• Title/Summary/Keyword: power splitting

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Mechatronic Control Model of the Wind Turbine with Transmission to Split Power

  • Zhang Tong;Li Wenyong;Du Yu
    • International Journal of Control, Automation, and Systems
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    • v.3 no.4
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    • pp.533-541
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    • 2005
  • In this paper, a wind turbine with power splitting transmission, which is realized through a novel three-shaft planetary, is presented. The input shaft of the transmission is driven by the rotor of the wind turbine, the output shaft is connected to the grid via the main generator (asynchronous generator), and the third shaft is driven by a control motor with variable speed. The dynamic models of the sub systems of this wind turbine, e.g. the rotor aerodynamics, the drive train dynamics and the power generation unit dynamics, were given and linearized at an operating point. These sub models were integrated in a multidisciplinary dynamic model, which is suitable for control syntheses to optimize the utilization of wind energy and to reduce the excessive dynamic loads. The important dynamic behaviours were investigated and a wind turbine with a soft main shaft was recommend.

Power Allocation and Splitting Algorithm with Low-complexity for SWIPT in Energy Harvesting Networks (에너지 하베스팅 네트워크에서 SWIPT를 위한 저복잡도를 갖는 파워 할당 및 분할 알고리즘)

  • Lee, Kisong;Ko, JeongGil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.5
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    • pp.917-922
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    • 2016
  • Recently, energy harvesting, in which energy is collected from RF signals, has been regarded as a promising technology to improve the lifetime of sensors by alleviating the lack of power supply problem. In this paper, we try to propose an efficient algorithm for simultaneous wireless information and power transfer. At first, we find the lower bound of water-level using the probability density function of channel, and derive the solution of power allocation in energy harvesting networks. In addition, we derive an efficient power splitting method for satisfying the minimum required harvested energy constraint. The simulation results confirm that the proposed scheme improves the average data rate while guaranteeing the minimum required harvested energy constraint, compared with the conventional scheme. In addition, the proposed algorithm can reduce the computational complexity remarkably with insignificant performance degradation less than 10%, compared to the optimal solution.

Field monitoring of splitting failure for surrounding rock masses and applications of energy dissipation model

  • Wang, Zhi-shen;Li, Yong;Zhu, Wei-shen;Xue, Yi-guo;Jiang, Bei;Sun, Yan-bo
    • Geomechanics and Engineering
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    • v.12 no.4
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    • pp.595-609
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    • 2017
  • Due to high in-situ stress and brittleness of rock mass, the surrounding rock masses of underground caverns are prone to appear splitting failure. In this paper, a kind of loading-unloading variable elastic modulus model has been initially proposed and developed based on energy dissipation principle, and the stress state of elements has been determined by a splitting failure criterion. Then the underground caverns of Dagangshan hydropower station is analyzed using the above model. For comparing with the monitoring results, the entire process of rock splitting failure has been achieved through monitoring the splitting failure on side walls of large-scale caverns in Dagangshan via borehole TV, micro-meter and deformation resistivity instrument. It shows that the maximum depth of splitting area in the downstream sidewall of the main power house is approximately 14 m, which is close to the numerical results, about 12.5 m based on the energy dissipation model. As monitoring result, the calculation indicates that the key point displacement of caverns decreases firstly with the distance from main powerhouse downstream side wall rising, and then increases, because this area gets close to the side wall of main transformer house and another smaller splitting zone formed here. Therefore it is concluded that the energy dissipation model can preferably present deformation and fracture zones in engineering, and be very useful for similar projects.

Nano-scale Power Splitters by using Plasmonic Multimode Interference Couplers (플라즈마 다중모드 간섭 결합기를 사용한 나노 크기의 전력분배기)

  • Ho, Kwang-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.4
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    • pp.47-52
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    • 2011
  • Nano-scale power splitter based on Si plasmonic waveguides are designed by utilizing the multimode interference (MMI) coupler. Effective dielectric method and longitudinal modal transmission-line theory are used for simulating the light propagation and optimizing the structural parameters at 3-D guiding geometry. The designed $1{\times}2$ 50:50 MMI power splitter has a nano-scale size of only $800nm{\times}850nm$. In order to achieve a variable power splitting ratio, a $2{\times}2$ MMI coupler is designed and the corresponding power splitting ratio can be tuned in the range of 78.5%:15.5%~5.5%:86.6%. Also, it is shown that it has a large bandwidth of $1.5{\mu}m{\sim}1.7{\mu}m$. In this range, the transmission is over 0.8.

