Line Selection Algorithm Research Articles

Fault line selection algorithm for single-phase high-impedance ground faults in distribution networks based on the hilbert-huang transform

Fault line selection algorithm for single-phase high-impedance ground faults in distribution networks based on the hilbert-huang transform

Fault line selection algorithm for single-phase grounding faults in distribution networks based on multi-feature fusion of multi-level wavelet decomposition coefficients

Fault line selection algorithm for single-phase grounding faults in distribution networks based on multi-feature fusion of multi-level wavelet decomposition coefficients

Fault line selection algorithm for distribution networks based on AdapGL‐GIN network

AbstractWhen a grounding fault occurs in the distribution network with distributed generation, the network topology becomes intricate, making it challenging to extract fault characteristics, resulting in a decrease in the precision of fault discrimination. To address this issue, a graph isomorphism network (GIN) approach based on the parameterized adaptive graph learning (AdapGL) module is proposed, transforming the distribution network fault selection problem into a graph classification task. First, the adjacency matrix of the distribution network's topology graph is initialized. This matrix, combined with feature vectors from the robust local mean decomposition energy entropy and transient dielectric loss angle of line, will be input into the GIN. Then, the AdapGL module is integrated into the GIN, dynamically learning and updating the one‐way relationships between actual network nodes to complete the graph classification task. Finally, a radial distribution network model (RDNM) and an improved IEEE 34 nodes model are established, and the fault selection results of the AdapGL‐GIN method are compared with those of other methods. The results indicate that the proposed method achieves higher accuracy than other methods, demonstrating significant practical importance in engineering applications.

A single-phase ground fault intelligent wire selection method based on an ant colony algorithm

For the single-phase ground fault, which has the highest probability of occurrence in a 10 kV distribution network, the ant colony algorithm is combined with a neural network for fault line selection, and the algorithm is optimized. The study builds a 10 kV distribution network model in MATLAB and simulates the neutral ground fault. It compares the results of the optimized line selection algorithm, and the traditional line selection algorithm proves that the accuracy of the method in identifying faulty lines is significantly better than that of the traditional method.

Correlation and K-means clustering based small current ground fault line selection algorithm

The existing small current grounding line selecting technique has consequences by transition resistance, fault closure angles, and the fault location, and there is a problem of low selection accuracy, which is addressed by proposing a line-choosing algorithm that employs a combination of transient zero-sequential current (TZSC) waveform correlation and K-means clustering. First, to obtain the correlation coefficient matrix, the correlation analysis is performed for each line of the zero-sequence currents transient measurement values; second, to address the issue of the difficulties in manually setting the threshold, we apply the K-mean cluster analysis algorithm to group the row vectors of the correlation coefficients matrices; and finally, we output the label of the cluster to realize the fault line selection. Simulation and real-world fault data validate the method, showing that it is independent of transition resistance, fault closure angles, and fault location. It can achieve precise and dependable line selectivity.

One-Phase Ground Fault Line Selection Technology for Distribution Network Based on Comprehensive Analysis of Phase Current

Due to the various types and different characteristics of one line-to-ground faults occurring in the partial network which is responsible for distribution, the adaptability of location technology applicable to a one fault type is poor. To ensure the operational reliability of the partial network which is responsible for distribution, this thesis shows a one-phase ground fault line selection technology for distribution networks that is applicable to various types of faults. By using this technology, we can comprehensively analyze the characteristics of phase current in transient state and steady state when different types of faults occur, and fault line selection algorithms suitable for intermittent arcing and resistance grounding respectively were proposed according to the steady-state phase and transient mutation characteristics of phase current. In addition, the feasible region of the proposed line selection technology was expanded by using the comprehensive analysis algorithm combined with two-line selection algorithms, which ensures the reliability of selecting fault line after different types of one line-to-ground fault s occur in the system. Finally, the ATP simulation software was used to verify the reliability and engineering applicability of this technology.

Fault Line Selection of Non-solidly Grounding System Based on EMD and Correlation Analysis of Zero Sequence Current Break-variable

When a single-phase grounding fault occurs in non-solidly grounding system, the zero sequence transient current is nonlinear and non-stationary. Especially when the resonant system is grounded with high resistance, the transient quantity is weak, which brings challenges to data processing. Therefore, empirical mode decomposition (EMD) is proposed to decompose the transient quantity and obtain different intrinsic mode functions (IMF). The IMF with the largest discrimination is selected as the characteristic quantity for correlation analysis. At the same time, considering the existence of unbalanced current in the actual system, in order to avoid the influence of unbalanced current, a single-phase grounding fault line selection algorithm based on EMD decomposition and correlation analysis of zero sequence current break-variable is proposed. Finally, the effectiveness of the method is verified by simulation and field test waveforms.

