• 제목/요약/키워드: Reactive power compensator

검색결과 171건 처리시간 0.03초

GA를 이용한 무효전력 보상기의 협조제어 (Coordinated Control of the Reactive Power Compensator Using a Genetic Algorithm)

  • 이송근
    • 대한전기학회논문지:전력기술부문A
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    • 제52권1호
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    • pp.58-61
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    • 2003
  • A loop power system has a nonlinear characteristics. Also it is very hard to analyse through a equation if a discontinuous characteristic of the ULTC is added to a system. However, the problem which is hard to analyse by equations can acquire the useful result with what use the genetic algorithm (GA) which is a multi-point search program. In this paper, we proved through a simulation that the proposed method can reduce an operation frequency of tap changers and improving the quality of voltage of the buses by decreasing the deviation between the actual voltage and the reference voltage through the coordinated control of the ULTC that use GA in the loop power system.

Coordination Control of Voltage Between STATCOM and Reactive Power Compensation Devices in Steady-State

  • Park, Ji-Ho;Baek, Young-Sik
    • Journal of Electrical Engineering and Technology
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    • 제7권5호
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    • pp.689-697
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    • 2012
  • This paper proposes a new coordinated voltage control scheme between STATCOM (Static Synchronous Compensator) and reactive power compensation devices, such as shunt elements(shunt capacitor and shunt reactor) and ULTC(Under-Load Tap Changer) transformer in a local substation. If STATCOM and reactive power compensators are cooperatively used with well designed control algorithm, the target of the voltage control can be achieved in a suddenly changed power system. Also, keeping reactive power reserve in a STATCOM during steady-state operation is always needed to provide reactive power requirements during emergencies. This paper describes the coordinative voltage control method to keep or control the voltage of power system in an allowable range of steady-state and securing method of momentary reactive power reserve using PSS/E with Python. In the proposed method of this paper, the voltage reference of STATCOM is adjusted to keep the voltage of the most sensitive bus to the change of loads and other reactive power compensators also are settled to supply the reactive power shortage in out range of STATCOM to cope with the change of loads. As the result of simulation, it is possible to keep the load bus voltage in limited range and secure the momentary reactive power reserve in spite of broad load range condition.

배전용 정지형 보상기의 위상변이를 이용한 순시 유효/무효전력 보상 (Instantaneously Active/Reactive Power Compensation of Distribution Static Compensator using Phase Shift)

  • 홍성민;최종우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2010년도 하계학술대회 논문집
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    • pp.468-469
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    • 2010
  • DSTATCOM(Distribution STATic COMpensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Conventional researches use a LPF(Low Pass Filter) to eliminate ripple component at the calculation of compensation current. This paper proposes a calculation of compensation current using phase shift that can be a counterproposal of conventional methods using LPF.

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전압형 컨버터 HVDC를 이용한 정적 안정도 해석 (Static Stability Analysis Using Voltage Source Converter HVDC)

  • 채병하;오세승;장길수;이병준;한병문;차준민;김찬기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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    • pp.66-68
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    • 2004
  • The current source HVDC using thyristor valves requires the reactive power compensator, the increasement of short circuit ratio(SCR) by AC source, and the harmonic filter in power transmission. The voltage source HVDC that controls active power and reactive power independently can minimize the requirements and also can be used as a reactive power source without additional reactive power compensators. In this paper, the solution of supplying active power using direct current transmission and compensating additional reactive power at the heavy load zone in metropolitan area is proposed and verified by simulations.

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Performance Analysis of a Three-Phase Parallel Active Power Filter which Compensates PCC Voltage and the Unbalanced Loads

  • Lee, Woo-Cheol;Lee, Taeck-Kie;Hyun, Dong-Seok
    • Journal of Power Electronics
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    • 제1권1호
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    • pp.9-18
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    • 2001
  • The performance analysis of a three-phase parallel active power filter that compensates PCC voltage and the unbalanced loads is presented in this paper. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. Firstly, it operates as a conventional active filter with reactive power compensation when PCC voltage is within the 15% voltage drop range. Secondly, it operates as a voltage compensator when PCC voltage is not within the 15% voltage drop range. And both APF and voltage compensator compensate asymmetries caused by nonlinear loads. Finally, two methods of detecting the negative sequence are reviewed, and the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rate at 10KVA.

