نتایج جستجو برای: and grounding potential rise

تعداد نتایج: 16930858  

In this paper, the effect of ocean-land mixed propagation path on the lightning performance of grounding rods is investigated. This effect is focused on two problems. The first is extracting exact equivalent circuit of grounding rods in the presence of oceans. The equivalent circuit can be used in transient analysis of power systems in the neighboring oceans. In the second one, this effect on t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده ادبیات و علوم انسانی 1392

in new management approaches, in the organizations with inflexible structure, existing of red tapes and interruptions caused by limitations and also non-compliance with environmental changes, create demotivation among staff. with regard to the influence of job motivational potential and its relationship to the type of organizational structure( enabling and dissuasive), the goal of this research...

2012
Chun - Yao Lee Yi - Xing Shen

This paper presents an application of particle swarm optimization (PSO) to the grounding grid planning which compares to the application of genetic algorithm (GA). Firstly, based on IEEE Std.80, the cost function of the grounding grid and the constraints of ground potential rise, step voltage and touch voltage are constructed for formulating the optimization problem of grounding grid planning. ...

2015
M. G. Unde B. E. Kushare

During ground faults, fault current flows in the ground which results in potential gradient and ground potential rise (GPR). The potential gradient affects the safety of operating person due to step and touch voltage and GPR affects the insulation of protective devices and control cables. The potential gradient and GPR are the functions of ground electrode geometry. In this paper, performance a...

Maziar Babaei Sajad Bagheri Zahra Moravej

This study presents the manner in which transient modeling concepts, which are fully analyzed in the referred standards, are implemented, for the purpose of evaluating the Transient Ground Potential Rise (TGPR). This is a phenomenon of 10–100kV voltages with up to 10µs duration on the grounded enclosure of Gas Insulated Substations (GIS), which may cause concern for personnel safety and pro...

Maziar Babaei Sajad Bagheri Zahra Moravej,

This study presents the manner in which transient modeling concepts, which are fully analyzed in the referred standards, are implemented, for the purpose of evaluating the Transient Ground Potential Rise (TGPR). This is a phenomenon of 10–100kV voltages with up to 10μs duration on the grounded enclosure of Gas Insulated Substations (GIS), which may cause concern for personnel safety and problem...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

2014
M. A. Abd - Allah N. Ali A. Said

Lightning protection systems (LPS) for wind power generation is becoming an important public issue. A serious damage of blades, accidents where low-voltage and control circuit breakdowns are frequently occur in many wind farms. A grounding system is one of the most important components required for appropriate LPSs in wind turbines WTs. Proper design of a wind turbine grounding system is demand...

2014
Mohammad E.M. Rizk Ebrahim A. Badran Mansour H. Abdel-Rahman

Lightning protection system (LPS) for wind power generation has become an important public issue due to greatly increasing installations of wind turbines (WTs) worldwide. Grounding system is one of the most important components required for appropriate LPS for WTs. Although the finite-difference time-domain (FDTD) method for solving Maxwell`s equations is difficult for computing earth potential...

Journal: :Journal of the Korean Institute of Illuminating and Electrical Installation Engineers 2013

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