Traveling Wave Fault Location Research Articles

Traveling wave velocity independent fault location scheme with adaptive mathematical filters for distribution network

In this paper, a novel traveling wave fault location scheme suitable for multi-branch distribution network is proposed. First, to overcome the negative impact of noise signals, a method based on multiscale mathematical morphology is designed to extract the arrival time of fault-generated traveling waves, with the structure elements adaptively adjusted according to the characteristic of input signals. Then, two proper criteria derived from multi-end traveling wave method are used to identify the faulty line section and filter the valid time recorded by traveling wave detectors, respectively. Finally, a velocity-independent formula is presented to achieve the accurate fault location. Extensive simulation tests are carried out to evaluate the feasibility of the proposed scheme, and the simulation results verified that it is independent of the fault location, inception angle, impedance and noise interference.

Novel travelling wave fault location principle based on frequency modification algorithm

Travelling wave (TW) fault location principle is widely utilized on actual power transmission line, which has higher fault location accuracy than conventional algorithms. But, considering the TW fault location principle is generally implemented using TW front arrival time and transmission velocity, the fault location accuracy is high influenced by frequency distortion. Therefore, in order to enhance the fault location accuracy, a novel TW fault location principle is proposed based on frequency modification algorithm. Firstly, the frequency modification algorithm of TW front is studied. Secondly, the detailed calculation principle of system impedance and transmission line’s wave impedance is proposed. Thirdly, the novel TW fault location principle based on modified frequency spectrum is described. Eventually, via PSCAD/EMTDC simulation software, a typical 500kV simulation model is constructed to validate the robustness of proposed TW fault location principle against fault type, grounding resistor and fault initial angle issues.

Bi-level decision matrix based fault location method for multi-branch offshore wind farm transmission lines

Multi-branch complex structure and harsh maintenance environment directly lead to the high-cost and time-consuming of fault detection in deep-sea offshore wind farms (DOWF). This paper proposes a traveling wave fault location method based on a bi-level decision matrix (BDM) aiming at multi-branch deep-sea offshore wind farm transmission lines. First, the first intrinsic mode function (IMF) signal is extracted by the variational mode decomposition (VMD) from initial traveling wave signals, which is further decomposed into S matrix by Stockwell-Transform (ST). Then based on the energy similarity between E matrix obtained through S matrix at all records, the area decision matrix is built to identify fault area. Second, S matrix recorded at both ends of fault area is extracted and analyzed by kurtosis to determine the traveling wave arrival time. Based on the fault area inherent topology and the traveling wave arrival time, the section decision matrix is built to identify fault section. Finally, the fault location is determined by the corresponding calculation process based on the identification results of BDM. Referring to the actual multi-branch topology of offshore wind farm (OWF), case studies are conducted under various fault conditions. The results show that the proposed method does not need to install recorders at all terminals, has high fault location accuracy, and is immune to noise.

Traveling Wave Fault Location Technology in Distribution Network Based on Non-Contact Sensor

In view of the fact that traditional traveling wave sensors need to be directly connected with primary high-voltage equipment, the layout is not flexible, construction is inconvenient, and the traditional ferromagnetic coil traveling wave sensors have problems such as low sensitivity and magnetic saturation. The use of magnetoresistance chip to design non-contact traveling wave sensor is proposed. Theoretical analysis of the magnetoresistance chip is carried out, and the tunnel magnetoresistance chip is selected as the non-contact sensor magnetic sensitive element; the non-contact sensor hardware circuit is designed, the sample is trial-produced, and the experimental test is carried out. The experiment shows that the non-contact sensor can detect a traveling wave signal with a bandwidth of 100kHz∼5MHz, which meets the requirements of traveling wave detection for common fault types in the distribution network. A demonstration project has been built, and operation shows that the non-contact sensor can successfully detect single-phase grounding, interphase short circuit, lightning strikes and other fault types traveling wave signal, sensitivity is higher than traditional traveling wave sensor, positioning error is less than 150m.

Travelling wave fault location for LCC–MMC–MTDC transmission lines based on frequency-dependent characteristic

The paper studies the fault location principles of multi-terminal direct-current (MTDC) hybrid transmission systems based on line-commutated converter (LCC) and modular multi-level converter (MMC). Two issues should be addressed: i) the travelling wave (TW) fault location principle adaptable for the hybrid multi-terminal transmission system; and ii) the algorithm of obtaining frequency-dependent characteristic of the TW signal. In the paper, a novel TW fault location principle adaptable for the LCC–MMC–MTDC hybrid transmission lines is developed based on the frequency-dependent characteristic of TW signal. Firstly, the frequency-dependent characteristic of HVDC transmission line is studied. Secondly, a novel TW fault location principle is proposed, comprised of TW arrival time detection, TW propagation velocity calculation, fault section identification and fault location method. A typical ±400kV LCC–MMC–MTDC hybrid system is constructed using PSCAD/EMTDC for case study to validate the accuracy of the proposed principle. Its robustness against fault location, fault resistance and fault type is well demonstrated.