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Implementation of a 35KVA Converter Base on the 3-Phase 4-Wire STATCOMs for Medium Voltage Unbalanced Systems

  • Karimi, Mohammad Hadi;Zamani, Hassan;Kanzi, Khalil;Farahani, Qasem Vasheghani
    • Journal of Power Electronics
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    • 제13권5호
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    • pp.877-883
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    • 2013
  • This paper discussed a transformer-less shunt static synchronous compensator (STATCOM) with consideration of the following aspects: fast compensation of the reactive power, harmonic cancelation and reducing the unbalancing of the 3-phase source side currents. The STATCOM control algorithm is based on the theory of instantaneous reactive power (P-Q theory). A self charging technique is proposed to regulate the dc capacitor voltage at a desired level with the use of a PI controller. In order to regulate the DC link voltage, an off-line Genetic Algorithm (GA) is used to tune the coefficients of the PI controller. This algorithm arranged these coefficients while considering the importance of three factors in the DC link voltage response: overshoot, settling time and rising time. For this investigation, the entire system including the STATCOM, network, harmonics and unbalancing load are simulated in MATLAB/SIMULINK. After that, a 35KVA STATCOM laboratory setup test including two parallel converter modules is designed and the control algorithm is executed on a TMS320F2812 controller platform.

STATCOM을 이용한 풍력단지가 연계된 전력계통의 과도안정도 향상 (Transient Stability Enhancement of Power System Connected to a Wind Farm Using STATCOM)

  • 서규석;박지호
    • 한국산학기술학회논문지
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    • 제16권6호
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    • pp.4115-4120
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    • 2015
  • 풍력단지가 연계된 전력계통의 과도안정도를 보장하기 위해서는 전력계통과 풍력단지의 접속점에 풍력발전기가 충분한 무효전력을 공급할 수 있어야 한다. 하지만 개별의 풍력터빈은 안정도를 유지하기 위한 충분한 무효전력 공급능력을 가지지 못한다. 또한 풍력단지와 접속점 사이의 케이블은 리액턴스가 크고 이에 따른 무효전력 손실도 크다. STATCOM(Static Synchronous Compensator)은 고속으로 동작할 수 있고 충분한 무효전력을 공급할 능력을 가지고 있기 때문에 과도안정도를 향상시킬 수 있다. 본 논문에서는 풍력단지가 연계된 전력계통의 과도안정도 향상에 있어서 STATCOM의 유효성을 보인다. 접속점에 STATCOM을 설치하고 동적 모의를 한 결과 과도 안정도가 향상되는 결과를 얻을 수 있었다.

PWM 전압형 컨버터에 의한 무효전력 보상에 관한 연구 (A Study on Reduction of Reactive Power by PWH Voltage Converter)

  • 박민호;최재호;김상훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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    • pp.269-272
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    • 1988
  • This paper introduces a method to reduce the reactive power required by electronic converters. The instantaeous reactive power is calculated and compensated by the current controlled PWH voltage source converter connected parallel between the power lines and the converter. A high performance current control technique which is based on the current deviation vector is used for the PWM converter as compensator of reactive power. Accurate compensation of the reactive power and t control system ensuring fast response to the sudden change of loaf are attained. The converter structure and control scheme are discussed. Simulation of the system is performed.

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축소모형에 의한 공진형 전류원 인버터식 무효전력보상기의 특성 분석 (Characteristic Analysis of Reactive-Power Compensator using Resonant Current-Source Inverter by simplification model)

  • 한병문;백승택;박덕희;소용철
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 전력전자학술대회 논문집
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    • pp.269-274
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    • 1998
  • This paper describes a scaled model for PWM thyristor current-source inverter with a commutation circuit. The system consists of a 6-pulse thyristor bridge and an LC resonant circuit with thyristor switches, which offers thyristors to have turn-off capability for PWM operation with minimal switching losses. The proposed system can be used as a reactive power compensator with PWM operation for the utilitity application. There would be two advantages in the proposed system over the existing voltage source inverter. One is the low system cost due to using the conventional thyristors. Another is easy expansion of system operation voltage because th series operation of thyristor devices is already proven in HVDC system.

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Effects of a Static Synchronous Series Compensator (SSSC) Based on a Soft Switching 48-Pulse PWM Inverter on the Power Demand from the Grid

  • Ustun, Taha Selim;Mekhilef, Saad
    • Journal of Power Electronics
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    • 제10권1호
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    • pp.85-90
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    • 2010
  • In this paper the effects of a Static Synchronous Series Compensator, which is constructed with a 48-pulse inverter, on the power demand from the grid are studied. Extensive simulation studies were carried out in the MATLAB simulation environment to observe the compensation achieved by the SSSC and its effects on the line voltage, line current, phase angle and real/reactive power. The designed device is simulated in a power system which is comprised of a three phase power source, a transmission line, line inductance and load. The system parameters such as line voltage, line current, reactive power Q and real power P transmissions are observed both when the SSSC is connected to and disconnected from the power system. The motivation for modeling a SSSC from a multi-pulse inverter is to enhance the voltage waveform of the device and this is observed in the total harmonic distortion (THD) analysis performed at the end of the paper. According to the results, the power flow and phase angle can be controlled successfully by the new device through voltage injection. Finally a THD analysis is performed to see the harmonics content. The effect on the quality of the line voltage and current is acceptable according to international standards.