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1
Hualong, Yu, Wang Shiyu und Wu Jiachen. „Development of long‐distance power supply system with high power laser over single mode fiber“. Microwave and Optical Technology Letters 63, Nr. 7 (16.04.2021): 1995–98. http://dx.doi.org/10.1002/mop.32863.
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2
Jia, Jinliang, und Xiaoqiang Yan. „Application of Magnetic Coupling Resonant Wireless Power Supply in a Torque Online Telemetering System of a Rolling Mill“. Journal of Electrical and Computer Engineering 2020 (14.05.2020): 1–9. http://dx.doi.org/10.1155/2020/8582131.
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The torque of the main drive system is one of the most important force and energy parameters of the rolling mill, and the strain type torque online telemetry system is a practical method for measuring torque parameters. The strain gauges and transmitters on the rotating shaft are driven by a high-frequency induction power system. Their installation, debugging, and maintenance are cumbersome, and their very low power transmission efficiency (PTE) has become a challenging problem for online telemetry systems. In this paper, a magnetic coupling resonant wireless power supply method is utilized to replace the high-frequency induction power supply. Through theoretical and experimental research, it is concluded that the magnetically coupled resonant wireless power supply method can realize long-distance power supply, overcoming many shortcomings of the high-frequency induction power supply system. In the laboratory, a maximum PTE of 83.7% is obtained for a transmission distance of 50 mm. Under the influence of environmental factors common for the transmission shaft of a rolling mill, the PTE decreases by 34%, but normal operation of the system can be achieved by adjusting the compensation capacitance. The proposed system provides a guarantee for a long-term stable power supply on the measured axis of a rolling mill torque online telemetry system.
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Li, Li Yi, He Zhu, Ming Na Ma und C. C. Chan. „Research on Power Supply Strategies of Long Stroke Primary Segmented Permanent Magnet Linear Synchronous Motor“. Applied Mechanics and Materials 416-417 (September 2013): 209–14. http://dx.doi.org/10.4028/www.scientific.net/amm.416-417.209.
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Long stroke linear motor has an unparalleled advantage in the field of long-distance transport, transfer and electromagnetic launch system. The paper presents a primary segmented permanent magnet linear synchronous motor (PS-PMLSM), which can solve the problems of the long stroke linear motor in excessive power dissipation, the difficulties of power supply. According to the motor structure characteristics and application background, the paper proposes four feasible strategies--a single inverter series alternating power supply (SISAP), a single inverter parallel alternating power supply (SIPAP), dual inverters alternating power supply (DIAP) and inter-segment optimal power supply (ISOP). Firstly, the article makes studies on those strategies from the economic cost, energy efficiency, the complexity of switching among the segments and the convenience of algorithm application by calculation and simulation. Secondly, the mathematics model of the motor and control system model is deduced from different strategies, respectively. Then, the available control method is derived from the analysis of these models and the motion characteristics. Finally, effects of performance are comparatively analyzed through the simulation.
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Wang, Zhen Hao, Dan Pang, Xiao Juan Han, Xi Lin Zhang, Chao Bin Wang und Huai Guang Gu. „Development of Relay Device in Monitoring Data Management of Cable Circulation in Urban Power Grid“. Advanced Materials Research 860-863 (Dezember 2013): 1982–86. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.1982.
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The monitoring points of cable circulation in cities are relatively scattered. The on-site collection devices restricted by the power supply, installation site and communication distance are usually unable to store large amounts of data or transmit data over a long distance. In this thesis the relay device of data management is developed, realizing the management and sorted storing of the data of the collection devices of close-distance wireless receiving data, and sending the data to remote places through the GSM/GPRS network. Therefore the scattered data can be transmitted to computer analysis and management system over a long distance after centralized processing of scattered data and long-distance data monitoring and comprehensive analysis can be realized. Key Words: Cable, Circulation Monitoring, Relay, Mega64
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Li, Su Ping, und Xiao Fei Chen. „Solar Wireless Charging Circuit System Designing“. Applied Mechanics and Materials 229-231 (November 2012): 1017–20. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.1017.
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The solar wireless charging circuit system based on resonance coupling power wireless transmission is aimed at addressing long wire, complex manual operation of wire charging type and short-distance, low efficiency of general electromagnetic induction-type power wireless transmission. Solar is conversed to electricity by photoelectric conversion then the electricity passes the following processing circuit: solar power supply circuit, power wireless transmission circuit and lithium battery charging circuit to complete lithium battery charging finally. The proposed circuit system owns perfect long-distance transmission, safe-operation, automotive rechargeable, flexible and efficient etc basic features and preventing over charge and over discharge double protection performance.
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Lukaitis, V. Yu, und S. Yu Glushkov. „Autonomous power generation facilities, hybrid structures comprising renewable energy sources“. Power and Autonomous equipment 2, Nr. 2 (30.06.2019): 111–20. http://dx.doi.org/10.32464/2618-8716-2019-2-2-111-120.
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Introduction: the implementation of land development programmes in the polar regions, Siberia andFar East turns more complex due to power shortages in these areas. High electric energy rates and the need to maintain special purpose buildings encourage engineers to develop autonomous energy supply systems.Methods: the co-authors have analyzed several types of autonomous power supply facilities and series of autonomous power supply units designated for the power supply to the production machinery installed as part of various economic and special-purpose facilities, located at a long distance from industrial sources of electric energy.Findings and discussion: the co-authors present an algorithm for the selection of the configuration of an autonomous power supply system. The co-authors employ the findings of their analysis to substantiate the choice of a solar power station as a supplementary source of energy used as part of hybrid power generation systems.Conclusion: the algorithm developed by the co-authors may be used to design an efficient autonomous power supply system comprising hybrid units.
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Hashimoto, Masashi, Tomihiro Utsumi und Ken-ichi Yukimatsu. „Networking System for Large Rice Field Using Independent Power Supply System and Long Distance Wireless LAN“. Agricultural Information Research 16, Nr. 1 (2007): 9–21. http://dx.doi.org/10.3173/air.16.9.
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Song, Yuanming, Yajie Liu und Xu Yang. „Wireless Energy Transmission Link Optimization considering Microwave Energy Relay“. Complexity 2020 (16.09.2020): 1–11. http://dx.doi.org/10.1155/2020/8871086.
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With the widespread application of intelligent unmanned units and the development of wireless energy transmission technology, it has become an urgent requirement in the field of using wireless power transmission to extend the continuous working time of unmanned units. To improve the wireless transmission energy efficiency in practical application as much as possible based on the current development level of wireless transmission technology, this paper first enumerates and analyzes existing wireless energy supply methods and shows that microwave wireless energy transmission technology is most suitable in this study. Then, the necessity of power transmission relay in long-distance microwave wireless power transmission is discussed. Based on the idea of microwave energy relay transmission, the paper constructs a microwave wireless transmission link planning model which considers power relay and uses the evolutionary algorithm to solve the wireless transmission link planning model with two-layer optimization. Finally, the results show that, when the wireless transmission distance exceeds a certain threshold, adding relay nodes to the link can improve the energy transmission efficiency from the power supply node to the power receiving node.
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Tian, Tian, und Shiwu Xiao. „Electrochemical Anti-corrosion System of Iron Tower Based on Solar Power Supply“. MATEC Web of Conferences 160 (2018): 03006. http://dx.doi.org/10.1051/matecconf/201816003006.
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Aiming at the serious problem of the corrosion of the transmission tower in the coastal area or in the harsh industrial area, a kind of electro-chemical anti-corrosion system based on solar power is designed. The system consists of a solar power module and an electrochemical anti-corrosion module: The solar power module consists of a solar panel, a photovoltaic controller, a accumulator and a constant potentiometer. The Electrochemical anti-corrosion modules include an anode block and an anode bed and reference electrode. The photovoltaic energy technology and forced current cathodic protection technology are used in the system, to achieve the effective protection of the tower anti-corrosion. Solar power supply to the nearest, solve the long-distance transmission loss and the high installation costs, form a simple structure, stable operation, low cost, clean and environmental protection, long service life of anti-corrosion system, with good economic efficiency and social benefits. It is of great significance to ensure the safe operation of the tower, maintain the normal operation of the power grid, and even promotes the optimization and upgrading of the industrial structure, save energy and reduces emissions, improve the safe and stable operation of the power system and the economic benefits, etc.
