Effect of Voltage Level Selection on Earthing and Protection of LVDC Distribution Systems

2015 ◽  
Author(s):  
J. Karppanen ◽  
T. Kaipia ◽  
A. Mattsson ◽  
P. Nuutinen ◽  
Jaehan Kim ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Voltage Level

scholarly journals Determining the optimum medium voltage level by analysis of different voltage levels

2020 ◽  
Vol 10 (2) ◽  
pp. 37-49
Author(s):  
Fatma Avli Firis
Keyword(s):  
Distribution Systems ◽  
Electric Energy ◽  
Electrical Energy ◽  
World Population ◽  
Operating Voltage ◽  
Voltage Level ◽  
Energy Unit ◽  
Modeling And Analysis ◽  
Cost Distribution ◽  
Network Losses

Electric energy, which is the main input of the growing world economy, depending on the consumption of the rapidly increasing world population and the devices fed with this energy, have become more indispensable in our lives with each passing day. In the consumption of electrical energy, determining the voltage level plays an important role in planning distribution systems that will directly affect consumers. Distribution systems in our country have been established at different levels for technical and financial reasons. Incorrect choices that can be made during the determination of the voltage level in distribution systems may increase energy unit costs and network losses, and may cause insulation and reliability problems. The aim of this study is to determine the optimum voltage level in distribution systems. A pilot region was determined for a local electricity distribution network in our country, and modeling and analysis were carried out at different voltage levels in the region with the help of a numerical analysis program. According to the results achieved, Insulation and reliability problems at low voltages are few and economic in terms of investment costs, but it has been observed that the operating load and cost are high due to high network losses. In high voltages, although the operating burden and cost are relatively low, it has been observed that the investment costs are high and the isolation and reliability problems are high.   Keywords: cost; distribution; investment; operating ;Voltage

An Ontological Approach to Water Distribution Systems Management

WRPMD'99 ◽  
1999 ◽  
Author(s):  
P. Costa ◽  
A. Esposito ◽  
C. Gualtieri ◽  
D. Pianese ◽  
G. Pulci Doria ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Systems Management ◽  
Ontological Approach

Robust Estimation of Integrated Hydraulics and Parameters in Water Distribution Systems

2001 ◽  
Author(s):  
Mietek A. Brdys ◽  
Kazimierz Duzinkiewicz ◽  
Michal Grochowski ◽  
Tomasz Rutkowski
Keyword(s):  
Robust Estimation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems

Dependence of Current Harmonics of Greenhouse Irradiators on Supply Voltage

2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva
Keyword(s):  
Mathematical Models ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Feasibility Studies ◽  
Power Losses ◽  
Voltage Level ◽  
Supply Networks ◽  
Current Harmonics ◽  
Cable Lines ◽  
Harmonic Composition

The article describes the results of the study concerning the effect of the voltage level on current harmonic composition in greenhouses irradiators. It is found that its change affects the level of current harmonics of all types of the studied greenhouse irradiators. With decrease of nominal supply voltage by 10 %, the total harmonic distortion THDi decreases by 9 % for emitters equipped with high pressure sodium lamps (HPSL), by 10 % for emitters with electrode-less lamps and by 3 % for LED based emitters. With increase of nominal supply voltage by 10 %, THDi increases by 23 % for lighting devices equipped with HPSL, by 10 % for irradiators with electrode-less lamps and by 3 % for LED based emitters. Therefore, changes of supply voltage cause the least effect on the level of current harmonics of LED based emitters and then the emitters with electrode-less lamps. Change of the level of supply voltage causes the greatest effect on the level of current harmonics of HPSL based irradiators. Mathematical models of dependence of THDi on the level of supply voltage for greenhouse emitters equipped with LED, electrode-less lamps and HPSL lamps were formulated. These mathematical models may be used for calculations of total current when selecting transformers and supply cable lines for greenhouse lighting devices, for design of new or reconstruction of existing irradiation systems of greenhouse facilities, and for calculation of power losses in power supply networks of greenhouse facilities during feasibility studies for energy saving and energy efficiency increasing projects.

TO THE STABILITY OF TANK VEHICLES IN THE BRAKE MODE

2019 ◽  
pp. 27-32
Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk
Keyword(s):  
Mathematical Model ◽  
Control Systems ◽  
Distribution Systems ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Center Of Mass ◽  
Dynamic Processes ◽  
Course Stability ◽  
The Stability ◽  
Tank Vehicles

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.

A Target Voltage Control Method for Distribution Systems based on Nodal P&Q Prices for PV Distributed Generators

2020 ◽  
Vol 140 (6) ◽  
pp. 456-464
Author(s):  
Naoto Yorino ◽  
Tsubasa Watakabe ◽  
Ahmed Bedawy Khalifa ◽  
Yutaka Sasaki ◽  
Yoshifumi Zoka
Keyword(s):  
Distribution Systems ◽  
Control Method ◽  
Voltage Control ◽  
Distributed Generators
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