A Novel Traveling Wave Fault Location Method Based on ICEEMDAN-NTEO for Distribution Network

Literature Review of Fault Location Research for HVDC Transmission Lines

In order to solve the problem of inaccurate fault location in the transmission network under some abnormal conditions, such as traveling wave location device faults, startup failure and time recording error, a novel traveling wave fault location method based on directed tree model and linear fitting is proposed. A directed tree model of the fault traveling wave transmission along the shortest path is established based on graph theory analysis of traveling wave transmission network. Two straight lines are fitted on the coordinate plane where the accurate fault location is obtained direct by coordinate information of the intersection of these two fitted straight lines (FSLs), according to the transmission characteristics of the fault traveling wave in the directed tree model. The wave velocity is used as the slope of the fitted straight line, and the influence of its uncertainty on the fault location is eliminated. The time record error points of the location device are automatically eliminated in the linear fitting. PSCAD simulation results prove that fault information of the entire transmission network is comprehensively utilized by the proposed method and the ring network is automatically unlooped. The reliability and accuracy of fault location are remarkably improved, particularly for the fault scenarios with recorded information abnormity.

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

单端辐射状配电网发生单相接地故障时，单端行波法故障测距的难点在于第二个到达测量点的故障行波波头的正确辨识。针对上述难点，本文提出了一种基于支持向量机的单端行波故障测距方法。首先，利用支持向量机正确地识别出故障段，然后根据行波传播的网格图确定第二个到达测量点的故障行波波头是来自于故障点还是来自于对端母线。通过相模变换消除电磁耦合的影响，通过对小波变换相关知识的研究，选择最优小波基进行小波变换，对故障行波波头进行识别，检测故障行波波头模极大值对应的时刻，进而利用相应波头到达测量点的时间差结合波速实现故障点的精确测距。 When single-phase-to-earth fault occurred in radial distribution network supplied by single power, the key problem of the single-ended traveling wave fault location lies in the correct recognition of the second travelling wave head to reach the measuring point. In view of the above problem, this paper introduces single terminal traveling wave fault location method based on SVM. After identifying the fault section by the SVM, the second traveling wave head coming from the fault point or bus at opposite terminal is recognized based on lattice diagram of traveling waves. Elec-tromagnetic coupling effect is eliminated by phase mode transformation. Through the study of relevant knowledge of wavelet transform, the optimal wavelet base is selected for wavelet trans-form in order to identify the fault traveling wave head. The time corresponding to fault traveling wave modulus maximum is detected and time difference of arrival and velocity of the corre-sponding wave head is used to achieve fault location.

A single-terminal traveling wave fault location method for VSC-HVDC transmission lines based on S-transform is proposed. S-transform is applied to analyze the amplitude variation of the line-mode fault traveling wave signal on each frequency component. The moments corresponding to the modulus maximums of the high frequency components are exactly the traveling wave arrival times. Combining with the propagation law of fault traveling wave in VSC-HVDC system, three wave heads can be identified, one is the wave head of the initial transient traveling wave, the other two are the wave heads of the first reflected traveling waves at the fault point and the opposite DC bus, respectively. The fault location can be implemented with the three wave heads, which can avoid the influence of wave velocity. The PSCAD simulation results show that the proposed method has high accuracy without being affected by transition resistance theoretically.

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

In railway automatic blocking/power continuous line, quickly determining the fault location after a ground fault occurs is of great significance to its safe operation. This paper studies a traveling wave fault location method based on noncontact distributed measurement of railway power continuous line. Use the distributed traveling wave acquisition terminal to receive the space electromagnetic wave signal of the railway power continuous line, and use the noncontact method to collect the traveling wave to obtain the three-phase composite traveling wave quantity of voltage and current. The collection terminal does not need to be installed on the transmission line, avoiding power outages caused by equipment installation and maintenance. Through the wave speed normalization method based on the equivalent line, the influence of the wave speed discontinuity of the mixed line of overhead lines and cables is eliminated. The wavelet transform modulus maximum method is used to determine the arrival time of the traveling wave to determine the fault location. Simulation and practical application test verify the effectiveness and practical value of the method.

