Based on the TLM Method 1000kV UHV Transmission Line Performance Analysis

2011 ◽  
Vol 383-390 ◽  
pp. 2917-2922
Author(s):  
Feng Xia Li ◽  
Yue Long Wang
Keyword(s):  
Performance Analysis ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Transmission Power ◽  
Long Distance ◽  
Transmission Distance ◽  
Transmission Line Modeling ◽  
Tlm Method ◽  
Ac Transmission

The TLM model of 3 - phase pow er t ran sm ission line is developed. Appling the transmission line modeling (TLM) method to analysis 1000kV ultrahigh voltage( UHV) AC transmission line, the obtained results prove that it is economical and reasonable to transmit the natural power by power transmission, and the transmission lines is a long-distance transmission power ; but both the super power and the power transmission, the transmission power reduce with the increase of transmission distance.

scholarly journals Corona Loss Minimization on High Voltage Transmission Line Network using Bundled Conductors.

2020 ◽  
Vol 9 (3) ◽  
pp. 887-891
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Hessian Matrix ◽  
Electrical Power ◽  
Power Transmission Lines ◽  
Long Distance ◽  
Power Stations ◽  
Line Network ◽  
Corona Losses

Electrical power generated and transmitted at a long distance away from the power stations is usually affected by inherent transmission line losses. The Ohmic and Corona losses which are predominantly common in power transmission lines are considered in this paper. These two losses are mathematically modeled with and without embedded bundled conductors. The resultant model which is a non-linear multivariable unconstrained optimized equation is minimized using the Hessian matrix determinant method for stability test purposes. The results obtained show that corona losses are minimized with embedded bundled conductors at a very low current value with large spacing distance between the bundled conductors. The decrease in the corona loss which is a consequence of spacing adjustment of the 2, 3, and 4 strands of bundled conductors was plotted using MATLAB 7.14. The plots obtained are in conformity with the inverse relation between corona loss and conductor spacing.

scholarly journals STUDY OF VOLTAGE MODE IN THE LONG-DISTANCE AC TRANSMISSION LINE

2021 ◽  
Vol 2021 (59) ◽  
pp. 43-55
Author(s):  
T.L. Katsadze ◽  
◽  
D.V. Nastenko ◽  
O.M. Panienko ◽  
O.M. Iankovska ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Transmission Line ◽  
Extreme Point ◽  
Transmission Lines ◽  
Power Transmission ◽  
Voltage Distribution ◽  
Long Distance ◽  
Third Order ◽  
Long Distance Transmission ◽  
Wide Range

The charging currents of EHV transmission lines cause the Ferranti effect, which causes an increase in voltage at intermediate points transmission line. The work aims to study the laws of the voltage distribution along the line route and to develop a method for determining the coordinates of a point with extreme voltage. Methodology. Mathematical modeling of long-distance transmission lines in Wolfram Mathematica allowed to form the laws of the voltage distribution along the line and determine the coordinate of the extreme point on the voltage. Results. It is shown that the application of the traditional model of idealized power transmission causes high modeling accuracy only in the modes of unloaded line and low loads. In the range of medium and high loads, the simulation error reaches unacceptably large values. The paper proposes more accurate models for determining the coordinate of an extreme voltage point: linearized and second- and third-order models. It is shown that the proposed models are characterized by higher accuracy in a wide range of loads. Increasing the degree of the model results in higher accuracy, but is associated with an increase in the cumbersomeness of the mathematical model. It is shown that first and second-order models provide sufficient accuracy for typical designs of 750 kV power transmission lines. It is shown that neglecting the losses on the corona has almost no effect on the accuracy of calculating the coordinates of the extreme point on the voltage, which simplifies the linear calculation model and models of the second and third-order. Originality. Mathematical models of the first, second and third orders have been developed for high-precision determination of the coordinate of a voltage-extreme point along a long-distance transmission line. Practical significance. The offered mathematical models are intended for application in problems of regulation and adjustment of parameters of flexible power transmissions. Ref. 12, figure, tables 4.

scholarly journals Similarity Criteria of EHF Physical Model of Long Distance Transmission Line with Plate Phases

1988 ◽  
Vol 13 (1) ◽  
pp. 7-18
Author(s):  
M. Hamed
Keyword(s):  
Transmission Line ◽  
Physical Model ◽  
Transmission Lines ◽  
Power Transmission ◽  
Similarity Criteria ◽  
Long Distance ◽  
Potential Coefficient ◽  
Overhead Transmission Line ◽  
Long Distance Transmission ◽  
Independent Parameters

Carson's equations for computation of frequency dependent parameters of overhead transmission line are modified. The earth is considered to be homogenous. The optimal required number of terms of Carson's series for applications on computer is determined. Accurate mathematical expressions for resistance and inductance of overhead transmission lines are obtained.Different arrangements of conductors for double circuit transmission lines are studied. The mutual inductance and potential coefficient (mutual capacitance) of such arrangements are computed. Double voltage class type double circuit transmission lines are suggested. The plate type double circuit lines are proposed for power transmission over long distances.This paper presents a mathematical analysis in order to determine the coefficients of similarity criteria of EHF physical model for the given long distance transmission line. The integral analogue method and PI-theorem are used. The independent parameters of EHF physical model are formulated. The scales of four independent parameters of the designed EHF physical model are obtained.

