Travelling Wave Fault Location Algorithm Research Articles

Travelling wave fault location algorithm for LCC-MMC-MTDC hybrid transmission system based on Hilbert-Huang transform

The paper looks through the fault location algorithm of multi-terminal direct-current (MTDC) hybrid transmission systems based on line-commutated converter (LCC) and modular multi-level converter (MMC). Generally, it has two issues which required to be addressed: (1) the travelling wave (TW) fault location algorithm suitable for the multi-terminal transmission system; and (2) the method of acquiring or processing the TW signal. In this paper, a novel TW fault location algorithm suitable for the LCC-MMC-HVDC hybrid transmission system is researched based on the Hilbert-Huang transform (HHT). Firstly, the TW propagation process characteristic of hybrid LCC-MMC-MTDC transmission system is studied. Secondly, a novel TW fault location algorithm based on HHT is proposed. Eventually, a typical ±400 kV LCC-MMC-MTDC hybrid transmission system is established via PSCAD/EMTDC software for the case study to investigate the accuracy of the proposed algorithm. Afterwards, its robustness against fault location issue, fault resistance issue and fault type issue is also confirmed.

Traveling-wave fault location algorithms in hybrid multi-terminal networks with a tree-like structure

Traveling-wave methods of the fault location prove their practical efficiency for the power transmission lines (TL) with an arbitrary configuration of any voltage class. This paper formulates algorithms to automate the process of the fault location in the TLs with a tree-like structure. The error of the simplified traveling-wave fault location (TWFL) algorithm based on the average propagation velocity of the transient signals (TS) is analyzed. A tabular algorithm for TWFL, which considers different propagation velocities of the TS in different segments of a hybrid network is proposed. An adaptive TWFL algorithm that considers the registration of the TSs with known places of their occurrence is proposed, to reduce the impact of the inaccuracy of the initial different network segments’ lengths and TS’s propagation velocity determination.

Self‐adapted single‐ended travelling wave fault location algorithm considering transfer characteristics of the secondary circuit

The transfer characteristics of a secondary circuit consisting of a current transformer) and a secondary cable are critical to the performance of single-ended travelling-wave-based fault locators. The non-ideal nature of the secondary cable often leads to distortion of the recorded travelling waves. In addition, this may lead to wave front identification failure. A high-frequency model of the secondary circuit is developed in this study. Based on the transfer function of the equivalent circuit, the distortion is found to be a superposition of two damped oscillation components. Recorded waveforms from an on-site device have been used to verify the model and analysis. A self-adapted single-ended fault location scheme is proposed to mitigate the influence of the damped oscillation components. The dyadic wavelet transform, pre-filtering Prony analysis and impedance fault location algorithm are used. The proposed method is tested on the recorded data, and precise fault location results are achieved. Different fault distances, fault impedances, secondary cable lengths and fault inception angles are also simulated to verify the proposed approach.

Study on Fault Location in the T-Connection Transmission Lines Based on Wavelet Transform

The results of T-Line Traveling Wave Fault Location is easily influenced by the wave arrival time and traveling wave propagation velocity; it proposes that the traveling wave uses wavelet transform to extract the modulus maxima of breakdown voltage, to confirm the time of the traveling wave reaching the three-terminal line. The speed of the traveling wave reaching three terminals is confirmed by the structural parameters of the transmission line. We apply the arrival time and propagation velocity to the T-type traveling wave fault location algorithm. Different transmission line distance select the corresponding algorithm, excluding the impact of fault branches and in some cases ranging accuracy, the failure dead zone will not appear. After MATLAB simulation analysis, the algorithm analysis is clear; the range accuracy is high, so that it can meet the requirements of fault location.

Waveform Recognition Technology in Distributed Fault Location of Transmission Line

Distributed way of traveling-wave fault location algorithm is a new theory founded in recent years. By installing sensing points in distributed way, the accuracy of fault location result can be clearly improved comparing to traditional methods. First, PSCAD is used to simulate the transmission line model and measure the three-phase current data. Second, by using wavelet transformation and phase to-module transformation, these current data is mathematically processed and modulus maximum is achieved easily. Finally, time difference between the adjacent modulus maximum points is calculated and the location is figured out by using the module time-difference algorithm. The test result shows that the method above is valid and the relative error is rather small.

An Improved Wide Area Travelling Wave Fault Location Algorithm

In order to enhance the reliability of traveling wave fault location (TWFL) systems, an improved wide area traveling wave fault location (WA-TWFL) algorithms is presented in this paper. In the disturbance area that near to the fault position, we can first get the possible fault positions by using the outgoing path data from the substation that first records the initial traveling wave, then use the possible fault position to verify the reasonableness of data recorded. The fault position that has no counter-example in logical is the real fault position. EMTP simulation verifies the validity and applicability of this algorithm.

Travelling Wave-Based Fault Location Scheme for Aged Underground Cable Combined with Overhead Line

This paper presents a novel wavelet-based travelling wave fault location algorithm for aged underground cables in transmission systems. Such transmission systems consist of overhead lines combined with underground power cables. Applying the singularity detection feature of wavelets as a powerful signal processing tool, the first and second initial arrival of the voltage travelling waves at the first end of the overhead as well as at the terminal end of the aged cable line can be identified reliably without the need for detection the sign of these waves. In this paper modal signals, rather than the phase signals, are the inputs to the relay.The proposed algorithm is capable of eliminating the effect of the change in the propagation velocity of the travelling waves over the age of the cable. It can be used on-line following the operation of digital relays or off-line using the data stored in the digital transient recording apparatus. Extensive simulation studies carried out using ATP/EMTP show that the proposed algorithm provides an accepted degree of accuracy in fault location under different fault conditions.