• 제목, 요약, 키워드: Transfer stability

검색결과 904건 처리시간 0.049초

Assessment of Total Transfer Capability Using IPLAN: An Application of UPFC for Total Transfer Capability Enhancement

  • Lee Byung Ha;Kim Jung-Hoon;Kwak No-Hong;Lee Woon-Hee
    • KIEE International Transactions on Power Engineering
    • /
    • v.5A no.3
    • /
    • pp.244-251
    • /
    • 2005
  • Power transfer capability has been recently highlighted as a key issue in many utilities. It is determined by the thermal stability, dynamic stability and voltage stability limits of generation and transmission systems. In particular, voltage stability affects power transfer capability to a great extent in many power systems. This paper presents a tool for determining total transfer capability from a static voltage stability viewpoint using IPLAN, which is a high level language used with the PSS/E program. The tool was developed so as to analyze static voltage stability and to determine the total transfer capability between different areas from a static voltage stability viewpoint by tracing stationary behaviors of power systems. A unified power flow controller (UPFC) is applied for enhancing total transfer capability between different areas from the viewpoint of static voltage stability. Evaluation of the total transfer capability of a practical KEPCO power system is performed from the point of view of static voltage stability, and the effect of enhancing the total transfer capability by UPFC is analyzed.

전체송전용량 향상을 위한 STATCOM 설비의 적용 위치 선정 및 과도안정도를 고려한 전체송전용량 분석 (A Study on Location of STATCOM for Improvement of Total Transfer Capability and Analysis of Total Transfer Capability Considering Transient Stability)

  • 이병하;백정명
    • 조명전기설비학회논문지
    • /
    • v.24 no.4
    • /
    • pp.17-24
    • /
    • 2010
  • 송변전설비들이 점점 중부하로 운용되어짐에 따라 송전용량이 전력회사에서 중요한 문제로 부각되어 왔다. 한전 시스템의 경우 전체송전용량은 주로 전압 안정도에 의해 제한을 받고 있으며, 이의 향상을 위한 연구들이 계속하여 수행되어 오고 있다. 본 논문에서는 전압안정도 관점에서의 전체송전용량을 향상시키기 위하여 STATCOM 설비를 설치하는 위치를 효과적으로 선택하기 위한 송전용량지수가 제시된다. 이 지수를 소규모 전력시스템인 IEEE 39모선 시스템에 적용하여 제시된 지수의 효과를 보여준다. 그리고, 이 소규모 시스템을 활용하여 부하가 증가할 때 전체송전용량에 전압안정도뿐 만이 아니라 과도안정도가 미치는 영향을 분석한다.

공벽유지용 유체에 따른 대구경 현장타설말뚝의 하중전이특성 (Load Transfer Characteristics on Drilled Shafts by Hole Stability Fluids)

  • 임대성;박성완;박정환;오세훈
    • 한국지반공학회:학술대회논문집
    • /
    • /
    • pp.1100-1105
    • /
    • 2008
  • In most drilled shafts construction sites, it is common, depending on the site condition, to use either water or slurry as fluids for maintaining stability of the holes, however, there are yet no design manuals by hole stability fluids. In this paper, in order to evaluate load transfer characteristics of the drilled shafts by hole stability fluids, two test piles are constructed over the soft ground of the lower Busan Bay based on the Bi-directional Pile Load Test. The test results showed that no ultimate states has found under the condition of applied loads with fresh water and slurry as hole fluids for drilled shafts. Then, the load transfer behavior were estimated with the data measured in fields and the effect of hole stability fluids were compared. All these results are presented in the paper.

  • PDF

MAG용접의 Arc안정성에 미치는 S의 영향 (Effect of S on Arc Stability of MAG Welding)

  • 안영호;이종봉;엄동석
    • Journal of Welding and Joining
    • /
    • v.17 no.1
    • /
    • pp.55-61
    • /
    • 1999
  • The effect of S content in welding wires on the arc stability was investigated, in the region of short circuit transfer and spray transfer. In the region of short circuit transfer, with increasing S content, average arcing time and average short circuit time were decreased. Therefore, droplet transfer frequency was increased, due to the reduction of arcing time and peak current at the moment of arc-reiginition was decreased, due to the decrease of short circuit time. In the region of spray transfer, the fluctuation degree of arc current and arc voltage became more stable, with increasing S content.

  • PDF

MAG용접의 Arc안정성에 미치는 Si의 영향 (Effect of Si on Arc Stability of MAG Welding)

  • 안영호;이종봉;엄동석
    • Journal of Welding and Joining
    • /
    • v.16 no.6
    • /
    • pp.52-58
    • /
    • 1998
  • The effect of Si content in welding wires on th arc stability was investigate, in the region of short circuit transfer and spray transfer. In the region of short circuit transfer, with increasing Si content, average arcing time and average short circuit time were increased. Therefore, droplet transfer frequency was decreased, due to the increase of arcing time and peak current at the moment of arc-reiginition was increased, due to the increase of short circuit time. In the region of spray transfer, the fluctuations of arc current and arc voltage was the most stable in wire with Si content of about 00.60 wt.%.