Single‐pole fault line selection method for MVDC distribution grid based on 0‐mode power

At present, the MVDC distribution grid is developing rapidly and relay protection is the key technology to ensure stable operation. Therefore, this paper focuses on the fault line selection method. Firstly, the fault characteristics are analysed when a fault occurs in the line, and a novel single-pole fault line selection method is proposed based on 0-mode power. The polarity of current fault component measured at the terminal of each line is used to identify the internal and external faults. And the 0-mode power is used to select the faulty line. Finally, to verify the correctness of the proposed method, a radial MVDC distribution grid is built in PSCAD to output fault data in different fault conditions, and the fault line selection algorithm is implemented in MATLAB. The simulation results show that the proposed method is fast, effective, reliable and it has a certain degree of tolerance to transition resistance with a strong anti-data delay and anti-interference ability. Moreover, the fault line selection method proposed in this paper can still correctly select the fault line in the case of serious faults such as multiple line faults, sudden removal of lines, and sudden changes in photovoltaic output power.

Zero CLABSI Is Achievable

<h3>Background</h3> Central Line Associated Blood Stream Infections (CLABSI) are one of the deadliest and most costly Hospital Associated Infections (HAI). Prevention of CLABSI is a primary objective when focusing on patient safety. Will a multi-pronged approach to CLABSI prevention, with the aim of changing organizational culture, prevent CLABSI in a community hospital with 350 beds? <h3>Methods</h3> In 2015, 16 CLABSIs were identified throughout the facility, with 9 of those in the Intensive Care Unit (ICU). A multifaceted approach was used to tackle the facility wide problem of CLABSI with particular focus on the ICU. Actions included creation of a new central line selection algorithm, assembling of a nurse driven vascular access team, implementation of a new central line dressing kit, launch of a drill down for each identified infection, including bedside caregivers, re-education on correct blood culture collection protocol, creation of a central line management policy, and a focus on communication throughout disciplines in the facility. The National Healthcare Safety Network (NHSN) Standardized Infection Ratio (SIR) was used to determine effectiveness of implementation plans. <h3>Results</h3> The CLABSI SIR in 2015 ranged from 0.4 to 1.8, with at least 3 infections per quarter. The facility has continued to see impressive decline in CLABSI annually. The facility was able to complete one year CLABSI free and is looking forward to doing so again. The ICU has remained CLABSI free for 3 years. <h3>Conclusions</h3> This project found that zero CLABSI is attainable. It requires a culture change and a new bundle beyond the standard insertion and maintenance. Learnings can be taken to facilities across the country to eliminate CLABSI.

Neutral Grounding Fault Line Selection Algorithms for Low Voltage Side of Distribution Transformers in Civil Buildings

The neutral grounding fault line selection of low-voltage side of distribution transformer in civil buildings is of great significance in the field of power system. It is necessary to analyze the grounding fault of distribution transformer in civil buildings, calculate the current energy of distribution transformer by using the frequency coefficient of wavelet packet decomposition, and analyze the current fault components of grounding fault phase and sound phase, get the energy ratio of grounding fault current component, and complete the grounding fault of distribution transformer. Experiments show that the proposed algorithm can reasonably judge the fault line of distribution transformer nodes, and has a high accuracy in the selection of grounding faults.

Fully Automated Active Contour Model Based Approach for Segmentation of Common Carotid Artery Using Ultrasound Images

Abstract In this paper, we have proposed an automated approach to segment common carotid artery from longitudinal carotid B-mode ultrasound images and calculate the carotid intima media thickness. The proposed approach extracts the contours in the ultrasound images using gradient vector flow snakes with an improved snake initialization process. The seed points for this improved snake initialization process are extracted using selected edges returned by the candidate line-selection algorithm. Intima media thickness is calculated from the extracted contours. The proposed approach is tested and clinically validated on a data set of 100 longitudinal ultrasound images of the carotid artery. There is no significant difference between intima media thickness measurements obtained using the proposed approach and the manual measurements. The intra-observer error of 0.088, a coefficient of variation of 12.99 %, Bland–Altman plots with small differences between experts (0.01 and 0.03 for Expert1 and Expert2, respectively) and figure of merit of 98.5 % are obtained. The proposed approach can be used successfully for carotid intima media thickness measurement, which can further be used for risk estimation of cardiovascular diseases and ischemic stroke. The proposed approach makes the segmentation process automated and yet reduces the risk of subjectivity and operator variability for intima media thickness measurement.