Field Tests of a Traveling Wave Fault Location Service for Overhead Transmission Lines

Field Tests of a Traveling Wave Fault Location Service for Overhead Transmission Lines

ELECTRICAL NETWORK OF FAULT REGIME MODEL CONSTRUCT FEATURES IN A SINGLE-END TRAVELING WAVE FAULT LOCATION METHOD

In the single-end traveling wave (TW) fault location methods, for determining TW front, the arrival time of which is determined by the place of the short circuit (SC) on the power line, electrical network of fault regime models are constructed. From the electrical network of fault regime models, only one is selected that allows, by the first TW front magnitude and its arrival time, to obtain estimations of the TWs fronts magnitudes and their arrival times which are closest to the corresponding quantities determined from locator measurements. Based on the selected electrical network of fault regime model the used TWs are identified and the fault place is determined. Known implementations of the single-end traveling wave fault location method use simplified electrical network of fault regime model: the influence of the fault type and its resistance, as well as the parameters of the electrical network elements, are not taken into account on the TWs fronts magnitude. These disadvantages can cause both an increased error in determining the fault location and even failure in the operation of the locator. In this article, the theory of constructing electrical network of fault regime model is presented: the influence of fault location and its type on the TWs fronts magnitude are considered. Particular attention is paid to the study of the issue of the TWs generation as a result of the cross-transmission effect. It is shown that in order to correctly determine the used TW front in the electrical network of fault regime model, in addition to the power line length and its characteristic impedance, it is necessary to take into account the short circuit type and its resistance, and the possible TWs generation in one mode under the influence of TWs in another one.

Fault location in overhead transmission line: A novel non-contact measurement approach for traveling wave-based scheme

Traveling wave fault location methods have gained considerable growth over the years, with the anticipation that power systems will be accurate and reliable everywhere. But the performance of classical traveling wave methods has focused only on traditional current transformer measurement in the literature till date. Therefore, in this paper, an innovative non-contact measurement of traveling wave formulation is proposed to achieve accurate fault location and time of arrival detection on a two-terminal overhead transmission line, since power cable naturally generates magnetic and electrical fields in the surrounding atmosphere. The proposed method solitary depends on the first two and successive time differences between the incident and reflective wave from the fault point of the transmission line. Thus, the proposed scheme does not depend on current transformer measurement that stimulates the accuracy and reliability of the conventional traveling wave fault location method. To ensure an accurate time of arrival waves detection, we exploit the magnetic field sensor array on each tower to measure the quality of current traveling waves generated on the transmission line and locate the transient disturbances as a result of a short circuit. By analyzing the line energization, a comprehensive fault analysis on a 500-kV line was simulated with PSCAD/MATLAB toolbox compared to the two-terminal classical method. The sensitivity analysis demonstrated that the proposed method is much accurate and reliable to be deployed and cost-effective, making it highly useful and efficient in comparison to the classical two terminals traveling wave method with an average error of 0.014%. The effectiveness of the proposed method was verified by laboratory experimental setup.

A multi-terminal traveling wave fault location method for active distribution network based on residual clustering

Since distribution networks have multiple branches, complex topologies and increasing penetration of the distributed energy resources (DERs), the accurate fault location is difficult to realize. The existing traveling wave fault location methods are strongly affected by the arrival time errors. To overcome the problems mentioned above, a multi-terminal traveling wave fault location method is proposed for active distribution networks based on residual clustering. Firstly, the traveling wave arrival times are utilized to construct a minimized optimization model for each section. The objective optimization function represents the minimization of the sum of squared errors (MSSE), and the global optimal solutions reflect the wave velocity and the fault distance. Subsequently, the particle swarm optimization algorithm (PSO) is used to solve the above optimization models, and the section with the minimum MSSE is judged as the faulty section. Finally, the density-based spatial clustering of applications with noise (DBSCAN) algorithm is utilized to group the residuals of the faulty section to identify the bad data, which are affected by the arrival time errors. And the normal data remained are applied to reconstruct the optimization model and calculate the optimal solution of the fault distance. Thus, the fault location results can be corrected. Simulation results and field tests indicate that the proposed method has high fault location accuracy, strong robustness to time errors and high adaptability for active distribution networks.

