• 제목/요약/키워드: instantaneous reactive power

검색결과 103건 처리시간 0.026초

Comparison of Two Reactive Power Definitions in DFIG Wind Power System under Grid Unbalanced Condition

  • Ha, Daesu;Suh, Yongsug
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2014년도 전력전자학술대회 논문집
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    • pp.213-214
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    • 2014
  • This paper compares two instantaneous reactive power definitions in DFIG wind turbine with a back-to-back three-level neutral-point clamped voltage source converter under unbalanced grid conditions. In general, conventional definition of instantaneous reactive power is obtained by taking an imaginary component of complex power. The other definition of instantaneous reactive power can be developed based on a set of voltages lagging the grid input voltages by 90 degree. A complex quantity referred as a quadrature complex power is defined. Proposed definition of instantaneous reactive power is derived by taking a real component of quadrature complex power. The characteristics of two instantaneous reactive power definitions are compared using the ripple-free stator active power control algorithm in DFIG. Instantaneous reactive power definition based on quadrature complex power has a simpler current reference calculation control block. Ripple of instantaneous active and reactive power has the same magnitude unlike in conventional definition under grid unbalance. Comparison results of two instantaneous reactive power definitions are verified through simulation.

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제어 자유도를 한 차원 증가시킨 순시무효전력 보상이론 (Instantaneous Reactive Power Compensation Theory Increasing The Control Freedom One Degree Higher)

  • 김효성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 F
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    • pp.2481-2483
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    • 1999
  • This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

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순시무효전력 보상에 의한 중성선 전류의 제거 (Eliminating the Neutral Current by the Instantaneous Reactive Power Compensation)

  • 김효성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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    • pp.131-133
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    • 1998
  • This paper, proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of the three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

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개선된 순시무효전력 보상기를 이용한 IPMSM의 센서없는 속도제어 (A Sensorless Control of IPMSM using the Improving Instantaneous Reactive Power Compensator)

  • 나재두
    • 전기학회논문지
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    • 제67권10호
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    • pp.1303-1307
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    • 2018
  • A improving sensorless compensator for the IPMSM(Interior Permanent Magnet Synchronous Motor) drive system is proposed. Generally, the motor drive system is required the robust parameter variation and disturbance. The speed estimation methods of the conventional IRP(Instantaneous Reactive Power) compensator is improved by the speed estimation techniques of the current model observer with the proposed instantaneous reactive power compensator. Performance evaluations of the novel speed error compensator and sensorless control system are carried out by the experiments.

순시 무효전력을 이용한 매입형 영구자석 동기 전동기의 센서리스 속도제어 (A Sensorless Speed Control of an Interior Permanent Magnet Synchronous Motor based on an Instantaneous Reactive Power)

  • 강형석;정우택;김영석
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권2호
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    • pp.107-115
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    • 2006
  • In this paper, a new speed sensorless control based on an instantaneous reactive power is proposed for the interior permanent magnet synchronous motor(IPMSM) drives. In proposed algorithm, the current observer estimates the line currents and the estimated speed can be yielded from the voltage equation because the information of speed is included in back EMF. To implement speed sensorless control, the current observer is composed by using the voltage equation of the IPMSM in the stationary reference frame fixed to the stator. The estimated speed of the rotor is composed by using the voltage equation of the IPMSM in the rotating reference frame fixed to the rotor The estimated speeds to minimize the speed error compensated by using the instantaneous reactive power. The instantaneous reactive power is calculated on the rotating reference frame fixed to the rotor. The effectiveness of the preposed algorithm is confirmed by the experiments.

