Enhanced selectivity of high resistance earth-fault clearing improves quality of electric energy supply in Slovenia

2005 ◽  
Author(s):  
J. Curk ◽  
V. Lenardic
Keyword(s):  
High Resistance ◽  
Energy Supply ◽  
Electric Energy ◽  
Earth Fault ◽  
Enhanced Selectivity

Automated Control of the Microclimate of Greenhouses

2021 ◽  
Vol 1 (42) ◽  
pp. 68-72
Author(s):  
Viktoriya Ukhanova ◽  
Keyword(s):  
Production Process ◽  
Energy Supply ◽  
Electric Energy ◽  
Research Purpose ◽  
Agricultural Producers ◽  
Best Available Technologies ◽  
Technological Processes ◽  
The Republic ◽  
The Impact

The protected soil industry is one of the most technologically complex and energy-intensive branches of agriculture. In recent years, especially in 2020, the demand for the products of greenhouse plants is increasing. Reducing the risks of the impact of the quality of energy supply, as well as reducing the cost of electricity due to the constant increase in tariffs are important tasks. Therefore, it is important to identify and analyze modern available technologies and equipment of Russian production for greenhouse farms. (Research purpose) The research purpose is in assessing the impact of the quality of energy supply on the technological processes of greenhouse farms, identifying and analyzing the existing modern domestic equipment that reduces the risks of the energy supply. (Materials and methods) Authors used a computational and analytical method for determining the average indicators of electric energy costs for technological processes in a greenhouse. The article presents a review of the automated greenhouse microclimate management system developed using the products of TM OWEN. (Results and discussion) Automated systems for controlling the greenhouse microclimate can reduce the impact of the quality of energy supply when deviating from normal values, minimize the impact of the human factor on the production process, and collect and archive the indicators of devices for further analysis. The system makes it possible to repair and replace failed equipment without stopping the production process and implies both fully automated and manual control, if necessary. The considered version of the automated greenhouse microclimate control system has been tested in practice and is used in the greenhouse economy of the Republic of Bashkortostan. (Conclusions) The efficiency of the greenhouse economy depends, among other things, on the level of automation, the quality of energy supply, and the use of energy-saving technologies. We stated that it is necessary to continue to work on the identification and analysis of modern Russian-made equipment, informing agricultural producers about the best available technologies.

MSHE-PWM Control of Modular Multilevel Direct Current Transmission System

2015 ◽  
Vol 9 (1) ◽  
pp. 553-559
Author(s):  
HU Xin-xin ◽  
Chen Chun-lan
Keyword(s):  
Pulse Width Modulation ◽  
Reactive Power ◽  
Balance Control ◽  
Electric Energy ◽  
Access Point ◽  
Experimental Result ◽  
Switching Frequency ◽  
Pwm Control ◽  
Harmonic Elimination

In order to optimize the electric energy quality of HVDC access point, a modular multilevel selective harmonic elimination pulse-width modulation (MSHE-PWM) method is proposed. On the basis of keeping the minimum action frequency of the power device, MSHE-PWM method can meet the requirement for accurately eliminating low-order harmonics in the output PWM waveform. Firstly, establish the basic mathematical model of MMC topology and point out the voltage balance control principle of single modules; then, analyze offline gaining principle and realization way of MSHEPWM switching angle; finally, verify MSHE-PWM control performance on the basis of MMC reactive power compensation experimental prototype. The experimental result shows that the proposed MSHE-PWM method can meet such performance indexes as low switching frequency and no lower-order harmonics, and has verified the feasibility and effectiveness thereof for optimizing the electric energy quality of HVDC access point.

