• 제목/요약/키워드: Reactive Power Control

검색결과 733건 처리시간 0.042초

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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전압 및 순동무효예비력 확보를 위한 지역 변전소에서의 무효전력제어장치 협조방식 연구 (Local Coordinative Reactive Power Control Method to Manage Voltage/Momentary Reactive Reserve)

  • 이근준;윤종수;장병훈;정성원;윤석호;이현철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.115-116
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    • 2008
  • This paper discusses local reactive power control method of substation which has FACTS controller(STATCOM) and other reactive power controllers. Not only The relation between entral control and local control method was discussed, but also local STATCOM control methd was done. With this results, revised coordinative control method which can implement system voltage sensitivity characteristics of each control devices. Also, this method can give proper solution for system status which requires momentary reactive reserve. This method is expected to be applied to control multiple substation reactive power devices which is combined with SCADA system.

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우리나라 계통의 전압제어지역별 무효전력 예비율 산정 (The estimation of reactive power reserves of generators in voltage control areas of KEPCO systems)

  • 김봉식;최윤혁;서상수;이병준;이흥재;송인준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.455-456
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    • 2007
  • Maintaining the voltages is important in the power systems and the voltage is closely associated with the reactive powers. Therefore, the voltages are maintained by controlling the reactive powers. However actually it is impossible to control reactive power for maintaining all bus voltages. Thus, Secondary Voltage Regulation was designed. It divides power systems into some control areas and controls pilot node with the included generators. The reactive powers of generators can control pilot bus voltage continuously and fast. Therefore we need to divide areas and select control generators for SVR with Electrical distance. Then estimation of the reactive power reserves of geneators is needed in voltage control areas to control voltages of the pilot nodes.

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Hybrid Control System for Managing Voltage and Reactive Power in the JEJU Power System

  • Seo, Sang-Soo;Choi, Yun-Hyuk;Kang, Sang-Gyun;Lee, Byong-Jun;Shin, Jeong-Hoon;Kim, Tae-Kyun
    • Journal of Electrical Engineering and Technology
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    • 제4권4호
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    • pp.429-437
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    • 2009
  • This paper proposes a hybrid voltage controller based on a hierarchical control structure for implementation in the Jeju power system. The hybrid voltage controller utilizes the coordination of various reactive power devices such as generators, switched shunt devices and LTC to regulate the pilot voltage of an area or zone. The reactive power source can be classified into two groups based on action characteristics, namely continuous and discrete. The controller, which regulates the pilot bus voltage, reflects these characteristics in the coordination of the two types of reactive power source. However, the continuous type source like generators is a more important source than the discrete type for an emergency state such as a voltage collapse, thereby requiring a more reactive power reserve of the continuous type to be utilized in the coordination in order to regulate the pilot bus voltage. Results show that the hybrid controller, when compared to conventional methods, has a considerable improvement in performance when adopted to control the pilot bus voltage of the Jeju island system.

배전계통에 연계된 전지전력저장시스템의 유.무효전력 제어 (Active and Reactive Power Control of the Battery Energy Storage System interconnected with Power Distribution System)

  • 김재철;문선호;최준호;김응상
    • 조명전기설비학회논문지
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    • 제13권4호
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    • pp.127-133
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    • 1999
  • 본 논문은 배전계통에 전지전력저장시스템(Battery Energy Storage System: BESS)를 연계하여 운전하는 경우 BESS의 유.무효전력 제어에 대하여 연구하였다. BESS을 배전계통에 연계하는 경우, 이의 유.무효전력 출력을 제어함으로써 배전계통에 일정 전력을 공급, 첨두 부하를 삭감하고 전압을 보상할 수 있다. 본 논문에서는 배전계통과 전지전력저장시스템을 등가 모델링 하였고 전지전력저장시스템의 유.무효 전력제어를 위한 전력 조류 방정식을 제시하였다. 본 논문에서는 BESS의 유.무효전력을 제어하기 위하여 $P-\delta$와 Q-V 제어를 사용하였고 이를 입증하기 위하여 BESS의 유.무효전력 제어를 PSCAD/EMTDC 프로그램을 이용하여 시뮬레이션 하였다.

