• Journal of Power Electronics
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• 제16권1호
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• pp.111-120
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• 2016

Generally, a single phase H-bridge converter feeding a single primary track is employed in conventional inductive power transfer systems. However, these systems may not be suitable for some high power applications due to the constraints of the semiconductor switches and the cost. To resolve this problem, a novel dual coupled primary tracks IPT system consisting of two high frequency resonant inverters feeding the tracks is presented in this paper. The primary tracks are wound around an E-shape ferrite core in parallel which enhances the magnetic flux around the tracks. The mutual inductance of the coupled tracks is utilized to achieve adjustable power sharing between the inverters by configuring the additional resonant capacitors. The total transfer power can be continuously regulated by altering the pulse width of the inverters' output voltage with the phase shift control approach. In addition, the system's efficiency and the control strategy are provided to analyze the characteristic of the proposed IPT system. An experimental setup with total power of 1.4kW is employed to verify the proposed system under power ratios of 1:1 and 1:2 with a transfer efficiency up to 88.7%. The results verify the performance of the proposed system.

• 전기학회논문지
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• 제65권5호
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• pp.760-768
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• 2016

Recently, as one of the policies for carbon free operation method of independent power system replacing diesel generator with renewable energy such as wind power and photovoltaic(PV) system has been presented. Therefore, this paper proposes an operation algorithm and modeling of independent power system by considering CVCF(constant voltage constant frequency) ESS(energy storage system) for constant frequency and voltage, LC(load control) ESS for demand and supply balancing and SVC(static var compensator) for reactive power compensation. From the simulation results based on the various operation scenario, it is confirmed that proposed operation algorithm and modeling may contribute stable operation and carbon free in independent power system.

• 전기학회논문지
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• 제65권5호
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• pp.711-717
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• 2016

Recently, fuel cell generation system with high energy efficiency and low CO2 emission is energetically interconnected with distribution power system. Especially, MCFC(molten carbonate fuel cell) operating at high temperature conditions is commercialized and installed as a form of large scale power generation system. However, it is reported that power system disturbances such as harmonic distortion, surge phenomenon, unbalance current, EMI(Electromagnetic Interference), EMC (Electromagnetic Compatibility) and so on, have caused several problems including malfunction of protection device and damage of control devices in the large scale FCGS(Fuel Cell Generation System). Under these circumstances, this paper proposes countermeasure algorithms to prevent power system disturbances based on the modelling of PSCAD/EMTDC and P-SIM software. From the simulation results, it is confirmed that proposed algorithms are useful method for the stable operation of a large scale FCGS.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 추계학술발표논문집
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• pp.834-836
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• 2009

The authors have been discussed the optimal voltage regulation method and on-line real time method using artificial neural networks in the distribution system interconnected with Distributed Generation and Storage(DSG) systems. However, these methods have difficulty in dealing with the random load variations and operation characteristics of a number of DSG systems. To overcome these problems, this paper shows the basic concepts of smart grid system which is considered as one of the power delivery system in the near future and presents an evaluation method on the impacts of customer voltages by the operation of smart grid system. The smart grid system can change the system configuration in a flexible manner by using the static switches and offer the different power qualities in power services through the power quality control centers.

• 전기학회논문지
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• 제67권2호
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• pp.186-193
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• 2018

Generally, it is difficult to operate moveable-weir due to the expensive cost of the facility management and manpower consumption. Also, when it is installed in a remote area, there is a problem that the cost of connection for power system increases as well as the operating cost. Therefore, this paper proposes an optimal design algorithm to replace an existing power system with an Eco-friendly power supply system for movable-weir using PCS, PV module and lithium-ion battery. Also, this paper proposes a modeling method of environment-friendly power supply system for a movable-weir based on the PSCAD/EMTDC S/W and implements 5[kW] prototype environment-friendly power supply system. As a result of the performance test using the S/W modeling and the prototype system, it is confirmed that the proposed system has stable characteristics in the independent operation mode and the interconnection mode.

