New Method Of Fault Location Research Articles

A new method for fault location in special parallel lines called “stitched lines”

Today, a special kind of parallel double-circuit line, designated "stitched lines," is employed in various transmission and sub-distribution networks in some countries, like Iran. In this type of unusual line, two circuits are connected at the beginning and end of the route and enter the high-voltage substations by a single line. Since on these lines there is no access to the current of each circuit separately, their protection, especially fault location, has faced a major challenge. Therefore, this article establishes a new method based on symmetrical components (positive sequence) to determine the location of the faults in the stitched lines. To scrutinize the performance of the proposed approach, comprehensive simulations have been run in the PSCAD/EMTDC software under a variety of different situations. The suggested method's accuracy has been established for a variety of fault locations and resistances. It has also been determined how the suggested approach performs when subjected to noise, current transformer saturation, arcing faults, transposition type, source impedance variation, and load changes. The obtained results show that the proposed approach is accurate under different scenarios, making it an excellent choice for practical applications.

A hybrid approach for fault location in power distributed networks: Impedance-based and machine learning technique

Fault location (FL) is one of the challenges in distribution networks. Many impedance-based methods have been developed to address this challenge. However, these impedance-based methods are not yet able to provide a unique answer, and they only can approximate the distance of the fault from the reference point, which creates challenges in systems that have a large number of separate lines. In this paper, using the impedance method, as well as a deep neural network, a new method for FL is suggested, which can provide a unique answer. In this approach, the FL is determined in less than 6 s, and the accuracy of 99 percent. The deep memory neural network is then used to accurately detect the exact fault location between candidate points. This method also identifies the line where the fault occurred. The performed simulations confirm the validity of the proposed method.

Fault Location Approach for Teed Transmission Line Independent of Wave Speed

The uncertainty of traveling wave speed always causes big deviations to the fault location. In order to conquer the influence of traveling wave speed on transmission line fault location, a new method of fault location was presented in this paper. The method contains two main parts: the establishment of the identification matrix for the fault section and fault point location. Firstly, the arrival times of the initial fault traveling waves are used to form the identification matrix for the fault section, and the fault section can be identified according to characteristics of element in the formed identification matrix, and the matrix avoids the influence of wave speed; Secondly, a new locating algorithm without influence of wave speed was derived based on the principle of double-node traveling wave fault location. The simulation results show that the arrival time of initial fault traveling wave can be detected accurately, and then the fault section and the fault point can be located exactly by using the method proposed by this paper. And the method is unsusceptible to wave speed, fault type, transition resistance.

A New Method for Fault Location in Distribution Networks Based on Voltage Sag Measurements

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.

Fault Location of Distribution Network Base on Improved Cuckoo Search Algorithm

A new method for fault location of a power distribution network based on Improved Cuckoo Search Algorithm is proposed. Cuckoo Search Algorithm uses Levy flight to simulate the global parasitic propagation mechanism of the cuckoo population. Therefore, the algorithm avoids falling into local optimum easily. According to the requirements of quickness and accuracy for fault location, the algorithm is improved by combining the search step size of the algorithm and the number of iterations. It improves the algorithm's early iteration speed and subsequent search accuracy. In this paper, the improved Cuckoo Search Algorithm is used to generate random status for all line segments. Then, convert it to the expected status for each switch. And next, update the line segment status by iteration of the algorithm, which makes the expected status of the switches approach to status uploaded by the FTU. Finally, the model outputs the fault location. In this way, a new generic switching function is proposed. It is suitable for single or multiple faults under single and multiple power conditions, which greatly extends the range of applications and versatility. In the evaluation function, the anti-false positive factor and the assumed fault number are introduced. Both of them improve effectiveness and adaptability. And, the validity of these ideas was proved by simulation. Compared with Cuckoo Search Algorithm, Binary Particle Swarm Optimization Algorithm and Genetic Algorithm, Improved Cuckoo Search Algorithm turns out to be good at finding an optimal solution to multiple faults location problems with a faster convergence speed and higher accuracy.

Real Fault Section Estimation in Electrical Distribution Networks Based on the Fault Frequency Component Analysis

: Fault location in electrical energy distribution networks is an important task, as faults in distribution grids are among the main causes of electricity supply disruption. Fault location in the distribution systems, however, is a challenging task because of the topology of the distribution networks, as well as the main and side branches. Therefore, it is necessary to address these challenges through an intelligent approach to fault location. In this paper, fault location in electric energy distribution networks is addressed considering the changes in fault distance and fault resistance in the presence of different fault types. A new method for fault location is developed for conditions where the minimum information is available and only information at the beginning of the feeder is used. This facilitates wide adoption of the technique as it does not require significant investments in instrumentation and measurement. The proposed intelligent method is based on the impedance and transient state estimation. This technique employs a specific impedance analysis for determining possible fault locations considering the unbalanced performance of distribution systems, distances, and different fault resistances. To determine the real faulty section, real fault frequency component analysis and the simulated faults at possible fault locations are used. At this stage of the process, it is possible to eliminate multiple estimations with the help of comparison and identification of the similarities. Therefore, a real faulty section is determined. It is observed that some conditions of electric energy distribution networks affect the accuracy and performance of the proposed method significantly; thus, a detailed investigation is conducted to neutralize these conditions. Simulation results and calculations based on MATLAB along with a practical test of the proposed method in power network simulator confirm a satisfactory performance.