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Sun, Yu Wen, Ming Xia Shen, Ying Jun Xiong, Ming Zhou Lu, Long Shen Liu und Xiao Li Kong. „Design on the System of Collection, Storage and Release for Field Information“. Advanced Materials Research 347-353 (Oktober 2011): 252–57. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.252.
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Based on WSN,GPRS,embedded system,database and Web server technology,a system of collection,storage and release for field information was designed.The WSN network is responsible to collect field information,such as air temperature,humidity, illumination,image and so on. The information collected can be not only save in gateway's embedded database,but also transferred to the long-distance Web server.Which solve the farmland monitoring information storage, distribution and mobile measurement of inconvenience issues. Solar power supply module has the role of long-term supply power.Experimental result shows the system can accurately and timely collect information agriculture farmland.
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Lu, E., Bei Huang, Shuang Shuang Li und Yan Yang. „A High Reliable Communication Method for the Terminal of a Networked and Distributed Power Supply System“. Applied Mechanics and Materials 644-650 (September 2014): 3453–58. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.3453.
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This paper relates to a high reliable communication method for the terminal of a networked and distributed power supply system. Terminal refers to the realization of two-way communication between high voltage source of distributed power supply and laden multiple electrical appliances. Due to the characteristics of long distance, complex electromagnetic environment and small amount of communication information between the voltage source and the electrical appliance, this paper designs a new kind of high reliable communication method along with high-voltage transmission, narrow-banded and single-ended synchronous [1,2,8]. Under the condition of satisfying the communication capacity and reliability, this method has been successfully applied to the city network and LED street lamp management system with the advantage of simple circuit design and inexpensive manufacturing cost.
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Chenhui, Wang, und Meng Qingjia. „Design of rapid monitoring system of geological disaster based on LoRa“. MATEC Web of Conferences 306 (2020): 03006. http://dx.doi.org/10.1051/matecconf/202030603006.
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According to the characteristics of the geological environment and disasters, this paper uses microelectronics, wireless communication, thin-film solar power supply and other technologies, combined with lightweight process design, a new scheme for rapid geological disaster monitoring system based on LoRa is proposed. The system is based on embedded microprocessor of STM32F103 and SX1278 module of LoRa, which uses self-organizing network design of star-type and constructs a monitoring system with long communication distance and stable and reliable data transmission. The system can realize real-time data collection of multiple monitoring parameters of the disaster body and transmit the monitoring data to the data center or dedicated data receiving terminal through LoRa/GPRS/BeiDou satellite, which can provide data support for expert analysis and decision-making. The system has the features of low power consumption, long transmission distance, ad hoc network, stable and reliable communication, which has wide application prospect in the field of geological disaster monitoring.
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Chisab, Raad Farhood. „An active technique for power saving in WSN under additive white gaussian noise channel“. International Journal of Electrical and Computer Engineering (IJECE) 9, Nr. 1 (01.02.2019): 386. http://dx.doi.org/10.11591/ijece.v9i1.pp386-396.
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The work with feature of self-power supply by solar cell or by the battery or together at the same time. Therefore, the power dissipation is the big problem in wireless sensor network (WSN) especially when it is works for long time. The efficient method for reducing the power consumption within working is needed. The process of reducing waste power is one of the top priorities of scientists and designers of wireless sensor networks. The aim of this paper is to find the dominant method to reduce the power consumption in the wireless sensor network in order to stay works for long time and maintain the links with other nodes without loss of connection and transfer the information correctly. In this paper, a modified method was invented to minimize power utilization per data bit in a connection. This new method depends on the optimization process for reducing the power consumption as low as possible. All the tests of simulation process were done in additive white Gaussian noise (AWGN) channel. Numerical results demonstrated that the new method reduce the power when different values of noise are present with different types of modulation. Also the distance that the WSN will reach the information to it will be increase with presence of various noise amounts with different types of modulation. As a result, the power was decreased and the signal was reach more distance.
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Morgan, James R., und Sam W. Swan. „The San Salvador Earthquake of October 10, 1986—Performance of Lifelines“. Earthquake Spectra 3, Nr. 3 (August 1987): 585–607. http://dx.doi.org/10.1193/1.1585447.
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Although the October 10, 1986 San Salvador earthquake was only a moderate event of magnitude 5.4 and the recorded ground motions had a relatively short duration, the high recorded peak accelerations caused substantial damage to lifelines. There was significant and widespread damage to buried lifelines. Long-distance telecommunications facilities were reportedly undamaged, but there was substantial loss of local phone service caused by damage to buildings, failures of equipment racks, and loss of emergency power (tilting of batteries). Power generating facilities (hydroelectric and geothermal) that supply electricity to San Salvador are located too far from the city to have been affected by the earthquake. Both 115-kV substations that serve San Salvador experienced a moderate level of damage, consisting mostly of ceramic column circuit breaker failures. As has been observed in past earthquakes, control and instrumentation systems and low-voltage power-supply equipment displayed an ability to withstand high ground accelerations.
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Elistratov, V. V. „Optimal solutions for an automatic control system for medium capacity power supply facilities using renewable energy sources“. Power and Autonomous equipment 2, Nr. 2 (30.06.2019): 69–85. http://dx.doi.org/10.32464/2618-8716-2019-2-2-69-85.
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Introduction: extensive logistics costs (including long distance transportation and high fuel prices) and a high cost of electric energy, generated by diesel power plants, are the main problem of power supply to consumers by off-grid power systems. The author unlocks the potential of hybrid power systems using renewable energy sources and saving expensive fuel. The author offers the analysis of automatic control systems capable of improving the efficiency of subordinate power plant elements.Methods: the author provides a classification of wind-diesel power plants and describes their performance pro rata to the share of wind energy consumption. The author has also compiled a set of specifications applicable to the technological solutions of wind-driven power plants. He also formulates the principles underlying an intelligent automatic control system for off-grid power supply facilities. This system served as the basis for a software and hardware module designed and developed for an intelligent power conversion/control/distribution system. The author provides diagrams of (1) electrical circuits of a software and hardware module for an intelligent power conversion/control/distribution system, and (2) the operation of an off-grid power supply package using renewable energy sources and controlled by the power conversion/control/distribution system. The author analyzes the primary and secondary sources of power in an off-grid power supply facility and describes principles of their operation within a software and hardware module.Results and discussions: the author offers a methodology of intelligent control over off-grid power supply facilities within the framework of the project for development of a wind-diesel power plant in thevillage ofAmderma. The author describes the results of incorporation of a wind-diesel power plant into the power supply facility operating in the permafrost environment of the Arctic region.Conclusion: presently,Russia has pre-conditions in place capable of boosting the development of power supply technologies using hybrid facilities comprising renewable energy sources. The implementation of such off-grid power supply facilities, controlled by newly designed software and hardware modules designated for an intelligent power conversion/ control/distribution system optimizes electric power generation and consumption modes and substantially reduces fuel consumption by diesel power plants.
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Wei, Li, und Chen Guang Zhao. „Study on Wireless Sensor Network Based on Laser Rangefinder“. Advanced Materials Research 403-408 (November 2011): 2776–79. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.2776.
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A system of wireless sensor network(WSN) based on laser rangefinder is studied, which adopts low power consumption ZigBee chip and SimpliciTI network protocol. 8 laser rangefinders are used to collecy the distance of the test points. The collection data is sent to upper computer by wireless data transmission module. It is rapid and real time to monitor the test point. The system can be installed in complex test environment to perform the monitor of all kinds of architecture structure. It dispenses with long time power supply and the user interface is friendly and has abundance function.
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Weigelt, Michael, Andreas Mayr, Alexander Kühl und Jörg Franke. „Methodical Comparison of Alternative Powertrain Technologies for Long-Distance Mobility Using Germany as an Example“. World Electric Vehicle Journal 10, Nr. 4 (15.11.2019): 77. http://dx.doi.org/10.3390/wevj10040077.
