Accurate Fault Location Method Research Articles

A Highly Accurate Double-Ended Traveling Wave Fault Location Method Using GWO-VMD and the Hilbert Transform for Offshore MMC-MTDC Grids

Accurate and reliable DC fault location methods can significantly enhance the resilience and reliability of offshore MMC-based multi-terminal direct current (MTDC) grids. This research proposes a novel double-ended DC fault location method using the GWO-VMD and the Hilbert transform. First, the propagation of traveling waves (TWs) in the faulty line-mode network is described, leading to the theoretical expressions for the Backward Line-mode Voltage TWs (BLVTWs). Next, the Grey Wolf Optimizer-Variational Mode Decomposition (GWO-VMD) algorithm is employed to extract the high-frequency components contained in the measured BLVTWs, and the Hilbert transform is used to obtain the Instantaneous Energy Spectrum (IES) of the specific IMFs, allowing for the determination of the arrival times of the TWs. Numerous simulations in the PSCAD/EMTDC and RTDS environments confirm that the fault location method is accurate under various sampling frequencies and for close-in faults. Comparison studies also demonstrate that the proposed method is more accurate than existing classical TW-based methods. Additionally, the RTDS tests show that the method can withstand noise disturbances of at least 30 dB and has the potential to be applied in real projects.

Accurate Fault Location Method for Multiple Faults in Transmission Networks Using Travelling Waves

Accurate Fault Location Method for Multiple Faults in Transmission Networks Using Travelling Waves

A Novel Machine Learning-Based Approach for Fault Detection and Location in Low-Voltage DC Microgrids

DC microgrids have gained significant attention in recent years due to their potential to enhance energy efficiency, integrate renewable energy sources, and improve the resilience of power distribution systems. However, the reliable operation of DC microgrids relies on the early detection and location of faults to ensure an uninterrupted power supply. This paper aims to develop fast and reliable fault detection and location mechanisms for DC microgrids, thereby enhancing operational efficiency, minimizing environmental impact, and contributing to resource conservation and sustainability goals. The fault detection method is based on compressed sensing (CS) and Regression Tree (RT) techniques. Besides, an accurate fault location method using the feature matrix and long short-term memory (LSTM) model combination has been provided. To implement the proposed fault detection and location method, a DC microgrid equipped with photovoltaic (PV) panels, the vehicle-to-grid (V2G) charging station, and a hybrid energy storage system (ESS) are used. The simulation results represent the proposed methods’ superiority over the recent studies. The fault occurrence in the studied DC microgrid is detected in 1 ms, and the proposed fault location method locates the fault with an accuracy of more than 93%. The presented techniques enhance DC microgrid reliability while conserving renewable resources, vital to promoting a greener and more sustainable power grid.

Ground fault identification and location of autotransformer traction network for high‐speed railway based on multi‐terminals synchronous measure information

AbstractWith the rapid development of high‐speed railway, the auto‐transformer traction network (ATN) is also expanding. However, due to the improved performance of electric multiple units (EMUs) and the non‐linear relationship between impedance and ground fault distance, distance protection has limited coverage and cannot accurately locate the fault distance by measuring impedance. This paper presents a model of the ATN considering the presence of EMUs, which effectively demonstrates the characteristics of current distribution under the ground faults. Furthermore, a ground fault identification method based on multi‐terminal currents is proposed to enhance the accuracy of fault identification and differentiate faults and EMUs. The mapping relationship between current distribution and fault location is derived, and an accurate fault location method is proposed. Compared to existing methods, this method is not affected by EMUs and AT parameters. The fault identification and location scheme for ATN employs multi‐terminal synchronous information. Finally, through simulation and experimental setups, case studies have been conducted to verify the accuracy and robustness of the proposed method in various fault scenarios. Certainly, this research has significant application prospects in fault analysis and detection for HSR.

