Fault indicator

About: Fault indicator is a research topic. Over the lifetime, 10057 publications have been published within this topic receiving 143482 citations. The topic is also known as: FCI & power line fault indicator.

An Accurate Noniterative Fault-Location Technique for Low-Voltage DC Microgrid

Abstract: The least erroneous knowledge on fault location in distribution systems helps the restoration process, expedites maintenance, and reduces power outage duration. A fault-location method using the probe power unit (PPU) in dc microgrid assumes that the natural frequency of the system is equal to the damped resonant frequency of probe current. This assumption leads to prominent error in fault-location calculation. To estimate the location of fault in the low-voltage dc microgrid system, a noniterative fault-location technique using PPU is proposed in this paper. Considering damping frequency and attenuation of the probe current, which is a function of fault distance and damping coefficient, the fault location is obtained. The technique is tested for high-resistance fault as well as radial and looped topologies and is found to be more accurate.

Fault-Location Scheme for Power Distribution System with Distributed Generation

Abstract: This paper presents a novel fault-location scheme for unbalanced power distribution system in the presence of distributed generation (DG). The proposed scheme first identifies the possible fault locations using a new formulation of the impedance-based method. The new formulation overcomes the requirement of fault-type identification by using only one fault-location equation. The proposed equation is applicable to all shunt fault types. From the possible fault locations, the exact fault location is then identified by matching the measured voltage at the substation bus and each DG unit bus with calculated ones. The proposed scheme is applicable for all DG types without the need for their individual parameters. The balanced and unbalanced laterals and the capacitive effect of distribution line are also considered. The proposed scheme was evaluated and tested on a modified IEEE 34-bus distribution system using PSCAD/EMTDC software.

A Novel Approach to Detect Symmetrical Faults Occurring During Power Swings by Using Frequency Components of Instantaneous Three-Phase Active Power

Abstract: Since distance relays are prone to interpret a power swing as a three-phase fault, they should be blocked during the power swing to prevent undesired trips. On the other hand, if any fault occurs during a power swing, they should be fast and reliably unblocked. Although unblocking the relay is straightforward in the case of asymmetrical faults by using the zero-sequence and/or negative-sequence component of current, detecting symmetrical faults during a power swing is still a challenge. This paper presents a novel method for detecting symmetrical faults occurring during a power swing. Based on the damping frequency component of 50 (or 60) Hz created on instantaneous three-phase active power profile after inception of a symmetrical fault, the proposed method will be able to detect the fault in less than one power cycle. This detection method can be readily implemented, and is immune to the power swing slip frequency, fault inception time, and fault location. To test the proposed method, several power swings and faults are numerically simulated in MATLAB/SIMULNK, and the simulation results show that the proposed method is sensitive as well as reliable.

Fault location in transmission lines using one-terminal postfault voltage data

Abstract: A new algorithm for fault location in transmission lines, with fault distance calculation based on steady-state measured phasors in local terminal is presented. For the postfault, only voltage phasors are required, avoiding possible errors due to current transformer saturation; the current phasors are required only in prefault time, when saturation does not occur. The algorithm does not use simplifying hypothesis but requires system equivalent data at both line terminals and the fault classification, considering fault resistance purely resistive. In order to verify the algorithm performance, a parametric analysis of variables that influences short-circuit conditions is developed, including an analysis of remote equivalent setting. The results show that the algorithm is very accurate, even in cases when the remote equivalent is not well fitted.