Mathematical Model for Automatic Short-Circuit Calculation Based On Incidence Matrix in Coal Mine High-Voltage Grid

2016 ◽  
Vol 9 (9) ◽  
pp. 375-390
Author(s):  
Wang XinLiang ◽  
Yang QianHui ◽  
Jin Xiang
2013 ◽  
Vol 273 ◽  
pp. 389-393
Author(s):  
Yu Mei Wang ◽  
Xu Yang ◽  
Hao Zhang

When the power supply system for coal mine underground take place a short circuit fault, multilevel switch often respond at the same time. And the existing comprehensive protector cannot satisfy the real-time and rapid quality requirements of preventing override trip system for high-voltage power grid of coal mine underground. So this paper put forward the research for comprehensive protector of preventing override trip based on the EtherCAT. This paper first analyzes the principle and characteristics of the EtherCAT technology; and then puts forward the overall scheme of preventing override trip system; Finally, study and design the slave station and master station of preventing override trip system based on the EtherCAT.


2009 ◽  
Vol 18 (6) ◽  
pp. 722 ◽  
Author(s):  
E. G. Psarros ◽  
A. D. Polykrati ◽  
C. G. Karagiannopoulos ◽  
P. D. Bourkas

Wildfires, which are uncontrolled fires spreading readily over vast areas, are usually the result of human negligence, arson or lightning. There are cases of fires close to electrical distribution lines for which the network has been blamed. In the present paper, the risk of a wildfire breaking out owing to the temperature of molten metal particles that are possibly created on bare conductors of low-voltage networks in short-circuit faults (unless they are interrupted by the protection systems) is examined. Thus, a mathematical model is proposed for the estimated temperature rise of those molten metal particles ejected from bare conductors of low-voltage overhead lines. Moreover, this model can be applied to medium- or high-voltage networks. The model takes into account the weather conditions and particles’ height above the ground. Further, an arithmetic example for an incandescent particle ejected from aluminium conductors of a low-voltage network is given. According to this example, there is no risk of dead leaves or wood catching fire owing to this particle.


2014 ◽  
Vol 494-495 ◽  
pp. 1753-1757
Author(s):  
Yan Gao ◽  
Feng Lin Ma ◽  
Guang Zhuai Dong ◽  
Hai Long Xing

According to the problems which are relay protection is difficult to adjust and when line fault occurs it will easily get override trip in the underground 6 kV power supply system in Gu Shu-yuan Coal Mine. This paper presents a centralized selective short circuit and leakage protection system. Which focuses on the analysis of the short circuit longitudinal differential protection, based on pattern recognition method of single-phase earth leakage protection principle, and completes the rapidity and selectivity of the leakage fault line selection . Through the simulation, experimental and field operation shows that the schemes can effectively improve the reliability and safety of high voltage power supply system in Gu Shu-yuan Coal Mine ,it also establishes the necessary foundation of the goal of "network relay protection" in high voltage power supply system for in China.


2012 ◽  
Vol 48 (3) ◽  
pp. 1046-1053 ◽  
Author(s):  
Filippo Chimento ◽  
Willy Hermansson ◽  
Tomas Jonsson

TEM Journal ◽  
2021 ◽  
pp. 1525-1533
Author(s):  
Allen A. Castillo ◽  
M. Natalia Galván Osuna ◽  
Norma A. Barboza Tello ◽  
Alejandra J. Vega

Teaching short-circuit analysis is conducted primarily through case studies; however, there are not many validated short-circuit studies available on the subject, especially when considering off-nominal turns ratio transformers. In order to improve the teaching of short-circuit analysis, a three phase short-circuit study in an industrial system according to ANSI/IEEE standards by means of Zmatrix method is presented; two case studies are considered: the industrial system with nominal and offnominal turns ratio transformers, in both cases the step by step solution is given in an explicit manner and the analytical results are validated through software simulation.


Author(s):  
Kim Hung Le ◽  
Ngoc Thien Nam Tran ◽  
Viet Tri Nguyen ◽  
The Khanh Truong ◽  
Minh Quan Duong

The increasing demand for electricity along with the development of distributed generators showed that improving transmission efficiency and reliability is an indispensable requirement in the operation of the power system. Advanced technologies need to be applied to modern power systems for purposes of conveying large power flows, mitigating the risk of faults. High-voltage direct current (HVDC) transmission is now considered an effective solution for investment in large-length power lines, replacing the conventional high-voltage alternative current (HVAC) transmission system, especially in period of increasing generation capacity due to the penetration of renewable energy sources. This study assesses the performance of the HVDC system on an actual power grid based on planning and improvement demands. The calculation results of power flows, power losses and short-circuit faults were investigated using ETAP software X  


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