Novel travelling wave fault location principle for VSC-HVDC transmission line

Currently, voltage source converter (VSC) based high voltage direct current (HVDC) technology is widely utilized in power transmission system. It has high transmission efficiency, no commutation failure issue and ability to supply power to passive system. In order to enhance the reliability of VSC-HVDC transmission system and accelerate the maintenance progress, travelling wave (TW) fault location principle is adopted to discriminate the exact location of transmission line (TL) fault, and its fault location accuracy is highly related to TW arrival time detection and TW propagation velocity. Therefore, aiming to enhance the fault location accuracy, the paper proposes a novel TW fault location principle for VSC-HVDC transmission line. Firstly, the detailed calculation method of propagation velocity of TW along HVDC-TL is described. Secondly, a novel TW fault location principle is proposed including TW arrival time detection method and TW’s accurate frequency calculation method. Eventually, based on PSCAD/EMTDC, a typical ±400kV VSC-HVDC simulation model is established to validate the robustness of novel TW fault location principle against fault type issue, fault resistance issue and fault location issue.

Research on Transmission Line Fault Location Based on the Fusion of Machine Learning and Artificial Intelligence

After a transmission line fails, quickly and accurately find the fault point and deal with it, which is of great significance to maintaining the normal operation of the power system. Aiming at the problems of low accuracy of traditional traveling wave fault location methods and many affected factors, this paper relies on distributed traveling wave monitoring points arranged on transmission lines to study methods to improve the accuracy of traveling wave fault location on transmission lines. First, when a line fails, a traveling wave signal that moves to both ends will be generated and transmitted along the transmission line. We use the Radon transform algorithm to process the traveling wave signal. Then, this paper uses ant colony algorithm to analyze and verify the location and extent of transmission line faults and then optimizes high-precision collection and processing. Finally, the simulation distance measurement is carried out on double-terminal transmission lines and multiterminal transmission lines (T-shaped lines) with branches. The results show that, for double-ended transmission lines, the algorithm increases the speed of matrix calculations and at the same time makes the fault location error of the transmission grid still maintain the improved effect.

A Novel Transmission Line Fault Location Method Based on Time Frequency Correlation

The fault location method based on the transient traveling wave has been widely used in power grid. The location accuracy and reliability of traveling wave fault location may get affected by some factors including: length error of transmission line, timing error, secondary signal cable in substation. The paper proposes a novel fault location method based on the time-frequency correlation of the fault data collected from two ends of transmission line. It takes advantage of the symmetry and similarity of reflected waves at both ends while the resonance and the reflected waves of adjacent lines are not correlated with each other. Through time-frequency correlation analysis at both ends, the influence of interference and resonance is suppressed, reliability of reflected wave identification and fault location, as well as accuracy of fault location are improved. Effectiveness of the method is verified by simulation and field data.

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.

Optimised Time for Travelling Wave Fault Locators in the Presence of Different Disturbances Based on Real-World Fault Data

The real-world travelling wave fault data investigated in this paper indicate disturbances generate unpredictable, non-stationary and random waveforms which may cause maloperation of protection and control elements in a power system including travelling wave fault locators (TWFL). This type of fault locator is directly dependent on the detection of an accurate time of arrival (ToA) of travelling waves (TW) generated by a fault. This detection becomes complicated in the presence of disturbances when their ToAs are detected earlier than the fault TWs. Since travelling waves occur in the high-frequency bands (e.g. >50 kHz), in this paper a capacitor voltage transformer is employed to measure the TW voltage signals; this involves acquiring the current flowing to the ground and removing the low-frequency components (50/60 Hz). Disturbances create high magnitude pulses in the pre-fault section of a TW fault signal that last for a short time. Therefore, the time when a TWFL starts its computations requires to be optimised so that the effect of the disturbances is eliminated. The analysis techniques mentioned in this paper are based on real-world travelling wave fault data, and the solution uses statistical tools, such as cost function, mean and standard deviation, alongside Digital Signal Processing algorithms.

Classification of diagnostic features of transient signals in the electric power industry

Problems of practical implementation of traveling wave fault location caused by the registration of signals of different nature are considered. Analysis of the experimentally recorded traveling waves made it possible to divide them into 4 groups caused by partial discharges, lightning overvoltages, scheduled switching and fault commutations. The network dispatchers only needs the fault commutation information. Traveling waves recorded near the place of their origin have different meanings of diagnostic signs. The magnitude of the pre-alarm noise, the number of pulses in the signal and the duration of the signal are used as diagnostic indicators. These three diagnostic signs allow one to recognize each of the 4 causes of the travelling waves.

Travelling Wave Fault Location of HVAC Transmission Line Based on Frequency-Dependent Characteristic

Travelling wave (TW) fault location has been widely utilized for high-voltage alternating current (HVAC) transmission lines, which is proven to have a higher accuracy than conventionalpower frequency data based fault location. However, as known, the performance of travelling wave-based fault location (TWFL) principles is often challenged by several factors including fault location, fault initial angle, fault resistance as well as frequency dependency of HVAC transmission lines. In this context, this paper proposes a novel off-line TW fault location principle for transposed HVAC transmission lines to address the robustness against those uncertain factors. Firstly, the frequency-dependent characteristic of HVAC transmission lines is analyzed. Then upon that, a novel TW fault location principle is proposed, which consists of two important components: i) arrival time detection of TW and ii) accurate frequency calculation of TW. Eventually, simulations are carried out on a 500 kV AC transmission system using PSCAD/EMTDC to validate the effectiveness of the proposed method and itsrobustness against different fault types, resistances, locations, initial angles and noises.

