scholarly journals Detection of Broken Strands of Transmission Line Conductors Using Fiber Bragg Grating Sensors

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2397 ◽  
Author(s):  
Long Zhao ◽  
Xinbo Huang ◽  
Jianyuan Jia ◽  
Yongcan Zhu ◽  
Wen Cao
Keyword(s):  
Wind Speed ◽  
Transmission Line ◽  
Fiber Bragg Grating ◽  
Natural Frequency ◽  
Monitoring System ◽  
Natural Frequencies ◽  
Modal Identification ◽  
Bragg Grating ◽  
Frequency Variation ◽  
Natural Frequency Variation

Transmission lines are affected by Aeolian vibration, which causes strands to break and eventually causes an entire line to break. In this paper, a method for monitoring strand breaking based on modal identification is proposed. First, the natural frequency variation of a conductor caused by strand breakage is analyzed, and a modal experiment of the LGJ-95/15 conductor is conducted. The measurement results show that the natural frequencies of the conductor decrease with an increasing number of broken strands. Next, a monitoring system incorporating a fiber Bragg grating (FBG)-based accelerometer is designed in detail. The FBG sensor is mounted on the conductor to measure the vibration signal. A wind speed sensor is used to measure the wind speed signal and is installed on the tower. An analyzer is also installed on the tower to calculate the natural frequencies, and the data are sent to the monitoring center via 3G. Finally, a monitoring system is tested on a 110 kV experimental transmission line, and the short-time Fourier transform (STFT) method and stochastic subspace identification (SSI) method are used to identify the natural frequencies of the conductor vibration. The experimental results show that SSI analysis provides a higher precision than does STFT and can extract the natural frequency under various wind speeds as an effective basis for discriminating between broken strands.

Effect on Vibroengineering of Material Deterioration in a Scale-Down Reinforced Concrete Containment Vessel Specimen

2013 ◽  
Vol 479-480 ◽  
pp. 13-19
Author(s):  
Wei Ting Lin ◽  
Yuan Chieh Wu ◽  
Tung Liang Chu ◽  
An Cheng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Frequency Variation ◽  
Accelerated Corrosion ◽  
Containment Vessel ◽  
Scale Down ◽  
Concrete Resistivity ◽  
Natural Frequency Variation

This study is aim to evaluate the natural frequency variation of the scale-down reinforced concrete containment vessel specimen under accelerated corrosion conditions. A plastic ring was sealed around the perimeter of the cylindrical vessel bottom with the 3.5 % NaCl solution to achieve the accelerated corrosion test. Concrete resistivity, open circuit potential, corrosion rate and natural frequencies were tested and discussed in this study. Test results presented that the accelerated corrosion method with a direct 60 voltage applied was a suitable method for estimating and accelerating the concrete vessel specimen. Therefore, the changes in natural frequencies were consistent with the material degradation of the concrete vessel specimen. The natural frequencies decreased with the increasing corrosion rate or decreasing resistivities for the specimen at higher mode, but would be no change for the specimen at the natural frequency of 1stmode.

scholarly journals A Vibration-Based Structural Health Monitoring System for Transmission Line Towers

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 515 ◽  
Author(s):  
Long Zhao ◽  
Xinbo Huang ◽  
Ye Zhang ◽  
Yi Tian ◽  
Yu Zhao
Keyword(s):  
Structural Health Monitoring ◽  
Transmission Line ◽  
Natural Frequency ◽  
Health Monitoring ◽  
Structural Changes ◽  
Natural Frequencies ◽  
Transmission Tower ◽  
Health Monitoring System ◽  
Wind Speeds ◽  
Before And After

In this paper, we present a vibration-based transmission tower structural health monitoring system consisting of two parts that identifies structural changes in towers. An accelerometer group realizes vibration response acquisition at different positions and reduces the risk of data loss by data compression technology. A solar cell provides the power supply. An analyser receives the data from the acceleration sensor group and calculates the transmission tower natural frequencies, and the change in the structure is determined based on natural frequencies. Then, the data are sent to the monitoring center. Furthermore, analysis of the vibration signal and the calculation method of natural frequencies are proposed. The response and natural frequencies of vibration at different wind speeds are analysed by time-domain signal, power spectral density (PSD), root mean square (RMS) and short-time Fouier transform (STFT). The natural frequency identification of the overall structure by the stochastic subspace identification (SSI) method reveals that the number of natural frequencies that can be calculated at different wind speeds is different, but the 2nd, 3rd and 4th natural frequencies can be excited. Finally, the system was tested on a 110 kV experimental transmission line. After 18 h of experimentation, the natural frequency of the overall structure of the transmission tower was determined before and after the tower leg was lifted. The results show that before and after the tower leg is lifted, the natural frequencies of each order exhibit obvious changes, and the differences in the average values can be used as the basis for judging the structural changes of the tower.