A Fault Location Method for Medium Voltage Distribution Network Based on Ground Fault Transfer Device

The arc suppression device based on ground fault transfer (GFT) has been preliminarily applied in the medium voltage distribution network (MVDN). An accurate travelling wave (TW) fault location method is proposed to extend the use of the ground fault transfer device. D-PMU is used as a travelling wave detection tool to record the transient voltage travelling waves of fault grounding and bus active grounding during arc suppression. Then, the faulty section is identified through the time difference of travelling wave arrival at the upstream and downstream measurement points. On this basis, the fault location equations of the arrival time and distance of the upstream travelling wave are established, and an accurate fault location method based on the arrival time difference of the travelling wave is proposed. The simulation model is established by PSCAD/EMTDC, and the results show that the method has high location accuracy, and the absolute error is less than 30 m. It is not affected by the TW velocity, the fault conditions, or the distributed power sources.

High pass filter based traveling wave method for fault location in VSC-Interfaced HVDC system

Due to the difficult topography and bad weather conditions across large distances, dc line breakdown is a serious danger to the safety of high-voltage direct-current systems (HVDC). Thus, there is a need of an accurate and reliable fault location method to safely isolate the dc grid in the occurrence of a dc fault. Traveling wave (TW) fault location techniques have gained in popularity over the decades, with the expectation that power networks will become considerably more credible and accurate throughout. However, in the existing traveling wave based location, the signal processing methodology for extracting the wave front consumes too many computer resources, necessitating the development of a new location method with a fast response and high accuracy. In this paper, a new algorithm of TW based on high pass filter is proposed, it can differentiate the TW peak more easily by removing the oscillation in a signal. To ensure more accuracy double ended method (Type D) is used to obtain the location for the fault. The theory behind this new algorithm is presented in detail. High pass filter is designed for this purpose and its validity tested on point to point (P2P) dc simulation model which is created in PSCAD software to gather the voltage data from both terminals during transient. Following that the proposed fault location algorithm is executed in the MATLAB environment to get the fault location results. A comparison of the proposed algorithm with two popular methods namely the wavelet transforms (WT) and the single ended method highlights the superiority.

Enhancing Resilience and Reliability of Active Distribution Networks through Accurate Fault Location and Novel Pilot Protection Method

The integration of distributed generation (DG) into the decentralized access of the distribution network transforms the existing structure into an active distribution network. The alteration in fault characteristics poses significant challenges to the coordinated operation of relay protection. Fault location within the distribution network plays a vital role in facilitating fault recovery and enhancing the resilience of the power system. It proves instrumental in improving the network’s ability to withstand extreme disasters, thereby enhancing the reliability of power distribution. Therefore, this paper provides a detailed analysis of the voltage fault components occurring during various fault types within an active distribution network. Building upon the identified characteristics of voltage fault components, a novel approach for the longitudinal protection of active distribution networks is proposed. This method involves comparing the calculated values of voltage fault components with their actual values. The proposed approach is applicable to various fault scenarios, including short-circuit faults, line break faults, and recurring faults. It exhibits advantages such as insensitivity to the penetration of distributed power supplies and robustness in withstanding transition resistance. The simulation results validate the effectiveness of the proposed method, affirming its applicability to diverse protection requirements within active distribution networks.

An accurate unsynchronized fault location method on practically transposed transmission lines with closed-form solutions

This paper proposes an unsynchronized two-terminal fault location method on three phase practically transposed transmission lines.Compared to the existing fault location methods, the proposed method considers the asymmetry of the practically transposed transmission lines during the fault in practice. First, the proposed method constructs the practically transposed transmission lines by connecting three untransposed transmission line sections. For each section, the fully distributed parameters line model is adopted to ensure the modeling accuracy. According to the physical laws that the line should obey, the unsynchronized angle is estimated with analytical formulation before the fault. Next, the closed-form solutions of fault location are derived for different fault events, to avoid the risks of unconvergence using the iterative algorithms. In the numerical experiments, the proposed method shows higher accuracy of fault location than the existing fault location methods, regardless of fault types, locations and impedances. The proposed method also demonstrates robustness against various unsynchronized angles, loading conditions, measurement noises and line lengths.

