• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.9-14
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• 2022

Social infrastructure facilities such as production, transportation, gas and electricity facilities may experience poor performance depending on time, load, temperature, etc. and may require maintenance, repair and management as they are used. In particular, in the case of transformers, the process of managing them for the purpose of preventing them from failing is necessary because a failure can cause enormous social damage. The management of transformers should consider both technical and economic aspects and strategic aspects at the same time. Thus, it applies the Asset Management concept, which is widely used in the financial industry as an advanced method of transformer management techniques worldwide. In this paper, the operation and power outage data were secured for the asset management of the transformer for distribution, and the asset status was analyzed. Analysis of asset status using actual operation and power outage data is essential for assessing the statistical life and failure rate of the facility. Through this paper, the status of transformer assets for arbitrary A group distribution was analyzed, and the end of life and replacement life were calculated.

• 한국콘텐츠학회논문지
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• 제8권1호
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• pp.300-307
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• 2008

전력관리는 전력상태 전환과 시스템 부하 (workload)에 의존성이 있다. 시스템 모델은 전력상태 전환과 시스템 큐에 대한 추계적 모델들로 구성된다. 본 논문에서는 다양한 전력관리 기법을 위한 추계적 모델들을 개발한다. 추계적 프로세스에 기반한 전력관리 모델은 시스템 큐와 다양한 모델링 기능을 표현할 수 있는 페트리 네트의 확장형인 SRN (Stochastic Reward Nets)을 이용하여 개발된다. 적응적 타임아웃기반 전력관리 SRN 모델을 개발하고 기존 전력관리 기법인 greedy, N-Policy 기법과 전력소모 및 성능비교를 수행한다.

• 대한전기학회논문지:전력기술부문A
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• 제53권5호
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• pp.257-265
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• 2004

The complex documentation involved in power system analysis software require a well-defined and friendly database system. We have developed an object-oriented database management system for power system analysis, and have described load flow analysis and transient stability analysis using object-oriented database(OODB). Database management systems are widely used and achieve high reliability of data management in the engineering fields. However relational database system have shortcomings in application to power system analysis. ill relational database, the data model is too simple for modeling complex data and database languages are very different from programming languages. Object-oriented techniques are sufficiently powerful to support data-modeling requirements of GUI applications. The GUI is implemented using C++ on a MS windows platform. The OODB supports data modeling requirements of GUI applications and the performance is well acceptable for Gill applications.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2211-2220
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• 2015

This paper analyzes multiple active management (AM) techniques of active distribution network (ADN), and proposes an optimal coordination model of intermittent distributed generation (IDG) accommodation considering the timing characteristic of load and IDG. The objective of the model is to maximize the daily amount of IDG accommodation under the uncertainties of IDG and load. Various active management techniques such as IDG curtailment, on-load tap changer (OLTC) tap adjusting, voltage regulator (VR) tap adjusting, shunt capacitors compensation and so on are fully considered. Genetic algorithm and Primal-Dual Interior Point Method (PDIPM) is used for the model solving. Point estimate method is used to simulate the uncertainties. Different scenarios are selected for the IDG accommodation capability investigation under different active management schemes. Finally a modified IEEE 123 case is used to testify the proposed accommodation model, the results show that the active management can largely increase the IDG accommodation and penetration.

• 산업경영시스템학회지
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• 제46권2호
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• pp.133-142
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• 2023

The large process plant is currently implementing predictive maintenance technology to transition from the traditional Time-Based Maintenance (TBM) approach to the Condition-Based Maintenance (CBM) approach in order to improve equipment maintenance and productivity. The traditional techniques for predictive maintenance involved managing upper/lower thresholds (Set-Point) of equipment signals or identifying anomalies through control charts. Recently, with the development of techniques for big analysis, machine learning-based AAKR (Auto-Associative Kernel Regression) and deep learning-based VAE (Variation Auto-Encoder) techniques are being actively applied for predictive maintenance. However, this predictive maintenance techniques is only effective during steady-state operation of plant equipment, and it is difficult to apply them during start-up and shutdown periods when rises or falls. In addition, unlike processes such as nuclear and thermal power plants, which operate for hundreds of days after a single start-up, because the pumped power plant involves repeated start-ups and shutdowns 4-5 times a day, it is needed the prediction and alarm algorithm suitable for its characteristics. In this study, we aim to propose an approach to apply the optimal predictive alarm algorithm that is suitable for the characteristics of Pumped Storage Power Plant(PSPP) facilities to the system by analyzing the predictive maintenance techniques used in existing nuclear and coal power plants.

