Determination of the power transmission line ageing failure probability due to the impact of forest fire

2018 ◽  
Vol 12 (16) ◽  
pp. 3812-3819 ◽  
Author(s):  
Yufeng Guo ◽  
Runxin Chen ◽  
Jianguo Shi ◽  
Jie Wan ◽  
Hongliang Yi ◽  
...  
2018 ◽  
Vol 8 (5) ◽  
pp. 3332-3337
Author(s):  
N. M. Khoa ◽  
D. D. Tung

The impact of thyristor controlled series capacitor (TCSC) on distance protection relays in transmission lines is analyzed in this paper. Voltage and current data are measured and collected at the relay locations to calculate the apparent impedance seen by distance protection relays in the different operating modes of the TCSC connected to the line. Short-circuit faults which occur at different locations on the power transmission line are considered in order to locate the fault for the purpose of evaluating the impact of TCSC on the distance protection relay. Matlab/Simulink simulation software is used to model the power transmission line with two sources at the two ends. Voltage source, transmission line, TCSC, voltage and current measurement, and discrete Fourier transform (DFT) blocks are integrated into the model. Simulation results show the impact of TCSC on the distance protection relay and determine the apparent impedance and fault location in the line.


Author(s):  
Maria Amirkhanian

Introduction. Influence of forest plantations on intensity of electromagnetic fields (EMF) of commercial frequency (50 Hz), generated by high voltage power transmission line (PTL), is considered. Materials and methods. The study was conducted near the village of Boltino in the Moscow Region. The EMF measurements were made on two profiles perpendicular to the 500 kV PTL (power transmission line) axis, one of which passes through the forest area, the other one does not cross it. Measurements of commercial frequency electromagnetic fields (CFEMF) were carried out using a measurement device and antennas, designed to measure the intensities of magnetic and electrical fields. Results. The comparative analysis of the character of change of electric and magnetic components of EMF with distance from the PTL axis allowed to establish the effect of EMF intensity decrease starting from the forest area boundary. Diagrams show that EMF reduction effect is more pronounced for the electrical component. Conclusions. The revealed effect to a certain extent shows the analogy of the forest area with the Faraday cage. However, such an analogy is not complete due to the fact that the forest area is not a perfectly conductive body, but has only a low conductivity. Additional EMF reduction occurs as a result of partial EMF energy absorption by the forest area


Author(s):  
M. I. Kazakevitch ◽  
Ye. V. Horokhov ◽  
M. S. Khorol'sky ◽  
S. V. Turbin

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  

Current measurement is a key part of the monitoring system for power transmission lines. Compared with the conventional current sensor, the distributed, self-powered and contactless current sensor has great advantages of safety and reliability. By integrating the current sensing function and the energy harvesting function of current transformer (CT), a time-multiplexed self-powered wireless sensor that can measure the power transmission line current is presented in this paper. Two operating modes of CT, including current sensing mode and energy harvesting mode, are analyzed in detail. Through the design of mode-switching circuit, harvesting circuit and measurement circuit are isolated using only one CT secondary coil, which eliminates the interference between energy harvesting and current measurement. Thus, the accurate measurement in the current sensing mode and the maximum energy collection in the energy harvesting mode are both realized, all of which simplify the online power transmission line monitoring. The designed time-multiplexed working mode allows the sensor to work at a lower transmission line current, at the expense of a lower working frequency. Finally, the proposed sensor is verified by experiments.


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