• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.9
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• pp.494-499
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• 2004

This paper presents to compute the power economic dispatch, an optimal power flow (OPF) computation algorithm, considering the load power factor limits constraint in developed. Efficient reactive power planning enhances economic operation as well as system security. Accordingly, an adequate level of power factor limits for the load busesshould be evaluated for economic operation. In this paper, the ranges of acceptable load power factors are portrayed as bandwidths of load power factor expressed as a function of load level. The load power factor limits are included and described into the OPF's objective function. The method Proposed is applied to IEEE 26 bus system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.160-161
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• 2011

우리나라는 냉방부하로 인해 여름철에 연중 전력소모량이 크게 증가한다. 이로 인해 전력설비의 여유도가 낮아져 전력계통의 취약성이 높아진다. 전기사업자는 송 변전설비 신설 및 보강, 발전설비 조기 준공을 통해 최대전력 발생에 대비한 준비를 한다. 전력거래소는 여름철을 기준으로 신규로 운영되는 송 변전설비 및 발전설비를 고려하여 최적의 전력계통 운영방안을 수립한다. 이때 수립된 전력계통 구성은 겨울철 운영방안 수립 전까지 우리나라 전력계통의 기본 틀이 된다. 본 논문은 2011년도 여름철 최대전력 발생에 대비하여 수립한 전력계통의 최적 운영방안을 제시한다. 주로 전년도와 비교하여 올해의 계통변화 내용 및 상정고장 발생에 대비한 전압안정도 및 과부하 해소대책을 다루고 있다.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.226-229
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• 2005

본 논문에서는 송전선로 도체의 경년열화(thermal deterioration)를 평가하기 위해 확률적 기법을 도입하였다. 선로의 경년열화를 나타내기 위해 선로의 장력(tensile strength) 감소를 계산하며 이는 해당 선로의 과거 전류 이력과 선로가 위치한 지역의 과거 기상데이터 및 부하량의 변화를 통해 산출한다 첫째로, 과거 데이터를 통해 확률분포를 구한 후 모든 데이터는 통계적으로 서로 간에 독립적이라는 가정 하에 Monte-Carlo Simulation을 수행하였다. 둘째로, 과거 데이터의 이력을 시간순서대로 추종하여 1시간 단위로 장력변화를 누적하는 순차적 계산(dynamic calculation)을 수행하였으며 그 결과를 MCS 기법과 비교하였다 주로 백분율로 표현하는 도체의 장력 감소분은 송전선로의 수명을 결정하는데 사용할 수 있는 중요한 지수이때, 계통계획에 있어서 유용한 기준으로 사용할 수 있을 것이다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.44-45
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• 2014

본 논문은 ITER의 플라즈마 제어를 위하여 자기적으로 결합된 초전도 PF 코일에 흐르는 전류를 제어하는 기법과 RTDS 실험결과를 분석하였다. MATLAB/SIMULINK를 이용하여 유도 결합된 4개의 초전도코일을 모델링하여 전류제어기법을 시뮬레이션하였으며, 실험은 RTDS를 이용하여 진행하였다. 각 부하전류가 전류 지령치를 추종할 때, 동시다발적으로 발생하는 상호 인덕턴스와 전류 극성변화의 영향을 MIMO(Multi Input Multi Output) 시스템 기반으로 하여 각 초전도코일의 전압변화 특성을 해석하였다. 시뮬레이션과 실험을 통해 MIMO 시스템 특성의 유도 결합된 초전도코일의 전류제어 특성을 검증하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.467-475
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• 2012

In this paper, a technical method of reducing torque load of exoskeleton device, with using of a gravity compensator based on a torsion bar, for human leg joints, is proposed. Design and structure analyses and also performance test were performed to estimate and to measure the characteristics of the torsion bar. On the basis of design and structure analysis, a new light and compact exoskeleton device has been developed. For the purpose of lightening and optimizing thickness of the links, FEM analysis has been performed.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.171-173
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• 1997

This study proposes a method for evaluating composite power system effective load duration curve(CMELDC) al load points. The concept of ELDC in power system planning is very useful and important in HLI as well as HLII. Effective load duration curve of composite power system can be obtained from convolution integral processing or both probability function of unarrival power and load duration curve at load points. The characteristics and effectiveness of this methodology arc illustrated by case studyings of simple system.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.282-283
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• 2008

This paper presents a overall study results for the Korea power system at yearly peak load time in 2008 summer period. The power system become more complex due to the gradual increase of power demand. We analyze the problems in power system operation, by the use of PSS/E(power flow, fault and transient stability study) and VSAT for voltage stability. The results of establishment of power system operating plan and countermeasure are described.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.209-211
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• 2002

This paper computes the regional, seasonal and hourly representative model of load power factor considering load characteristics of all 154/22.9 kV substations. An accurately computed representative model of load power factor is studied to present a precision improvement of power system analysis and the security of the system. The method to compute representative model of load utilizes the method of applicable moving average based on the method of flow average. The EMS data are used as the source to assess the load power factor.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1033-1035
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• 1998

This paper presents a new analytical method for assessing outage cost of composite power system with considering transmission system uncertainty. Composite power system ELDC(CMELDC) was developed and proposed from reliability evaluation of composite power system in order to analysis the outage cost on HLII. In this study, considering the characteristic of each load point, the CMELDC was used for outage cost assessment and reliability evaluation at each load point. The characteristics and effectiveness of this methodology are illustrated by the case study (IEEE-RTS 24Buses).

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.98-100
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• 2003

This paper presents the method for computing the power economic dispatch with an optimal power flow (OPF) computation algorithm, considering the power factor limits constraint. Efficient reactive power planning enhances economic operation as well as system security. Accordingly, an adequate level of power factor limits for the load buses should be evaluated for economic operation. The power factor limits are included and described into the OPF's objective function. The proposed method is applied to IEEE 26 buses system.