Frequency analysis and research of the traveling wave signal of catenary line

SummaryDue to the characteristic of traveling wave dispersion, the wave shape distortion is caused, and the technical difficulty of traveling wave fault location is increased. The frequency analysis and research of the traveling wave signal of the catenary line are presented, based on the wavelet theory and discrete Fourier transform. At first, the frequency information of the traveling wave signal is extracted by DFT, which turns on that the amplitude of each frequency and its distribution characteristics are clarified. Then, the analysis and verification of the traveling wave signal of the catenary line rely on the wavelet theory. The simulation results show that the frequency distribution of the catenary line is obvious, and it has great significance for the further understanding of the characteristics of the traveling wave dispersion and the use of traveling wave ranging technology.

A novel traveling wave fault location method for transmission network based on time linear dependence

Transmission network faults may not be located accurately in some abnormal conditions, such as traveling wave location device faults, startup failure and time recording error. In order to improve them, a novel traveling wave fault location method based on time linear dependence is proposed. The proximal point optimization algorithm (PPOA) is used to find the shortest transmission path of fault traveling wave. The linear fitting between the arrival time of the traveling wave head recorded by each substation and the transmission distance is made on the Cartesian coordinate plane, according to the characteristic that the length of the shortest path is directly proportional to the traveling wave transmission time. The information fusion for the traveling wave arrival time at each substation is achieved by linear regression analysis to correct the error information. The accurate fault location is obtained direct by coordinate information of the intersection of the fitted line and the coordinate axis. Finally, the traveling wave location system based on this method has been successfully tested in Hunan Power Grid. PSCAD simulation and field test results prove that the proposed method can effectively reduce the recording error in the arrival time of the fault traveling wave at each substation while improving the reliability and accuracy of fault location.

Traveling-Wave-Based Fault Location Method for Hybrid Distribution Network Mixed with Three-Phase and Phase to Phase Supply Lines

In China, a hybrid distribution network mixed with three-phase main lines and phase to phase supply lines can be found in many MV distribution networks due to lower cost of using two lines from three-phase main lines as well as lower cost of phase to phase transformer. For such a hybrid distribution network it is a challenge for traditional fault location techniques. This paper presents a traveling wave fault location method based on double-terminal measurement techniques. The proposed method analyses the traveling wave propagation mechanism of both aerial mode and zero mode components for a fault. The method then determines which mode component is used for the fault location according to fault types. The method has been developed and assessed on a typical distribution network using ATP power network simulation tool. The tests were conducted under various fault scenarios. The results show that zero mode component is more effective for a fault on the phase of three-phase main lines which is not linked to the phase to phase supply lines. However for a phase-to-phase fault, aerial mode component is more effective. For the remaining fault types, either aerial or zero mode component can be used.

Design of Traveling Wave Location Method for Transmission Line Fault Based on EMD-TEO

<p>With the rapid development of the social economy and the continuous extension of Internet technology, China’s power grid has entered the ranks of large-scale, high-voltage, and intelligent. The main purpose of the fault location of the transmission line is to eliminate hidden trouble and restore the fault line in time to ensure the safe and stable operation of the power system. With the advent of the smart grid, higher requirements are put forward for fault location accuracy, while the traditional wavelet transform and Hilbert-Huang transform have larger defects.</p><p>Therefore, this paper extensively analyses the generation and characteristics of fault traveling waves in transmission line fault, which proves that the traveling wave location method has higher location accuracy than the fault analysis method. Among them, the two-terminal traveling wave positioning method only uses the arrival time of the initial traveling wave, avoiding the principled defects and locating the dead zone of the single-terminal traveling wave positioning method, so the two-terminal traveling wave positioning method is generally used. The key of the two-terminal traveling wave location method is that it can accurately detect the arrival time of the initial traveling wave head. Although the Hilbert-Huang Transform (HHT) method can be used to detect the arrival time of the initial traveling wave head, the problem of inaccurate detection or failure of the wave head may arise when the instantaneous frequency of the IMF component decomposed by the Hilbert-Huang transform is used because of the mode aliasing in the empirical mode decomposition algorithm. Based on the above analysis, an empirical mode decomposition (EMD) combined with the Teager energy operator(TEO) is proposed for the traveling wave fault location of transmission lines. A large number of simulations prove that the EMD-TEO method in this paper can solve the problem of inaccuracy or failure of the HHT method using instantaneous frequency to detect the arrival time of wave head, and has higher fault location accuracy.</p>