scholarly journals Asymmetrical Modes of Outdoor Lighting Lines

Author(s):  
V. B. Kozlovskaya ◽  
V. N. Kalechyts

Asymmetrical modes of the outdoor lighting network can be caused by disconnecting of a part of the luminaires in order to electrical energy savings at night; also – by asymmetry of voltage in power points. The possible alternative symmetric modes of energy saving to replace the incomplete-phase operation of the line have been analyzed. Calculations of various symmetric and asymmetric modes of the lighting line were carried out without taking into account and taking into account high harmonics up to the 39th one. Calculations have been performed with the programs of MathCad software. As light sources, in the calculations the widely used luminaries with high-pressure sodium arc lamps connected through electromagnetic start-up equipment were considered. Such luminaries are sources of high harmonics, and they distort the sinusoidal voltage. The values of currents, power, power loss, voltage drop in all areas of the lighting line, the voltage at the terminals of the lamps for each phase (operating parameters) are determined. The diagrams of the voltage distribution at the points of the lighting line are plotted for the considered modes of operation. The annual electric power consumption of the lighting line has been calculated for different variants of operation, and the obtained results have been compared. When refusing to disconnection of part of the luminaires at night and using a smooth transition to a lower voltage (symmetrical) at a power point or using two-stage ballast devices, uneven illumination appears less when the level of electricity consumption is comparable. The presence of voltage asymmetry at the power point, as well as the disconnection of one phase, leads to an increase in currents, power losses and voltage. The current in the zero working conductor can exceed the currents in the phase conductors (when calculated taking into account the higher harmonics). Accounting for higher harmonics allows one to determine the operating parameters more accurately, on the basis of which the electricity power consumption can be estimated.

Author(s):  
S. Denysiuk ◽  
T. Bazyuk

Peculiarities of estimation of total energy losses in electric networks and estimation of nature of electricity consumption in local power supply systems (LES) are given. The structure of additional electricity losses in LES in the presence of higher harmonics of current and voltage is carried out, the generalized schedule of instantaneous functions of current i(t), voltage u(t), and power p(t) on components. The offered indicators of an estimation of the performance of criterion of a minimum of losses of the electric power in LES allow to estimate levels of distortion of power processes at consideration both exchange processes, and at the analysis of additional losses of the electric power. The accuracy of measuring the integrated characteristics of energy exchange depending on the available levels of distortion of voltage and current signals is considered. It is shown that in order to take into account the influence of higher harmonics on the total power consumption, it is necessary to determine the change of Frize QFpower as an indicator of additional electricity losses in the presence of non-sinusoidal currents and voltages in at different ratios between the value of current and voltage of the first and higher harmonics. The evaluation of the efficiency of power consumption regulation using the Frize QF power at an arbitrary time interval, as well as the corresponding current distribution into active and reactive components are considered. The peculiarities of increasing the efficiency of power consumption regulation in LES at the cyclic change of generator parameters and load are analysed.


2020 ◽  
Vol 7 (4) ◽  
pp. 520-526
Author(s):  
Saidjon Sheralievich Tavarov ◽  
Alexander Ivanovich Sidorov ◽  
Yulia Vladimirovna Kalegina

The article is devoted to solving the problem of increasing the energy efficiency of urban electrical networks based on identifying factors affecting power consumption. According to the established patterns, a forecasting model has been developed, on the basis of which seasonal schedules of electricity consumption by household consumers are proposed. To monitor and control the operating parameters of the urban electrical network, taking into account the functionality of smart electricity meters, a control algorithm is proposed based on the proposed seasonal power consumption schedules by household consumers and a schematic implementation using smart electricity meters.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2771
Author(s):  
Leszek Kotulski ◽  
Artur Basiura ◽  
Igor Wojnicki ◽  
Sebastian Siuchta