A Kind of Vibration Sensor and Testing System in Electromechanical Equipment Based on Fiber Bragg Grating

2016 ◽  
Vol 693 ◽  
pp. 1300-1307
Author(s):  
Qi Jiang ◽  
Teng Yun Guo
Keyword(s):  
Fiber Bragg Grating ◽  
Monitoring System ◽  
Experimental Analysis ◽  
Mechanical Vibration ◽  
Vibration Sensor ◽  
Vibration Monitoring ◽  
Bragg Grating ◽  
Element Analysis ◽  
Finite Element Analysis Simulation ◽  
Electromechanical Equipment

Mechanical vibration analysis is an important index to measure the running state of the electromechanical equipment. The vibration signals contain the information about the equipment running state. This paper studies and designs the vibration monitoring system based on fiber Bragg grating (FBG). Through the finite element analysis simulation, optimizes the sensor's structure, and uses the labview software to compile the corresponding vibration monitoring analysis software. Finally verifies the detection effect of the monitoring system, through the pulse signal and continuous signal dynamic experimental analysis. The result of the experimental analysis shows: this vibration monitoring system can monitor the vibration information and analyze vibration state effectively. It has the advantages of reducing the temperature interference and lateral disturbance, and detects the vibration of three direction at the same time. So it is feasible to monitor the electromechanical equipment.

Oil Pipeline Sliding Monitoring System Based on Fiber Bragg Grating Sensor

2010 ◽  
Vol 39 (1) ◽  
pp. 33-36 ◽  
Author(s):  
胡志新 HU Zhi-xin ◽  
马云宾 MA Yun-bin ◽  
谭东杰 TAN Dong-jie ◽  
陈朋超 CHEN Peng-chao ◽  
李俊 LI Jun
Keyword(s):  
Fiber Bragg Grating ◽  
Monitoring System ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Oil Pipeline ◽  
Bragg Grating Sensor

Monitoring system of railway track based on identity weak fiber Bragg grating array

2019 ◽  
Vol 48 (6) ◽  
pp. 622001
Author(s):  
张 翠 Zhang Cui ◽  
陶 渊 Tao Yuan ◽  
童杏林 Tong Xinglin ◽  
邓承伟 Deng Chengwei ◽  
何 为 He Wei ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Monitoring System ◽  
Railway Track ◽  
Bragg Grating ◽  
Grating Array

scholarly journals Temperature monitoring system using fiber Bragg grating (FBG) approach

2020 ◽  
Author(s):  
N. A. Rosman ◽  
C. B. M. Rashidi ◽  
S. A. Aljunid ◽  
R. Endut
Keyword(s):  
Fiber Bragg Grating ◽  
Monitoring System ◽  
Temperature Monitoring ◽  
Bragg Grating

Effect of Residual Stress in Ductile Iron Component on its Natural Frequency

2011 ◽  
Vol 308-310 ◽  
pp. 967-972 ◽  
Author(s):  
Xue Wu Dong ◽  
Dai Ren ◽  
Dong Qiang Wang ◽  
Ya Fei Zhai
Keyword(s):  
Residual Stress ◽  
Natural Frequency ◽  
Ductile Iron ◽  
Diffraction Method ◽  
Stress Relief ◽  
Quantitative Relation ◽  
Frequency Variation ◽  
Natural Stress ◽  
The Status ◽  
Natural Frequency Variation

In the paper four components of ductile iron cast in different stress status, including the cast status, the status of vibratory stress relief and the status of thermal stress relief with 3 months of the natural stress relief and 10 years of the natural stress relief, are selected.X-ray diffraction method is used to measure residual stress and experimental modal analysis is for measuring natural frequency. A quantitative relation between residual stress in ductile iron cast component and its natural frequency variation is obtained. Thus we provide a reference for using natural frequency to evaluate the macroscopic residual stress of ductile iron material component. The results show that the peak value variation of macro residual stress in ductile iron component have a logarithmic relation to its natural frequency variation, and same as the mean value variation in macro-residual stress and its natural frequency variation.

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