scholarly journals Lumped-Circuits Model of Lossless Transmission Lines and Its Numerical Characteristics

2021 ◽  
Vol 9 ◽  
Author(s):  
Huiyi Zhou ◽  
Tianlin Lu ◽  
Shuting Zhang ◽  
Xin Zhang
Keyword(s):  
Dynamic Response ◽  
Transmission Line ◽  
Transmission Lines ◽  
Digital Simulation ◽  
Euler Method ◽  
Step Response ◽  
Root Cause ◽  
Unit Step ◽  
Simulation Results ◽  
Lumped Circuits

Aiming at the lumped-circuits model of the lossless transmission line in the digital simulation, the article discusses and analyzes the unit step response generation of the lumped-circuits model by comparing the numerical simulation results of the implicit trapezoidal method, the implicit Euler method, and a multi-step formula. The root cause of numerical oscillations pointed out that using the L-stable numerical algorithm to indirectly simulate the dynamic response of the lumped-circuits model is a numerical method that does not truly reflect the original model, but it can directly reflect the true dynamic response of the lossless transmission line. In this study, a method for determining the chained number in the digital simulation of a lumped-circuits model is given. The simulation results prove the effectiveness of the method.

Simulation System Research on Live Working for 500kV Transmission Line

2013 ◽  
Vol 325-326 ◽  
pp. 673-676
Author(s):  
Lian Yang ◽  
Bin Wang ◽  
Xiao Feng Li ◽  
Chuan Hu
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Safety Margin ◽  
Stable Operation ◽  
System Research ◽  
Transmission Tower ◽  
Transmission Networks ◽  
Simulation Results ◽  
New System ◽  
The Way

500kV EHV transmission networks have become the main one of the national grid, carring out live working for 500kV EHV transmission lines is the objective requirements to ensure the stable operation of the grid system. This paper uses a new system to simulate and analyse the way of entering the high electric area on 500kV transmission line. The system has built the ZM1 transmission tower and line model, accurately accounted the complex gap and satety distance. The simulation results show that the system can effectively get the best secure route and determine the way to enter into the equipotential with the safety margin.

Study on the Identification of Lightning Over-Voltage Based on ATP-EMTP

2014 ◽  
Vol 672-674 ◽  
pp. 799-802
Author(s):  
Xiao Gang Li ◽  
Li Xue Li ◽  
Yi Hui Zheng ◽  
Xin Wang ◽  
Jian You Yu ◽  
...  
Keyword(s):  
Power System ◽  
Transmission Line ◽  
Transient Process ◽  
Transmission Lines ◽  
Weak Link ◽  
Simulation Models ◽  
Transmission Line Model ◽  
Lightning Stroke ◽  
Line Model ◽  
Simulation Results

Lightning overvoltage often leads to transmission lines trip, which is the weak link of power system. In this paper, 110-kV transmission line model is studied on the basis of the EMTP software. Several simulation models are established for back flashover lightning, induced lightning, shield failure. The transient process of lightning stroke is studied. According to the contrast of simulation results of three kinds of lightning, a set of discriminant basis to distinguish lightning on transmission line is put forward.

An Integrated Boundary Protection Scheme for Power Transmission Line Systems

2008 ◽  
Vol 9 (2) ◽  
Author(s):  
Zhiqian Bo ◽  
Baohui Zhang ◽  
Jinghan He ◽  
Xinzhou Dong ◽  
Andrew Klimek
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Power Transmission Line ◽  
Communication Link ◽  
Power System Protection ◽  
Protection Scheme ◽  
System Protection ◽  
Simulation Results ◽  
Transient Based Protection

This paper presents an integrated boundary protection scheme for power transmission line systems. The scheme combines the latest developments in two areas of power system protection, the transient based protection and the integrated protection. In the proposed scheme, an integrated relay based on the boundary protection principle installed at a substation is responsible for the protection of all transmission lines associated with the substation. The relay is able to offer a fast trip for any fault on its protected line sections without the need for a communication link. The paper outlines the integrated protection system based on the substation communication network, and gives a description of the basic principle and algorithm of the boundary protection technique. Some typical simulation results are then used to demonstrate the performance of the scheme.