Line Selection Device Based on Double Tree Complex Wavelet

Single phase ground fault has the highest rate to happen in distribution network, use the method based on transient component can improve line selection accuracy effectively. sensitivity and directional selectivity can improved by using dual tree complex wavelet transform than using discrete wavelet translation, there is a decaying current fault line and normal line of difference, the difference is phase to phase delay reflected in current after wavelet transformation , the fault line and normal line zero sequence current and zero sequence current proportion relationship, there still worse a decaying direct current component, the normal phase between the two zero sequence currents are equal, therefore according to the phase relation after wavelet decomposition when will still be able to distinguish the fault line and normal line. Using the fast operation speed of digital signal processor can realized the fault line selection algorithm.

Line Selection Algorithm of Coal Mine High Leakage Based on Fuzzy

In order to solve the high-voltage grid electricity coal mine one-phase ground fault (high leak), choose the theory of fuzzy algorithm. According to the current harmonic fault diagnostic, zero sequence active power method and transient zero sequence current mutual product summation method, three methods set fault measure membership function and weight coefficient membership function, realize fuzzy comprehensive decision, judge single-phase grounding line. Through the Matlab/Simulink simulation experiment, fuzzy theory algorithm can accurately choose single-phase grounding line.

Lyα Absorption in the Quasar Triplet Q0107-025A, Q0107-025B, and Q0107-0232: Data Calibration and Line Selection

We present spectroscopic observations for quasars Q0107-025A, Q0107-025B, and Q0107-0232. For the first time, all data obtained with the Hubble Space Telescope's GHRS and FOS for these three quasars are combined. Lyα absorbers selected from the spectra can be used to trace the coherence of the intergalactic medium (IGM) on scales of 1-2 h Mpc over the redshift range 0.4 < za < 0.9. A new analysis of double and triple absorber coincidences derived from the improved spectra is performed. Automated line-selection algorithms were used to detect absorption lines in the QSO spectra; coincident absorbers were identified across two and three sight lines based on their proximity to each other in velocity space. A control simulation designed to generate artificial absorption-line spectra was used to gauge the significance of the coincidences. Four intervening metal-line absorption systems are detected, with three of the four coincident to the A and B sight lines and one coincident across all three sight lines. This is evidence for substantial clustering among the objects responsible for the metal-enriched gas. By contrast, large-scale coherence of the IGM gas is detectable but weak. Fewer than half of the absorbers are coincident on scales of 1-2 h Mpc, a result that is significant at the 99% confidence level, and coherence arises preferentially in the higher column density gas. Triple absorber coincidences occur at a level that is significant at the 99% confidence level, which indicates that the higher column density gas has a planar geometry.

A fast line-by-line method

A new spectral line selection algorithm is developed. The algorithm makes it possible to decrease the number of spectral lines with the increase in altitude. In order for the computer code based on a line-by-line method to operate efficiently two line selections must be carried out. The first selection is rough. This enables the most weak lines not contributing to the optical thickness of the layer z 1– z 2 to be eliminated. The other lines are subjected to the second selection. In this case the maximum height up to which the line should be taken into account is determined. At the same time for each line at each altitude the maximum resonance frequency difference within the limits of which the contribution of the line to absorption should be taken into account is determined. The gain in the time of calculation of the integral transmittance may be of five times or greater. The calculation error of the integral transmittance is not larger than 0.5%.

On-Line Security Monitoring by Detecting of Specified Modes Through Power Flow Observation

A transmission line selection algorithm is developed for the security monitoring by detecting of a specified mode through the power flow observation. The algorithm is based on the coherent grouping approach by Chow's group. The combination of the synchronizing coefficients and grouping matrices, is used for the selection of the appropriate line for the monitoring. The concept of the flow monitoring is reasonable for the security check, which is confirmed through the field data. The proposed approach has been tested by 19-generator, 28-bus and 39-line model. Application of FFT is also discussed.