• 제목/요약/키워드: Phase shifting transformer

검색결과 26건 처리시간 0.032초

계통 혼잡처리를 위한 Phase-Shifting Transformers의 최적 위치 선정 (Optimal Placement Design of Phase-Shifting Transformers for Power System Congestion Problems)

  • 김규호;송경빈
    • 대한전기학회논문지:전력기술부문A
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    • 제54권12호
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    • pp.567-572
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    • 2005
  • This paper presents a scheme to design optimal placement of phase-shifting transformers for power system congestion problems. A good design of phase-shifting transformers placement can improve total transfer capability in interconnected systems. In order to find the optimal placement of phase-shifting transformers, the power flows of the interesting transmission lines are evaluated using sequential quadratic programming technique. This algorithm considers power balance equations and security constraints such as voltage magnitudes and transmission line capacities. The proposed scheme is tested in 10 machines 39 buses and IEEE 57 buses systems. Test result shows that the proposed method can find the optimal placement of phase-shifting transformers to solver power system congestion problems.

배전계통에서 위상조정 변압기를 사용한 고조파 저감에 관한 연구 (A Study on the Harmonics Reduction using Phase Shifting Transformer in a Electric Power Distribution System)

  • 김경철
    • 조명전기설비학회논문지
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    • 제16권2호
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    • pp.38-44
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    • 2002
  • 전력변환기와 같은 비선형 부하의 사용증가는 전력시스템에 고조파를 발생시킨다. 고조파를 포함하는 전류와 전압은 전기설비에 고장과 오동작을 일으키게된다. 위상조정 변압기는 고조파 발생원이 병렬로 설치되어 있는 곳에 설치하면 고조파 문제를 효과적으로 해결할 수 있다. 본 논문에서는 EDSA고조파 분석 프로그램을 사용하여 고조파를 제거하기 위한 위상조정 변압기의 효과를 분석하고 검증하였다.

Phase-Shifting Transformer를 이용한 계통 혼잡처리 방안 (Congestion management Using Phase-Shifting Transformer in Power Systems)

  • 김규호;신호성;송경빈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.822-824
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    • 2005
  • This paper presents a scheme to solve the congestion problem using phase-shifting transformer(PST) in power systems. Available transfer capability(ATC) is an important indicator of the usable amount of transmission capacity accessible by several parties for commercial trading in power transaction activities. This paper deals with an application of optimization technique for ATC calculation. Sequential quadratic programming(SQP) is used to maximize power flow of tie line subject to security constraints such as voltage magnitude and real power flow. The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

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다단 H-브릿지 인버터의 입력전류특성 (I) - 입력단 변압기 결선과 위상이동특성 (Line Current Characteristics of Multilevel H-Bridge Inverters: Part I - Connection of Input Transformer and Phase Shift Characteristics)

  • 정승기
    • 전력전자학회논문지
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    • 제13권3호
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    • pp.229-236
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    • 2008
  • 최근 중대용량의 교류전동기 구동에 다단 H-브릿지 인버터의 적용이 늘어나고 있다. 이 인버터의 주된 장점 중의 하나는 입력전류에 고조파성분이 적다는 것으로 이는 2차측이 다중의 위상이동 권선으로 이루어진 변압기를 사용함으로써 이루어진다. 본 논문은 다단 H-브릿지 인버터에 적용되는 위상이동 변압기의 권선 설계의 기본 방안과 입력전류 고조파의 이론적인 해석을 제시하고 있다. I부에서는 먼저 위상이동변압기의 입출력 전압관계식을 유도하고 위상이동과 변압기 설계와의 관련성에 대하여 서술하고 있다.

다단 H-브릿지 인버터의 입력전류특성(II) - 다중 변압기 결선에 의한 고조파 저감 (Line Current Characteristics of Multilevel H-Bridge Inverters: Part II - Harmonic Reduction with Multiple Transformer Windings)

  • 정승기
    • 전력전자학회논문지
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    • 제13권3호
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    • pp.237-245
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    • 2008
  • 최근 중대용량의 교류전동기 구동에 다단 H-브릿지 인버터의 적용이 늘어나고 있다. 이 인버터의 주된 장점 중의 하나는 입력전류에 고조파성분이 적다는 것으로 이는 2차측이 다중의 위상이동 권선으로 이루어진 변압기를 사용함으로써 이루어진다. 본 논문은 다단 H-브릿지 인버터에 적용되는 위상이동 변압기의 권선 설계의 기본 방안과 입력전류 고조파의 이론적인 해석을 제시하고 있다. 위상이동 변압기를 다룬 I부에 이어 II부에서는 입력 선전류의 고조파 특성을 해석함으로써 고조파 제거를 위한 등간격 위상차 설정방식의 이론적 근거를 규명하였다.

