Stillbirth and residential proximity to extremely low frequency power transmission lines: a retrospective cohort study: Table 1

2011 ◽  
Vol 69 (2) ◽  
pp. 147-149 ◽  
Author(s):  
Nathalie Auger ◽  
Alison L Park ◽  
Soumana Yacouba ◽  
Marc Goneau ◽  
Joseph Zayed
Keyword(s):  
Cohort Study ◽  
Transmission Lines ◽  
Retrospective Cohort ◽  
Power Transmission ◽  
Low Frequency ◽  
Power Transmission Lines ◽  
Residential Proximity ◽  
Extremely Low Frequency ◽  
Low Frequency Power ◽  
Frequency Power

scholarly journals CALCULATION OF POWER LINE FIELDS BETWEEN CIRCULAR CONDUCTORS

2012 ◽  
Vol 04 (01) ◽  
pp. 1250025
Author(s):  
ANDREW SEAGAR ◽  
SALAKCHIT NILBOWORN
Keyword(s):  
Electric Field ◽  
Transmission Lines ◽  
Power Transmission ◽  
Circular Cross Section ◽  
Low Frequency ◽  
Test Cases ◽  
Power Transmission Lines ◽  
System Matrix ◽  
High Voltage Direct Current ◽  
Frequency Components

It is important to calculate the electric field at the surface of high voltage direct current power transmission lines, since it is this field which governs the onset of corona discharge and the power loss arising therefrom. A method is presented here to calculate the electric field based on an implementation of the boundary element method for conductors of strictly circular cross section. Given the circular geometry it is possible to resolve all integrals involved analytically. A Galerkin approach is adopted, giving the solution in the spatial frequency domain. That allows a controlled truncation of the system matrix by choice of which frequency components to keep. It transpires that the low frequency components are the most important ones. Two test cases are used to quantify the accuracy of the solution with respect to truncation and distance from the surface. It is found that the accuracy increases with distance from the surface, but for all distances can be controlled by choosing an appropriate level of truncation.

Study on Dynamic Simulation of 4-Bundle Ice-Coated Conductor Galloping Based on 3-D Model

2011 ◽  
Vol 105-107 ◽  
pp. 474-477
Author(s):  
Shi Jing Wu ◽  
Zeng Lei Zhang ◽  
Zhen Hao Liu ◽  
Ji Cai Hu
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Low Frequency ◽  
Element Model ◽  
Wake Flow ◽  
Power Transmission Lines ◽  
Ansys Software ◽  
Frequency Coupling ◽  
D Model ◽  
The Finite Element Model

Galloping of power transmission lines is a low frequency self-oscillation with large amplitude. The aerodynamic effect on each sub-conductor of 4-bundle conductor is different due to wake-flow-influence. In order to explore the reasons leading to galloping, a 3-D model for power transmission line is built. A two-node quadratic beam element in 3-D and a structure mass element are applied to establish the finite element model of iced 4-bundle conductor in ANSYS software. Then dynamic transient response calculations are made on this model. According to the results, difference in vibration of sub-conductors and frequency coupling of torsional and transverse vibration can be confirmed. The simulation results illustrate the wake-flow-influence effect and the coupled motions effect on galloping of 4-bundle conductor.

ESTIMATION OF THERMAL POWER PLANT WORKERS EXPOSURE TO MAGNETIC FIELDS AND SIMULATION OF HAZARD ZONES

2020 ◽  
Vol 190 (3) ◽  
pp. 289-296
Author(s):  
Majid Bagheri Hosseinabadi ◽  
Narges Khanjani ◽  
Mohammad Hossein Ebrahimi ◽  
Jamal Biganeh
Keyword(s):  
Power Plant ◽  
Magnetic Fields ◽  
Transmission Lines ◽  
Thermal Power Plant ◽  
Power Transmission ◽  
Thermal Power ◽  
Low Frequency ◽  
Exposure Level ◽  
Power Transmission Lines ◽  
Indoor Space

Abstract Extremely low-frequency magnetic fields (ELF-MFs) have raised some concerns due to their possible effects on workers’ health. In this study ELF-MFs were measured in different units of the thermal power plant based on gridding the indoor space. The exposure level was measured by spot measurement based on the IEEE Std C95.3.1 and then simulated in units with the highest magnetic field intensity by using ArcGIS software. The operators and balance of plant (BOP) technicians (12.64 ± 9.74 μT) and office workers (2.41 ± 1.22 μT) had the highest and lowest levels of both measured and estimated ELF-MFs exposure. The highest measured ELF-MFs were in the vicinity of the power transmission lines in the transformers’ building (48.2 μT). Our simulation showed the high and low exposure areas and ranked exposure well; but, the actual measurements of ELF-MFs exposure were in all cases higher than the estimated values, which means we still need to improve our estimations.

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