• Title/Summary/Keyword: Power Reduction

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Fuel Consuming Reduction by Power Steering System Optimization (동력 조향계 최적화에 의한 연비 개선)

  • Jo, Sok-Hyun;Nam, Kyung-Woo;Kwon, O-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.119-124
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    • 2006
  • This paper deals with energy-saving effort in the hydraulic power steering system. Commonly, the hydraulic power steering systems are used for passenger cars and the reduction of pumping loss under non-steering condition is important to improve fuel economy. Experiments and simulations are performed simultaneously to examine the main factors to reduce the pumping loss-pressure loss and flow rate of the power steering systems. Fuel economy effect of the optimal design of power steering system is verified by vehicle test - more than 1% fuel consuming reduction is attained.

Standby Power Reduction Technique due to the Minimization of voltage difference between input and output in AC 60Hz (대기전력 최소화를 위한 교류전압 입력에 따른 저전압 구동회로 설계)

  • Seo, Kil-Soo;Kim, Ki-Hyun;Kim, Hyung-Woo;Lee, Kyung-Ho;Kim, Jong-Hyun
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1018-1019
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    • 2015
  • Recently, standby power reduction techniques of AC/DC adaptor were developed, consuming power almost arrived to 300mW level. The standby power losses are composed of the input filter loss 11.8mW, the control IC for AC/DC adaptor 18mW, the switching loss 9.53mW and the feedback loss 123mW. And there are the standby power reduction techniques. In this paper, in order to reduce the standby power of SMPS more, the loss due to a voltage difference between input and output is reduced by the control circuit which is composed of the low voltage driving circuit and voltage regulator. The low voltage driving circuit operates on the low voltage of input and off the high voltage. The low voltage driving IC was produced by the $1.0{\mu}m$, high voltage DMOS process.

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RBF Neural Network Based SLM Peak-to-Average Power Ratio Reduction in OFDM Systems

  • Sohn, In-Soo
    • ETRI Journal
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    • v.29 no.3
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    • pp.402-404
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    • 2007
  • One of the major disadvantages of the orthogonal frequency division multiplexing system is high peak-to-average power ratio (PAPR). Selected mapping (SLM) is an efficient distortionless PAPR reduction scheme which selects the minimum PAPR sequence from a group of independent phase rotated sequences. However, the SLM requires explicit side information and a large number of IFFT operations. In this letter we investigate a novel PAPR reduction method based on the radial basis function network and SLM.

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Effects of District Energy Supply by Combined Heat and Power Plant on Greenhouse Gas Emission Mitigation (열병합발전을 이용한 집단에너지사업의 온실가스 감축효과)

  • Shin, Kyoung-A;Dong, Jong-In;Kang, Jae-Sung;Im, Yong-Hoon;Kim, Da-Hye
    • Journal of Climate Change Research
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    • v.8 no.3
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    • pp.213-220
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    • 2017
  • The purpose of this study is to analyze effects of Greenhouse Gas (GHG) emission reduction in district energy business mainly based on Combined Heat and Power (CHP) plants. Firstly this paper compares the actual carbon intensity of power production between conventional power plants and district energy plants. To allocate the GHG from CHP plants, two of different methods which were Alternative Generation Method and Power Bonus Method, have been investigated. The carbon intensity of power production in district energy plants ($0.43tonCO_2e/MWh$) was relatively lower than conventional gas-fired power plants ($0.52tonCO_2e/MWh$). Secondly we assessed the cost effectiveness of reduction by district energy sector compared to the other means using TIMES model method. We find that GHG marginal abatement cost of 'expand CHP' scenario (-$134/ton$CO_2$) is even below than renewable energy scenario such as photovoltaic power generation ($87/ton$CO_2$). Finally the GHG emission reduction potential was reviewed on the projected GHG emission emitted when the same amount of energy produced in combination of conventional power plants and individual boilers as substitution of district energy. It showed there were 10.1~41.8% of GHG emission reduction potential in district energy compared to the combination of conventional power plants and individual boilers.

