A new fault diagnosis method based on damped least square QR-factorization algorithm in grounding grid

2014 ◽  
Author(s):  
Yao Degui ◽  
Kou Xiaokuo ◽  
Zhu Guangjie ◽  
Yang Fan ◽  
Dai Feng ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Least Square ◽  
Qr Factorization ◽  
Factorization Algorithm ◽  
Grounding Grid ◽  
Diagnosis Method

Research on Fault Diagnosis Method of Wind Turbine Based on Wavelet Analysis and LS-SVM

2013 ◽  
Vol 724-725 ◽  
pp. 593-597 ◽  
Author(s):  
Chang Liang Liu ◽  
Wei Xue Qi
Keyword(s):  
Fault Diagnosis ◽  
Wavelet Analysis ◽  
Wind Turbine ◽  
High Speed ◽  
Wavelet Decomposition ◽  
Least Square ◽  
Support Vector ◽  
Vibration Signals ◽  
Training Samples ◽  
Diagnosis Method

Aiming at the fault characteristics of high-speed gearbox fault diagnosis of wind turbine, a fault diagnosis method of combining wavelet analysis with least square-support vector machine (LS-SVM) is proposed. According to the method, the energy of frequency bands generated by wavelet decomposition and reconstruction of the high-speed gearbox's vibration signals in different fault states is normalized as eigenvectors, forming training and testing samples of LS-SVM fault classifier. Train the LS-SVM fault diagnosis model with the training samples and test the accuracy with the testing samples. The result of research shows that the fault diagnosis method based on the wavelet analysis and LS-SVM has good diagnostics effect.

Fault Diagnosis for Grounding Grids Based on Genetic Algorithm and Support Vector Machine

2013 ◽  
Vol 787 ◽  
pp. 909-913
Author(s):  
Ling Jian Li ◽  
Min Fang Peng ◽  
Ke Xin Zhao
Keyword(s):  
Genetic Algorithm ◽  
Support Vector Machine ◽  
Fault Diagnosis ◽  
Support Vector ◽  
Grounding Grid ◽  
Grounding Grids ◽  
Diagnosis Method ◽  
Simulation Results ◽  
Type Of Failure ◽  
Corrosion Simulation

This paper presents a genetic algorithm to optimize support vector machine parameters for grounding grid fault diagnosis method. Grounding grid is equivalent to a pure resistance model, extract characteristics of different kinds of corrision states, Using genetic algorithm optimize support vector machine kernel function parameters, achieve the identification of the type of failure mode, Grounding grid of 6 × 6 test can quickly detect the grounding grid corrosion, simulation results show that the method has higher accuracy than support vector machine.

Application on State Evaluation of the Grounding Conductor Based on Fault Diagnosis Method

2014 ◽  
Vol 635-637 ◽  
pp. 815-818
Author(s):  
Da Xing Wang ◽  
Shou Bao Liu ◽  
De Gang Gan ◽  
Bin He
Keyword(s):  
Sensitivity Analysis ◽  
Fault Diagnosis ◽  
Network Theory ◽  
Electrical Network ◽  
Large Area ◽  
Power Failure ◽  
Grounding Grid ◽  
State Evaluation ◽  
Diagnosis Method ◽  
Diagnosis Model

In this paper, fault diagnosis model of grounding grid is established combining electrical network theory with sensitivity analysis. A new method which is used to select the node pairs to calculate the corrosion situation of grounding grid is presented. Based on this method, the fault branch of grounding grid can be efficiently judged through topology diagram and port resistance without power failure and the excavation of large area. Field test was carried out at 220 kV electrical substations using the diagnosis method. The conductors diagnosed as severely corroded was excavated. The result was identical to the diagnosis results, indicating that this diagnosis method has engineering practicality.

A Fault Diagnosis Method for Substation Grounding Grid Based on the Square-Wave Frequency Domain Model

2012 ◽  
Vol 19 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Peng-He Zhang ◽  
Jun-Jia He ◽  
Dan-Dan Zhang ◽  
Lan-Min Wu
Keyword(s):  
Fault Diagnosis ◽  
Frequency Domain ◽  
Domain Model ◽  
Wave Frequency ◽  
Scale Model ◽  
Frequency Model ◽  
Square Wave ◽  
Grounding Grid ◽  
Diagnosis Method ◽  
Grid Based

A Fault Diagnosis Method for Substation Grounding Grid Based on the Square-Wave Frequency Domain ModelCurrent methods of fault diagnosis for the grounding grid using DC or AC are limited in accuracy and cannot be used to identify the locations of the faults. In this study, a new method of fault diagnosis for substation grounding grids is proposed using a square-wave. A frequency model of the grounding system is constructed by analyzing the frequency characteristics of the soil and the grounding conductors into which two different frequency square-wave sources are injected. By analyzing and comparing the corresponding information of the surface potentials of the output signals, the faults of the grounding grid can be diagnosed and located. Our method is verified by software simulation, scale model experiments and field experiments.

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