive and negative of power transfer angle. The presented method which has been carried out on the IEEE 14 bus benchmark is executed in PSCAD/EMTDC and MATLAB software, and the results show the accurate performance of mentioned configuration. [ABSTRACT FROM AUTHOR]