An accurate fault location method for distribution lines based on data fusion of outcomes from multiple algorithms

Accurate fault location technology for distribution lines is of great importance as it can shorten power outage time and enhance power supply reliability. Current and voltage transformer errors and line parameter errors will result in location error of the existing algorithms, which cannot meet the requirements of power supply reliability. To solve this problem, a data-fusion model based on multiple algorithms is proposed in this study, which makes full use of the location results of existing algorithms. First, the complementarity among the four selected algorithms is analyzed. Then the feasibility of improving fault location accuracy by constructing a data-fusion model is explained and the overall structure of the data-fusion model is determined. Finally, an artificial neural network with a strong fitting ability is used to complete the construction of the data-fusion model. The performance of the model is tested for different factors, such as fault positions, line parameters, fault resistances, and fault inception angles. The test cases based on PSCAD/EMTDC show that the constructed model has excellent generalization ability. Additionally, performance of the model is not affected by distributed generation and sampling rate. The proposed method does not use high-sampling devices and is cost-effective.

An accurate fault location method for wireless sensor network based on random matrix theory

In order to improve the effect of fault location, this paper proposes an accurate fault location method for wireless sensor networks based on random matrix theory. The standard non Hermite matrix is used to extract accurate fault location data. Considering the volatility of the original data, the original random matrix is preprocessed. Based on the real-time sliding time window method, the space-time characteristic data of network faults are determined, and the precise fault location of wireless sensor networks based on random matrix theory is realized.Experimental results show that the false positive rate of the proposed method is only 2%. The average fault location accuracy is as high as 96.4% and the fault location time is only 15.1 s, which shows that the proposed method has a good location effect.

Fault location of cable hybrid transmission lines based on energy attenuation characteristics of traveling waves

The overhead-cable hybrid transmission lines are alternately connected by two types of lines, with a more complex structure and higher difficulty in fault location. This paper presents an ac-curate fault location method for overhead-cable hybrid lines based on traveling wave energy. Firstly, the basic concept of traveling wave energy is defined. Based on the attenuation charac-teristics of the traveling wave, the mapping relationship between traveling wave energy and fault location is analyzed. Secondly, considering the influence of S-transform error on the traveling wave energy propagation law, the traveling wave energy attenuation characteristics of common A-type and B-type hybrid lines are analyzed. Then, for the overhead-cable hybrid lines with different structures, the mapping relationship between the traveling wave energy at both ends of the line and the fault distance is quantitatively derived, and an accurate fault location method based on the initial traveling wave energy ratio at the same frequency at both ends of the line is proposed. Finally, a 110 kV hybrid transmission line fault simulation model is built in PSCAD/EMTDC, and the faults under different conditions are simulated in different line sections. The effectiveness and robustness of the proposed method are verified through the simulation.

Undersea observation network fault location method considering the ocean circuit

Due to the harsh marine environment, submarine cables in the undersea observation networks are easily damaged which leads to the fault and power failure. An accurate fault location method is required for the fast power recovery and repairment for the undersea observation networks. Most of the fault location methods for undersea power system ignore the ocean circuit, which result in a decrease in fault location accuracy. This paper proposes a fault location model for undersea observation system based on steady-state post-fault power system operation data considering ocean circuits. The ocean as an equipotential body is considered as a node for calculation. According to Kirchhoff's current law, the current vector can be reconstructed and the influence of the current error of each branch on the fault location can be eliminated, which improves the accuracy of fault location method. A simplified model of NEPTUNE is simulated in PSCAD to prove that the proposed method is available to locate multi types of faults in the undersea observation network power system. The results show that the improved fault location method is more precise than the original method.