Utilization of Food Waste Extract as an Eco-friendly Biocatalyst for Indigo Reduction (식품 폐기물을 이용한 친환경 생촉매의 발굴과 인디고 환원에 응용)

  • Son, Kunghee;Yoo, Dong Il;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.32 no.4
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    • pp.193-198
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    • 2020
  • In this study, the validity of extracts from food waste as biocatalyst for indigo reduction was examined. Dried food wastes such as apple peel and corn waste were water-extracted and freeze-dried. The reducing power of extracts for indigo was evaluated by the oxidation-reduction potential(ORP) measurement of reduction bath and color strength(K/S value) of the fabrics dyed in the indigo reduction bath. Total sugar contents of the apple peel and corn waste extracts were 60.56% and 62.36%, respectively. Antioxidant activity was 64.78% for the extract of apple peel and 7.96% for the extract of corn waste. Indigo reduction took place quickly with both extracts, and maximum color strength was obtained up to 15.91 and 12.11 within 1-3 days, respectively. The oxidation-reduction potential of reduction bath was stabilized in the range of -500 ~ -620 mV according to the kinds of food waste and the extract concentration. At higher concentration of the extracts, reduction power was maintained for longer time and stronger color strength was obtained. Compared to sodium dithionite, the reducing power of the studied extracts was lower, but the reduction stability was superior to it. The studied extracts were effective biocatalyst as biodegradable and safe alternatives to sodium dithionite for indigo reduction.

Case Studies on the Electric Power Loss Reducing Methodology for Transformer Installation in Sewage Treatment Plant (하수처리장 변압기 설치사례 연구를 통한 전력손실 저감방안)

  • Kim, Chu-Young;Choi, Chang-Gyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.1
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    • pp.70-77
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    • 2011
  • Sewage treatment plants, consuming 1,756[GWh] which is 0.53[%] of national wide electricity consumption, is one of the electricity consuming facilites. At the research of electricity consumption and power quality analysis on sewage treatment plants, average utilization of transformer was less than 40[%] because peak load was very lower than its capacity due to excess capacity. So reduction of power loss can be achieved by transformer design optimization. The achievement in this research, is to meet reduction of power loss through optimizing the capacity and to improve as high efficiency-low loss transformer while the transformer is operating.

Partial Shift Mapping for PAPR Reduction with Low Complexity in OFDM Systems

  • Ouyang, Xing;Jin, Jiyu;Jin, Guiyue;Wang, Zhisen
    • ETRI Journal
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    • v.34 no.2
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    • pp.268-271
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    • 2012
  • The high peak-to-average power is one of the main drawbacks in OFDM systems. This letter proposes a partial shift mapping (PSM) method for peak power reduction in OFDM systems. By utilizing the properties of the discrete Fourier transform, the proposed method generates a set of candidate signals without additional complex multiplication and selects the one with minimum peak power for transmission. Analyses and simulations confirm that the PSM method achieves satisfactory peak power reduction performance and low complexity compared with other kindred methods, for example, selected mapping and partial transmit sequences.

Design and Implementation of an Active EMI Filter for Common-Mode Noise Reduction

  • Lee, Kuk-Hee;Kang, Byeong-Geuk;Choi, Yongoh;Chung, Se-Kyo;Won, Jae-Sun;Kim, Hee-Seung
    • Journal of Power Electronics
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    • v.16 no.3
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    • pp.1236-1243
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    • 2016
  • This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

A Study on the Dynamic Reduction for Large Power System

  • Kim, Jin-Yi;Won, Dong-Jun;Moon, Seung-Il
    • KIEE International Transactions on Power Engineering
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    • v.12A no.1
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    • pp.1-5
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    • 2002
  • This paper presents the procedure to construct equivalent model of large power system based on nonlinear time simulation responses. It consists of coherency identification, generator aggregation and network reduction. Coherency index that can be directly implemented to this procedure is proposed. Generator aggregation based on detailed model is performed. This procedure can be used to construct equivalent model in PSS/E. It is also possible to reduce the large power system directly from the nonlinear time responses. This procedure is applied to the transient stability analysis of Korea power system that now experiences rapid changes. The equivalent model is compared with the original model in its size, accuracy, speed and performance. This paper shows that the developed equivalent model is a good estimate of the original system.

A Study on Simultaneous Load Factor of Intelligent Electric Power Reduction System in Korea (한국의 지능형 전력동시부하율 저감시스템에 관한 연구)

  • Kim, Tae-Sung;Lee, Jong-Hwan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.1
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    • pp.24-31
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    • 2012
  • This study is designed to predict the overall electric power load, to apply the method of time sharing and to reduce simultaneous load factor of electric power when authorized by user entering demand plans and using schedules into the user's interface for a certain period of time. This is about smart grid, which reduces electric power load through simultaneous load factor of electric power reduction system supervision agent. Also, this study has the following characteristics. First, it is the user interface which enables authorized users to enter and send/receive such data as demand plan and using schedule for a certain period of time. Second, it is the database server, which collects, classifies, analyzes, saves and manages demand forecast data for a certain period of time. Third, is the simultaneous load factor of electric power control agent, which controls usage of electric power by getting control signal, which is intended to reduce the simultaneous load factor of electric power by the use of the time sharing control system, form the user interface, which also integrate and compare the data which were gained from the interface and the demand forecast data of the certain period of time.