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The main barriers to the wide acceptance of electric vehicles, such as the limited driving range or the high acquisition costs, are to be countered by various technology alternatives for the powertrain of the future. Promising developments include improved battery technologies, fuel cell technologies or a constant power supply of the vehicle while driving, for example through dynamic inductive charging. In this context, a holistic technology comparison would contribute to a comprehensive and understandable information situation by making the heterogeneous technological concepts comparable with regard to different evaluation criteria. Therefore, this work describes the basic assumptions of the proposed holistic comparison of alternative powertrain technologies for long-distance mobility. Relevant framework conditions are structured and a procedure for the evaluation of infrastructure expenditures is shown. Building on this, a selection of key performance indicators is defined and explained. The proposed KPI framework is applied to a passenger car in the economic area Germany. The results show that by using electrified roadways, ecological as well as economic advantages against other alternative powertrain designs can be derived.
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Handayani, Oktaria, Tasdik Darmana und Christine Widyastuti. „Analisis Perbandingan Efisiensi Penyaluran Listrik Antara Penghantar ACSR dan ACCC pada Sistem Transmisi 150kV“. Energi & Kelistrikan 11, Nr. 1 (09.07.2019): 37–45. http://dx.doi.org/10.33322/energi.v11i1.480.
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Electricity need in Indonesia continues to increase in accordance with the rate of recovery of the economy and industry and the increase in population. The transmission line transmits electricity from the power plant to the load center via the High Voltage transmission lines (SUTT) or Extra High Voltage Transmissio lines (SUTET), because the long distance causes power losses. The condition before the reconducting of Tebing Tinggi - Kuala Tanjung transmission uses ACSR conductor types and after the reconducting has been replaced by the ACCC, where ACCC has 2 times the current trying of the type of ACSR. In this study, we will examine and analyze the magnitude of the power losses and the efficiency of the distribution of the two types of ACSR and ACCC supply channels with a case study of the 150 kV transmission system Tebing Tinggi - Kuala Tanjung which has a distance of 71.5 km. From the calculation results obtained, after the reconducting process using the conductor the ACCC was able to reduce power losses and increase efficiency by 1.35%.
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Hsieh, Chen, Cang Chin Yang, Chen Chiu Huang und Chih Hong Chen. „Fast Nanometer Positioning of Heavy Loads Using a Hybrid Driver“. Materials Science Forum 594 (August 2008): 235–40. http://dx.doi.org/10.4028/www.scientific.net/msf.594.235.
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Current motion tables can hardly exhibit the capabilities of positioning with nanometer precision and carrying heavy loads simultaneously. This is mainly because that the driver used to drive the table cannot fulfill the requirements needed for driving an ultra precision system without sacrificing the power it can offer. In this research, the concept of a hybrid driver is introduced and tested. This driver is basically a combination of a linear amplifier and an on-off large power supply. Although there are still some defects need to be overcome, preliminary experimental tests have shown that this kind of driver does have potential to carry heavy loads to do fast and long distance positioning with nanometer precision and in-position vibration.
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Meng, Ming, und Yun Ma. „Route Optimization of Electric Vehicle considering Soft Time Windows and Two Ways of Power Replenishment“. Advances in Operations Research 2020 (20.05.2020): 1–10. http://dx.doi.org/10.1155/2020/5612872.
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Under the background of severe air pollution and energy shortage, electric vehicles (EVs) are promising vehicles to support green supply chain and clean production. In the world, the renewal of EVs has become a general trend. Therefore, the concern about EVs is a hot issue at present, but EVs have the characteristics of limited driving distance and long charging time. When the EVs are used in logistics transportation, these characteristics have a significant impact on the vehicle routing problems. Therefore, based on the research experience of traditional vehicle routing optimization, combining with the characteristics of EVs, this paper presents an optimal problem of electric vehicle routes with time windows based on two charging methods and it also designs a mathematical model which was caused by early and late arrival as the objective function to minimize the transportation cost, vehicle use cost, power supply cost, and penalty cost. The model is solved using an ant colony algorithm. Finally, the ant colony algorithm is tested and analysed with an example.
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Kolesov, L. M., und V. V. Mozhzhukhina. „Designing of a distance protection stage based on data on branched line supply end currents“. Vestnik IGEU, Nr. 4 (2019): 44–53. http://dx.doi.org/10.17588/2072-2672.2019.4.044-053.
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At present, in 110–220 kV transmission lines the problem of interphase short-circuits in the long-distance backup protection zone, in most cases, is solved by a backup level of current or distance protection. The existing protection solutions for lines with branching are based on the use of special high-voltage equipment, various current components and their ratios, a virtual resistance relay; on the control of emergency and orthogonal current components with adaptive braking and signal correction as well as with correction of the response characteristics according to the data on the voltage change and the state of the switching devices of the main substation. A number of developments are aimed at increasing the sensitivity of back-up protection of branch substations by changing the connection circuit, improving the response characteristics and refining the method for selecting the settings. However, these protection solutions in many cases do not provide the required sensitivity during short circuits on the low voltage side of a low-power branch transformer. All this means that an urgent problem to be solved is developing an algorithm for the operation of backup protection, providing the required sensitivity to short circuits on the low voltage side of the branch transformer. Analytical methods and simulation in the Simulink and SimPowerSystems packages of the Matlab modeling system were used to determine the impedance measurement of the distance protection measuring element. A mathematical model of the lumped-parameter line was used. When deriving analytical expressions, the impedances of the positive and negative sequences were assumed to be equal. Analytical expressions were obtained for determining the impedance measurement of the proposed and existing distance protection during phase-to-phase short-circuits appearing after a branch transformer and under load conditions. The studies have shown that the proposed distance protection has the required sensitivity to short circuits on the low voltage side of the branch transformer and the necessary detuning from load modes. The characteristics and methods for selecting response parameters of the additional stage of distance protection were determined using information on the currents of the line supply ends. The use of an additional distance protection stage developed by the authors based on the sum of currents of the line supply ends can ensure the required sensitivity to phase-to-phase short circuits on the low voltage side of the branch transformer with a star-delta connection circuit and solve the problem of distant backup protection of low power branch substations. The reliability of the data obtained is confirmed by the correspondence of the results of the analytical research and simulation modeling.
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Kumrey, G. R., und S. K. Mahobia. „STUDY AND DESIGN OF SINGLE PHASE CONVERTER USING OF SINGLE PHASE TRANSFORMER“. International Journal of Research -GRANTHAALAYAH 4, Nr. 8 (31.08.2016): 46–51. http://dx.doi.org/10.29121/granthaalayah.v4.i8.2016.2562.
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The field of electrical transformer are most important equipment which is use to convert ac voltage or current like lower to higher , higher to lower without change in the frequency . its primary side and secondary side are isolate from each other and it can higher or lower voltage level the apparent value of electrical passive element like inductive , resistive . It use to transfer electrical energy for long distance with higher voltage level .the electrical power transmission,distribution through transformer for factories and home . AC supply can easily generated by a convenient voltage and transformed into much higher voltage for transmission and distribution purpose.
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Li, Yu Shu, Zhi Hong Guo und Guang Ming Yi. „Discussion about the Information Management and the Intellectualization of Unattended Substation“. Advanced Materials Research 317-319 (August 2011): 1353–56. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1353.
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Carry on unattended substation at the voltage of 220kV and the following is a technological innovation which having the profound influence to the current power supply system, is also the most important technology safeguard measure of the downsizing for efficiency in the power supply system. Along with the development of modern communication technology, computer technology, network technology, automatic control technology, image technology, monitoring technology and weak electricity integration technology, we had already realized the image and the sound signal's digitization, the audio and video signal's processing and the long-distance transmission. To the substation, besides the remote measurement, the remote signaling, the remote control, and the remote regulating functions which have already realized, the remote monitoring has also increased which called “five remote”. The “five remote” caused unattended substation become the reality and give a higher request to the information management and the intellectualization simultaneously. According to many years unattended substation's operational guidance experience, I proposed my ideas about the information management and the intellectualization of unattended substation, I hope that it is helpful to the promotion of the unattended substation.
