• Title/Summary/Keyword: Line-of-Balance Method

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Power System Security Control Method for Quench Characteristic of High-Temperature Superconducting Cable (초전도 케이블의 퀜치 특성에 대한 계통안전성 제어방식)

  • Lee, Geun-Joon;Hwang, Si-Dol;Lee, Jeong-Phil;Kim, Chang-Hyun;Park, Hye-Chul
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.375-380
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    • 2004
  • This paper presents the basic quench protection idea for the HTS(High-Temperature Superconducting) cable. In Korea power system, the transfer capability of transmission line is limited by the voltage stability, and HTS cable could be one of the countermeasure to solve the transfer limit as its higher current capacity and lower impedance[1]. However, the quench characteristic of HTS cable makes HTS cable to loss its superconductivity, and therefore change the impedance of the line and power system operating condition dramatically. This pheonominum threats not only HTS cable safety but also power system security, therefore a proper protection scheme and security control counterplan have to be established before HTS cable implementation. In this paper, the quench characteristics of HTS cable for the fault current based on heat balance equation was established and a proper protection method by FCL(Fault Current Limiter) was suggested.

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Implementation of One-Cycle Control for Switched Capacitor Converters

  • Yang, Lei;Zhang, Xiaobin;Li, Guann-pyng
    • Journal of Power Electronics
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    • v.16 no.6
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    • pp.2057-2066
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    • 2016
  • An extension of the one-cycle control (OCC) method for switched-capacitor (SC) converters is proposed in this paper, featuring a fast dynamic response, wide line and load operation ranges, and simplicity in implementation. To illustrate the operation principle of this nonlinear control method and to demonstrate its simplicity in design, a dual-phase unity gain SC converter is examined. A new control loop based on the charge balance in a flying capacitor is formulated for the OCC technique and implemented with a 15W dual-phase unity gain SC converter on a circuit board for control verification. The obtained experimental results show that external disturbances can be rejected in one switching cycle by the OCC controlled SC converter with good line and load regulations. When compared to other control methods, the proposed nonlinear control loop exhibits superior dynamic performance in suppressing input and load disturbances.

The Study on the improvement of vehicle fuel economy test method according to the characteristics of test fuel (시험용 연료 특성에 따른 자동차 연비측정 방법 개선에 관한 연구)

  • Lee, Minho;Kim, Jeonghwan
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.9-18
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    • 2014
  • These test methods, the current domestic vehicles fuel economy calculation method is tested on a dynamometer for vehicles after you have installed the vehicle, given the test mode(FTP-75 & HWFET mode, etc.) are measured by vehicle emissions and fuel economy by seeking to have the results approach, the carbon balance method. At this point, using the carbon balance method is a test method was developed seeking fuel for a standard fuel properties, where the value of the constant and saved test was measured in THC, CO, $CO_2$ has a value calculation. Therefore, use fuel which is changed every time you test the fuel properties characteristics are not considered exactly. In this study, using the carbon balance method and fluid flow rate of the fuel used in the actual test is measured by comparing the results with the flow measurement methods, properties of the fuel used for the test attribute to study ways that can be considered, taking into account the physical attributes of a more diverse fuel line and fuel economy improved measurement methods that can be reviewed.

Application of Computer-coupled Mass Spectrometer for Continuous On-line Monitoring of Cell Growth and Growth Rate (세포증식과 증식속도의 On-line Monitoring을 위한 Computer- coupled Mass Spectrometer의 응용)

  • 남수완;최춘순;김정회
    • Microbiology and Biotechnology Letters
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    • v.17 no.3
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    • pp.241-246
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    • 1989
  • Continuous on-line monitoring of cell concentration and growth rate in aerobic batch fermentation process was carried out by analyzing the exhaust gas composition of tormentor with a quadrupole mass spectrometer. From the mass spectrometric analyses of major gaseous components, i.e. $N_2$, $O_2$, $CO_2$ and $H_2O$, and the material balance equations for oxygen and carbon dioxide, oxygen uptake rate (OUR) rind carbon dioxide evolution rate (CER) were instantaneously calculated using a computer (16-bit IBM PC-AT) interfaced to a quadrupole mass spectrometer. The calculated OUR and CER data were used for the estimation of cell concentration and growth rate of Candida utilis during batch culture. It was found that the cell concentration could be satisfactorily estimated from the data of OUR arid CER during the culture and this method could be successfully und for the continuous monitoring of cell growth and growth rate.

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Estimation of Mass Error in the Simulation of Mixing of Instantaneously Released Pollutants (순간 유입된 오염물질의 혼합 모의 시 질량 오차 산정)

  • Lee, Myung Eun;Seo, Il Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5B
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    • pp.475-483
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    • 2008
  • 2D finite element model for analysis of transport of accidentally released pollutants in the flow was developed by SUPG method, and the mass balance of this model was checked though two example problems: line source and point source problem in the straight channel and unidirectional 2D flow field, respectively. All the test cases were simulated with both SUPG and conventional Galerkin method to compare the accuraccy of the numerical mass balance. Test results show that the model with SUPG can adequately conserve the released mass though simulation than the model using Galerkin method, so the developed model verified to be appropriate to solve this accidental mass release problem.

