• Convergence Security Journal
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• v.18 no.5_1
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• pp.93-98
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• 2018

Korea Hydro & Nuclear Power Co., Ltd., Korea Electric Power Corporation, and Korea South-East Power Corporation are major infrastructure facilities of power supplying countries. If a malicious hacking attack occurs, the damage is beyond the imagination. In fact, Korea Hydro & Nuclear Power has been subjected to a hacking attack, causing internal information to leak and causing social big problems. In this paper, we propose a strategy and countermeasures for stabilization of various power generation control systems by analyzing the environment and the current status of power generation control system for convergence security research, which is becoming a hot issue. We propose a method to normalize and integrate data types from various physical security systems (facilities), IT security systems, access control systems, to control the whole system through convergence authentication, and to detect risks through fusion control.

• 한국초전도학회:학술대회논문집
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• v.15
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• pp.64-64
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• 2005

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1637-1639
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• 2014

In the past, the analog protection relays have been widely used for the safety-related systems in the nuclear power plants due to their stability and reliability. Meanwhile, as the high performance digital system has been developed, the digital systems have been adopted in the non-safety systems. However, since the digital systems currently used in the non-safety systems were not developed according to Q-class standard, Commercial Grade Item Dedication (CGID) procedure should be performed in order to apply them to the safety-related system. The purpose of this paper is to describe the CGID procedure including the analysis of the hardware architecture as well as the software embedded in protective relay to apply to the emergency diesel generator in the nuclear power plant. The entire CGID procedure was performed strictly according to the international standard and regulations.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.5
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• pp.299-310
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• 2009

Fuel cells are expected to be promising future power sources in both aspects of thermal efficiency and environmental friendliness. Accordingly, worldwide research and development efforts have been enormously increasing recently in various applications such as power plants, transportation and portable power sources. Among others, high temperature fuel cells, such as solid oxide fuel cells and molten carbonate fuel cells, are suitable for electric power plants. Moreover, their high operating temperature is quite appropriate to construct further advanced integrated systems. This paper reviews recent literatures on research and development of integrated power generation systems based on high temperature fuel cells. Research and development efforts are summarized in the area of fuel cell/ gas turbine hybrid systems, application of carbon capture technology to fuel cell systems, integration of coal gasification with fuel cells, and the use of alternative fuels.

• Journal of Power Electronics
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• v.16 no.2
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• pp.553-563
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• 2016

This paper presents a digital hardware implementation of a real-time simulator for a multiphase drive using a field-programmable gate array (FPGA) device. The simulator was developed with a modular and hierarchical design using very high-speed integrated circuit hardware description language (VHDL). Hence, this simulator is flexible and portable. A state-space representation model suitable for FPGA implementations was proposed for a dual three-phase induction machine (DTPIM). The simulator also models a two-level 12-pulse insulated-gate bipolar transistor (IGBT)-based voltage-source converter (VSC), a pulse-width modulation scheme, and a measurement system. Real-time simulation outputs (stator currents and rotor speed) were validated under steady-state and transient conditions using as reference an experimental test bench based on a DTPIM with 15 kW-rated power. The accuracy of the proposed digital hardware implementation was evaluated according to the simulation and experimental results. Finally, statistical performance parameters were provided to analyze the efficiency of the proposed DTPIM hardware implementation method.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.2
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• pp.74-91
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• 2023

This study provides an in-depth comparison and analysis of various risk assessment models widely used in modern industries, and proposes the most suitable model for risk assessment of offshore wind power in Korea. The assessment models were selected by considering various factors such as the purpose of risk assessment, stakeholder requirements, and characteristics of offshore wind power. We also emphasized the importance of using different risk assessment models in combination in situations of high uncertainty. To systematize the combination of risk assessment models, we used systems engineering which is effective to develop a new system. Systems engineering was used to define the complete, traceable functions from site requirements, and model-based systems engineering was used to manage the design information from requirements to detailed functions in a single model. The developed risk assessment module provide automatic conversion between risk assessment models to enable risk assessment suitable for offshore wind power. The functionality and usability of the offshore wind risk assessment module were verified by the evaluation of three wind power experts.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.187-188
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• 2011

본 논문은 SMPS 및 가전기기와 휴대 전자기기 등에서 전원회로로 폭넓게 사용되고 있는 플라이백 컨버터의 트랜스포머를 기존의 샌드위치권선 방식이 아닌 동축권선 방식을 적용하여 기존의 샌드위치권선 방식보다 우수한 1,2차 커플링을 지니는 트랜스포머를 제안한다. 제안된 트랜스포머를 적용한 컨버터는 기존의 컨버터에 비하여 동일한 조건에서 보다 우수한 효율을 나타내고 있다. 제안된 컨버터용 트랜스포머의 구조 및 커플링을 설명하고 커플링계수를 비교 한 후 34[W]급 프로토 타입을 이용하여 검증하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.432-437
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• 1998

Power systems have uncertain dynamics due to a variety of effects such as lightning, severe storms and equipment failures. The variation of the effective reactance of a transmission line due to a fault is an example of uncertainty in power system dynamics. Hence, a robust controller to cope with these uncertainties is needed. Recently fuzzy controllers have become quite popular for robust control due to its capability of dealing with unstructured uncertainty. Thus in this paper we design an adaptive fuzzy controller using an input-output linearization approach for the transient stabilization and voltage regulation of a power system under a sudden fault. Simulation results show that satisfactory performance is achieved by the proposed controller.

• Journal of electromagnetic engineering and science
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• v.10 no.2
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• pp.50-55
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• 2010

Orthogonal Frequency Division Multiplexing(OFDM) dual-hop systems can take full advantages of the techniques of both multi-hop communication and OFDM. To achievethis end, we propose a joint subcarrier matching, power allocation and bit loading algorithm operating under a total power constraint and the same Bit Error Rate(BER) threshold over all subcarriers. Simulation results demonstrated system throughput improvement compared to single-hop systems and dual-hop systems with different bit loading algorithms for each relay position, power constraint, and required BER.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.158-159
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• 2011

최근 발표된 제5차 전력수급계획에 의하면 제주도에 3번째 HVDC 연계선 설치가 계획되고 있다. 이전까지 설치된 2개의 HVDC는 LCC(전류형) HVDC로써 안정적이고 우수한 성능으로 제주지역의 전력 수급에 기여를 했지만 전압 불안정 문제를 초래할 가능성을 가지고 있다. 따라서 3번째 HVDC는 VSC(전압형)으로 설치하는 것을 고려해야 한다. VSC HVDC는 유무효 전력이 동시에 제어가 가능하다는 장점이 있으나 비싼 가격과 높은 변환 손실, 그리고 작은 용량으로 제한적인 용도로만 사용되어 왔다. 그러나 최근 Multi-Level Converter 기술이 적용되면서 이전의 많은 문제들이 해결되었다. 이 논문에서는 VSC HVDC의 최신 동향에 대해서 간략히 소개하고 제주 전력망에 VSC HVDC가 설치되었을 때의 효과에 대해서 논의하고자 한다.