• Title/Summary/Keyword: Power-Saving

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A Study on Sensitivity to Temperature of Electricity Consumption in School Buildings (학교 건축물 전력소비의 기온감응도에 관한 연구)

  • Kim, Tae-Woo;Lee, Kang-Guk;Kim, Ho-Soon;Hong, Won-Hwa
    • Journal of the Korean Institute of Educational Facilities
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    • v.18 no.5
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    • pp.13-21
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    • 2011
  • In case of school buildings, energy consumption has been noticeably on the increase, along with the changes in outdoor temperature triggered by the improvement in national economic development and educational environments. Research on the characteristics of energy consumption in school buildings influenced by the changes in outdoor temperature is considered very significant in social aspects in that it will be fundamental to the suggestion of the alternatives, such as saving energy consumption in construction buildings and control of emitting carbon dioxide. In this regard, this study examined sensitivity to temperature of power consumption in school buildings, based on the changes of outdoor temperature for the past five years in the target buildings of elementary, middle and high schools and the amount of energy consumption. From the results, it has been believed that this study was very significant in terms of figuring out a quantitative, optimum level of energy consumption, maintenance of pleasant environments and functions, and the necessity of effective energy use and management in school buildings.

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Dynamic Cell Reconfiguration Framework for Energy Conservation in Cellular Wireless Networks

  • Son, Kyuho;Guruprasad, Ranjini;Nagaraj, Santosh;Sarkar, Mahasweta;Dey, Sujit
    • Journal of Communications and Networks
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    • v.18 no.4
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    • pp.567-579
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    • 2016
  • Several energy saving techniques in cellular wireless networks such as active base station (BS) selection, transmit power budget adaptation and user association have been studied independently or only part of these aspects have been considered together in literature. In this paper, we jointly tackle these three problems and propose an integrated framework, called dynamic cell reconfiguration (DCR). It manages three techniques operating on different time scales for ultimate energy conservation while guaranteeing the quality of service (QoS) level of users. Extensive simulations under various configurations, including the real dataset of BS topology and utilization, demonstrate that the proposed DCR can achieve the performance close to an optimal exhaustive search. Compared to the conventional static scheme where all BSs are always turned on with their maximum transmit powers, DCR can significantly reduce energy consumption, e.g., more than 30% and 50% savings in uniform and non-uniform traffic distribution, respectively.

Comparative study on the effect of cooling & heating loads by lighting energy of various light sources in an office building

  • Hong, Won Pyo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.3
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    • pp.94-105
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    • 2016
  • The objective of the work was to evaluate the impact of lighting energy to cooling and heating consumption in medium scale office building, when currently installed fluorescent lights were replaced with various LED lighting fixtures. This evaluation comes from an integrated approach combining the proper indoor lighting environment and the thermal aspects of cooling & heating consumption in office building. These simulations were performed by coupling an appropriate luminaire analysis for energy consumption and a dynamic thermal simulation software (TRNSYS). To analyze comparative study of effects on the heating, cooling loads, and energy consumption of an LED lamp application, 2 types of LED lamp with low light power watt(LPW) 24W and high LPW 7.5W and a fluorescent lights(FL) with 37W are used respectively. Integrated building energy consumption decreased up to 3.2% when fluorescent lamps were replaced with LEDs. Thus, the high LPW of LED(7.5W) replaced with the same number of FL shows an effective energy saving and cost- effective luminary.

The Implement of Medium Access Control Protocol with Energy Efficiency in Multi-hop Sensor network (에너지 효율을 고려한 다중홉 센서망에서의 MAC 프로토콜 구현)

  • 김동일;송창안
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.4
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    • pp.793-797
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    • 2004
  • Wireless sensor networks use battery-operated computing and sensing devices. And It can be expected to be deployed in an ad hoc networs. MAC is different from traditional wireless MACs such as IEEE 802.11 in almost every way. so self-configuration and power saving in sensor network are very important goals, while per-node fairness and latency are less important. In this paper, so we use a given prototype for efficient energy conservation to reduce power consumtion that is one of the important character in sensor network and compare energy consumption and collision with IEEE 802.11 MAC. finally we conclude the paper and analyze it.

Control Design of the Brushless Doubly-Fed Machines for Stand-Alone VSCF Ship Shaft Generator Systems

  • Liu, Yi;Ai, Wu;Chen, Bing;Chen, Ke
    • Journal of Power Electronics
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    • v.16 no.1
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    • pp.259-267
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    • 2016
  • This paper presents a stand-alone variable speed constant frequency (VSCF) ship shaft generator system based on a brushless doubly-fed machine (BDFM). In this system, the output voltage amplitude and frequency of the BDFM are kept constant under a variable rotor speed and load by utilizing a well-designed current vector controller to regulate the control winding (CW) current. The control scheme is proposed, and the hardware design for the control system is developed. The proposed generator system is tested on a 325 TEU container vessel, and the test results show the good dynamic performance of the CW current vector controller and the whole control system. A harmonic analysis of the output voltage and a fuel consumption analysis of the generator system are also implemented. Finally, the total efficiency of the generator system is presented under different rotor speeds and load conditions.