Recovery of Lactic Acid from Fermentation Broth by the Two-Stage Process of Nanofiltration and Water-Splitting Electrodialysis

  • Lee, Eun-Gyo;Kang, Sang-Hyeon;Kim, Hyun-Han;Chang, Yong-Keun
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.4
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    • pp.313-318
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    • 2006
  • A two-stage process of nanofiltration and water-splitting electrodialysis was investigated for lactic acid recovery from fermentation broth. In this process, sodium lactate is isolated from fermentation broth in the first stage of nanofiltration by using an NTR-729HF membrane, and then is converted to lactic acid in the second stage by water-splitting electrodialysis. To determine the optimal operating conditions for nanofiltration, the effects of pressure, lactate concentration, pH, and known added impurities were studied. Lactate rejection was less than 5%, magnesium rejection approximated 45%, and calcium rejection was at 40%. In subsequent water-splitting electrodialysis, both the sodium lactate conversion to lactic acid and sodium hydroxide recovery, were about 95%, with a power requirement of $0.9{\sim}1.0\; kWh$ per kg of lactate.

Resource allocation in downlink SWIPT-based cooperative NOMA systems

  • Wang, Longqi;Xu, Ding
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.1
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    • pp.20-39
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    • 2020
  • This paper considers a downlink multi-carrier cooperative non-orthogonal multiple access (NOMA) transmission, where no direct link exists between the far user and the base station (BS), and the communication between them only relies on the assist of the near user. Firstly, the BS sends a superimposed signal of the far and the near user to the near user, and then the near user adopts simultaneous wireless information and power transfer (SWIPT) to split the received superimposed signal into two portions for energy harvesting and information decoding respectively. Afterwards, the near user forwards the signal of the far user by utilizing the harvested energy. A minimum data is required to ensure the quality of service (QoS) of the far user. We jointly optimize power allocation, subcarrier allocation, time allocation, the power allocation (PA) coefficient and the power splitting (PS) ratio to maximize the number of data bits received at the near user under the energy causality constraint, the minimum data constraint and the transmission power constraint. The block-coordinate descent method and the Lagrange duality method are used to obtain a suboptimal solution of this optimization problem. In the final simulation results, the superiority of the proposed NOMA scheme is confirmed compared with the benchmark NOMA schemes and the orthogonal multiple access (OMA) scheme.

Power Allocation and Splitting Algorithm for SWIPT in Energy Harvesting Networks with Channel Estimation Error (채널 추정 오차가 존재하는 에너지 하베스팅 네트워크에서 SWIPT를 위한 파워 할당 및 분할 알고리즘)

  • Lee, Kisong;Ko, JeongGil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1277-1282
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    • 2016
  • In the next generation wireless communication systems, an energy harvesting from radio frequency signals is considered as a method to solve the lack of power supply problem for sensors. In this paper, we try to propose an efficient algorithm for simultaneous wireless information and power transfer in energy harvesting networks with channel estimation error. At first, we find an optimal channel training interval using one-dimensional exhaustive search, and estimate a channel using MMSE channel estimator. Based on the estimated channel, we propose a power allocation and splitting algorithm for maximizing the data rate while guaranteeing the minimum required harvested energy constraint, The simulation results confirm that the proposed algorithm has an insignificant performance degradation less than 10%, compared with the optimal scheme which assumes a perfect channel estimation, but it can improve the data rate by more than 20%, compared to the conventional scheme.

Performance Optimization Method of Relay undergo Co-Channel Interference using Power Splitting Protocol (전력 분배 프로토콜을 통한 동일 채널 간섭을 겪는 중계기의 성능 최적화 방안)

  • Kim, Tae-Wook;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.67-71
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    • 2015
  • In this Paper, we proposed optimization of system performance, power splitting protocols applied to relay in the cooperative communication undergo co-channel interference. When relay adjust power distribution factors undergo co-channel interference, it is possible to optimize and maximize the channel capacity of the receiver. Because of energy haversting, interfence transfer to new power source. If finding the optimal power levels, to solve inability in system, and to increase the efficiency of the network. Finally, performance of the proposed protocol is analyzed in terms of outage probability, capacity of system.

LOCAL SPLITTING PROPERTIES OF ENDOMORPHISM RINGS OF PROJECTIVE MODULES

  • Lee, Sang Cheol
    • Honam Mathematical Journal
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    • v.35 no.4
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    • pp.747-755
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    • 2013
  • This paper deals with the unit groups of the endomorphism rings of projective modules over polynomial rings and further over formal power series rings. A normal subgroup of the unit group is defined and discussed. The local splitting properties of element of endomorphism rings of projective modules over polynomial rings are given.

Blast Excavation of Small Diameter Tunnel near Underground pipe lines (지하 관 시설물과 인접한 소규모 단면 터널의 발파굴착 사례)

  • Won, Yeon-Ho;Kim, Kang-Gyu
    • Explosives and Blasting
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    • v.28 no.1
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    • pp.40-54
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    • 2010
  • The messer shield method applys mainly to a tunnel with small cross-section of a weathered soil or weathered rock district and is fulfilled mostly by man-power excavation. but in case that hard rock exposes on tunnel face, incredible is an application of the rock-splitting method using a hydraulic power or a blasting method. This study represents the case of a blasting method which can control to be practiced by the minimum charges of 125 g an initial vibration occurring at the cut instead of the rock-splitting method, even though water pipe and gas pipe are closely adjacent.