  • PDF

GMAW에서 와이어 송급속도의 변동이 아크안정성에 미치는 영향에 관한 연구 (Effects of Wire speed Fluctuation on Arc Stability in GMA Welding)

  • 신현욱;최용범;성원호;장희석
    • Journal of Welding and Joining
    • /
    • v.13 no.4
    • /
    • pp.85-102
    • /
    • 1995
  • Weld quality of GMA welding processes is closely related to arc stability. Although many researches on arc stability have been performed, real-time estimation of arc stability has not been attempted. For instance, Mita proposed a off-line statistical method in which short circuiting and arcing time, and voltage and current wave forms were sampled to assess arc stability. But this method is not suitable to assess arc stability for GMA welder which employ inverter power source due to its controlled current and voltage wave forms. In this paper, the relationship between are stability and wire feed rate fluctuation is analyzed to propose new criterion for inverter power source. When arc voltage and arc current and arcing time are analyzed, we can assess arc stability only for short circuit transfer mode. When wire feed rate is analyzed, we can estimate arc stability udner the condition of spray transfer mode as well. Hence, the wire feed rate is chosen for monitoring process variable to cover possible metal transfer modes in GMAW. Through this research, it has been identified that arc stability in GMA welding processes is closely related to wire fed rate. When inverter power source is used, conventional statistical method of estimating arc stability, such as Mita index, is no longer valid due to its controlled voltage and current wave forms. Arc stability has been also examined in phase plane diagram.

  • PDF

Calculation of Active Power Transfer Capability using Repeated Power Flow Program

  • Ham, Jung-Pil;Kim, Jung-Hoon;Lee, Byung-Ha;Won, Jong-Ryul
    • KIEE International Transactions on Power Engineering
    • /
    • v.12A no.1
    • /
    • pp.15-19
    • /
    • 2002
  • The power transfer capability is determined by the thermal, dynamic stability and voltage limits of the generation and transmission systems. The voltage stability depends on the reactive power limit and it affects the power transfer capability to a great extent. Then, in most load flow analysis, the reactive power limit is assumed as fixed, relatively different from the actual case. This paper proposes a method for determining the power transfer capability from a static voltage stability point of view using the IPLAN which is a high level language used with PSS/E program. The f-V curve for determining the power transfer capability is determined using Repeated Power Flow method. It Is assumed that the loads are constant and the generation powers change according to the merit order. The maximum reactive power limits are considered as varying similarly with the actual case and the effects of the varied maximum reactive power limits to the maximum power transfer capability are analyzed using a 5-bus power system and a 19-bus practical power system.

보 및 비틀림계에 대한 Frontal 전달매트릭스법의 적용성에 관한 연구 (A Study on the Application of Frontal Transfer Matrix Method to the Beam and the Torsional System)

  • 김영식
    • 수산해양기술연구
    • /
    • v.22 no.2
    • /
    • pp.46-52
    • /
    • 1986
  • The transfer matrix method has been extensively used to analyze the vibration problem. The final stage in this method is to find out solutions which make the frequency determinant zero. However, the frequency determinant includes the exponential terms and it causes instability to calculation and increases error. Recently the frontal transfer matrix method was suggested by Okada to heighten stability and effectivity in calculation. This paper applied the frontal transfer method to both the beam and torsional system, and confirmed stability and effectivity in comparsion with the transfer matrix method and the Holzer method.

  • PDF

전체송전용량 결정을 위한 전압안정도 측면에서의 상정사고 순위 매김 (Contingency Ranking for Determining Total Transfer Capability from Voltage Stability Point of View)

  • 이병하;백정명
    • 조명전기설비학회논문지
    • /
    • v.22 no.2
    • /
    • pp.148-154
    • /
    • 2008
  • 송전용량산정은 최근에 많은 전력회사에서 중요한 문제로 부각되어 왔다. 한전 시스템의 경우 전체송전용량은 주로 전압 안정도에 의해 제한을 받고 있으며, 전체송전용량 산정을 위하여서는 수많은 상정사고들에 대해서 분석하여야 한다. 따라서 전체송전용량 결정을 위한 전압안정도 측면에서의 상정사고를 효과적으로 선정하는 기법이 절실히 요청되고 있으며, 본 논문에서는 전체송전용량 결정을 위한 전압안정도 측면에서의 상정사고를 효과적으로 선정하는 새로운 상정사고 선정지수를 제시한다. 그리고 이 전체송전용량 결정을 위한 전압안정도 측면에서의 상정사고 선정지수의 효율성을 검증하기 위해 이 지수를 한전의 실계통에 적용하고 PSS/E 패키지와 개발한 IPLAN 프로그램을 사용하여 이 지수의 상정사고 선정에 대한 효용성이 분석된다.

전압 안정도 제약계통에 대한 고온초전도 케이블 적용효과 (Effects of HTS Cable Applied to the Voltage Stability Limited Power System)

  • 이근준;황시돌
    • 조명전기설비학회논문지
    • /
    • v.18 no.5
    • /
    • pp.169-173
    • /
    • 2004
  • 본 논문은 전력계통의 전압 안정도 제약 문제를 해결하는데 고온 초전도 케이블을 적용하기 위한 기법을 제시하였다. 대전력계통의 유효 송전용량은 종종 전압 안정도 제약에 의해 결정된다. 기존의 초전도 케이블 응용 연구는 주로 도심지역의 고밀도 전력 수송 문제를 해결하는 대안으로 연구의 초점을 두어왔지만, 고온 초전도 케이블의 선로정수 개선효과를 이용하면 전압 안정도로 제약된 계통의 송전용량을 증가시킬 수 있어 그 응용 범위가 확대될 수 있다. 전압 안정도에 의한 최대 수송전력을 결정하는 데는 IPLAN에 의한 P-V곡선을 이용하였고, 대체 대상선로는 부하 증가시 무효전력 손실감도가 가장 큰 선로로 하였다. 결과의 타당성을 검증하기 위해 IEEE 14모선 계통을 사용하였으며, 적용결과 Case II는 70[%], Case III에서는 160[%]의 추가 수송 능력 증가를 가져올 수 있었다.