• 한국콘텐츠학회논문지
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• 제8권9호
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• pp.42-54
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• 2008

오늘날의 내장형 시스템은 군사 무기체계, 로봇, 인공위성 등과 같이 전통적인 내장형 시스템과 휴대폰, PMP(Portable Multimedia Player), PDAs(Personal Digital Assistants)와 같이 통신과 멀티미디어 기기가 결합된 디지털 컨버전스 시스템에서 먹는 PC, 웨어러블 컴퓨터와 같은 차세대 PC 개념으로 진화하고 있다. 차세대 PC는 문서작성 인터넷 검색 데이터 관리 등에서 사용되었던 기존의 PC에서 분기된 네트워크 기반의 인간중심 디지털 정보기기이다. 웨어러블 컴퓨터는 극히 전력과 메모리 제한적인 시스템으로, 구성 하드웨어의 제약 사항을 극복하고 사용자 서비스의 QoS를 제공하기 위해 초소형이면서 저전력 기능을 갖춘 실시간 운영체제를 사용해야만 한다. 본 논문에서는 웨어러블 컴퓨터를 위한 저전력 실시간 운영체제 eRTOS를 설계 및 구현하였다. 본 논문에서 구현한 eRTOS는 18KB의 풋프린트(footprint)로 동적 전력 관리 기법(Dynamic Power Management)과 장치 전력 관리 기법(Device Power Management)의 저전력 기법이 구현되어 있다. 웨어러블 컴퓨터의 응용프로그램을 실험하여 47%의 전력 소모 감축효과를 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1434-1439
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• 2011

The purpose of this study is based on the optimize the system life cycle cost apply to the advanced systems engineering techniques consideration thought to the system life cycle for the power system which is the one of the major component of the light rail transit system. Generally, the systems engineering techniques apply to the LRT's power systems are not optimize the whole life cycle cost of the power systems because systems engineering management activities are concentrate in performing the key-technology oriented at the construction stage of the dedicated power systems for light rail transit. Through this study, All the stakeholders can be utilize a this advanced systems engineering techniques which is fully considered the life cycle cost through the considering in whole system life cycle (such as concept, design, operation, maintenance and dispose stage as well as construction stage) and adopted by KSX ISO/IEC 15288 system life cycle processes.

• 대한안전경영과학회지
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• 제24권2호
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• pp.67-76
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• 2022

Power generation construction projects involving large amounts of capital can affect the survival of a company along with huge economic losses in the event of a business failure. In general, private companies are organizations with challenging risk taking tendencies while public companies have a risk averse tendency to avoid risk, so these differences in organizational tendencies make it difficult to respond to risk. In particular, public companies are more likely to fail than private companies because they choose the contradiction of risk picking to enter overseas markets with high uncertainty despite their tendency to risk averse due to the nature of the organization. Therefore, these organizations need risk management techniques that reflect a risk-averse strategy. Accordingly, this paper analyzes the risk management research papers of the existing overseas development EPC business in order to find the risk management techniques related to the organizational tendencies of public companies and proposes "establishing a performance audit system for risk management of the organizational tendencies of public companies" as a way to extract the risk factors through the examples of overseas development projects of public companies and to manage the organizational tendencies of public companies that affect them.

• 한국콘텐츠학회논문지
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• 제7권6호
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• pp.69-78
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• 2007

오늘날의 내장형 이동 시스템은 MP3플레이어나 디지털 캠코더와 같이 하나의 기능만을 지원했던 단일 응용프로그램 시스템에서 PMP(Portable Multimedia Player), PDA(Personal Digital Assistants)와 같이 MPEG, W3플레이어, 전자사전, DMB(Digital Multimedia Broadcasting), 게임, 통신 기능 등을 모두 포함하는 하나의 디지털 컨버전스 기기로 변화해가고 있다. 이러한 변화는 CPU 성능 향상과 메모리, 저장장치의 증가, LCD의 크기 증가와 같은 하드웨어적인 요구사항의 증가로 이어졌고, 이로 인해 단말기에서 소모하는 전력이 그에 비례하여 증가하였다. 소모 전력의 증가에 따른 배터리 용량의 증가는 더딘 상황이며, 이를 해결하기 위해 소프트웨어적으로 소모 전력을 감축시키는 연구들이 많이 진행되고 있다. 본 논문에서는 소모 전력 감축 기법이 적용된 실시간 운영체제 UbiFOSTM을 ARM9계열의 MBA2440에 탑재하였다. 전력 감축 기법으로 시스템 작업량 관찰에 기반한 동적 전력 관리 기법과 장치 전력 관리기법을 적용하였다. 본 논문의 저전력 기법을 통해 작업량에 따라 24% 이상의 소모 전력 감축효과가 있음을 확인하였다.

• 전기학회논문지
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• 제65권12호
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• pp.1965-1970
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• 2016

This paper studies generator rescheduling technique for congestion management in power system with wind farms. The proposed technique is formulated to minimize the rescheduling cost of conventional and wind generators to alleviate congestion subject to operational line overloading. The generator rescheduling method has been used with incorporation of wind farms in the power system. The locations of wind farms are selected based upon power transfer distribution factor (PTDF). Because all generators in the system do not need to participate in congestion management, the rescheduling has been done by generator selection based on the proposed generator sensitivity factor (GSF). The selected generators have been rescheduled using linear programming(LP) optimization techniques to alleviate transmission congestion. The effectiveness of the proposed methodology has been analyzed on IEEE 14-bus systems.