scholarly journals Simulation of Electromagnetic Coupling on Pipelines close to Overhead Transmission Lines: A Parametric Study

2017 ◽  
Vol 1 (2) ◽  
pp. 116 ◽  
Author(s):  
A. H. Al-Badi ◽  
H. M. Al-Rizzo
Keyword(s):  
Transmission Lines ◽  
Electromagnetic Interference ◽  
Electromagnetic Coupling ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Separation Distance ◽  
Interference Effects ◽  
Voltage Level ◽  
Oil Pipelines ◽  
Water Gas

Electromagnetic interference effects caused by electric power lines on neighboring metallic utilities such as water, gas or oil pipelines became a major concern due tosignificant increase in the load and short circuit current levels needed to satisfy the load requirements. Another reason for increased interference levels originates from the environmental concerns, which impose on various utilities the obligation to share common corridors. This paper presents three different scenarios of a pipeline in which all types of electromagnetic interferences (coupling) will be investigated and their effects on the pipeline will be predicted. The level of the calculated voltage, owing to each type of coupling, depends on different factors (voltage level, length of parallelism, separation distance, soil resistivity, load current magnitude and pipeline coating). The effects of these factors are discussed; some factors such as the fault current level, separation distance and soil resistivities are found to exhibit a large influence on the pipeline voltage. To the best of the authors’ knowledge, the comprehensive analyses presented in this paper considering all types of interferences have not yet been publishedelsewhere.

scholarly journals A Novel Overcurrent Suppression Strategy during Reclosing Process of MMC-HVDC

2019 ◽  
Vol 9 (9) ◽  
pp. 1737 ◽  
Author(s):  
Bin Jiang ◽  
Yanfeng Gong
Keyword(s):  
Transmission Lines ◽  
Short Circuit ◽  
Current Method ◽  
Short Circuit Current ◽  
Simulation Software ◽  
Fault Current ◽  
Overhead Lines ◽  
Hvdc System ◽  
Electromagnetic Transient Simulation ◽  
Current Calculation

A modular multilevel converter based high-voltage DC (MMC-HVDC) system has been the most promising topology for HVDC. A reclosing scheme is usually configured because temporary faults often occur on transmission lines especially when overhead lines are used, which often brings about an overcurrent problem. In this paper, a new fault current limiter (FCL) based on reclosing current limiting resistance (RCLR) is proposed to solve the overcurrent problem during the reclosing process. Firstly, a mesh current method (MCM) based short-circuit current calculation method is newly proposed to solve the fault current calculation of a loop MMC-HVDC grid. Then the method to calculate the RCLR is proposed based on the arm current to limit the arm currents to a specified value during the reclosing process. Finally, a three-terminal loop MMC-HVDC test grid is constructed in the widely used electromagnetic transient simulation software PSCAD/EMTDC and the simulations prove the effectiveness of the proposed strategy.

Grounding Connections

2018 ◽  
pp. 84-123
Keyword(s):  
Transmission Lines ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Power Sources ◽  
Grounding Resistance ◽  
Overhead Transmission Lines ◽  
Ground Fault ◽  
Multiple Power

This chapter sheds light on the following: TT system (earthed neutral), automatic disconnection for TT system, TN system (exposed conductive parts connected to the neutral), TN-C system, TN-S system- TN-C-S system, IT system (isolated or impedance-earthed neutral), IT system (impedance-earthed neutral), grounding transformer connection and design, grounding of industrial and commercial generators, Zigzag grounding transformer earthed systems (solid grounding, resistance grounding, reactance grounding, resonant grounding (ground-fault neutralizer), location of system grounding points selection and grounding locations specified by the NEC and multiple power sources. The chapter contains also the different methods used in determining the levels of short circuit current. It contains also details about the grounding through resistances for transformers and generators and reactances for overhead transmission lines.