Research and Establishment of UHV AC Transmission Model

2015 ◽  
Vol 752-753 ◽  
pp. 1139-1145
Author(s):  
Hao Yang ◽  
Fei Tang
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Power Transmission ◽  
Simulation Software ◽  
Transmission Capacity ◽  
Transmission Model ◽  
Optimization Strategy ◽  
Transmission Distance ◽  
Ac Transmission ◽  
Continuous Power

There is different applicable transmission capacity and range between 1000kV and 500kV AC transmission. The traditional method is to use the continuous power flow algorithm by BPA simulation software. But this method is complicated and time-consuming. Calculation is particularly large when electricity has a variety of power demand analysis. This paper presents an algorithm based on the AC line transmission capacity, using MATLAB software programming to achieve the establishment of UHV AC transmission model and economical optimization strategy. The method can use thermal limit, voltage limit, landing stability constraints to get the AC line transmission capacity curve by considering the factor of power network strength. On the basis of this method, an UHV AC transmission model can be built combining with unit capacity annual cost algorithm, which can meet the power transmission of arbitrary transmission capacity and the optimal economic of any transmission distance, has an important reference significance and practical value for the planning and construction of electric transmission lines in China.

scholarly journals Time-Multiplexed Self-Powered Wireless Current Sensor for Power Transmission Lines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Current Measurement ◽  
Current Sensor ◽  
Power Transmission Line ◽  
Power Transmission Lines ◽  
Current Sensing ◽  
Self Powered

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.

A multi-unit serial inspection robot for power transmission lines

2019 ◽  
Vol 46 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Guanghong Tao ◽  
Lijin Fang
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Power Transmission Line ◽  
The Novel ◽  
Power Transmission Lines ◽  
Obstacle Crossing ◽  
Content Type ◽  
Inspection Robot ◽  
Serial Robot

Purpose The purpose of this paper is to introduce a robot mechanism designed for power transmission line inspection. The focus for this design is on obstacle-crossing ability with a goal to create a robot moving and crossing obstacle on not only the straight line but also the steering line. Design/methodology/approach A novel four-unit tri-arm serial robot mechanism is proposed. Every novel unit designed for pitching motion is based on parallelogram structure, which is driven by cables and only one motor. There is gripper-wheel compounding mechanism mounted on the arm. The prototype and obstacle environments are established, and the obstacle-crossing experiments are conducted. Findings The novel unit mechanism and robot prototype have been tested in the lab. The prototype has demonstrated the obstacle-crossing ability when moving and crossing fundamental obstacles on the line. The experimental results show that the robot mechanism meets the obstacle-crossing requirements. Practical implications The novel robot technology can be used for defect inspection of power transmission line by power companies. Social implications It stands to lower the intense and risk of inspection works and reduce the costs related to inspection. Originality/value Innovative features include its architecture, mobility and driving method.

scholarly journals An Optimized Coordination Strategy between Line Main Protection and Hybrid DC Breakers for VSC-Based DC Grids Using Overhead Transmission Lines

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1462 ◽  
Author(s):  
Zheng ◽  
Jia ◽  
Gong ◽  
Zhang ◽  
Pei
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Short Circuit ◽  
Power Grids ◽  
Fault Line ◽  
Long Distance ◽  
Coordination Strategy ◽  
Overhead Transmission Lines ◽  
Depth Analysis ◽  
Dc Breaker

Compared with alternating current (AC) power grids, the voltage-sourced converter (VSC)-based direct current (DC) grid is a system characterized by “low damping”, as a result, once there is a short-circuit fault on the DC transmission line, the fault current will rise more sharply and the influence range will be much wider within the same time scale. Moreover the phenomenon that a local fault causes a whole power grid outage is more likely to occur. Overhead transmission lines (OHLs) have been regarded as the mainstream form of power transmission in future high-voltage, large-capacity and long-distance VSC-based DC grids. However, the application of overhead transmission lines will inevitably lead to a great increase in the probability of DC line failure. Therefore, research on how to isolate the DC fault line quickly is of great significance. Based on the technology route for fault line isolation using DC breakers, on the basis of in-depth analysis of traditional coordination strategy, an optimized coordination strategy between line main protection and a hybrid DC breaker for VSC-based DC grids using overhead transmission lines is proposed in this paper, which takes the start-up output signal of line main protection as the pre-operation instruction of the corresponding hybrid DC breaker. As a result, the risks of blockage of the modular multilevel converter (MMC) closer to the fault position and of damage to power electronic devices in main equipment can be reduced effectively. Finally, the proposed coordination strategy was verified and analyzed through simulation.

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