A fast and accurate Bi-level fault location method for transmission system using single ended phasor measurements

To guarantee continuous and reliable operation of power systems working near their stability margins, it is necessary to clear faults quickly. For this purpose, accurate and fast fault location methods are required. Single-ended phasor based methods are a category of fault location strategies which are favourable due to simplicity of their implementation. However, enhancing the accuracy of these methods is a challenging task due to unavailability of data from the remote end of the line. In this paper, a novel fault location method that requires the measured data of one end of the line is proposed. As a result, this method does not need communication links. The proposed method is bi-level and in its first level, fault characteristics such as current, voltage, and impedance of the fault are calculated for a given fault location obtained from Level-2. Then, based on the calculated fault characteristics, fault location is updated in the second level. The presented fault location method considers magnetic coupling between lines and it is also applicable for both transposed and un-transposed lines. Numerous simulation studies verify the accuracy of the proposed method in presence of uncertainties such as noise, fault impedance and error in input line parameters. Furthermore, although the proposed method is based on a bi-level iterative approach, the presented results confirm that it converges quickly in 2 or 3 iterations.

Accurate fault location method for distribution network in presence of DG using distributed time‐domain line model

In this paper a novel technique is presented for fault location in distribution networks in the presence of distributed generators (DGs). The proposed approach uses recorded voltage and current at the beginning of feeder and DG terminals. This method is based on transient state data, and due to presence of high frequencies in this state, to achieve high accuracy it utilizes the distributed time-domain (DTD) line model. The fault location problem is formulated as an optimization problem and is solved using Genetic Algorithm (GA). Through modal transformation, in addition to locate the symmetrical three-phase to ground (3LG) faults, the location of asymmetrical faults including single line to ground (SLG) and double line (LL) faults can also be determined. The effects of fault distance, fault resistance and fault inception angle on the accuracy of the proposed algorithm have also been investigated. A solution is also proposed to overcome the multi-response problem. The simulations are conducted and the results are obtained via PSCAD and MATLAB softwares, respectively. The effectiveness of the proposed approach has been verified using the modified IEEE 34-node test feeder under different fault conditions. The simulation results demonstrate the high efficiency and accuracy of the proposed method.

An accurate fault location method for distribution network based on active transfer arc-suppression device

Active transfer arc-suppression device is a kind of arc suppression device which has been widely used in the distribution network. When a single-phase grounding fault occurs, the bus of faulty phase is actively grounded metallicity in the substation to limit the voltage of faulty phase, so as to realize arc extinction. In this paper, an accurate fault location method is proposed for the distribution network equipped with active transfer arc-suppression device. According to the variation characteristics of the fault traveling wave signals before and after arc-suppression device operation, the fault location formula based on the traveling wave velocity difference of different modes and the fault location formula based on the mutation of aerial-mode traveling wave are combined to obtain the final fault location method that is not affected by ground-mode wave velocity. The proposed method expands the function of active transfer arc-suppression device, makes it have additional fault location ability, and greatly improves the economy of the device. Simulation verifies that the proposed method is not affected by fault conditions, soil resistivity and extreme fault. The absolute error is within 50 m in all cases, which has high reliability.

CNN based accurate fault location method in distribution network

CNN based accurate fault location method in distribution network

A New Fast and Accurate Fault Location and Classification Method on MTDC Microgrids Using Current Injection Technique, Traveling-Waves, Online Wavelet, and Mathematical Morphology

A New Fast and Accurate Fault Location and Classification Method on MTDC Microgrids Using Current Injection Technique, Traveling-Waves, Online Wavelet, and Mathematical Morphology

A novel single-ended fault location method for long-distance HVDC transmission lines based on cross-correlation analysis