A study on diagnosis method by chonguinyoung pulse(寸口人迎脈診) based on 《Youngchu·Kyoungmaek 靈樞·經脈》 (《영추(靈樞)·경맥(經脈)》의 촌구인영맥진(寸口人迎脈診)에 관(關)한 연구(硏究))

  • Sin, Kwang-Sun;Jang, Jun-Hyuk;Yoon, Jong-Hwa
    • Journal of Acupuncture Research
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    • v.19 no.1
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    • pp.203-209
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    • 2002
  • Objective : The chonguinyoung pulse diagnosis method is convenient than twelve meridian pulse diagnosis method The $\ll$Maek-bup(脉法)$\gg$ are founded at Mawangtweo(馬王堆) of the han dynasty tomb in 1973, but it could diagnosis the exsitance of illness of twelve meridian also . Methods : In accordance to $\ll$Naekuoung(內經)$\gg$ inyoungmaek(人迎脈) in could be taken at the which is the pulse point of carotid artery on the line of foot yangmyoung stomach meridian (足陽明胃經) and chongumaek (寸口脈) at the taeyoun acu-point (太淵穴) pulse point on the line of hand taeyeun lung meridian (手太陰肺經). Results : Chonguinyoung pulse diagnosis method could be emphased on the point of diagnosing sick person and healthy person by the balance of yin (陰) yan (陽) composition in the body. Conclusion : Chonguinyoung pulse diagnosis method could be the indication of improvement and progress of disease also it could be adapt to diagnosis of twelve meridian and it is impossible to making choice of acupuncture, medication, moxibustion, vene-section and strengthing-eleminating treatment method (補瀉方法).

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Determining Optimal WIP Level and Buffer Size Using Simulated Annealing in Semiconductor Production Line (반도체 생산라인에서 SA를 이용한 최적 WIP수준과 버퍼사이즈 결정)

  • Jeong, Jaehwan;Jang, Sein;Lee, Jonghwan
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.3
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    • pp.57-64
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    • 2021
  • The domestic semiconductor industry can produce various products that will satisfy customer needs by diversifying assembly parts and increasing compatibility between them. It is necessary to improve the production line as a method to reduce the work-in-process inventory (WIP) in the assembly line, the idle time of the worker, and the idle time of the process. The improvement of the production line is to balance the capabilities of each process as a whole, and to determine the timing of product input or the order of the work process so that the time required between each process is balanced. The purpose of this study is to find the optimal WIP and buffer size through SA (Simulated Annealing) that minimizes lead time while matching the number of two parts in a parallel assembly line with bottleneck process. The WIP level and buffer size obtained by the SA algorithm were applied to the CONWIP and DBR systems, which are the existing production systems, and the simulation was performed by applying them to the new hybrid production system. Here, the Hybrid method is a combination of CONWIP and DBR methods, and it is a production system created by setting new rules. As a result of the Simulation, the result values were derived based on three criteria: lead time, production volume, and work-in-process inventory. Finally, the effect of the hybrid production method was verified through comparative analysis of the result values.

Integrated Torque and Speed Control Algorithm for Motor Drive System In Continuous Strip Processing Line (연속 공정용 전동기 구동장치를 위한 통합형 토크 및 속도제어 알고리즘)

  • 송승호
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.2
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    • pp.186-193
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    • 2002
  • A new integrated torque and speed control algorithm has been proposed for the load balancing of rollers in continuous strip processing line(CSPL). Using the proposed method, the output torque and speed can be controlled to follow the reference in spite of nonideal effects such as the speed reference error and/or the controller gain difference between rolls. This new algorithm can be easily implemented in a motor drive system of each roll as it does not require the torque feedback of the others. Through the simulation and experiments for a simple CSPL consists of four driven rolls, the load balancing performance of the proposed scheme is presented and compared with that of conventional method.

Effects on Balance and Gait for Chronic Stroke Patients with Side Walking Training (만성 뇌졸중 환자에게 측방 보행 훈련이 균형과 보행에 미치는 영향)

  • Kim, Inseop;Jeon, Seungjae;Lee, Geoncheol;An, Byungwook
    • Journal of The Korean Society of Integrative Medicine
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    • v.1 no.1
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    • pp.1-9
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    • 2013
  • Purpose : The purpose of this study is to investigate the impact on the ability to walk, balance after side walking training of hemiplegic patients caused by stroke. Method : The subjects were training before stroke onset whether more than one year elapsed 15 patients with chronic stroke patients, and Berg balance scale(BBS) and Timed up and go test(TUG), Functional reaching test(FRT), 20m walking time 200m walking time were measured and recorded. Training period, a total of three weeks, and training frequency circuit training times 10 minutes per training, 5-minute break, the 10-minute training total 25-minute training was conducted. Gait line of 3m to be based on the patient's side walking, and the risk of falling compared to the presence of the experimenter trained under was carried out. Result : 1. TUG, 2. 20m walking time, 3. 200m walking time 4. FRT, 5. All showed significant improvement in BBS. Judging from the results, the side walking training conducted three weeks due to chronic stroke hemiplegic patient's ability to balance and showed a positive effect on the improvement of walking ability. Conclusion : Accordingly, it was more effective to train hemiplegic patients with chronic stroke on side walking.

A Load Flow Based Approach to Transaction Cost Allocation in Transmission Network (조류계산에 기초한 탁송요금 계산)

  • Park, Young-Moon;Lim, Jung-Uk;Won, Jong-Ryul;Park, Jong-Bae
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1149-1152
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    • 1997
  • This paper describes a novel approach for allocating transmission costs among users of transmission services. In the suggested approach, the cost share of each participant is proportional to amount of its line flow. To develop individual user's impact, the line utilization factors of each participant are derived by power flow equations of all nodes (i.e., load-flow equations). To deal With the slack bus problem inherent in the conventional load-flow analysis more practically, a additional power supply/demand balance equation is incorporated. Although the developed allocation rule is basically similar to the existing MW-mile method in the aspect of embedded cost allocation, it does not require to get load flow solutions of each wheeling transaction when multiple transmission transactions are considered.

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