An improved traveling wave fault location method based on network is presented in this paper. The traveling wave fault location system is composed of fault location units (FLU) and traveling wave analysis host (TWAH). FLU monitor the switch condition, record the arrival time of traveling wave and report the fault data. TWAH analyzes the fault data to determine the fault line and eliminate the invalid data. All the valid data at each side of the fault line are respectively formed two arrays according to the time sequencing. Setting weights for each substation, and the true fault location can be calculated by information fusion technology. Base on the topology of the power grid in Zhuzhou, China, the fault location principle and scheme was proposed. Simulation results of EMTP show that the proposed method can improve the accuracy and reliability of fault location, satisfy the n-1 principle and is also free from the influence of some time recording errors.

This paper presents a multiport traveling wave fault location method which is based on PLC. In this method, we use the different time that traveling wave, which is generated at the moment when a fault arising in the medium voltage distribution lines, arrive at each transformer, then use the PL3105 chip sending the time signal to the central station, after the central station getting the time signal, it analysis these time signal to determine quickly the location of the fault. This method does not require external signal source, can be fast and accurate fault location. This method improves the efficiency of distribution network fault location significantly. This article gives the design of multiport traveling wave fault location, and use the PL3105 chip to send high-speed signal at the 10KV distribution network

A method is provided to make natural frequency method be applied to single terminal traveling wave fault location in the paper. A group of fault distance suspected is calculated by single terminal method of traveling wave fault location method firstly, then deal with current travelling wave of fault by FFT to get the natural frequency reflecting fault location so that a fault distance can be calculated by it. Contrast the fault distance from natural frequency method and everyone of the group of fault distance suspected from single terminal method of traveling wave fault location method to determine the suspected fault distance closed to it is the calculation results we want. Numerical simulation shows the method can improve effectively the reliability of single terminal traveling wave fault location.

Two-terminal fault combination location method on MMC-HVDC transmission lines based on ensemble empirical mode decomposition

Fault location of transmission lines connecting with short branches based on polarity and arrival time of asynchronously recorded traveling waves

Due to its own advantages, MMC-HVDC transmission system has been widely used in power transmission and grid connection. According to the existing double-terminal traveling wave fault location method of MMC-HVDC transmission lines, a double-terminal traveling wave location method is proposed, which is not affected by wave velocity. The wavelet transform is performed on the voltage traveling wave signals at both ends to determine the time when the traveling wave reaches both ends of the line, and the distance of the fault point is calculated. It effectively reduces the influence of the uncertainty of traveling wave velocity on the positioning results and improves the positioning accuracy. The simulation of PSCAD and Matlab software proves the effectiveness and correctness of the method.

A traveling wave fault location method based on multi measuring points for distribution network with distributed generation is proposed in this paper. A novel fault location algorithm based on the time difference between the first aerial-mode and zero-mode wave-fronts of the traveling wave are used to obtain the preliminary fault location without the wide area precision time synchronization. This method acquires the information gathered by measuring points at the distribution network busbar and the terminals of the trunk feeder and the random error is eliminated by using network redundant data. It's verified that the method proposed in this paper can achieve accurate location of the fault section and fault distance for distribution network with distributed generation effectively by using the IEEE 34 node network simulation.

Based on the analysis of the transient process of the electric line’s developing ground fault, this paper applies the oppositely-directed travelling wave fault location method to fault location in distribution network. Simultaneously, this paper chooses proper wavelet generating functions to find the modulus maximum of oppositely-directed travelling waves and summarizes the methods and steps of this oppositely-directed travelling wave fault location. Finally, PSCAD/EMTDC is used to simulate the single-phase ground fault to verify the oppositely-directed travelling wave fault location method.