The use of formal methods and artificial intelligence has made it possible to automatically design outdoor lighting. Quick design for large cities, in a matter of hours instead of weeks, and analysis of various optimization criteria enables to save energy and tune profit stream from lighting retrofit. Since outdoor lighting is of a large scale, having luminaires on every street in urban areas, and since it needs to be retrofitted every 10 to 15 years, choosing proper parameters and light sources leads to significant energy savings. This paper presents the concept and calculations of Levelized Cost of Electricity for outdoor lighting retrofit. It is understood as cost of energy savings, it is in the range from 23.06 to 54.64 EUR/MWh, based on real-world cases. This makes street and road lighting modernization process the best green “energy source” if compared with the 2018 Fraunhofer Institute cost of electricity renewable energy technologies ranking. This indicates that investment in lighting retrofit is more economically and ecologically viable than investment in new renewable energy sources.


Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 178
Author(s):  
Michel Pirchio ◽  
Marco Fontanelli ◽  
Fabio Labanca ◽  
Mino Sportelli ◽  
Christian Frasconi ◽  
...  

Turfgrass mowing is one of the most important operations concerning turfgrass maintenance. Over time, different mowing machines have been developed, such as reel mowers, rotary mowers, and flail mowers. Rotary mowers have become the most widespread mowers for their great versatility and easy maintenance. Modern rotary mowers can be equipped with battery-powered electric motors and precise settings, such as blade rpm. The aim of this trial was to evaluate the differences in power consumption of a gasoline-powered rotary mower and a battery-powered rotary mower. Each mower worked on two different turfgrass species (bermudagrass and tall fescue) fertilized with two different nitrogen rates (100 and 200 kg ha−1). The battery-powered mower was set at its lowest and highest blade rpm value, while the gasoline-powered mower was set at full throttle. From the data acquired, it was possible to see that the gasoline-powered mower had a much higher primary energy requirement, independent of the turf species. Moreover, comparing the electricity consumption of the battery-powered mower over time, it was possible to see that the power consumption varied according to the growth rate of both turf species. These results show that there is a partial waste of energy when using a gasoline-powered mower compared to a battery-powered mower.


2016 ◽  
Vol 50 (4) ◽  
pp. 631-650 ◽  
Author(s):  
N Gentile ◽  
T Goven ◽  
T Laike ◽  
K Sjoberg

Indoor lighting is facing a massive retrofit to LED lighting. Research is needed to assess whether LED-based lighting can promote energy efficiency, boost visual comfort and support biological functions. This field study considered the lighting of four identical classrooms in an upper secondary school in Helsingborg, Sweden. Two classrooms were fitted with state-of-the-art ceiling pendants containing T5 fluorescent tubes and that had a direct/indirect light distribution (the control rooms). The other two classrooms were fitted with an experimental LED indirect lighting system (the experimental rooms). In the classrooms, 72 students aged 17–18 years performed their usual educational activities over a whole academic year. The light environment, electricity consumption, and students’ mood, light perception and saliva cortisol concentration were monitored. The two lighting systems produced only marginal differences. Overall, the experimental rooms were slightly preferred but achieved only small energy savings due to high parasitic losses.


Author(s):  
N. Rudenko ◽  
S. Leshchenko ◽  
Yu. Kovalenko

Solar and hydrogen energy play an important role in providing a variety of industrial facilities with electricity and heat. One of the priorities of modern industry is to increase the production of environmentally friendly energy source – electrochemical synthesis of hydrogen. Modern methods of electrolysis of water do not meet the need for its use, due to the high cost of electrosynthesis of water-alkaline electrolysis, which depends on the material and energy consumption of electrolysis. The useful energy consumption for the production of energy – hydrogen at the cathode and "unnecessary" costs - for the release of oxygen at the anode, depend on the overvoltage of the respective reactions. Therefore, the most important problem of hydrogen energy is the synthesis of electrode materials with low overvoltage of O2 and H2. Electrode materials with low overvoltage will reduce the specific consumption of electricity in obtaining hydrogen by "classical" electrolysis. The prospects of reducing the cathodic and anodic overvoltage, which is a significant part of the voltage at the terminals of the cell, for the development of highly efficient and competitive technologies for hydrogen production by low-temperature electrolysis of an alkaline solution have been theoretically substantiated and experimentally confirmed. To reduce the overvoltage of the cathodic hydrogen evolution, it is proposed to modify the surface of the cathodes. The application of a small amount of electrolytic alloys of metals of the iron family with molybdenum and tungsten on nickel, cobalt, titanium and steel electrodes significantly (by 40–50 %) reduces the overvoltage of cathodic release of hydrogen from alkali solution. The use of steel electrodes, the surface of which is modified with vanadium and ni-ckel, reduces the voltage drop on the cell during the synthesis of H2 and O2 by 0.2–0.3 V, which creates conditions for reducing energy costs and energy savings.