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Chien, Zi-Jie, Hung-Pin Cho, Ching-Song Jwo, Chao-Chun Chien, Sih-Li Chen und Yen-Lin Chen. „Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells“. International Journal of Photoenergy 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/490124.
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This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC) power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP) of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines.
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Márquez-Fernández, Francisco J., Sönke Schuch, Lars Lindgren und Mats Alaküla. „Electric Safety Challenges with a Conductive Electric Road System—Chassis Potential Modeling and Measurement“. World Electric Vehicle Journal 10, Nr. 2 (24.05.2019): 30. http://dx.doi.org/10.3390/wevj10020030.
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Conductive Electric Road Systems (ERS) appear as a promising solution for the electrification of transportation, particularly for heavy vehicles and long-distance trips but also for light vehicles. Significant research efforts are currently devoted to the development of conductive ERS systems, with up to four pilot test sites with different technologies in operation only in Sweden. With the help of electric models and experimental measurements on a pilot test track, this article assesses the potential safety challenges associated with one aspect of this technology: the absence of a reliable protective earth connection while the vehicle is connected to the ERS power supply. The results highlight the importance of monitoring the chassis potential at all times and the need of an active safety mechanism to disconnect the vehicle from the ERS supply if a severe fault occurs.
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Li, Hong Tao, Zhan Qiang Xu und Ben Rui Zhu. „Design of Cooling Water Scheme of Gas Compressing Station in West-to-East Gas Pipeline“. Applied Mechanics and Materials 577 (Juli 2014): 580–83. http://dx.doi.org/10.4028/www.scientific.net/amm.577.580.
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This document focuses on motors and frequency conversion equipments of stations of West-to-East Gas Pipeline, and introduces the present main cooling ways. Against water consumption, power consumption, and other economical index, analyze the selection process of cooling scheme in engineering design. Compare with the cost, workload of operation and maintenance of water cooling, air cooling and motor cooling. The result shows that water cooling is practicable in West-to-East Gas Pipeline and has validated in the established engineering. The method of scheme comparison proposed by this paper provides a reference for subsequent design.With the development of electronics technology, medium voltage high power frequency conversion speed regulation technology is increasingly mature. The technology that frequency conversion motor drives compressor unit has been gradually used in the long distance pipeline pressure field of oil and gas under the condition of reliable power supply, to replace the traditional gas turbine, and becomes the first choice of the pressurization equipment of the long distance pipeline, because of advantages of high technology, high efficiency, energy conservation and environment protection, economic benefits and so on[1-3].Stations of West-to-East Gas Pipeline are usually electrical driven. When the compressors operate, motors and frequency converters will produce large amounts of heat, which affects running state and equipment life. So choosing the economic and technological cooling water scheme is important for stations and the whole network to operate safely and stably[4-6].
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Li, Yong, Xiong Liang, Zhao Dong Wang, Jia Dong Li und Tian Liang Fu. „Study on Three Dimensional Direct Coupling Simulation of Induction Heating for Hot Stamping“. Advanced Materials Research 1063 (Dezember 2014): 280–89. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.280.
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As to the conventional hot stamping furnance’s shortcomings of long heating time, easy oxidized, high energy consumption, the application of induction heating for hot stamping were studied. By using COMSOL Multiphysics software, we calculated the electromagnetic induction field and temperature field by use of the direct coupling (Direct Coupling Method) in the heating process of hot forming sheet and studied the influence of inductor device parameters (such as induction length, distance between inductor and sheet etc.) and various process parameters (such as the power supply frequency, current density, sheet thickness etc.) on heating rate and temperature distribution. That will have a good guidance on the application of induction heating to hot stamping field.
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Pu, Yue, Yunting Li und Yingzi Wang. „Structure Characteristics and Influencing Factors of Cross-Border Electricity Trade: A Complex Network Perspective“. Sustainability 13, Nr. 11 (21.05.2021): 5797. http://dx.doi.org/10.3390/su13115797.
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Electricity is one of the most widely used forms of energy. However, environmental pollution from electricity generation and the mismatch between electricity supply and demand have long been bothering economies across the world. Under this background, cross-border electricity trade provides a new direction for sustainable development. Based on the complex network approach, this paper aims to explore the structural characteristics and evolution of cross-border electricity trade networks and to figure out the factors influencing the formation of the network by using the more advanced network analysis method—ERGM. The results show that: (1) The scale of the electricity trade network is expanding, but there are still many economies not involved. (2) The centrality of the network shifts from west to east. The level of internal electricity interconnection is high in Europe, and Asian countries’ coordination role in cross-border electricity trade networks is enhanced. (3) Cross-border electricity trade helps to reduce CO2 emissions, achieve renewable energy transformation, and reduce power supply and demand mismatch. Large gaps in GDP, electricity prices, industrial structure, geographical distance and institutional distance between economies are not conducive to form the cross-border trade network, while the common language is on the contrary.
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Prishchepov, M. A., A. I. Zelenkevich und V. M. Zbrodyga. „Advanced power transformer with improved parameters for rural electrical networks“. Proceedings of the National Academy of Sciences of Belarus. Agrarian Series 59, Nr. 3 (05.08.2021): 366–77. http://dx.doi.org/10.29235/1817-7204-2021-59-3-366-377.
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The problem of power quality supply is relevant for rural electrical networks, due to long distance and branching, as well as connection of a large number of single-phase and non-linear loads. Asymmetry of electrical loads causes voltage asymmetry, which adversely affects the operation of all elements of the electrical system, causing additional power losses, reducing the service life of electrical equipment and its economic performance, as well as reliability of operation of individual electrical equipment and power supply system as a whole. Reduction of voltage asymmetry can be ensured by rational construction of electrical network circuit and use of special correcting devices. The authors consider it reasonable to use relatively simple and reliable by design and inexpensive power transformers with a “star - double zigzag with a zero wire” (Y/2Zн) winding connection circuit with a neutral winding connection group. The paper deals with design and processes of converting electrical energy in a transformer. It has been proved that phase EMF of the secondary winding coincides in phase with the same EMF of the primary winding, i.e. the proposed circuit has a neutral windings’ connection group. Results of theoretical studies of transformer operation with an asymmetric and non-linear load are presented. Decrease in voltage asymmetry is due to the neutral sequence components compensation. Decrease of the higher harmonic voltage components level occurs due to the compensation of the higher harmonics multiplied three times. It is theoretically substantiated that transformer will not emit higher harmonic components of zero sequence voltages into the supply network. Experimental studies have confirmed the theoretical conclusions that a transformer with Y/2Zн winding connection circuit allows obtaining the highest level of voltage symmetry with an asymmetric load. In single-phase load mode, the values of voltage unbalance factor in reverse sequence do not exceed 1.7 %, in neutral sequence - 2.9 %. The transformer allows obtaining 1.2-1.5 times lower value of total harmonic components factor at non-linear load, which is the best result among circuits studied. This power transformer is resistant to load effects that distort voltage quality and is capable to provide a high level of symmetry and sinusoidal voltage as well as parallel operation with commercially available transformers. This makes it possible to use it in rural electrical networks to reduce power losses, increase service life and efficiency of electrical equipment, and increase reliability of the power supply system.
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Dhakal, Megha Nath, und Rudra Ghimire. „Efficiency Improvement on a Distribution Feeder: A Case Study“. Journal of the Institute of Engineering 15, Nr. 3 (13.10.2020): 97–103. http://dx.doi.org/10.3126/jie.v15i3.32033.