Variable-Frequency Prony Method in the Analysis of Electrical Power Quality

2012 ◽  
Vol 19 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Jarosław Zygarlicki ◽  
Janusz Mroczka
Keyword(s):  
Least Squares ◽  
Power Quality ◽  
Electrical Power ◽  
Electric Energy ◽  
Variable Frequency ◽  
Prony Method ◽  
Analysis Window ◽  
Proposed Modification ◽  
Selection Of

Variable-Frequency Prony Method in the Analysis of Electrical Power QualityThe article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time.

scholarly journals Analysis of Vertical Integration Motivation in Coal-Electric Energy Supply Chain Using ISM-MICMAC

2021 ◽  
Vol 793 (1) ◽  
pp. 012006
Author(s):  
Wang Qiang ◽  
Liu Haiying ◽  
Wu Ping ◽  
Gao Haiwen ◽  
Wang Jiaxin ◽  
...  
Keyword(s):  
Supply Chain ◽  
Vertical Integration ◽  
Energy Supply ◽  
Electric Energy

Improved Alignment Technique for Dish Concentrators

Solar Energy ◽  
2003 ◽  
Author(s):  
Charles E. Andraka ◽  
Richard B. Diver ◽  
K. Scott Rawlinson
Keyword(s):  
Focal Length ◽  
Electric Energy ◽  
Parabolic Systems ◽  
Companion Paper ◽  
Quantitative Information ◽  
Key Factors ◽  
Look Back ◽  
Parabolic Dish ◽  
The Individual

Parabolic dish concentrators have shown significant promise of generating competitive electric energy for grid and off-grid applications. The efficiency of a dish-electric system is strongly affected by the quality of the concentrator optics. Most parabolic systems consist of a number of facets mounted to a support structure in an approximate parabolic arrangement, where the individual facets have spherical or parabolic optical shapes. The individual facets must be accurately aligned because improper alignment can compromise performance or create hot spots that can reduce receiver life. A number of techniques have been used over the years to align concentrator facets. In the Advanced Dish Development System (ADDS) project, a color look-back alignment approach that accurately aligns facets (mirror panels) and in addition indicates quantitative information about the focal length was developed. Key factors influencing the alignment, some of which had very large effects on the quality of the alignment, were also identified. The influence of some of the key factors was characterized with a flux mapping system on the second-generation ADDS concentrator. Some of these factors also affect other alignment approaches. The approach was also successfully applied to two other concentrators with differing facet arrangements. Finally, we have extended the method to a 2-f approach that eliminates the need for a distant line-of-sight to the dish and permits alignment at near vertical dish attitudes. In this paper, we outline the color look-back alignment approach, discuss the key alignment factors and their effect on flux distribution, and discuss extensions to non-gore dishes. A companion paper discusses the 2-f color alignment approach in detail.

The most common violations of regulatory indicators of the quality of electric energy in electric networks

2021 ◽  
pp. 44-49
Author(s):  
A. G. Soshinov ◽  
T. H. Aisin
Keyword(s):  
Quality Indicators ◽  
Electric Energy ◽  
Electrical Equipment ◽  
Operating Conditions ◽  
Regulatory Requirements ◽  
Electric Networks ◽  
High Quality ◽  
The Asymmetry

Work on ensuring the quality of electric energy in accordance with the requirements of GOST 32144-2013 is currently relevant and requires prompt and high-quality solutions. The article lists the main consumers of electric energy that negatively affect its quality, provides the results of measurements of electric energy quality indicators and the most common violations of regulatory requirements, analyzes the influence of voltage asymmetry on the operating conditions of electrical equipment. The basic formulas for calculating the asymmetry coefficients and ways to reduce the voltage asymmetry are proposed.

An Appraisal of Electric Energy Supply Security in Residential Estates of Ado-Ekiti, Nigeria

2021 ◽  
pp. 466-479
Author(s):  
S. E. Okosun ◽  
J. O. Fasakin ◽  
J. O. Basorun ◽  
I. O. Olamiju ◽  
E. A. Aluko
Keyword(s):  
Energy Supply ◽  
Electric Energy ◽  
Energy Supply Security
Sign in / Sign up

Export Citation Format

Share Document