2021 ◽  
Vol 288 ◽  
pp. 01109
Author(s):  
Alexander Semenov ◽  
Yuriy Bebikhov ◽  
Ayaal Egorov ◽  
Vladislav Shevchuk ◽  
Marina Glazun ◽  
...  

The paper presents the evaluation of the implementation of innovative methods of energy savings in electric drive and power supply systems at mining enterprises. The evaluation involves mathematical simulation and instrumental monitoring of the defined indicators that allow obtaining a multiplier economic benefit through the appropriate approach to the implementation and subsequent exploitation of energy-saving technologies. For this purpose, the potential of energy savings in industry in general, and at mining enterprises in particular, is shown. Such indicators as power consumption in mining, the dynamics of power losses in public grids, specific power consumption for lighting and household needs, specific power consumption for lifting and supplying water, as well as for sewage treatment were evaluated. As an example, such measures as reactive power compensation, the introduction of frequency-controlled electric drive systems, the development and implementation of the systems for continuous monitoring of power quality indicators were considered pointwise (at some sites of enterprises). The mathematical simulation method was implemented using the MatLab software package. The instrumental monitoring was carried for 7 days with a ten-minute interval. As a result of the assessment of such measures, the total economic benefit approaching to 9.0 million rubles a year was obtained.


2017 ◽  
Vol 2017 ◽  
pp. 1-22 ◽  
Author(s):  
Jihyun Kim ◽  
Thi-Thu-Huong Le ◽  
Howon Kim

Monitoring electricity consumption in the home is an important way to help reduce energy usage. Nonintrusive Load Monitoring (NILM) is existing technique which helps us monitor electricity consumption effectively and costly. NILM is a promising approach to obtain estimates of the electrical power consumption of individual appliances from aggregate measurements of voltage and/or current in the distribution system. Among the previous studies, Hidden Markov Model (HMM) based models have been studied very much. However, increasing appliances, multistate of appliances, and similar power consumption of appliances are three big issues in NILM recently. In this paper, we address these problems through providing our contributions as follows. First, we proposed state-of-the-art energy disaggregation based on Long Short-Term Memory Recurrent Neural Network (LSTM-RNN) model and additional advanced deep learning. Second, we proposed a novel signature to improve classification performance of the proposed model in multistate appliance case. We applied the proposed model on two datasets such as UK-DALE and REDD. Via our experimental results, we have confirmed that our model outperforms the advanced model. Thus, we show that our combination between advanced deep learning and novel signature can be a robust solution to overcome NILM’s issues and improve the performance of load identification.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Antonio Peña-García ◽  
Luisa-María Gil-Martín ◽  
Roberto Escribano ◽  
Antonio Espín-Estrella

Shifting the threshold zone of road tunnels with semitransparent tension structures has shown itself to be an effective way of saving energy in regards to electricity consumption, maintenance, and construction materials used in the electrical lighting, thus lessening negative environmental impacts. Even though the shape of the tension structure has a major influence on energy savings, the optimal type of structure for each tunnel is often difficult to determine, because experiments using real tunnels are extremely expensive. It is thus necessary to find methods of doing this that are both reliable as well as economical. In this research study, three candidate structures were set up at the portal of a scale model of a real tunnel. The energy savings in each case were analyzed and compared. As a result, it was possible to formulate a new equation that calculates the energy savings in the threshold zone.


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