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Electricity is a necessary requirement for accelerating the economic development of any country and is considered an important input to improve quality of life. Electricity supply to consumer end is possible by the combine function of power generation, transmission and distribution instantly. One of the most chronic areas of power loss in power system is power distribution feeder. Loss in feeders are identified mainly due to overloaded conductors and transformers, long distance feeder, unbalance load on transformer, low power factor load, uses of energy inefficient load, hooking etc. The distribution losses which are more predominant can be categorized as technical losses and non-technical losses. The main target of the study is to improve the technical and overall efficiency of a distribution feeder. A high loss feeder is selected for efficiency study. Direct method of loss calculation is used to calculate total losses of the feeder and indirect method is used to find the technical losses on the feeder in existing condition. Technical losses of existing feeder and improvement on same distribution system through technical loss reduction options is analyzed by implementing the conductor replacement, rerouting and optimum capacitor placement (OCP) methods using electrical transient analyzer program (ETAP) simulation. Technical efficiency and overall efficiency for the different non-technical loss values are calculated and analyzed. Implementation of results will improve financial health of the power distribution company and provide reliable electricity supply to the consumers. In addition, it provides further inputs to energy planners and managers for a number of remedial measures to loss reduction and improvement of overall efficiency of the power distribution system.
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Li, Jing, Jinrui Tang, Xinze Wang, Binyu Xiong, Shenjun Zhan, Zilong Zhao, Hui Hou, Wanying Qi und Zhenhai Li. „Optimal Placement of IoT-Based Fault Indicator to Shorten Outage Time in Integrated Cyber-Physical Medium-Voltage Distribution Network“. Energies 13, Nr. 18 (20.09.2020): 4928. http://dx.doi.org/10.3390/en13184928.
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Traditional fault indicators based on 3G and 4G cannot send out fault-generated information if the distribution lines are located in the system across remote mountainous or forest areas. Hence, power distribution systems in rural areas only rely on patrol to find faults currently, which wastes time and lacks efficiency. With the development of the Internet of things (IoT) technology, some studies have suggested combining the long-range (LoRa) and the narrowband Internet of Things (NB-IoT) technologies to increase the data transmission distance and reduce the self-built communication system operating cost. In this paper, we propose an optimal configuration scheme for novel intelligent IoT-based fault indicators. The proposed fault indicator combines LoRa and NB-IoT communication technologies with a long communication distance to achieve minimum power consumption and high-efficiency maintenance. Under this given cyber network and physical power distribution network, the whole fault location process depends on the fault indicator placement and the deployment of the communication network. The overall framework and the working principle of the fault indicators based on LoRa and NB-IoT are first illustrated to establish the optimization placement model of the proposed novel IoT-based fault indicator. Secondly, an optimization placement method has been proposed to obtain the optimal number of the acquisition and collection units of the fault indicators, as well as their locations. In the proposed method, the attenuation of the communication network and the power-supply reliability have been specially considered in the fault location process under the investment restrictions of the fault indicators. The effectiveness of the proposed method has been validated by the analysis results in an IEEE Roy Billinton Test System (IEEE-RBTS) typical system.
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Cao, Haibin, Peng Jiang und Ming Zeng. „A Novel Comprehensive Benefit Evaluation of IEGES Based on the TOPSIS Optimized by MEE Method“. Energies 14, Nr. 3 (01.02.2021): 763. http://dx.doi.org/10.3390/en14030763.
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The integrated electricity–gas energy system (IEGES) coordinates the power system and natural gas system through P2G equipment, gas turbines and other coupling components. The IEGES can realize wide-range and long-distance transmission of electricity, heat and natural gas, and truly realize large-scale cross-regional energy supply in space. At present, the theoretical system applicable to the comprehensive benefit evaluation of the IEGES has not been established, and the economic, environmental and social benefits of the system are still at a preliminary study stage. Therefore, the comprehensive benefit evaluation model of the IEGES is constructed, and the integrated benefit evaluation indicator system of the IEGES is designed along the investment and planning, energy supply, equipment operation, power distribution and terminal user. Through the combination of subjective and objective indicator weighting methods, the weights of each indicator are clarified and the matter-element extension theory (MEE) is used to improve the technique for order preference by similarity to ideal solution (TOPSIS), and the comprehensive benefit evaluation model of the IEGES is established. Finally, taking Beijing Yanqing IEGES, Tianjin Eco-city No. 2 Energy Station and Hebei IEGES III as an example, the practicability and effectiveness of the evaluation indicator system and model are verified.
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Kim, Juyong, Hyunmin Kim, Youngpyo Cho, Hongjoo Kim und Jintae Cho. „Application of a DC Distribution System in Korea: A Case Study of the LVDC Project“. Applied Sciences 9, Nr. 6 (14.03.2019): 1074. http://dx.doi.org/10.3390/app9061074.
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With the rapid expansion of renewable energy and digital devices, there is a need for direct current (DC) distribution technology that can increase energy efficiency. As a result, DC distribution research is actively underway to cope with the sudden digitization and decentralization of load environment and power supply. To verify the possibility of DC distribution, Korea Electric Power Corporation (KEPCO) Research Institute made a DC distribution system connected with a real power system in Gwangju. The construction of the demonstration area mainly includes design of protection and grounding systems, operating procedures of insulation monitoring device (IMD), and construction of power converters. Furthermore, this paper goes beyond the simulation and the lab testing to apply DC distribution to a real system operation in advance. It is designed as a long-distance low-loaded customer for rural areas and operated by the DC distribution. In addition, safety and reliability are confirmed through field tests of DC distribution elements such as power conversion devices, protection and grounding systems. In particular, to improve the reliability of non-grounding system, the insulation monitoring device was installed and the algorithms of its operational procedures are proposed. Finally, this paper analyzes the problems caused by operating the actual DC distribution and suggests solutions accordingly.
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Pienaar, Wessel. „A proposed regulatory framework for road and rail freight transport in South Africa“. Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 26, Nr. 4 (22.09.2007): 265–78. http://dx.doi.org/10.4102/satnt.v26i4.140.
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The increase in the number of freight vehicles on South Africa’s rural road network has received substantial attention. Insinuations persist that long-distance road freight haulage is of a somewhat unsavoury economic nature, and that strict economic re-regulation of the land freight transport is necessary. During the 1970s road transport replaced rail carriage as the dominant form of long-distance freight transport (excluding minerals and ore) in South Africa. On long hauls road freight carriers transport certain primary products of an organic nature (such as timber, fish and agricultural produce), some semi-finished goods, many finished goods and most consumer goods. Road freight carriers are continuously gaining market share on long-distance links where rail transport is the more cost efficient mode. The greater value added by road freight carriers in comparison with rail transport through service effectiveness is often more than the cost premium paid for utilising their service rather than making use of rail transport. Throughout history, governments have involved themselves in transport. A diverse range of arguments have been advanced for this involvement in transport, including the following:Control of excessive competition, co-ordination of transport, integration of transport with economic policy, maintenance of safety, security, and order, provision of costly infrastructure, provision of public goods, recovery of the true resource cost of transport inputs, regulation of harmful conduct and externalities, restraint of monopoly power, and social support. A set of nine instruments can be identified that governments apply to influence the performance of the freight transport industry: Legislation, direct supply, fiscal measures, monetary measures, moral appeal and persuasion, policies relating to strategic commodities, procurement policy, provision of information, and research and development. The best prospects for a sound development of land freight transport activity in South Africa will be offered within the framework of a free-functioning freight transport market.
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Wang, Qingpeng, Baodong Bai, Zhen An und Dezhi Chen. „The study of design and harmonic suppression for 800 kV EHV MSCR in engineering applications“. COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, Nr. 6 (06.11.2017): 1774–82. http://dx.doi.org/10.1108/compel-12-2016-0580.
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Purpose The purpose of this paper is to solve the reactive power adjustment and the overvoltage suppression problems in the extra high voltage (EHV) long distance grid, which often appears transient overvoltage, light load loss and other issues. Design/methodology/approach One 800 kV EHV magnetically saturation controllable reactor (MSCR) used self-power supply control system is designed. The structure and the working mechanism of the novel MSCR are analyzed in detail. Then the control and capacity step adjustment characteristics are obtained by experiments. The harmonic characteristic is studied by theoretical analysis and low voltage test. Findings To solve the problem of harmonics in the working current of nets windings, the fifth and the seventh filers are equipped between the compensation windings and the control system. The effectiveness of the harmonic suppression method is proved by simulation and experiments. Originality/value It proves that the 800 kV EHV MSCR design in this paper can achieve the purpose of the reactive power continuous linear adjustment, and the capacity adjustment is sensitive. After filtering, the harmonics level of the working current meets the standard of the EHV grid.
