• Title/Summary/Keyword: Compensation factor

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Novel Current Compensation Technique for Harmonic Current Elimination (고조파 전류 제거를 위한 새로운 전류 보상 기법)

  • Jeong Gang-Youl
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.587-591
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    • 2004
  • This paper proposes a novel current compensation technique that can eliminate the harmonic currents included in line currents without computation of harmonic current components. A current controller with fast dynamics for an active filter is described. Harmonic currents are directly controlled without the need for sensing and computing the harmonic current of the load current, thus simplifying the control system. Current compensation is done in the time domain, allowing a fast time response. The DC voltage control loop keeps the voltage across the DC capacitor constant. High power factor control by an active filter is described. All control functions are implemented in software using a single-chip microcontroller, thus simplifying the control circuit. Any current-controlled synchronous rectifier can be used as a shunt active filter through only the simple modification of the software and the addition of current sensors. It is shown through experimental results that the proposed controller gives good performance for the shunt active filter.

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Static VAR Compensator Using PWM Voltage type Converter (PWM전압형 콘버어터에 의한 정지형 무효전력 보상장치)

  • 정연택;이훈구;황락훈
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.8
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    • pp.836-846
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    • 1990
  • This paper presents a Static Var Compensator (SVC) system compensating the reactive power for power system, which consists of a voltage type Pulse Width Modulation (PWM) converter and a reactance linking the converter to the source. The system drives the four quadrant modes. The system determines the magnitude of the input voltage, and then compares it with the magnitude of the source voltage by regulating the phase of the SVC about the source. Therefore, the system generates leading compensation currents when the input voltage is larger than the source in magnitude, and lagging compensation currents for smaller input voltage. Reactive power about voluntary load in power system is smoothly compensated by those compensation currents, and also power factor of source is improved. Furthermore, the SVC system using PWM method may improve the source current waveforms by eliminating the 5th and 7th harmonic components from the input voltages.

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Fault Location Algorithm with Ground Capacitance Compensation for Long Parallel Transmission Line (장거리 병렬 송전선로용 대지 정전용량 보상에 의한 고장점 표정 알고리즘)

  • Park, Chul-Won;Kim, Sam-Ryong;Shin, Myong-Chul
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.54 no.4
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    • pp.163-170
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    • 2005
  • This paper deals with an improved fault location algorithm with compensation ground capacitance through distributed parameter for a long parallel T/L. For the purpose of fault locating algorithm non-influenced by source impedance and fault resistance, the loop method was used in the system modeling analysis. This algorithm uses a positive and negative sequence of the fault current for high accuracy of fault locating calculation. Power system model of 160km and 300km long parallel T/L was simulated using EMTP software. To evaluate of the proposed algorithm, we used the several different cases 64 sampled data per cycle. The test results show that the proposed algorithm was minimized the error factor and speed of fault location estimation.

Analysis of Loss Compensation Efficiency Factor in the Uniform Price Market (단일가격시장에서 손실보상효율계수의 특성 분석)

  • Hahn, Tae-Kyung;Kim, Jin-Ho;Park, Jong-Keun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.5
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    • pp.871-881
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    • 2010
  • In the uniform price electricity market or bilateral electricity market, the energy transactions in which the network is not considered and ISO's system operation costs which ISO try to minimize are settled separately. In this paper, transmission loss, one of the ISO's system operation costs, was dealt. The conventional marginal loss allocation method gives economic signals but three aspects have to be considered; excessiveness, arbitrariness and cross-subsidy. In this paper, marginal loss compensation efficiency method was suggested which consider those aspects of the conventional marginal loss allocation method. Also the characteristics of the marginal loss compensation efficiency were analyzed in the appendixes. And simple 2-bus system and IEEE 14 bus system were used to explain these characteristics.

A Study on the Factors of Dissatisfaction and Complaint in Foodservice Consumers (외식소비자 불만족의 요인 및 불평 행동에 관한 연구)

  • Jin, Yang-Ho;Jun, Jin-Hwa
    • Culinary science and hospitality research
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    • v.11 no.2
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    • pp.14-31
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    • 2005
  • The findings of the study would be valuable for the basis of marketing strategies to be implemented in the foodservice industry. As a result of the exploratory factor analysis, major consumer dissatisfaction factors identified in this study can be categorized based on the followings: food, service, and facilities. It appears that most preferred medium for unsatisfied consumers to file their employees how to cope with complaints on the Internet. In terms of psychological compensation, it appears that consumers need to be provided with a through explanation in addition to a heartfelt apology against a complaint. On the physical side of compensation solution for everybody. The ideal timing of compensation for complaints can vary but it would be appropriate to leave it up to consumers to choose when they want to be rewarded.

