• 제목/요약/키워드: Independent power system

검색결과 558건 처리시간 0.037초

Maximum Power Point Tracking in PMSG Using Fuzzy Logic Algorithm

  • ;이홍희
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2009년도 정기총회 및 추계학술대회 논문집
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    • pp.135-138
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    • 2009
  • In this paper, a novel maximum power point tracking (MPPT) for a PMSG-based variable speed wind power system is proposed using the fuzzy logic algorithm. The control algorithm is developed based on the normal hill climb searching (HCS) method, commonly used in wind energy conversion systems (WECS). The inputs of fuzzy-based controller are the derivations of DC output power and the step size of DC/DC converter duty cycles. The main advantages of the proposed MPPT method are no need to measure the wind velocity and the generator rotational speed. As such, the control algorithm is independent of turbine characteristics, achieving the fast dynamic responses with non-linear fuzzy systems. The effectiveness of the proposed MPPT strategy has been verified through the simulated results.

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새로운 전력 부하모형 (New Electricity Load Model)

  • 김주락;최준영;김정훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.289-291
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    • 2000
  • In a competitive electricity power market, the price of electricity changes instantly, that of conventional market is predetermined and hardly changes. In such a new environment, customers' behaviors change instantly according to the changing electricity prices. If we develop a electricity load model that well describes the behavior of electricity consumers, we can utilize that model in forecasting the amount of future load, solving the load flow problem and finding the weak point of the system. In this paper new electricity model that considers the price of electricity and power factor of the load is presented. While conventional load model, which is demand function of electricity, uses the price of real and reactive power as the independent variable of the demand function. this new load model uses price of real power and penalty factor according to the power factor for the calculation of amount of electricity demand.

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고속전철용 와전류제동장치 구동에 관한 연구 (A Study on Eddy Current Brake For a High-speed Railway Train)

  • 류홍제;우명호;김종수;강경호;강도현;임근희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 F
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    • pp.2745-2747
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    • 1999
  • Recently, the eddy current braking system has an advantage as the high speed railway train is developed. Because it is independent on wheel-rail coefficient of adhesion and it can be used in adverse weather conditions by reason of non-acting on wheels. In this paper we designed down-scaled eddy current brake model and developed control algorithm to generate constant braking torque. Our algorithm is verified through experiments to generate constant torque.

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매우 넓은 입력전압 범위를 갖는 스위치모드 플라이백 파워서플라이에 대한 연구 (Study of Flyback Switching Power Supply With Very Wide Input Voltage Range)

  • 나재두;이춘택;박형남;이용근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.1008-1009
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    • 2015
  • An emergency diesel generator system is an independent source of power that supports important electrical systems on loss of normal power supply. AVR(Automatic Voltage Regulator) is a regulator which regulates the output voltage at a nominal constant voltage level. Specially, a power supply for the AVR must be operated at the very wide input range. In this paper, a flyback power supply with very wide input voltage range is proposed.

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PMCR-A Power Mapping and Calibration Routing for 600 MWe CANDU-PHW Reactors

  • Oh, Se-Ki;G.Kugler
    • Nuclear Engineering and Technology
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    • 제11권4호
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    • pp.275-286
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    • 1979
  • PMCR은 600MWe CANDU-PHW의 지역 과출력 제어 계통의 일환으로 발전소 내에 설치된 computer를 이용하여 off-line으로 계산을 수행한다 이 프로그램은 계산된 중성자속 분포로부터 연료 연소도를 고려한 출력 분포를 계산하여 정확한 channel 출력 분포를 얻는다. PMCR은 따라서 발전소의 제어 프로그램과 별도로 연료 연소도를 계산한다. 이 논문에서는 기존의 균일 중성자속-출력 전환법을 이용한 계산결과와 비교하여 PMCR이 매우 정확한 출력 분포를 얻고 있음을 보여 준다.

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A Two-dimensional Steady State Simulation Study on the Radio Frequency Inductively Coupled Argon Plasma

  • Lee, Ho-Jun;Kim, Dong-Hyun;Park, Chung-Hoo
    • KIEE International Transactions on Electrophysics and Applications
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    • 제2C권5호
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    • pp.246-252
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    • 2002
  • Two-dimensional steady state simulations of planar type radio frequency inductively coupled plasma (RFICP) have been performed. The characteristics of RFICP were investigated in terms of power transfer efficiency, equivalent circuit analysis, spatial distribution of plasma density and electron temperature. Plasma density and electron temperature were determined from the equations of ambipolar diffusion and energy conservation. Joule heating, ionization, excitation and elastic collision loss were included as the source terms of the electron energy equation. The electromagnetic field was calculated from the vector potential formulation of ampere's law. The peak electron temperature decreases from about 4eV to 2eV as pressure increases from 5 mTorr to 100 mTorr. The peak density increases with increasing pressure. Electron temperatures at the center of the chamber are almost independent of input power and electron densities linearly increase with power level. The results agree well with theoretical analysis and experimental results. A single turn, edge feeding antenna configuration shows better density uniformity than a four-turn antenna system at relatively low pressure conditions. The thickness of the dielectric window should be minimized to reduce power loss. The equivalent resistance of the system increases with both power and pressure, which reflects the improvement of power transfer efficiency.