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Cavallo, Alfred J. „High-Capacity Factor Wind Energy Systems“. Journal of Solar Energy Engineering 117, Nr. 2 (01.05.1995): 137–43. http://dx.doi.org/10.1115/1.2870843.
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Wind-generated electricity can be fundamentally transformed from an intermittent resource to a baseload power supply. For the case of long distance transmission of wind electricity, this change can be achieved at a negligible increase or even a decrease in per unit cost of electricity. The economic and technical feasibility of this process can be illustrated by studying the example of a wind farm located in central Kansas and a 2000 km, 2000 megawatt transmission line to southern California. Such a system can have capacity factor of 60 percent, with no economic penalty and without storage. With compressed air energy storage (CAES) (and with a negligible economic penalty), capacity factors of 70–95 percent can be achieved. This strategy has important implications for the development of wind energy throughout the world since good wind resources are usually located far from major demand centers.
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Li, Miao, Wei Gao und Ri Sheng Jiao. „Smart Grid Supports the Future Sustainable Development“. Advanced Materials Research 1092-1093 (März 2015): 352–55. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.352.
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With the developing of technology, such as application of new energy, new material, large scale energy storage technology, ultra-long distance large scale transmission technology, intelligent control, estimation, message communication, internet, we establish a new industrial era. Well, sustainable development became an important issue. We need to supply much more cleanable and efficiency energy to meet the environment protecting and unstopping load of power gird increasing. So, smart grid came to our sight.In this paper, first we discuss that electricity is the foundation of modern industry. Second, we put forward the new problems that modern industry brings about, and discuss the necessity of developing smart grid. And then we particularly discuss the rewards that developing intelligent grid, such as solving the energy crisis, changing the running mode of grid, advancing the intelligent life, promoting the electricity client involved in the power market adjusting process and so on, as well as provided the relevant examples. All of these do well to future sustainable development. At last, we sum up the whole paper.
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He, Ming Xing, Wei Wang, Ce Yue Liu und Yuan Zhang. „The Research of Communication System of Civil Defense Engineering Based on Siemens PPI Bus“. Applied Mechanics and Materials 672-674 (Oktober 2014): 929–35. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.929.
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In civil defense engineering, three anti-ventilation, air conditioning dehumidification, power supply and other electrical control equipment have long distance, distributed monitoring area and are not convenient for centralized monitoring. To improve the level of civil air defense system of automatic monitoring, enhance the system's rapid response ability, adapt to the need of modern war, this paper based on data communication problems of distributed electrical system in civil defense engineering, combined with the low communication rate and high security requirements in civil defense engineering, puts forward the communication solutions based in Siemens PPI fieldbus, configures the communications PLC which has powerful functions, compiles multipoint PPI communication program, designs remote monitoring system and gives results of test analysis when it is running. Actual operation results show that the communication system of civil defense engineering based on Siemens PPI fieldbus has fast communication speed, low error rate, strong expansibility and other advantages..
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Pavlenko, O., V. Nefyodov und D. Velykodnyi. „BUILDING OF CONSOLIDATED CARGOESSUPPLY LOGISTICS FROM UKRAINE TO EUROPE“. Municipal economy of cities 1, Nr. 161 (26.03.2021): 191–98. http://dx.doi.org/10.33042/2522-1809-2021-1-161-191-198.
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The paper analyzes the existing trends and prospects for the cargo delivery logistics development in the direction from Ukraine to the European Union within the individual companies work and certain routes, which allowed to form the research purpose in this development. The chosen topic is quite relevant, because the consolidated cargoes delivery processes are an logistics formation integral part in modern production processes. One of the ways to reduce the cargoes cost and services is to reduce the supplying cargoes cost. In the scientific works of Ukrainian and foreign scientists it was determined that a well-developed logistics services market with appropriate operators and infrastructure, will effectively implement the consolidated cargoes delivery technology in international traffic to reduce costs for all participants in this process. It is determined that it is necessary to choose a methodical approach to building efficient consolidated cargoes delivery logistics from Ukraine to Europe. It is proposed to consider this process in the two alternative channels to determine the effective consolidated cargoes supply building from Ukraine to Europe: "Shippers - Departure country terminal - Consignees" - "Logistics Channel-1"; "International Transport Company - Shippers – Destination terminal - Consignees" - "Logistics Channel-2". For example, "Logistics Channel-1" should be used for the consolidated cargoes delivery over long distances, where the use of light and medium load capacity vehicles is inefficient. The total supply logistics cost was chosen as an evaluation indicator of the efficient supply channel choice. Influence relevant parameters are taken into account: cargo shipment volume, shippers (consignees)number, carges transportation distance in international traffic, distance between shippers (consignees), one ton cargoes loading time, one ton cargoes warehousing time. A full-factor experiment simulation was performed, based on the results of which a regression model in power form with a nonzero coefficient was determined, in which each coefficient indicates the corresponding factor influence degree on the performance indicator. It is established that this model is the most adequate. When comparing the evaluation indicator values - the total costs, for each option, showed that the lowest value of 7.13 euros was obtained at the minimum cargoes orders volume values, the cargo transportation distance, the orders intensity. And the biggest difference of 199.86 euros was obtained when using "Logistics Channel-2" for the maximum cargo orders volume values, the cargo transportation distance through the Ukraine territory.
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S., SKRYPNYK. „Substantiation of the choice of the replacement scheme of line for mathematical modeling of 20 kV power supplies.“ Journal of Electrical and power engineering 24, Nr. 1 (21.05.2021): 69–72. http://dx.doi.org/10.31474/2074-2630-2021-1-69-72.
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In the current global economic crisis and acute shortage of energy resources, increasing importance is attached to energy saving measures, economical and careful consumption of raw materials, materials, electricity and heat, environmental safety of industrial production. During the reconstruction of existing power supply systems of industrial enterprises, modern progressive solutions should be considered and implemented, morally and physically obsolete electrical equipment should be replaced, namely the introduction of new electrical equipment for transition from 6/10 kV to 20 kV in Ukrainian power systems. It is also necessary to pay attention to the improvement of power supply circuits and distribution networks, the implementation of complex automation of complex technological processes, rational compensation of reactive power at all levels of power supply systems. In the power system, the main transport link is the power line. Power lines (transmission lines) are long conductors suspended at a safe distance from the ground overhead lines (overhead lines) or cable lines (overhead lines) in which conductors are insulated from each other and from the environment and protected by insulation and armor electricity. Power lines are the most massive elements of the power supply system, they connect the individual nodes of its circuit. Longitudinal and transverse parameters are distinguished in alternative schemes. The load current flows through the longitudinal parameters, voltage is applied to the transverse ones. The replacement circuit of the electrical network consists of replacement circuits of the following elements: power lines, transformers, reactors, capacitors, loads, power sources. Calculating the steady-state modes of power systems, the substitution schemes of the elements are given in a single-line design, because the parameters of all phases are symmetrical. In local and local electrical networks with a relatively short length and low rated voltage, the conduction currents are small compared to load currents. Therefore, in typical electrical calculations of these networks, the capacitive conductivity of the lines is not taken into account. However, for these networks, the accounting of capacitive conductivities is necessary when considering some modes, the existence of which in itself is due only to the presence of capacitive conductivities. For example, the mode of single-phase ground fault in a network with isolated or compensated neutral or analysis of the modes of operation of neutrals of electrical networks of different voltage classes cannot be performed without taking into account the capacitive conductivity of these networks. When switching the power system of Ukraine to the nominal voltage of 20 kV, it should be taken into account that the transmission line will be replaced in the sections of both the overhead power line and cable power line, namely 35, 10, 6 kV. The replacement scheme must describe all the characteristics and properties of the elements of cable and overhead lines in accordance with real conditions. Thus, it is not expedient to use simplified substitution circuits that neglect energy parameters and properties of conductors to study the parameters of transmission lines. The use of a complete "P" -shaped scheme for the analysis of the parameters of transmission lines and transmission lines for a voltage of 20 kV is the basis of mathematical modeling of the transmission system in the distribution networks of our country.
