• Transactions on Electrical and Electronic Materials
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• 제11권5호
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• pp.197-201
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• 2010

As the world population increases and technology advances, the energy consumption and need for more energy increase. Communities and governments regularly address these needs and set policies for future energy generation and uses. This paper reviews current energy policies of the USA and the current trends in research and development efforts, for sustainable and renewable energy sources. Furthermore, the recent topic of IEEE's Smart Grid initiatives is discussed, and its role in the dielectrics and electrical insulation research is presented.

• The Transactions of the Korean Institute of Power Electronics
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• 제18권2호
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• pp.161-168
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• 2013

This paper presents an algorithm of a compensation of the grid current distortion caused by the grid voltage unbalance and distortion in 3-phase bi-directional DC to AC inverter. Usually 3-phase grid system has unbalance and distortion because of connecting 1-phase and non-linear load with 3-phase load using same input node. Controlling 3-phase inverter by general method under the unbalanced and distorted grid voltage, the grid current has distortion. This distortion of the grid current cause the grid voltage distortion again. So, it need to control the grid current balanced and non-distorted, even the grid voltage gets unbalanced and distorted. There are some complex method to compensate the gird current distortion. it suggest simple method to solve the problem. Simulation and experiment is used to validate the proposed algorithm.

• Proceedings of the KIEE Conference
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.57-59
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• 2007

When onsite power is supplied from grid due to electrical transient in NPP, the effect of the nuclear plant risk will be increased by the change of grid performance. It is important to analyze the effect for bus voltage of onsite according to grid reliability. Therefore, we analytically accomplish the effect for bus voltage by electrical transient in KSNP.

• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.698-704
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• 2012

This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제62권7호
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• pp.898-904
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• 2013

In order to minimize the damage from power outage, power system should be restored quickly. In this paper, a procedure for the restoration of microgrid is proposed. After elimination of the causes of power outage, a black start algorithm is executed by considering the characteristics of distributed generation control. After all resources have been recovered to the normal state, a grid reconnecting algorithm for stable operation in grid-connected mode is performed. In order to verify the proposed algorithm, low voltage microgrid is simulated using PSCAD/EMTDC.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1296-1304
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• 2013

This study performed an analysis on power demand reduction effects exhibited by demand response programs, which are advanced from traditional demand-side management programs, in the smart grid environment. The target demand response systems for the analysis included incentive-based load control systems (2 month-ahead demand control system, 1~5 days ahead demand control system, and demand bidding system), which are currently implemented in Korea, and price-based demand response systems (mainly critical peak pricing system or real-time pricing system, currently not implemented, but representative demand response systems). Firstly, the status of the above systems at home and abroad was briefly examined. Next, energy saving effects and peak demand reduction effects of implementing the critical peak or real-time pricing systems, which are price-based demand response systems, and the existing incentive-based load control systems were estimated.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2385-2391
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• 2018

This paper is devoted to detecting decomposition characteristics of Iodotrifluoromethane ($CF_3I$) under alternating current (AC) discharges or load current interruptions. The decomposition products are measured utilizing chromatography-mass spectroscopy. It is found that less than 1% $CF_3I$ gas decomposed after several interruptions at load current of 200 A or hundred times of AC discharges. However, under interruptions at a current of 400 A, more than 95% $CF_3I$ gas decomposed into carbon tetrafluoride ($CF_4$) and hexafluoroethane ($C_2F_6$). The equilibrium compositions based on Gibbs free energy minimization of $CF_3I$ was calculated to explain the decomposition mechanism.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.2193-2194
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• 2006

This paper presents the results of a grid-connected photovoltaic (PV) system modeling that contain incremental conductance MPPT(Maximum Power Point Tracking) controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(THD) and total demand distortion(TDD). The measured data the PV array modeling of PSCAD/EMTDC in Cheongwadae, Seoul, Korea is used in the paper.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.561-562
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• 2006

This paper presents the results of a grid-connected photovoltaic(PV) system modeling that contain incremental conductance MPPT(Maximum Power Point Tracking) controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power Quality, i.e. voltage drop, total harmonic distortion(THD) and total demand distortion(TDD) The measured data the PV array modeling of PSCAD/EMTDC in Cheongwadae, Seoul, Korea is used in the paper.

• Journal of Power Electronics
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• 제17권5호
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• pp.1278-1287
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• 2017

Inverters are widely used in distributed power generation and other applications. However, their lack of inertia and variable impedance may cause system instability and power transfer inaccuracy. This paper proposes a control scheme for a single phase voltage-controlled inverter with some grid-friendly characteristics. The proposed control algorithm enables the inverter to function as a voltage source with an inner output impedance in both the islanded and grid-connected modes. Virtual inertia and rotor equations are embedded in the PLL part. Thus, the frequency stability can remain. The inner output impedance can be adjusted freely, which helps to accurately decouple and transmit the output active and reactive power. The proposed inverter operates like a traditional synchronous generator. Simulations and experiments are designed and carried out to verify the proposed control strategy.