scholarly journals Modeling and Analysis of Progressive Ice Shedding along a Transmission Line during Thermal De-Icing

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yunyun Xie ◽  
Linyan Huang ◽  
Da Wang ◽  
Huaiping Ding ◽  
Xiaochun Yin
Keyword(s):  
Dynamic Response ◽  
Transmission Line ◽  
Transmission Lines ◽  
Dynamic Equilibrium ◽  
Propagation Speed ◽  
Experimental Results ◽  
Small Scale ◽  
Equilibrium Equations ◽  
Modeling And Analysis ◽  
Ice Shedding

Progressive ice shedding (PIS) along transmission lines is a common type of ice shedding during thermal de-icing that requires investigation to ensure the security of transmission lines. In current research, PIS is commonly analyzed using a constant speed for ice detaching from the conductor, which is not accurate for PIS simulation. Therefore, a mechanical model of PIS is established in this study to analyze PIS during thermal de-icing. First, an ice detachment model during thermal de-icing is built to determine the detachment times of the initial ice and remaining ice. Then, a two-node isoparametric truss element is employed to derive the static and dynamic equilibrium equations of an iced conductor to simulate the dynamic response of PIS. Relative to commercial software, these equations can easily accommodate the changing mass of ice with the flow of melted water. The dynamic equilibrium equations are then solved using the ice detachment model to obtain the dynamic response of PIS. Finally, small-scale and full-scale experimental results are employed to verify the proposed method. The simulation results show that the results of the proposed method are more consistent with the experimental results than are the results of existing methods that assume a constant propagation speed. The proposed method can be further applied to optimize transmission line designs and evaluate the application of thermal de-icing devices.

Simulation and Experiential Research for Broken Conductor Load of Suspension Towers of UHVDC Power Transmission

2012 ◽  
Vol 249-250 ◽  
pp. 798-803
Author(s):  
Zi Fu Zhang ◽  
Zeng Lu Mo ◽  
Jing Du Geng
Keyword(s):  
Dynamic Response ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Dynamic Strain ◽  
Power Transmission Lines ◽  
Transmission Tower ◽  
Research Results ◽  
Experiential Research ◽  
First Time

The breakage of conductor/ground wire seriously affects the secure operation of transmission line. According to the features of UHVDC power transmission lines, the broken conductor model for bundled conductors of continuous span is built and the broken conductor load is calculated; A simulating test was carried out the first time in China for a series of "broken conductor" events on one continuous span on the field to study the dynamic response of the transmission tower because of impact, then the dynamic strain and displacement were obtained. On the basis of the simulation and experiential research results, the paper discussed about the rational values of broken wire loads for the suspension towers of UHVDC.

Calculation of Lighting-Induced Overvoltage on Transmission Line Based on Simplified Wagner Field Cancellation Method

2013 ◽  
Vol 448-453 ◽  
pp. 1951-1954
Author(s):  
Xun Zhang ◽  
Hua Rong Zeng ◽  
Yan Ling Li ◽  
Hua Lin Liu ◽  
Hai Zhou ◽  
...  
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Time Varying ◽  
Induced Voltage ◽  
Square Wave ◽  
Lightning Current ◽  
Wave Response ◽  
Simplified Method ◽  
Duhamel Integral ◽  
Simulation Results

Based on Wagner field cancellation method, the paper presents a simplified method to calculate the induced overvoltage on transmission lines excited by lightning striking on tower. Firstly the square-wave response of lightning-induced voltage is calculated, and then the responses produced by other excitations can be calculated by Duhamel integral. This method can reflect the time-varying characteristic of the induced overvoltage. The simulation results show that the amplitude of lightning current and the length of upward leader have greater impacts on the induced overvoltage.