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Archer, Cristina L., und Mark Z. Jacobson. „Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms“. Journal of Applied Meteorology and Climatology 46, Nr. 11 (01.11.2007): 1701–17. http://dx.doi.org/10.1175/2007jamc1538.1.
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Abstract Wind is the world’s fastest growing electric energy source. Because it is intermittent, though, wind is not used to supply baseload electric power today. Interconnecting wind farms through the transmission grid is a simple and effective way of reducing deliverable wind power swings caused by wind intermittency. As more farms are interconnected in an array, wind speed correlation among sites decreases and so does the probability that all sites experience the same wind regime at the same time. The array consequently behaves more and more similarly to a single farm with steady wind speed and thus steady deliverable wind power. In this study, benefits of interconnecting wind farms were evaluated for 19 sites, located in the midwestern United States, with annual average wind speeds at 80 m above ground, the hub height of modern wind turbines, greater than 6.9 m s−1 (class 3 or greater). It was found that an average of 33% and a maximum of 47% of yearly averaged wind power from interconnected farms can be used as reliable, baseload electric power. Equally significant, interconnecting multiple wind farms to a common point and then connecting that point to a far-away city can allow the long-distance portion of transmission capacity to be reduced, for example, by 20% with only a 1.6% loss of energy. Although most parameters, such as intermittency, improved less than linearly as the number of interconnected sites increased, no saturation of the benefits was found. Thus, the benefits of interconnection continue to increase with more and more interconnected sites.
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Dong, Lijing, Mingfu Qiu und Sing Kiong Nguang. „Design and Advanced Control of Intelligent Large-Scale Hydraulic Synchronization Lifting Systems“. Journal of Control Science and Engineering 2019 (29.09.2019): 1–10. http://dx.doi.org/10.1155/2019/4641289.
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Lifting systems are in great demand since more and more massive buildings or bridges tend to be shifted or lifted integrally. Hydraulic cylinders in traditional lifting systems are usually supplied by a common pump with an oil tank, which brings long distance hydraulic pipes and signal lines. This paper designs a new architecture of an intelligent lifting system, with self-contained hydraulic power supply system, wireless communication modules, and distributed controller. Based on the designed architecture of the intelligent lifting system, an advanced iterative learning control strategy is proposed to enhance its synchronization performance. With the proposed advanced control strategy, synchronization is achieved in a finite time interval even under the effect of communication time delays and saturations. The distributed controller of a lifting subsystem only uses the delayed information received from subsystems around. This is distinguished from traditional lifting systems, in which all of the lifting subsystems are normally controlled in a centralized way.
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Senen, Adri. „Perancangan Pemanfaatan Tenaga Surya untuk Penyaluran Air Bersih Bagi Pesantren Attuma’ninah Kab. Lebak, Banten“. TERANG 3, Nr. 1 (02.10.2020): 1–9. http://dx.doi.org/10.33322/terang.v3i1.1035.
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Clean water is one of the most vital human needs. Indonesia, which the largest part of its territory is water, in fact is still experiencing difficulties to meet the clean water needs of its population. Based on the data from the Central Statistics Agency in 2018, the percentage of households with clean drinking water sources is 72.99%. Sajira Subdistrict in Lebak, Banten is one that is affected by severe drought. They always experience drought for 6-9 months annually. The people independently built water reservoirs from mountain water sources. Water is pumped using a water pumping machine and accommodated in reservoirs, then distributed to local residents through pipes with minimum distribution distance is 1 km from the reservoir. Due to long distance of the water distribution,many houses can’t be reached by the water. It can be solved by adding a water pump in the reservoir. So the clean water distribution, which is initially only relies on pipes and gravity, can be maximized by the thrust of the water pump. Beside the water pump, the solar panel is also added to the system as a power supply. Thus, the residents don't need to pay for electricity bill to run the pumping system.
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Xia, Jinzhu. „Development planning of deepwater gas fields: the application of floating production platforms“. APPEA Journal 54, Nr. 2 (2014): 512. http://dx.doi.org/10.1071/aj13085.
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Producing North West Australia (NWA) deepwater hydrocarbon reserves, particularly gas reserves to LNG plants, poses unique challenges. These include extreme metocean conditions, unique geotechnical conditions, long distances to infrastructure and LNG plants, as well as high reliability/availability of supply. This extended abstract addresses important technical, commercial, and regulatory factors that drive the field development planning, including the selection of suitable production facilities for these deepwater hydrocarbon developments off NWA. While all-subsea developments have been an inspiration for offshore engineers for a few decades, subsea gas compression, dehydration, power supply, and control are still technically and commercially demanding, especially for long distance tie-backs. Subsea well intervention and facility maintenance requirements also favour the application of dedicated floating platforms. A wet or dry-tree floating production platform, therefore, is required in most cases. Whereas Semisubmersible, TLP, Spar, FPSO, and FLNG (or LNG FPSO) designs all have the attributes to be a host gas production facility or a part of a production system, only oil FPSOs have been installed in this region to date. Linkages between key reservoir and fluid characteristics and surface facility functionalities are discussed in this extended abstract. Advantages and disadvantages of various platform designs are compared. A focus is on the influence of regional drivers and site characteristics, in particular, metocean and geotechnical conditions and remoteness of the NWA fields. The differentiation between oil and gas developments are addressed. It is emphasised that platform applicability and compatibility should be assessed in the context of field development planning for individual projects to achieve optimum risked life cycle financial values.
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Rahman, Tawfikur, S. M. A. Motakabber und M. I. Ibrahimy. „Design and Simulation of a PWM Based Phase Synchronous Inverter for Utility Grid Systems with 20km Feeder Line“. Scientific Research Journal 14, Nr. 2 (31.12.2017): 17. http://dx.doi.org/10.24191/srj.v14i2.4903.
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In recent years, the utility grid system is more essential for the power transmission and distribution system because it cannot produce harmful gases or no discharge waste in the environment. PWM based phase synchronous invert systems are generally utilised in the high efficiency energy supply, long distance and higher power quality. The inverter output voltage depends on the coupling transformer, input sources and invert controllers. An inverter using a three leg IGBT has been designed for utility grid and simulated by using MATLAB2014a. In this paper, both sides of the LCL filters are used for removing the DC ripple current, reducing the noise and synchronous the output phase between inverter and the utility grid. The PWM controller has created pulse signal to control the inverter, electronic switches and precisely synchronise with grid line frequency. In this system, the input DC voltage 500V, switching frequency 1.65 kHz, grid frequency 50Hz, 20 km feeder (resistance, inductance and capacitance per unit length, which are 0.1153, 1.05e-3 and 11.33e-09 ohms/km) with 30MW three phase load (active and inductive reactive power which are 30e6 W and 2e6 var) and also a balanced utility grid load of star configuration (00, 1200, and 2400 degree) are considered in the design. On the other hand, three phase transformer consists of three signal phase transformers, normal power 100e3, magnetization resistance and inductance which are 500 pu and 416.67pu are considered in this design. The system conversion efficiency is 99.94% and 99.96%, while the total THD are 0.06% on inverter side and 0.04% on grid side.
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Rahman, Tawfikur, S. M. A. Motakabber und M. I. Ibrahimy. „Design and Simulation of a PWM Based Phase Synchronous Inverter for Utility Grid Systems with 20km Feeder Line“. Scientific Research Journal 14, Nr. 2 (31.12.2017): 17. http://dx.doi.org/10.24191/srj.v14i2.9359.
