• 전기학회논문지
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• 제67권1호
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• pp.8-15
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• 2018

New methodology for probabilistic reliability based grid expansion planning of HVDC in power system including Wind Turbine Generators(WTG) is developed in this paper. This problem is focused on scenario based optimal selection technique to decide best connection bus of new transmission lines of HVDC in view point of adequacy reliability in power system including WTG. This requires two kinds of modeling and simulation for reliability evaluation. One is how is reliability evaluation model and simulation of WTG. Another is to develop a failure model of HVDC. First, reliability evaluation of power system including WTG needs multi-state simulation methodology because of intermittent characteristics of wind speed and nonlinear generation curve of WTG. Reliability methodology of power system including WTG has already been developed with considering multi-state simulation over the years in the world. The multi-state model already developed by authors is used for WTG reliability simulation in this study. Second, the power system including HVDC includes AC/DC converter and DC/AC inverter substation. The substation is composed of a lot of thyristor devices, in which devices have possibility of failure occurrence in potential. Failure model of AC/DC converter and DC/AC inverter substation in order to simulate HVDC reliability is newly proposed in this paper. Furthermore, this problem should be formulated in hierarchical level II(HLII) reliability evaluation because of best bus choice problem for connecting new HVDC and transmission lines consideration. HLII reliability simulation technique is not simple but difficult and complex. CmRel program, which is adequacy reliability evaluation program developed by authors, is extended and developed for this study. Using proposed method, new HVDC connected bus point is able to be decided at best reliability level successfully. Methodology proposed in this paper is applied to small sized model power system.

• 전기학회논문지
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• 제67권8호
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• pp.994-1001
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• 2018

In this paper, to studied about future power system construction using PSS / E-Python API. Python-based future system automatical construction methods and modeling of renewable sources. it confirmed the stability of the powert system for each renewable area by calculating the weighted short circuit ratio (WSCR) index. it calculated the short circuit ratio (SCR) and selected the transmission line linkage scenario to improve the stability of vulnerable areas. it confirmed the WSCR index improvement through the selected transmission line linkage of scenario, and analyzed the stability of the renewable power system applying the scenario. It describes Facts and Shunt devices adjustment for the load flow convergence. It describes the stable methed of the bus voltage through the transformer Ratio Tap adjustment. By performing PSS/E ASCC using the Python it was performed three-phase short circuit fault capacity analysis, it is confirmed whether excess of the fault current circuit breaker capacity. In order to contingency accident analysis, it have described the generation of one or two line list of each areas using the Python. The list is used to contingency analysis and describe the soluted of the transmission line overload through comparison before and after adding the scenario line.

• KIEE International Transactions on Power Engineering
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• 제5A권1호
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• pp.9-15
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• 2005

In the operation of distribution systems, DGs (Distributed Generations) are installed as an alternative to extension and the establishment of substations, transmission and distribution lines according to the increasing power demand. In the operation planning of DGs, determining optimal capacity and allocation achieves economical profitability and improves the reliability of power distribution systems. This paper proposes a determining method for the optimal number, size and allocation of DGs in order to minimize the operation costs of distribution systems. Capacity and allocation of DGs for economical operation planning duration are determined to minimize total cost composed with power buying cost, operation cost of DGs, loss cost and outage cost using the GA (Genetic Algorithm).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.292-294
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• 1998

It is very important for electric utility to expand generating facilities and transmission equipments in accordance with the increase of electricity demand. Regional electricity demand forecasting is among the most important step for long-term investment and power supply planning. The main objectives of this paper are to develop the methodologies for forecasting regional load demand. The Model consists of four models, regional economy, regional electricity energy demand, areal electricity energy demand. and areal peak load demand. This paper mainly suggests regional electricity energy demand model and areal peak load demand. A case study is also presented.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.33-38
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• 2010

As for an oil hydraulic vane pump of vehicle hydraulic systems, the highest of planning technique required by the acquisition of optimum profile data which can be available to predict noises and vibrations. Pressure pulsation may result in considerable vibration and noise of pump component as well as cavitation in hydraulic system. The influences of the discharge pressure and rotating speed of the vane on the dynamic pressure in chamber surrounding a vane have been investigated. It is very important to predict pressure pulsation in vane pump. This paper presents analysis of technique of vane pump for automatic transmission. The predicted result using AMESim model were good agreement with the experimentally obtained results.