가스터빈의 규모별 성능차이를 고려한 고체산화물 연료전지/가스터빈 하이브리드 시스템의 성능해석 (Analysis of Performance of SOFC/GT Hybrid Systems Considering Size-Dependent Performance of Gas Turbines)

  • 명노성;박성구;김동섭
    • 대한기계학회논문집B
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    • 제35권4호
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    • pp.399-407
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    • 2011
  • 고체산화물 연료전지(SOFC)와 가스터빈을 결합한 하이브리드 발전시스템에서 가스터빈의 규모별 성능차이가 시스템의 성능에 미치는 영향에 대하여 해석하였다. 이를 위해 kW급, MW 이하급, 수 MW급 등 서로 다른 세 가지 가스터빈을 선정하여 사용하였다. 가스터빈이 순 출력을 거의 내지 못하는 kW급 시스템에서도 연료전지 단독 시스템과 비교해 효율이 증가하였으며, 가스터빈의 출력이 커질수록 (즉, 성능이 좋아질수록) 하이브리드 시스템에서 가스터빈이 차지하는 비중이 커지고 시스템의 효율이 높아짐을 확인하였다. 가스터빈의 압력비 증가에 따른 성능 변화를 살펴본 결과 세 가지 하이브리드 시스템에서 모두 출력은 증가하지만, 효율의 변화는 크지 않음을 확인하였다.

손떨림이 켐코더 화면에 미치는 영향

  • 방교윤;조암
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1998년도 춘계학술대회논문집
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    • pp.87-92
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    • 1998
  • It is needed that the small, cheap and low power dissipated image stabilizing system is used in a small camcorder. It is essential to detect the hand shake of human exactly for the good design of image stabilizing system. In this study, the hand shake is measured by the experiment on 17 peoples in peak-to- peak voltage and frequency. The shake of image by hand by hand is independent of human age or weight, and dependent of calmness of character or concentration of mind.

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전력선 통신을 위한 2-반송파 DS방식의 특성과 MODEM의 구현 (Performance of 2-Carrier DS system and its MODEM designed for Power Line Transmission)

  • 김인태;이무영
    • 한국통신학회논문지
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    • 제19권3호
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    • pp.582-590
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    • 1994
  • 전력선 통신을 위한 간단하면서 융통성이 큰 2-반송과 DS방식의 데이터 전송모뎀을 구현하고, 그 특성을 해석적으로 검토하였으며 실험을 통해 이것을 확인 하였다. 제안된 시스템은 DS모뎀 출력에 극성에 따라 독립된 2개의 반송파 주파수를 할당하여 전송케 하므로서 완전한 DSSS 동작을 보장 하도록 한다. 수신단말기의 두 포락선 검파출력은 재래방식 처리 비교기에 입력되지 않고 먼저 DS 상관기에 입력시켜서 그 출력을 잡음과 비교판정 하게 된다. 이때, 역확산되어 약화된 잡음전략이 신호와 비교되기 때문에 데이터의 에러율은 현저하게 개선 된다. 이 시스템은 구성이 비교적 간단함에도 불구하고, 2400bps의 데이터를 전송 할때, 재래식의 FSK 방식에 비하여 10dB정도 더 높은 선로잡음아래에서도 에러율 10 정도를 유지할 수가 있다.

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A High Performance Interleaved Bridgeless PFC for Nano-grid Systems

  • Cao, Guoen;Lim, Jea-Woo;Kim, Hee-Jun;Wang, Huan;Wang, Yibo
    • Journal of Electrical Engineering and Technology
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    • 제12권3호
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    • pp.1156-1165
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    • 2017
  • A high performance interleaved bridgeless boost power factor correction (PFC) rectifier operating under the critical current conduction mode (CrM) is proposed in this paper to improve the efficiency and system performance of various applications, such as nano-grid systems. By combining the interleaved technique with the bridgeless topology, the circuit contains two independent branches without rectifier diodes. The branches operate in interleaved mode for each respective half-line period. Moreover, when operating in CrM, all the power switches take on soft-switching, thereby reducing switching losses and raising system efficiency. In addition, the input current flows through a minimum amount of power devices. By employing a commercial PFC controller, an effective control scheme is used for the proposed circuit. The operating principle of the proposed circuit is presented, and the design considerations are also demonstrated. Simulations and experiments have been carried out to evaluate theoretical analysis and feasibility of the proposed circuit.