선형계획기반 선로혼잡처리에 대한 총송전용량 평가 (Assessment of Total Transfer Capability for Congestion Management using Linear Programming)

  • 김규호;송경빈
    • 대한전기학회논문지:전력기술부문A
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    • 제55권11호
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    • pp.447-452
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    • 2006
  • This paper presents a scheme to solve the congestion problem with phase-shifting transformer(PST) controls and power generation controls using linear programming method. A good design of PST and power generation control can improve total transfer capability(TTC) in interconnected systems. This paper deals with an application of optimization technique for TTC calculation. Linear programming method is used to maximize power flow of tie line subject to security constraints such as voltage magnitude and real power flow in interconnected systems. The results are compared with that of repeat power flow(RPF) and sequential quadratic programming(SQP). The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

다중 H-브릿지 인버터의 입력전류특성 (Line Current Characteristics of Multilevel H-Bridge Inverters)

  • 정승기
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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    • pp.335-340
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    • 2004
  • Recently, multilevel H-bridge inverters have become more popular in medium to high power ac drive applications. One of significant advantages of them is low harmonic contents in their input line currents thanks to the transformer with multiple phase-shifted secondary windings. This paper attempts to provide basic guidelines for the design of the phase shifting transformer windings and theoretical analysis of input line current harmonics.

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단상 인버터의 동작에 의한 이중접속 3상 전압원 인버터의 출력파형 개선 (Output Waveform Improvement of Double-Connected 3-Phase Voltage Source Inverter by Single-Phase Inverter)

  • 최세완
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2000년도 전력전자학술대회 논문집
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    • pp.330-334
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    • 2000
  • This paper proposes a new double-connected 3-phase voltage source inverter with improved output voltage waveform. An auxiliary single-phase inverter injects a ripple voltage into the double- connected inverter to convert 12-step operation to 36-step operation. The KVA rating of the output phase-shifting transformer is reduced by employing a harmonic canceling reactor. The whole rectifier-inverter system including the proposed technique is introduced and the experimental results are provided.

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Analysis of a Harmonics Neutralized 48-Pulse STATCOM with GTO Based Voltage Source Converters

  • Singh, Bhim;Saha, Radheshyam
    • Journal of Electrical Engineering and Technology
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    • 제3권3호
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    • pp.391-400
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    • 2008
  • Multi-pulse topology of converters using elementary six-pulse GTO - VSC (gate turn off based voltage source converter) operated under fundamental frequency switching (FFS) control is widely adopted in high power rating static synchronous compensators (STATCOM). Practically, a 48-pulse ($6{\times}8$ pulse) configuration is used with the phase angle control algorithm employing proportional and integral (PI) control methodology. These kinds of controllers, for example the ${\pm}80MVAR$ compensator at Inuyama switching station, KEPCO, Japan, employs two stages of magnetics viz. intermediate transformers (as many as VSCs) and a main coupling transformer to minimize harmonics distortion in the line and to achieve a desired operational efficiency. The magnetic circuit needs altogether nine transformers of which eight are phase shifting transformers (PST) used in the intermediate stage, each rating equal to or more than one eighth of the compensator rating, and the other one is the main coupling transformer having a power rating equal to that of the compensator. In this paper, a two-level 48-pulse ${\pm}100MVAR$ STATCOM is proposed where eight, six-pulse GTO-VSC are employed and magnetics is simplified to single-stage using four transformers of which three are PSTs and the other is a normal transformer. Thus, it reduces the magnetics to half of the value needed in the commercially available compensator. By adopting the simple PI-controllers, the model is simulated in a MATLAB environment by SimPowerSystems toolbox for voltage regulation in the transmission system. The simulation results show that the THD levels in line voltage and current are well below the limiting values specified in the IEEE Std 519-1992 for harmonic control in electrical power systems. The controller performance is observed reasonably well during capacitive and inductive modes of operation.

Two-Phase Hybrid Forward Convertor with Series-Parallel Auto-Regulated Transformer Windings and a Common Output Inductor

  • Wu, Xinke;Chen, Hui
    • Journal of Power Electronics
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    • 제13권5호
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    • pp.757-765
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    • 2013
  • For conventional interleaved two-phase forward converters with a common output inductor, the maximum duty cycle is 0.5, which limits the voltage range and increases the difficulty of the transformer's optimization. A new two-phase hybrid forward converter with series-parallel auto-regulated transformer windings is presented in this paper. With interleaved control signals for the two phases, the secondary windings of the transformers can work in series when the duty cycle is larger than 0.5, and they can work in parallel when duty cycle is lower than 0.5. Therefore, the maximum duty cycle is extended and the turns ratio of the transformer can be optimized. Duty cycle dependent auto-regulated windings result in the steady states of the converter being different in different duty cycle ranges (D>0.5 and D<0.5). Fortunately, the steady state gains of the proposed hybrid converter are identical at different duty cycle ranges, which means a stepless shift between two states. A prototype is built to verify the theoretical analysis. A conventional control loop is compatible for the whole input voltage range and load range thanks to the stepless shifting between the different duty cycle ranges.