A New Data Fusion Method for Multi Terminal Fault Location Based on Sensor Networks

Data fusion with different types of data that used for grid fault location can bring more accurate and clear results. Therefore, a new method for fault location which contains multi grid current and voltage, time and coordinate data information is proposed. Transient traveling wave is analyzed for determine the required data information in the first place, and then affirm the positioning principle and the selection rules of positioning network according to characteristics of multi fault traveling wave. Finally, Grid fault location will be precisely positioned by applying multiple data grid fault location algorithm. Simulation results shows that the proposed method is feasible, and the new algorithm has higher positioning accuracy.

基于萤火虫算法的含DG配电网故障区段定位

萤火虫算法是一种新近提出的高级启发式算法，其具有概念简明、需要设置的参数少、收敛性好的优点。对配电网进行区域划分来降低解的维度并对萤火虫算法进行适当改进，提出了基于二进制萤火虫算法的含DG配电网故障定位方法。算例分析结果表明该方法在配电网发生单点以及多点故障，并伴有部分开关信息畸变情况下，均能够得到准确的结果，证明了其有效性。通过与粒子群算法进行对比，验证了萤火虫算法应用于配电网故障定位的快速性与可靠性。 Firefly algorithm is a new advanced heuristic algorithm, which has advantages of concise concept, few parameters need to be set and good astringency. By dividing the distribution network to reduce the solution’s dimension and improving the firefly algorithm, this paper puts forward a new method of fault location for distribution networks with DG based on binary firefly algorithm. Analysis of example shows that the proposed method is able to get accurate results when it is used to locate single fault or multiple faults in distribution networks accompanied by part of the switch under the distortion of information, which proves its effectiveness. Finally, the comparison results with particle swarm optimization algorithm testify its speed and reliability.

Expression of transient phenomena at faults on ideal transmission lines by Laguerre functions

The paper presents analytical expressions for transient waveforms at faults on ideal transmission lines, and shows that impulse-like waveforms which intermittently appear in the transient waveforms are Laguerre functions, which are well known orthogonal functions. The transient waveforms for multi-phase transmission lines are also investigated, and it is shown that the expressions for them are also given by Laguerre functions. In addition, a new method of fault location by a correlation filter bank is demonstrated which uses the orthogonality of Laguerre functions.

96/03906 New method of fault location on double-circuit two-terminal transmission lines

A new quench protection method for superconducting magnets is presented. The method utilizes ZnO arresters as external dump resistors instead of conventional resistors. The ZnO arresters, which are widely used in power systems to limit overvoltages, can be used as the energy absorbing element with a constant discharge voltage. By introducing the ZnO arresters, both the discharge time and the heat dissipation in the superconducting magnet are reduced. The authors carried out some experiments using small experimental magnets. The results show that the ZnO arrester works as a dump resistor for a superconducting magnet and it is confirmed that the heat dissipation in the superconducting magnet with ZnO arresters is about one-third smaller than that with conventional dump resistors for the same maximum transient voltage.

A new technique, based on voltages, for fault location on three-terminal transmission lines

A new method for fault location on three-terminal transmission lines is described in this paper. Through this method, the faulty line branch is determined and the fault point located in a reliable and simple manner. For this, to reduce mathematical errors, a complete line model including the various characteristics of the network is used and a simple calculation method is applied, based on a new concept referred to as the ‘branch factor’. The method only uses the main components (50/60 Hz) of fault and prefault voltage values measured at the three terminals of the transmission line. Moreover, this method is independent of the fault and prefault current, type of fault and fault resistance, as well as the synchronization of recording devices located at the three terminals of the transmission line, and the prefault conditions. This paper also reviews the sensitivity of this method to errors in input data.

New method of fault location on double-circuit two-terminal transmission lines

A new method to locate faults on double-circuit transmission lines is described in this paper. This method only uses the fundamental components (50/60 Hz) of fault and prefault currents, measured at one of the ends of the line. From these measured values a function is established from which the point at which a fault occurred is determined. The definition of a new concept called the ‘distance factor’ will allow a method to be developed which is independent of fault resistance, type of fault, mutual coupling between the two circuits and initial prefault conditions. The accuracy of this method has been assessed by using a fault simulation software program. In the first stage the accuracy of the method was determined on the basis of accurate input data. In the second stage the sensitivity of the method was analyzed from errors in the input data.

52 km-long single-mode optical fibre fault location using the stimulated Raman scattering effect

A new method of fault location for an ultra-long single-mode optical fibre is proposed. It uses the Stokes light pulses as a probing pulse, which is generated by the stimulated Raman scattering effect in the measured fibre. Experimental results show that the fibre broken points with no Fresnel reflection up to 52 km are observable with this method.

An Accurate Method for Fault Location on Electric Power Transmission Lines

This paper proposes a new method for fault location on electric power transmission lines. The problem is here approached by identifying from pre-fault records an equivalent circuit for the far end of a transmission line. Based on the assumption that this equivalent is valid for the first few post fault cycles the position of the fault is calculated by solving the system of nonlinear equations, which can be formulated for each type of fault, using recorded fault waveforms. These equations are solved by applying Newton-Raphson technique. The method is finally examined by analysing two computer simulated faults on a 130 kV transmission line.