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Position Control of Servo Systems Using Feed-Forward Friction Compensation (피드포워드 마찰 보상을 이용한 서보 시스템의 위치 제어)

  • Park, Min-Gyu;Kim, Han-Me;Shin, Jong-Min;Kim, Jong-Shik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.508-513
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    • 2009
  • Friction is an important factor for precise position tracking control of servo systems. Servo systems with highly nonlinear friction are sensitive to the variation of operating condition. To overcome this problem, we use the LuGre friction model which can consider dynamic characteristics of friction. The LuGre friction model is used as a feed-forward compensator to improve tracking performance of servo systems. The parameters of the LuGre friction model are identified through experiments. The experimental result shows that the tracking performance of servo systems with higherly nonlinear friction can be improved by using feed-forward friction compensation.

Compensation of the Repeatable Run Out using Repetitive Controller in HDD (반복제어기를 이용한 하드디스크의 주기적인 외란 보상)

  • 신호철;박성원;박태욱;양현석;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.1083-1088
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    • 2003
  • This paper presents three algorithms of repetitive controller for compensation of the repeatable uncut in hard disk drive. The basic theory of the repetitive controller and the analysis of the disturbance in hard disk drive are introduced. The tracking controller is designed in order to design the "plug-in type" repetitive controller. Design of the repetitive controller is considered as the design of the filter, determination of Gain and design of additional compensation for the various types. Specially, trade-off relationship between stability and performance is important factor for the design. The thee kinds of "plug-in type" repetitive controllers are designed simulated and experimented. Performance and characteristic of them are compared by the analysis of the experimental results

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Unified Active Power Filter System of control Power Flow (전력조류 제어에 의한 병.직렬 능동전력필터 시스템)

  • Kang, Min-Hyung;Yang, Lee-Woo;Kim, Young-Seok
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.984-985
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    • 2006
  • This paper presents control algorithms for unified active power filter. The algorithm is based in the performance function. The performance function is defined, and the compensation voltage reference is calculated for harmonics voltage and the compensation current reference is calculated for power factor. The proposed control algorithm can be applied to 3-phase 3-wire system and has a superior compensation characteristics for both harmonic current sources and harmonic voltage sources.

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The Optimal Compensation Gain Algorithm Using Variable Step for Buck-type Active Power Decoupling Circuits (벅-타입 능동 전력 디커플링을 위한 가변 스텝을 적용한 최적 보상 이득 알고리즘)

  • Baek, Ki-Ho;Kim, Seung-Gwon;Park, Sung-Min
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.2
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    • pp.121-128
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    • 2018
  • This work proposes a simple control method of a buck-type active power decoupling circuit that can minimize the ripple values in the dc link voltage. The proposed method utilizes a simplified duty calculation method and an optimal compensation gain tracking algorithm with variable-step approach. Thus, the dc link voltage ripple can be effectively reduced through the proposed method along with rapid response in tracking the optimum compensation gain. Moreover, the proposed method has better dynamic responses in the load fluctuation or abnormal situation. MATLAB/Simulink simulation and hardware-in-the-loop-simulation(HILS)-based experimental results are presented to validate the effectiveness of the proposed control method.

College Students' Dissatisfaction, Complaints, Compensation and Repurchase Intentions of Food services (대학생 외식소비자의 불만족, 불평행동, 보상방법 등이 재방문 의도에 미치는 영향에 관한 연구)

  • Yoo, Doo-Ryon
    • Journal of the Korean Home Economics Association
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    • v.46 no.10
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    • pp.119-132
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    • 2008
  • The aim of this study was to analyse the consumer dissatisfaction, complaint and repurchase intentions in foodservices with a particular focus on college students. For this investigation we analysed the responses of 520 college students interviewed from Daegu Gyeongbuk Province. The SPSS/WIN version 12.0 and AMOS version 6.0 were used to analyse collected data. The results were as follows : 1) Factor analysis identified 5 different consumer dissatisfaction factors: facilities, waiter/waitresses behavior, food quality, service, store operating. The level of food quality dissatisfaction was most high. Consumer complaints came in three forms: public, personally and no action. The level of personal complaint was most high. 2) AMOS analysis found that public complaints had the most influence on repurchase intentions. 3) Dissatisfaction was highest with fast food restaurants, which also received the most public complaints. 4) Dissatisfaction, complaints, and compensation strongly influenced eating-out and spending motivation of college students.