Experimental Research on the Power Saving Effect Evaluation of a Variable Displacement Vane Pump for an Automatic Transmission (자동변속기용 가변 용량 베인 펌프의 파워 절감 효과 평가에 대한 실험적 연구)

  • Kim, Chulsoo;Bae, Chulyong;Kim, Chanjung;Kim, Kyusik;Son, Taekwan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.7
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    • pp.1-7
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    • 2014
  • A variable displacement vane pump is possible to improve the fuel economy by varying the pump capacity with a vane mechanism according to the engine operating speed range and reducing its driving torque. In general the experimental evaluation of the vane pump for the transmission has been performed mainly not with the vehicle or dynamometer test rig but with component test rig due to the implementation and safety problems. In this paper, in order to evaluate the performance of the developed vane pump as well as the compatibility with other rotary and hydraulic components of the target transmission, the transmission dynamometer based test rig is implemented where the developed pump is built into it and then the variable pump capacity and effect of power reduction are investigated experimentally.

Development of the Harmonics Reduction and Energy Saving Equipment in Variable Loads (부하변동 시의 고조파제거 및 절전기 개발)

  • Song, Young-Bok;Cho, Yong-Hyun;Choi, Dong-Jin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.6
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    • pp.87-95
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    • 2006
  • In this study, in order to obtain high qualify of electric power, single phase active filter which is composed of Zig-Zag transformer and three phase bridge rectifier and capacitor at the secondary of its transformer to be able to reduce the components of the zero phase current and the third harmonic current in neutral line and power line respectively. By connecting this filter to the Zig-Zag transformer and nonlinear load, their third harmonic components due to the nonlinear loads were reduced.

The Implement of Medium Access Control Protocol with Energy Efficiency in Multi-hop Sensor network (에너지 효율을 고려한 다중홉 센서망에서의 MAC 프로토콜 구현)

  • 송창안;이우철;김동일
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.182-185
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    • 2004
  • Wireless sensor networks use battery-operated computing and sensing devices. And It can be expected to be deployed in an ad hoc networs. MAC is different from traditional wireless MACs such as IEEE 802.11 in almost every way. so self-configuration and power saving in sensor network are very important goals, while per-node fairness and latency are less important. In this paper, so we use a given prototype for efficient energy conservation to reduce power consumtion that is one of the important character in sensor network and compare energy consumption and collision with IEEE 802.11 MAC. Finally we conclude the paper and analyze it.

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An Energy-Efficient MAC Protocol for Wireless Wearable Computer Systems

  • Beh, Jounghoon;Hur, Kyeong;Kim, Wooil;Joo, Yang-Ick
    • Journal of information and communication convergence engineering
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    • v.11 no.1
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    • pp.7-11
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    • 2013
  • Wearable computer systems use the wireless universal serial bus (WUSB), which refers to USB technology that is merged with WiMedia physical layer and medium access control layer (PHY/MAC) technical specifications. WUSB can be applied to wireless personal area network (WPAN) applications as well as wired USB applications such as PAN. WUSB specifications have defined high-speed connections between a WUSB host and WUSB devices for compatibility with USB 2.0 specifications. In this paper, we focus on an integrated system with a WUSB over an IEEE 802.15.6 wireless body area network (WBAN) for wireless wearable computer systems. Due to the portable and wearable nature of wearable computer systems, the WUSB over IEEE 802.15.6 hierarchical medium access control (MAC) protocol has to support power saving operations and integrate WUSB transactions with WBAN traffic efficiently. In this paper, we propose a low-power hibernation technique (LHT) for WUSB over IEEE 802.15.6 hierarchical MAC to improve its energy efficiency. Simulation results show that the LHT also integrates WUSB transactions and WBAN traffic efficiently while it achieves high energy efficiency.

Design of a K-band CW Radar Transceiver (24GHz 대역 CW 레이더 송수신기 설계)

  • Nam, Byung-Chang;Chae, Gyoo-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.7
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    • pp.1532-1535
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    • 2009
  • This paper describes a K-band CW radar transceiver suitable for power saving motion sensor. The presented transceiver module is designed and contains patch antennas, dielectric resonator oscillator (DRO), IF amplifier, mixer, divider. The designed divider and antenna are measured and the transmitting frequency and the power were fairly good for using in commercial applications. The transceiver is manufactured with a dimension of 35${\times}$35${\times}$10(mm) and can be adapted in various applications.