The transmission line, as the faultiest device in power system, cross many complex areas which will cause worse work condition. This is, both the rate of faulty and the difficulty of the manual fault location are raised. While accurate fault location method could reduce the workload and outage cost, increase the speed of repairing and improve both the reliability and economics of power system. Therefore, it is essential for HVDC systems which have much longer transmission lines. The existing fault location device of HVDC transmission lines are based on the principle of transient travelling-wave. However, due to the interference caused by on-off of power electronic devices and signal resonances, the single-ended travelling-wave method can not be applied in HVDC. The characteristics of clutter interferences of HVDC system and the coupling between double pole lines are analyzed in paper. A novel single-ended travelling-wave fault location method for HVDC transmission lines based on the correlation between two pole lines is proposed. The signal of the non-fault pole line is applied as reference signal; the method suppresses interference through the cross-correlation calculation between the fault and the no-fault pole line. So the reflected wave is enhanced and the identification reliability of the reflected wave is improved. The validity of the method is verified by simulation and on-site data analysis.

Accurate Fault Location Method of the Mechanical Transmission System of Shearer Ranging Arm

In the process of coal mine production, the fault of the mechanical transmission system of the shearer ranging arm directly affects safety production. Therefore, it is very important to achieve the accurate fault location of the shearer ranging arm. The combination method of optimized continuous complex Morlet wavelet envelope demodulation spectrum analysis and spectrum analysis is proposed. Firstly, the spectrum contrast analysis of vibration signals between the normal state and fault state is performed, which can obtain the fault characteristics frequency and preliminary fault location. Then, the optimized continuous complex Morlet wavelet envelope demodulation algorithm is proposed to extract the side-bands characteristics of vibration signals, which can obtain the rotation frequency of fault location by the contrast analysis of side-bands characteristics in normal and fault state. In the algorithm, the center frequency and bandwidth of Morlet wavelet are optimized by wavelet Shannon entropy, and the optimal scale factor can be accurately determined by spectrum contrast analysis of vibration signals in normal and fault state. Finally, the accurate gear fault location is achieved by comprehensive analysis results of optimized continuous complex Morlet wavelet envelope demodulation spectrum and spectrum contrast. The simulation signals and practical vibration signals are applied to verify the proposed accurate gear fault location method. The experiment results indicate that the center frequency and bandwidth determined by wavelet Shannon entropy make the wavelet waveform best match the fault impact signal, and the optimal scale factor can be accurately determined by spectrum contrast analysis of vibration signals in normal and fault state, and the proposed method can achieve the precise fault location of the mechanical transmission system of shearer ranging arm. It provides the method for the on-site rapid accurate fault location of the mechanical transmission system. It is of great significance to the safe and efficient production of the coal mine.

A Hybrid Method Based on Optimized Neuro-Fuzzy System and Effective Features for Fault Location in VSC-HVDC Systems

One of the most important issues with HVDC systems are the occurrence of various faults that can lead to considerable electrical power losses, serious damage to expensive equipment and huge financial losses. Hence, it is highly required to design an accurate and automatic fault location method in HVDC systems for maintaining uninterrupted supply of energy and protecting sensitive equipment such as rectifiers and inverters. Accordingly, this paper proposes a new hybrid system based on adaptive neuro-fuzzy inference system (ANFIS) with optimal parameters and Hilbert-Huang (HH) transform for fault location in voltage sourced converter-HVDC (VSC-HVDC) systems. The proposed fault location method consists of three major sections. In the first section, HH transform is applied to extract new features from current signal. In the second part, ANFIS uses the extracted features to estimate the fault location in transmission lines. Learning algorithm determines the accuracy and efficiency of each machine-learning algorithm. In the third section of the developed system, enhanced version of particle swarm optimization (PSO) algorithm named chaotic dynamic weight PSO (CDWPSO) algorithm is implemented as learning algorithm to train the ANFIS. The developed fault detection and location system was tested on a VSC-HVDC system with 250 km length and the obtained results using MATLAB simulations have shown that combination of new features, and CDWPSO-based ANFIS has high accuracy in fault detection and location in VSC-HVDC systems. High fault location accuracy, robust performance of neuro-fuzzy system, optimal training of ANFIS, extraction of novel effective features from current signal and fault location only with six features are the main contribution of the developed system.