Experiment of a Resistive Superconducting Fault Current Limiter Based on MgB2 under Different Supply Voltages

2013 ◽  
Vol 721 ◽  
pp. 527-530
Author(s):  
Lei Yao ◽  
Jun Mei ◽  
Jian Yong Zheng ◽  
Bin Liu ◽  
You Xu
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Test System ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Voltage Level ◽  
Superconducting Fault Current Limiter ◽  
Current Limiting ◽  
Current Limiter ◽  
Test Result

In order to limit the short-circuit current, and to prevent the power grid and its equipment from the shock of the short circuit, the fault current limiter with detection, trigger and limiting was introduced. A small resistive type superconducting fault current limiter prototype based on MgB2, cooled by liquid helium and heliumgas, was developed and tested by a test system. The test result showed that the prototype based on MgB2 produced superior limiting performance, the short-circuit current suppressing ratio was up to more than 45%, and with the rise of the voltage level, the current limiting capability was also gradually increased, up to 56%.

scholarly journals Assessment of Triboelectricity in Colossal-Surface-Area-Lanthanum Oxide Nanocrystals Synthesized via Low-Temperature Hydrothermal Process

2021 ◽  
Author(s):  
SUNIL METI ◽  
Hosangadi Prutvi Sagar ◽  
Mohammad Rizwanur Rahman ◽  
Udaya Bhat K
Keyword(s):  
Surface Area ◽  
Lanthanum Oxide ◽  
Short Circuit ◽  
Hydrothermal Process ◽  
Active Material ◽  
Short Circuit Current ◽  
Separation Distance ◽  
Open Circuit ◽  
Mechanical Pressure ◽  
Present Contribution

Abstract Triboelectric nanogenerators (TENGs) have marked their applications in various fields, most importantly, in medical devices. The electrical output of the TENGs mainly concentrated on parameters such as electrode separation distance, applied mechanical pressure, surface charge density, and overlapping surface-area. The surface-area of the active layer in TENGs plays a crucial role. Given this, the present contribution is the first report on the utilization of lanthanum oxide (La2O3) as an active material with a large surface-area (~72.33 m2/g) in TENGs. The nanocrystals of La2O3 have been successfully embedded into TENGs architecture through a high-quality screen-printed film with a Teflon-counter surface. The in-house test-rig of TENGs resulted in an output open-circuit voltage of 120 V and a short-circuit current of 23.7 μA. Further, the maximum power density is 7.125 W/m2 at an external load resistance of 30 MΩ. These results suggest that La2O3 is a suitable contender in various self-powered devices.

scholarly journals Electromagnetic interference in a multiconductor transmission system – MTL

2019 ◽  
Vol XXII (2) ◽  
pp. 343-351
Author(s):  
Ciocioi I.
Keyword(s):  
Transmission Lines ◽  
Electromagnetic Interference ◽  
Printed Circuit Boards ◽  
Electronic Circuit ◽  
Electromagnetic Coupling ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Different Types ◽  
Correct Function ◽  
Coupling Phenomena

In electrical and electronic practice, many connection and transmission elements (cables) are used as a multi-conductor transmission lines (MTL). The electromagnetic fields existing in the environment of these multiconductor transmission lines and can generate different types of coupling phenomena, causing EMC problems by the appearance of the unwanted EMI, disturbing the correct function and altering the information. Electromagnetic coupling between the circuits/cables of a circuit (also known as crosstalk) can also occur between the signal and power paths of an assembly made on printed circuit boards, PCB (printed board circuit), so it is important that when designing such an electrical / electronic circuit, these aspects should be taken into account.

Research on Optimization Control Strategy for Limiting Short-Circuit Current Based on Fuzzy Quantitative Control

2012 ◽  
Vol 214 ◽  
pp. 527-530
Author(s):  
Guang Lei Li ◽  
Shu Min Sun ◽  
Yan Cheng ◽  
Hong Bo Li ◽  
Shuai Yuan
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Control Strategy ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Sensitivity Index ◽  
Impedance Change ◽  
Large Power ◽  
Control Evaluation

To decrease short-circuit current, adjusting the power network operation by breaking transmission lines is the most economic and convenient measure. For large power grid, breaking transmission lines has thousands of combinations, so it's very difficult to find the best combination in a short time. Firstly, this paper formulated the sensitivity relationship between transmission line outage and impedance change. Then preliminary combinations schemes of transmission line outage were selected according to the sensitivity. Index values of factors were given using the fuzzy control evaluation. Finally, this paper determined optimal scheme from maximum priority and accomplished the accessorial intelligent optimize system of limiting short-circuit current. The rapidity and rapidity of the proposed control strategy was verified by calculating the actual power grid.

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