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델터 변조 방식을 이용한 전류형 무효전력 보상장치 (Current-Fed Reactive Power Compensator Using Delta Modulation Technique)

  • 백형래;김한성
    • 대한전기학회논문지
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    • 제41권3호
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    • pp.244-252
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    • 1992
  • This paper describes a reactive power compensator using current-source delta modulation converter, which compensates the reactive power in the ac sides of 3-phase rectifier. In the conventional current control methods for the current-type reactive power compensators, it is usual to compare the reactive reference current signal with the triangular wave and hence to generate the ON-OFF signals for the reactive power compensator. To improve the response as well as the control capability, the delta modulated current control technique is used in this paper. As a result, the input power factor is improved close to unity and both simulation and experimental results show good compensating performances.

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전압.무효전력제어에 있어서의 최적운전 목표상태의 간략결정법 (A simplified method for the determination of the optimal operating patterns in system voltage-reactive power control)

  • 송길영
    • 전기의세계
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    • 제15권3호
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    • pp.1-7
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    • 1966
  • The past several years have strongly anticipated the advent of a more integrated system control combining active power and voltage-reactive power controls. This paper presents a new approach to the intergrated system control with primary emphasis on the development of a new control method which combines the conventional economical load dispatching(ELD) and voltage-reactive power controls. The control method, in its fundamental principle, first determines the optimal active power allocation in accordance with the conventional ELD controller. By a proper manipulation of the remaining reactive power sources in the system, the control method then reduces the transmission losses of the system by the adjustment of system voltage distribution and also by the proper allotment of reactive power flows.

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계통 연계형 태양광 발전 시스템의 부하 무효전력 보상이 적용된 단독운전 인지법 (The Anti-Islanding Method with Compensation of Load Reactive Power for Grid-connected Photovoltaic Generation System)

  • 정진범;신동현;김희준
    • 전기학회논문지
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    • 제57권1호
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    • pp.58-64
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    • 2008
  • In this paper, we present an active anti-islanding method with a load monitoring system using reactive power control. The proposed method, which is based on reactive power control, has fewer harmonics components than those in conventional methods, and it can minimize the reactive power component of the grid because it compensates the reactive power component with the load monitoring. The proposed quick islanding detection method was confirmed from the experimental results with an inverter for a 3kW photovoltaic system.

Minimize Reactive Power Losses of Dual Active Bridge Converters using Unified Dual Phase Shift Control

  • Wen, Huiqing;Su, Bin
    • Journal of Electrical Engineering and Technology
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    • 제12권2호
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    • pp.654-664
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    • 2017
  • This paper proposed an unified dual-phase-shift (UDPS) control for dual active bridge (DAB) converters in order to improve efficiency for a wide output power range. Different operating modes of UDPS are characterized with respect to the reactive current distribution. The proposed UDPS has the same output power capability with conventional phase-shift (CPS) method. Furthermore, its implementation is simple since only the change of the leading phase-shift direction is required for different operating power range. The proposed UDPS control can minimize both the inductor rms current and the circulating reactive current for various voltage conversion ratios and load conditions. The optimal phase-shift pairs for two bridges of DAB converter are derived with respect to the comprehensive reactive power loss model, including the reactive components delivered from the load and back to the source. Simulation and experimental results are illustrated and explained with details. The effectiveness of the proposed method is verified in terms of reactive power losses minimization and efficiency improvement.

An Enhanced PCC Harmonic Voltage Mitigation and Reactive Power Sharing in Islanded Microgrid

  • Pham, Minh-Duc;Lee, Hong-Hee
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2018년도 전력전자학술대회
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    • pp.138-140
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    • 2018
  • Parallel distributed generators (DGs) in the islanded microgrid are generally operated autonomously by means of the droop control scheme. However, the traditional droop control methods which use the P-${\omega}$ and Q-E curve to share power between DGs are still concerned to improve the accuracy of reactive power sharing. Moreover, the uncontrolled harmonic power reduces the point of common coupling (PCC) voltage quality and microgrid stability. In order to solve these problems, this paper proposes an enhanced PCC harmonic control strategy and an improved reactive power sharing control scheme. Based on the low bandwidth communications, a secondary control is implemented with both central controller and local controller. The effectiveness of the proposed control scheme is analyzed through the simulation.

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