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In recent years, the utility grid system is more essential for the power transmission and distribution system because it cannot produce harmful gases or no discharge waste in the environment. PWM based phase synchronous invert systems are generally utilised in the high efficiency energy supply, long distance and higher power quality. The inverter output voltage depends on the coupling transformer, input sources and invert controllers. An inverter using a three leg IGBT has been designed for utility grid and simulated by using MATLAB2014a. In this paper, both sides of the LCL filters are used for removing the DC ripple current, reducing the noise and synchronous the output phase between inverter and the utility grid. The PWM controller has created pulse signal to control the inverter, electronic switches and precisely synchronise with grid line frequency. In this system, the input DC voltage 500V, switching frequency 1.65 kHz, grid frequency 50Hz, 20 km feeder (resistance, inductance and capacitance per unit length, which are 0.1153, 1.05e-3 and 11.33e-09 ohms/km) with 30MW three phase load (active and inductive reactive power which are 30e6 W and 2e6 var) and also a balanced utility grid load of star configuration (00, 1200, and 2400 degree) are considered in the design. On the other hand, three phase transformer consists of three signal phase transformers, normal power 100e3, magnetization resistance and inductance which are 500 pu and 416.67pu are considered in this design. The system conversion efficiency is 99.94% and 99.96%, while the total THD are 0.06% on inverter side and 0.04% on grid side.
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Picchioni, G. A., Wayne A. Mackay und Mario Valenzuela-Vázquez. „Correlative Supply and Demand Functions in Lupinus havardii: A Forgotten Side of Cut Flower Physiology?“ Journal of the American Society for Horticultural Science 132, Nr. 1 (Januar 2007): 102–11. http://dx.doi.org/10.21273/jashs.132.1.102.
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Correlative control of long-distance transport processes consists of an attraction or mobilizing power of a sink organ coupled to internal degradative reactions in a target source organ and the reallocation of its resources. This phenomenon is widely recognized in the agronomic whole plant literature but poorly recognized in the floriculture literature. We calculated supply and demand balances for water, total dry matter (TDM), and minerals during a 6-day postharvest evaluation of the spatially diverse, detached, indeterminate inflorescence of Lupinus havardii Wats. ‘Texas Sapphire’ held in deionized water. The apex approximately doubled its original (harvest day) amounts of total N, P, K, Mg, and S and increased its TDM and water content by 55% and 85%, respectively, all at the expense of lower-most mature flowers. Net export from the lower mature flower fraction and, when applicable, upper mature flowers, accounted for the following apical gains: 46% of TDM, 102% of water, 100% of N, 94% of P, 99% of K, and 54% of Mg and S. Directed reallocation of resources from the senescing lower mature flowers (the main “target”) to the apical sink (the “mobilizing center”) bore a marked resemblance to the coupling of remote sink demand with vegetative decline reported in monocarpic plants (i.e., vegetative-to-reproductive exchanges), but with two distinguishing characteristics: 1) the TDM and mineral exchanges were strongly restricted to flowering units, and 2) the contributions of water, N, P, and K exports to apical sink demand were at or near 100%. This article is the first that we are aware to provide an internal supply and demand balance sheet reflecting, quantitatively, the postharvest reallocation of internal resources from mature reproductive tissues to generative reproductive tissues of a cut inflorescence.
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Haff, P. K. „Technology and human purpose: the problem of solids transport on the earth's surface“. Earth System Dynamics Discussions 3, Nr. 1 (24.05.2012): 417–31. http://dx.doi.org/10.5194/esdd-3-417-2012.
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Abstract. Displacement of mass of limited deformability ("solids") on the Earth's surface is opposed by friction and (the analog of) form resistance – impediments relaxed by rotational motion, self-powering of mass units, and transport infrastructure. These features of solids transport first evolved in the biosphere prior to the emergence of technology, allowing slope-independent, diffusion-like motion of discrete objects as massive as several tons, as illustrated by animal foraging and movement along game trails. However, high-energy-consumption technology powered by fossil fuels required a mechanism that could support advective transport of solids, i.e., long-distance, high-volume, high-speed, unidirectional, slope independent transport across the land surface of materials like coal, containerized fluids, and minerals. Pre-technology nature was able to sustain large-scale, long-distance solids advection only in the limited form of piggybacking on geophysical flows of water (river sediment) and air (dust). The appearance of a generalized mechanism for advection of solids independent of fluid flows and gravity appeared only upon the emergence of human purpose. Purpose enables solids advection by, in effect, enabling a simulated continuous potential gradient, otherwise lacking, between discrete and widely separated fossil-fuel energy sources and sinks. Invoking purpose as a mechanism in solids advection is an example of the need to import anthropic principles and concepts into the language and methodology of modern Earth system dynamics. As part of the emergence of a generalized solids advection mechanism, several additional transport requirements necessary to the function of modern large-scale technological systems were also satisfied. These include spatially accurate delivery of advected payload, targetability to essentially arbitrarily located destinations (such as cities), and independence of structure of advected payload from transport mechanism. The latter property enables the transport of an onboard power supply and delivery of persistent-memory, high-information-content payload, such as technological artifacts ("parts").
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Yi, Joong Yong, Kyung Min Kim, Jongjun Lee und Mun Sei Oh. „Exergy Analysis for Utilizing Latent Energy of Thermal Energy Storage System in District Heating“. Energies 12, Nr. 7 (11.04.2019): 1391. http://dx.doi.org/10.3390/en12071391.
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The thermal energy storage (TES) system stores the district heating (DH) water when the heating load is low. Since a TES system stores heat at atmospheric pressure, the DH water temperature of 115 °C has to be lowered to less than 100 °C. Therefore, the temperature drop of the DH water results in thermal loss during storage. In addition, the DH water must have high pressure to supply heat to DH users a long distance from the CHP plant. If heat is to be stored in the TES system, a pressure drop in the throttling valve occurs. These exergy losses, which occur in the thermal storage process of the general TES system, can be analyzed by exergy analysis to identify the location, cause and the amount of loss. This study evaluated the efficiency improvement of a TES system through exergy calculation in the heat storage process. The method involves power generation technology using the organic Rankine cycle (ORC) and a hydraulic turbine. As a result, the 930 kW capacity ORC and the 270 kW capacity hydraulic turbine were considered suitable for a heat storage system that stores 3000 m3/h. In this case, each power generation facility was 50% of the thermal storage capacity, which was attributed to the variation of actual heat storage from the annual operating pattern analysis. Therefore, it was possible to produce 1200 kW of power by recovering the exergy losses. The payback period of the ORC and the hydraulic turbine will be 3.5 and 7.13 years, respectively.
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Ko, Seung-Woo, und Seong-Lyun Kim. „Impact of Node Speed on Energy-Constrained Opportunistic Internet-of-Things with Wireless Power Transfer“. Sensors 18, Nr. 7 (23.07.2018): 2398. http://dx.doi.org/10.3390/s18072398.
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Wireless power transfer (WPT) is a promising technology to realize the vision of Internet-of-Things (IoT) by powering energy-hungry IoT nodes by electromagnetic waves, overcoming the difficulty in battery recharging for massive numbers of nodes. Specifically, wireless charging stations (WCS) are deployed to transfer energy wirelessly to IoT nodes in the charging coverage. However, the coverage is restricted due to the limited hardware capability and safety issue, making mobile nodes have different battery charging patterns depending on their moving speeds. For example, slow moving nodes outside the coverage resort to waiting for energy charging from WCSs for a long time while those inside the coverage consistently recharge their batteries. On the other hand, fast moving nodes are able to receive energy within a relatively short waiting time. This paper investigates the above impact of node speed on energy provision and the resultant throughput of energy-constrained opportunistic IoT networks when data exchange between nodes are constrained by their intermittent connections as well as the levels of remaining energy. To this end, we design a two-dimensional Markov chain of which the state dimensions represent remaining energy and distance to the nearest WCS normalized by node speed, respectively. Solving this enables providing the following three insights. First, faster node speed makes the inter-meeting time between a node and a WCS shorter, leading to more frequent energy supply and higher throughput. Second, the above effect of node speed becomes marginal as the battery capacity increases. Finally, as nodes are more densely deployed, the throughput becomes scaling with the density ratio between mobiles and WCSs but independent of node speed, meaning that the throughput improvement from node speed disappears in dense networks. The results provide useful guidelines for IoT network provisioning and planning to achieve the maximum throughput performance given mobile environments.