• 대한전기학회논문지:전력기술부문A
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• 제55권3호
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• pp.123-127
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• 2006

The recent movement to deregulated and competitive electricity market requires new concepts in applying dispatch algorithms to system operation and planning. As power systems tend to be operated more closely to their ultimate ratings, the role of Contingency Constrained Optimal Power Flow is changed and the importance for security enhancement will be more increased in the new and competitive electricity market. This paper presents a contingency constrained optimal power flow (CCOPF) algorithm. The proposed algorithm maintains the nodal voltage levels and transmission line's power flow within the specified limits before and after a contingency. A case study demonstrates the proposed algorithm with the IEEE-14RTS under N-1 contingency criterion.

• 한국의학물리학회지:의학물리
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• 제28권4호
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• pp.197-206
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• 2017

We develop guidelines for the quality assurance of radiation treatment planning systems (TPS) by comparing and reviewing recommendations from major countries and organizations, as well as by analyzing the AAPM, ESTRO, and IAEA TPS quality assurance guidelines. We establish quality assurance items for acceptance testing, commissioning, periodic testing, system management, and security, and propose methods to perform each item within acceptable standards. Acceptance includes tests of hardware and network environments, data transmission, software, and benchmarking as specified by the system supplier, and apply the IAEA classification criteria. Commissioning includes dosimetric and non-dosimetric items for assessing TPS performance by applying the AAPM classification criteria and the latest technical items from the IAEA. Periodic quality assurance tests include daily, weekly, monthly, yearly, and occasional items by applying the AAPM classification criteria. System management and security items include the state and network connectivity of TPS, periodic data backup, and data access security. The guidelines for TPS quality assurance proposed in this study will help to improve the safety and quality of radiotherapy by preventing incidents related to radiotherapy.

• 전기학회논문지
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• 제58권3호
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• pp.437-443
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• 2009

In recent years, electric power systems have been experiencing a rapid change due to the increasing electricity market. For the effective use of power system under the deregulated environment, it is important to make a fast and accurate calculation of the maximum available transfer capability (ATC) from a supply point to a demand point. In this paper, the purpose of this research is to calculate ATC fast and accurately for securing the stability of system and raising the efficiency as a result of anticipating transmission congestion according to transmission open access progressed in the future under the regulated environment of electricity market. In this paper, a study utilized a relation of the potential energy and energy function by which calculated CCT and then utilized a relation of PEBS for transient stability ATC calculation. In this paper, ATC was calculated as RPF and Energy Function method and calculation results of each method was compared. Contingence ranking method decided the weak bus by the Eigenvalues of Jacobian matrix and overloading branches by PI-index. As a result, a study proved the fast and accurate ATC calculation method considering transient stability suggested in this paper. Through the case study using New England 39 bus system, it is confirmed that the proposed method can be used for real time operation and the planning of electric market.

• 전기학회논문지
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• 제60권6호
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• pp.1079-1085
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• 2011

To supply electrical power with high quality, the power system must be optimized in many ways such as planning, control and management. In order to optimize the power system, the analysis of the power system is necessary. The elements of the power system require an accurate model to analysis of the power system. The components of the power systems such as generators, transformers and transmission lines have been studied and researched a lot in their modeling and very sophisticated models have been proposed. However, in case of load in-depth studies on the exact model are required. In this paper, measurement-based load modeling method using real-time measured data is proposed in various methods to reflect the characteristics of the load. To prove the validity of the proposed method, PSCAD/EMTDC program is used to configure the power system and measurement data according to the various failures are used to study on load modeling.

• 디지털콘텐츠학회 논문지
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• 제16권6호
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• pp.871-882
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• 2015

AIS-ASM은 AIS의 고유 기능인 선박의 위치 정보 외에 다양한 해양안전정보를 제공하기 위한 연구 중 하나로, 2004년부터 관련 규정을 정비하여 진행 중이다. 하지만 AIS 메시지 사용량 증가에 따라 기존 AIS 채널에서 ASM을 사용하는 것은 기존의 선박위치정보 전송 등의 안전메시지 처리 부분에 영향을 줄 것으로 보고된 바 있고, 기존 AIS의 낮은 통신속도로는 원활한 MSP 서비스가 어렵기 때문에 ITU-R은 VHF 대역을 이용하는 해상디지털 무선통신 권고서를 제정하고 개정작업을 진행하였다. 본 연구는 차세대 해상디지털 통신 기술인 ASM2.0을 활용하여 여객선의 출항에서 입항까지 안전항해를 위해 필요한 국내 여객선 선장의 의무보고 내용을 조사하고 업무 부하를 줄이기 위해 자동화 할 수 있는 부분을 자동화하는데 목적이 있으며, 국내 여객선 운항 관련 법규를 조사하여 상호 교환해야 하는 정보를 도출하고 국제적으로 사용하고 있는 AIS-ASM 메시지 분석을 통해 ASM2.0에서 활용하기 위한 신규 프로토콜을 설계하고 프로토타입을 구현하였다.