Influence of Icing to the Corona Loss Characteristics of the AC Power Transmission Lines

2013 ◽  
Vol 385-386 ◽  
pp. 1112-1116
Author(s):  
Jun Zhu ◽  
Zi Qiang Xu ◽  
Qing Zhong Geng ◽  
Yun Peng Liu ◽  
Jiang Hai Geng
Keyword(s):  
Electric Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Experimental Results ◽  
Power Transmission Lines ◽  
Ac Power ◽  
Test Platform ◽  
Surface Electric Field ◽  
Simulation Results

The transmission line corridor will inevitably cross the icing area in China. Icing will influence the corona characteristics of transmission lines. In order to deeply analyze the influence law of the icing to corona loss characteristics, an icing test platform that can be utilized to simulate icing conditions was built. Icing test was done in the corona cage of 1.8m×1.8m×4m. Through changing the conductivity of freezing water and the length of icicle, corona loss of the icing conductor was measured and the surface electric field was also simulated with the software ANSYS. The results show that the length of icicle is an important factor affecting the corona loss of the AC conductor and the conductivity of freezing water on that impact is not obvious. Owing to the icicles, the distortion of the conductor electric field is serious. With the increase of icicle length, conductor corona loss value increases significantly. When the length of icicle increases to about 18mm, the increase of the corona loss value is no longer obvious trending to be saturated . The simulation results coincided with the experimental results very well.

Miniaturized Bagley Polygon power divider by using composite right-/left-handed transmission lines

2017 ◽  
Vol 9 (9) ◽  
pp. 1833-1837 ◽  
Author(s):  
Kaijun Song ◽  
Te Kong ◽  
Xue Ren ◽  
Yu Zhu ◽  
Yong Fan
Keyword(s):  
Phase Shift ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Divider ◽  
Microstrip Transmission Line ◽  
Left Handed ◽  
Simulation Results ◽  
Length Reduction ◽  
Good Agreement

A miniaturized Bagley Polygon power divider based on composite right/left-handed transmission line is presented. The composite right/left-handed transmission line and conventional microstrip transmission line are utilized to realize the 0° phase shift transmission line, which is used to replace the 180° transmission line of the conventional Bagley Polygon power divider. As a result, miniaturization is realized, without deteriorating the isolation between the output ports. The design equations are presented. This power divider shows advantages compared with other miniaturized ones. For verification, a miniaturized Bagley Polygon power divider is designed and fabricated. The 58.2% length reduction of the counterpart is realized. The measurement and simulation results show good agreement.

scholarly journals Adaptive neuro-fuzzy inference system based evolving fault locator for double circuit transmission lines

2020 ◽  
Vol 9 (3) ◽  
pp. 448 ◽  
Author(s):  
A Naresh Kumar ◽  
P Sridhar ◽  
T Anil Kumar ◽  
T Ravi Babu ◽  
V Chandra Jagan Mohan
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Fuzzy Inference System ◽  
Fault Location ◽  
Fuzzy Inference ◽  
Cost Effective ◽  
Inference System ◽  
Protection Method ◽  
Neuro Fuzzy ◽  
Simulation Results

<p>Evolving faults are starting in one phase of circuit and spreading to other phases after some time. There has not been a suitable method for locating evolving faults in double circuit transmission line until now. In this paper, a novel method for locating different types of evolving faults occurring in double circuit transmission line is proposed by considering adaptive neuro-fuzzy inference system. The fundamental current and voltage magnitudes are specified as inputs to the proposed method. The simulation results using MATLAB verify the effectiveness and correctness of the protection method. Simulation results show the robustness of the method against different fault locations, resistances, time intervals, and all evolving fault types. Moreover, the proposed method yields satisfactory performance against percentage errors and fault location line parameters. The proposed method is easy to implement and cost-effective for new and existing double circuit transmission line installation</p>

Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20502
Author(s):  
Behrokh Beiranvand ◽  
Alexander S. Sobolev ◽  
Anton V. Kudryashov
Keyword(s):  
Transmission Line ◽  
Terahertz Radiation ◽  
Transmission Lines ◽  
Software Package ◽  
Optical Pulses ◽  
Capacitively Coupled ◽  
Voltage Difference ◽  
Left Handed ◽  
Microwave Transmission ◽  
Commercial Software Package

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.

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