• Journal of Power Electronics
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• 제19권5호
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• pp.1087-1098
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• 2019

In this paper, a detuning factor (DeFac) method is proposed to design the key parameters for optimizing the transfer power and efficiency of an Inductively Coupled Power Transfer (ICPT) system with primary-secondary side compensation. Depending on the robustness of the system, the DeFac method can guarantee the stability of the transfer power and efficiency of an ICPT system within a certain range of resistive-capacitive or resistive-inductive loads. A MATLAB-Simulink model of a ICPT system was built to assess the system's main evaluation criteria, namely its maximum power ratio (PR) and efficiency, in terms of different approaches. In addition, a magnetic field simulation model was built using Ansoft to specify the leakage flux and current density. Simulation results show that both the maximum PR and efficiency of the ICPT system can reach almost 70% despite the severe detuning imposed by the DeFac method. The system also exhibited low levels of leakage flux and a high current density. Experimental results confirmed the validity and feasibility of an ICPT system using DeFac-designed parameters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.41-43
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• 2001

This paper presents a Web-based educational tool for Power System Engineering, especially for power engineers. This tool has Web-oriented educational courses for power system education. The Web-based learning has become more popular year by year in the various fields[1-2]. The proposed educational tool provides some courses such as power system introduction Course, KEPCO's system introduction Course, Power system devices Course, Power Flow Course, OPF Course, ELD Course, Stability Analysis Course, Fault analysis Course, Voltage & Frequency control Course, and power system planning & operation Course. Finally, it will be scheduled to install for the education tool of the power system engineering for KEPS[3].

• 전력전자학회논문지
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• 제4권1호
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• pp.35-42
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• 1999

본 논문에서는 전력계통 고장해석 교육 및 훈련을 위한 대화식 컴퓨터 소프트웨어를 개발하였다. 개발된 소프트웨어는 고장해석에 대한 손쉬운 이해 및 소프트웨어의 사용자 편의를 증가시키기 위하여 윈도우, 그래픽 아이콘, 다양한 그래픽 출력 기능 등을 포함하고 있다. 특히, 대화식 기능을 부가함으로서 사용자가 다양한 사고 조건에서 고장해석을 모의할 수 있도록 하였다. 이러한 기능을 통하여 사용자는 전력계통 고장해석의 기본 개념 및 사고로 인한 계통의 영향에 대한 이해를 손쉽게 습득할 수 있다. 제안된 소프트웨어는 16모선 전력계통을 통하여 사례연구를 수행함으로 전력계통 고장해석의 교육 및 훈련에 유용한 기능들을 갖추고 있음을 확인하였다.

• Journal of Electrical Engineering and Technology
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• 제1권1호
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• pp.23-27
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• 2006

In this paper a Hybrid Real Time HVDC Simulator fur both operator Training and Researching in the Cheju-Haenam HVDC System is proposed and its performance is studied by means of RTDS (Real Time Digital Simulator), EMTDC (Electro-Magnetic Transients system for DC), PSS/E (Power System Simulator for Engineering), and experienced scenarios. The objective of this paper is to represent the strategy in development for KEPCO's hybrid HVDC simulator for the Cheju-Haenam HVDC system. This simulator consists of two DC stations, DC cables, external digital/analog controllers, monitoring systems and control desk for education, and AC networks. Its suitability for operator's education is tested during startup/shutdown and normal state operations. Dynamic performances of it are also verified.

• 한국항행학회논문지
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• 제17권6호
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• pp.609-615
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• 2013

어떤 선박에서도 마찬가지로 적정한 전력의 공급은 매우 중요하며, 육지와 거리가 먼 대양 운항 선박에서는 특히 더욱 중요하다. 이와 같이 운항 중인 선박의 전력 공급 시스템의 효율성과 경제성 측면의 문제를 해결하기 위해서 본 논문에서는 선박에서의 전력공급을 지능적으로 제어하는 전력관리 시스템을 제안한다. 본 설계에서의 전력관리 시스템은 부하전력 감지 시스템, 발전기 제어 시스템, 그리고 전력 모니터링 시스템으로 각각 구성된다. 부하전력 감지 시스템에서는 CT 및 PT 센서를 이용하여 전류와 전력량을 측정하며, 그리고 발전기 제어 시스템에서는 여러 가지 다양한 센서로 부터의 취합정보를 이용하여 주/부 발전기를 On/Off 하게 된다. 마지막으로 모니터링 시스템은 부하 전력 감지 시스템과 발전기 관리 시스템에서 수집된 정보를 사용자가 한눈에 알아볼 수 있게 상태 정보를 출력한다. 본 논문에서 구현된 전력관리 시스템은 실시간 실험을 통해서 설계된 바와 같이 잘 작동하는 것을 확인하였으며, 그리고 공인 인증기관으로부터 KSCIEC61892-1:2012 및 KSCIEC60950-1:2008 인증을 획득하였다.