scholarly journals Fault identification of double-circuit transmission lines on the same pole based on EEMD energy ratio

2022 ◽  
Vol 355 ◽  
pp. 03035
Author(s):  
Yicen Liu ◽  
Ying Chen ◽  
Songhai Fan ◽  
Yiyu Gong ◽  
Xi Zou

In order to improve the sensitivity and reliability of traveling wave protection, on the basis of analyzing the relationship of the anti-traveling wave current amplitude in the window after the internal/external failure of the double circuit line on the same tower, a fault identification method based on EEMD energy ratio is proposed. Use EEMD decomposition to decompose the anti-traveling wave current in a time window after the fault into 7 scales, and extracts the EEMD energy ratio at each scale at both ends to form a feature vector. Then it is sent to the particle swarm optimization support vector machine (PSO-SVM) for training and testing, and the internal and external faults are identified. Experiments show that the algorithm has good fault identification ability, the fault accuracy is 95% and the method sensitivity is high.

2012 ◽  
Vol 503 ◽  
pp. 3-7
Author(s):  
Meng Zhao ◽  
Ji Bin Zou ◽  
Jing Shang

According to researching the spin traveling wave pump, the relationship of the characteristics of magnetic fluid and the press is investigated under the spin magnetic field by the theory method. The relationship of moving, magnetic field and press is investigated by the decoupled computation between the magnetic field and force. The method is scientificity and rationality by the testing. The distributing shape of magnetic fluid in the pump is affected by the adding magnetic field under the spin magnetic field when the magnetic fluid is filled in the pump. At the same time, the adding magnetic field is affected by magnetic particles of magnetic fluid. The magnetic fluid can be moved by the effect of the adding magnetic field in the pump. The flux of magnetic fluid increases with the magnetic field.


2014 ◽  
Vol 945-949 ◽  
pp. 2873-2879
Author(s):  
Zhong An Yu ◽  
Ming Zhao Cheng ◽  
Pei Yu Guo ◽  
Neng Ling Tai

The application of traditional distance relay for four-parallel transmission lines is adversely affected by the mutual coupling between the lines. The result will lead to not achieved measured impedance calculation. And it has an effect on the operation of ground protection. In this paper, A new ground distance algorithm is proposed for single-phase grounding fault of four-parallel transmission lines. Based on the case of single-phase grounding fault, The first the relationship between fault point voltage and the voltage at protection installed location is presented by twelve-sequence component method. In the basis, According to the relationship of phase corner between the fault voltage and the fault current to eliminate the effect of fault voltage. The simulation results show that the new scheme has high sensitivity and reliability under different single-phase grounding fault of four-parallel transmission lines.


2013 ◽  
Vol 760-762 ◽  
pp. 320-324
Author(s):  
Shi Lei Zhou ◽  
Ya Lin Guan ◽  
Xin Kun Tang

High-speed signal connector has become a key factor of the signal transmission quality in telecommunications and data communications system. Signal integrity of connector is an inevitable problem. This paper based on the theory of differential transmission lines and Multimode S-Parameters, analyzed the USB3.0 connector signal integrity. And use 3D simulation software CST to build model and analyze the relationship of signal integrity and connectors geometry.


Author(s):  
M. K. M. R. Guerrero ◽  
J. A. M. Vivar ◽  
R. V. Ramos ◽  
A. M. Tamondong

Abstract. The sensitivity to changes in water quality inherent to seagrass communities makes them vital for determining the overall health of the coastal ecosystem. Numerous efforts including community-based coastal resource management, conservation and rehabilitation plans are currently undertaken to protect these marine species. In this study, the relationship of water quality parameters, specifically chlorophyll-a (chl-a) and turbidity, with seagrass percent cover is assessed quantitatively. Support Vector Machine, a pixel-based image classification method, is applied to determine seagrass and non-seagrass areas from the orthomosaic which yielded a 91.0369% accuracy. In-situ measurements of chl-a and turbidity are acquired using an infinity-CLW water quality sensor. Geostatistical techniques are utilized in this study to determine accurate surfaces for chl-a and turbidity. In two hundred interpolation tests for both chl-a and turbidity, Simple Kriging (Gaussian-model type and Smooth- neighborhood type) performs best with Mean Prediction equal to −0.1371 FTU and 0.0061 μg/L, Root Mean Square Standardized error equal to −0.0688 FTU and −0.0048 μg/L, RMS error of 8.7699 FTU and 1.8006 μg/L and Average Standard Error equal to 10.8360 FTU and 1.6726 μg/L. Zones are determined using fishnet tool and Moran’s I to calculate for the seagrass percent cover. Ordinary Least Squares (OLS) is used as a regression analysis to quantify the relationship of seagrass percent cover and water quality parameters. The regression analysis result indicates that turbidity has an inverse relationship while chlorophyll-a has a direct relationship with seagrass percent cover.


Author(s):  
B. Samanta ◽  
C. Nataraj

A procedure is presented for monitoring and prognostics of machine conditions using computational intelligence (CI) techniques. The machine condition is assessed through an energy-based feature, termed as ‘energy index’, extracted from the vibration signals. The progression of the ‘monitoring index’ is predicted using CI techniques, namely, recursive neural network (RNN), adaptive neuro-fuzzy inference system (ANFIS) and support vector regression (SVR). The proposed prediction procedures have been evaluated through benchmark datasets. The prognostic effectiveness of the techniques has been illustrated through vibration dataset of a helicopter drivetrain system gearbox. The performance of SVR was found to be better than RNN and ANFIS for the dataset used. The results are helpful in understanding the relationship of machine conditions, the corresponding indicating feature, the level of damage/degradation and their progression.


2021 ◽  
Vol 65 (1) ◽  
pp. 1-13
Author(s):  
Michal Čevelíček ◽  
◽  
Adéla Tarinová ◽  
Tomáš Řiháček

Objectives. The study aimed to explore which barriers adult people perceive when deciding whether to enter psychotherapy and how these barriers influence their decision to start psychotherapy. Sample and setting. The sample consisted of 392 adult respondents who considered entering individual psychotherapy during the last five years. They completed a questionnaire on perceived barriers to entering psychotherapy, the phase of decision-making, and the severity of psychological symptoms. Hypotheses. This was an exploratory study with the following questions: a) What is the perceived importance of specific barriers to entering psychotherapy? b) What groups (principal components) of barriers to entering psychotherapy can be identified? c) What is the relationship between the perceived importance of barriers and the decision to enter psychotherapy? Statistical analysis. The number of barriers was reduced using PCA. The relationship of the decision-making phase to other variables was explored via multinomial regression analysis. Results. The most severe barrier to entering psychotherapy were price, reluctance to express emotions in front of others and the assumption that one’s problems were not as severe as the problems of people in psychotherapy. Respondents who decided not to enter psychotherapy were older, expressed more distrust of psychotherapy, and perceived it as more stigmatizing than those who contacted a therapist. Respondents who decided to enter psychotherapy (but who had not contacted a therapist) had less severe symptoms and perceived psychotherapy as more stigmatizing than those who contacted a therapist. Study limitations. Limits of the study include a non-representative sample and the time window used for the retrospective rating of symptoms and barriers.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


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