약계자 영역에서의 순시무효전력을 이용한 PMSM의 센서리스 제어 (Sensorless Control of a Permanent Magnet Synchronous Motor based on an Instantaneous Reactive Power in the Field-Weakening Region)

  • 이정흠;김영석;최양광
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제54권2호
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    • pp.71-80
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    • 2005
  • This paper presents the position sensorless vector control of a cylindrical permanent magnet synchronous motor(PMSM) in the field weakening region. The position sensorless algorithm using an instantaneous reactive power of the PMSM is proposed. An instantaneous reactive power can be obtained from the vector product of rotor currents and back emf of the PMSM. Back emf includes the information of rotor speed. So the estimated speed can be yielded from the voltage equation of the PMSM. In other words, the estimated speed is compensated by using an instantaneous reactive power. To extend the speed range of the PMSM in the constant horsepower region, the field weakening control is applied. The proposed algorithm is not affected by mechanical motor parameters because the mechanical equation is not used. The effectiveness of the proposed algorithm is verified by the experimental results.

에너지저장요소를 사용하지 않는 전력보상기에 의한 중성선 전류의 제거 (Eliminating the Neutral Current by the Power Compensator without using Energy Storage Elements)

  • 김효성
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제48권6호
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    • pp.330-335
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    • 1999
  • This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers qq, qr were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storge element.

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전류제어형 PWM 컨버터에 의한 순시 무효전력 보상장치 (Instantaneous Reactive Power Compensator using Current Controlled PWM Converter)

  • 최재호;김상훈;박민호
    • 대한전기학회논문지
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    • 제38권7호
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    • pp.539-548
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    • 1989
  • 본 논문에서는 싸이리스터 부하에서 발생하는 무효전력과 고조파를 보상하기 위한 순시무효전력 보상장치에 관하여 기술하였다. 저자는 기본파 위상 지연과 고조파 전류외형에 기인하는 순시무효전력을 새로이 정의하고 순시전력흐름의 관점에서 그 물리적 의미를 고찰하였다. 순시전압 및 순시전류의 궤환에 의해 순시무효전력을 계산하고, 이를 부하와 병렬로 연결된 전류제어형 PWM컨버터에 의해 보상하였다. PWM컨버터는 전류오차 백터제어방식에 의한 전류제어 PWM 기법을 사용함으로써 우수한 전류제어특성을 실현할 수 있었다. 시뮬레이션과 실험을 통하여 정상상태 및 과도상태에서의 탁월한 보상특성이 입증되었다.

맵핑 매트릭스를 사용한 일반화 순시전력 이론 (The Generalized Instantaneous Power Theory Using Mapping Matrices)

  • 김효성;최재호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 F
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    • pp.1930-1932
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    • 1997
  • Instantaneous active/reactive powers are defined in three phase four wire systems. The definition can be generally applicable to any source conditions and load conditions including nonlinear circuits. The zero-sequence power resulted from the zero-sequence voltage and zero-sequence current between two sub-systems affects both to the instantaneous active and reactive powers. The zero-sequence current can be controlled by compensation of the reactive power without power storage elements.

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시간영역에서 순시 유효/무효전력을 이용한 마이크로그리드의 단독운전 판단 (Islanding Detection for a Micro-Grid based on the Instantaneous Active and Reactive Powers in the Time Domain)

  • 이영귀;김연희;정태영;김태현;강용철
    • 전기학회논문지
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    • 제61권1호
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    • pp.22-27
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    • 2012
  • Correct and fast detection of a micro-grid (MG) islanding is essential to the MG since operation, control and protection of the MG depend on an operating mode i.e., an interconnected mode or an islanding mode. When islanding occurs, the frequency of the point of common coupling (PCC) is not the nominal frequency during the transient state owing to the frequency rise or drop of generators in the MG. Thus, the active and reactive power calculated by the frequency domain based method such as Fourier Transform might contain some errors. This paper proposes an islanding detection algorithm for the MG based on the instantaneous active and reactive powers delivered to the dedicated line in the time domain. During the islanding mode, the instantaneous active and reactive powers delivered to the dedicated line are constants, which depend on the voltage of the PCC and the impedance of the dedicated line. In this paper, the instantaneous active and reactive powers are calculated in the time domain and used to detect islanding. The performance of the proposed algorithm is verified under various scenarios including islanding conditions, fault conditions and load variation using the PSCAD/EMTDC simulator. The results indicate that the algorithm successfully detects islanding for the MG.