Thermal Stability of Overhead Power Transmission Lines Under Growing Short-Circuit Current Levels

2018 ◽  
Vol 52 (3) ◽  
pp. 361-365
Author(s):  
O. Yu. Gusev ◽  
A. P. Dolin
2020 ◽  
Vol 220 ◽  
pp. 01071
Author(s):  
Dmitry Ivanov ◽  
Marat Sadykov ◽  
Aleksandr Golenishchev-Kutuzov ◽  
Danil Yaroslavsky ◽  
Tatyana Galieva ◽  
...  

The length of overhead power transmission lines in the Russian Federation is over 2.8 million kilometers. Power grids are rapidly becoming obsolete. The level of deterioration of the equipment achieves 70% [1]. This leads to breakdowns on overhead power transmission lines and reduce the quality of electricity supply. One of the focus areas towards improving the situation is a deep modernization of the power grid with an orientation on energy efficiency. The purpose of this work is the creation a system for operative monitoring of the technical condition of high-voltage power-transmission lines based on modular devices. The modular device is configured depending on the issues at hand: control of ice formation; control of ice melting; localization of the place of short circuit, breakage, lightning strike; determination of electrical loads on the wire or control of the load of overhead power transmission lines; determination of mechanical loads at the wire suspension point; determination of conditions for the occurrence of ice formation, determination of defects in insulators. This will equip the overhead line diagnostic systems without serious financial costs by simple installation on the wire of the developed device which design allows to change the configuration of the equipment and solve a wide range of tasks.


Electrical power systems are different in their sizes because of their amount of generation power stations, substations, transmission lines and loads. Therefore, these factors may impact on short circuit levels values. Capacity of power stations and dummy transmission lines in Extra high voltage grid (400kV) of the Iraqi Electrical power grids cause high short circuit levels values such that exceed both rating of the peak and breaking capacity of switchgear equipment's. Reduction of short-circuit levels by using Fast-acting Flexible Alternating Current Transmission Systems (FACTS) types devices in power grids maintain the operation of power grids with acceptable value of short circuit levels for their electrical equipment's and preventing cascading event outages which may lead to blackouts. This paper mainly studies strategies on how to add Short Circuit Current Limiter (SCCL) device by determining its number, value and location of connection in power grids by programing with (PSS™E version 30.3 Package Program). IEEE 25-bus system is used for testing the adding series SCCL at power transmission lines method procedure. The results of adding series SCCL with power transmission lines give significant reducing short circuit levels for the stations have highest short circuit levels in order to prevent the blackouts of overall power grid.


2021 ◽  
Vol 14 (2) ◽  
pp. 100-107
Author(s):  
E. M. Farhadzadeh ◽  
A. Z. Muradalyiev ◽  
S. A. Muradalyiev ◽  
A. A. Nazarov

The organization of operation, maintenance and repair of the basic technological facilities of electric power systems (EPS), which are beyond their designed service life (hereinafter referred to as ageing facilities, or AFs) is one of the problems that determine the energy security of many countries, including economically developed nations. The principal cause of insufficient overall performance of AFs is the traditional focus of the EPS management on economic efficiency and the insufficient attention to reliability and safety of AFs. The tendency to nonlinear growth in the frequency of occurrence of unacceptable consequences in the EPS requires ensuring the operational reliability and safety of AFs. The averaged estimates of reliability and safety used at designing power facilities are not suitable for characterization of overall operational performance. Among the basic and the least investigated (in terms of operational reliability and safety) EPS facilities are overhead power transmission lines (OPL) with a voltage of 110 кV and above. This is for a reason. OPL are electric power facilities with elements distributed along a multi-kilometer line (supports, insulators, wires, accessories, etc.). That is what makes the organization of continuous monitoring of the technical condition of each of these elements, and, consequently, the assessment of operational reliability and safety, so problematic. A method is suggested for assessment of “weak links” among the operated OPL on operative intervals of time along with a method for assessment of the technical condition of OPL at examination of a representative sample.


2014 ◽  
Vol 17 (1) ◽  
pp. 16-29
Author(s):  
Long Van Hoang Vo ◽  
Tu Phan Vu

The population explosion and development of the national economy are two main causes of increasing the power demand. Besides, the Distributed Generations (DG) connected with the power transmission and distribution networks increase the transmission power on the existing lines as well. In general, for solving this problem, power utilities have to install some new power transmission and distribution lines. However, in some cases, the install of new power lines can strongly effect to the environment and even the economic efficiency is low. Nowadays, the problem considered by scientists, researchers and engineers is how to use efficiently the existing power transmission and distribution lines through calculating and monitoring their current carrying capacity at higher operation temperature, and thus the optimal use of these existing lines will bring higher efficiency to power companies. Generally, the current carrying capacity of power lines is computed based on the calculation of their thermal fields illustrated in IEEE [1], IEC [2] and CIGRE [3]. In this paper, we present the new approach that is the application of the finite element method based on Comsol Multiphysics software for modeling thermal fields of overhead power transmission lines. In particular, we investigate the influence of environmental conditions, such as wind velocity, wind direction, temperature and radiation coefficient on the typical line of ACSR. The comparisons between our numerical solutions and those obtained from IEEE have been shown the high accuracy and applicability of finite element method to compute thermal fields of overhead power transmission lines.


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