• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.123-126
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• 2005

Recently, because of the depletion of fossil fuels and the environmental pollution by using fossil fuels and harmfulness of atomic power plants. the interests concerning new and renewable energy resources are rising increasingly. And of all new and renewable energy sources the PV generation systems are recognized as the most useful and desirable renewable energy source in allowance for installation conditions. In this development, the 3kWp photovoltaic power generation system is realized to verify the performance of the 3kWp PCS developed by Hyundai Heavy Industries Co. (HHI). The photovoltaic array used in this system is composed of 60 modules of 50Wp capacity. The developed system is tested as procedures and items of test regulation recognized by governmen and the experimental results show the excellent electrical characteristics. Now, the 3kWp PCS developed is installed in the PV model house built in HHI plant and is being tested for practical use commercialization.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.513-521
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• 2017

Robust optimal operation of a microgrid is required since the increase of the penetration level of renewable generators in the microgrid raises uncertainty due to their intermittent power output. In this paper, an application of probabilistic optimization method to economical operation of a microgrid is studied. To simplify the treatment of the uncertainties of renewable generations and load, the new 'band of virtual equivalent load variation' is introduced considering their uncertainties. A simplified robust optimization methodology to generate the scenarios within the band of virtual equivalent load variation and to obtain the optimal solution for the worst scenario is presented based on Monte Carlo method. The microgrid to be studied here is composed of distributed generation system(DGs), battery systems and loads. The distributed generation systems include combined heat and power(CHP) and small generators such as diesel generators and the renewable energy generators such as photovoltaic(PV) systems and wind power systems. The modeling of the objective function for considering interruption cost by the penalty function is presented. Through the case study for a microgrid with uncertainties, the validity of proposed robust optimization methodology is evaluated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.486-492
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• 2017

In recent years, renewable energy sources have been mentioned as solution to environmental regulation and energy supply-demand. Energy storage systems are needed to mitigate the intermittent output characteristics of renewable energy sources and to operate micro grid efficiently using renewable energy generation systems. However, despite the necessity of energy storage system, this cannot secure the economical efficiency of the energy storage system by high initial cost. In this paper, a micro grid is constructed to supply electric power to industrial customers by using solar power generation system and energy storage system among renewable energy generation power sources and operated to improve energy independence. In the case study, we use photovoltaic system which is representative renewable energy generation system. Unlike conventional photovoltaic system, this system uses floating photovoltaic system with the advantage of having high output and no land area limitations. It is operated for the purpose of improving energy independence in the micro grid. In order to secure economical efficiency, the energy storage system operates a micro grid with a minimum capacity. Finally, this paper calculates the appropriate subsidy for the energy storage capacity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.62-69
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• 2023

Recently, renewable energy has been increasing in Korea to reduce greenhouse gas, and solar power generation, which accounts for the largest proportion of renewable energy, is noteworthy. The government policy will further increase solar power generation. In order to implement the policy, it is important to understand the current status of domestic solar power generation facilities. Therefore, the current status of solar power generation facilities in Jinju city close to the south coast and Jeonju city close to the west coast was investigated and compared. By 2020, 618 solar power plants had been installed in Jeonju city and 269 in Jinju city. However, there is not much difference in the amount of solar power generation for business at 9 GWh. The reason is that Jinju city has a lower population density than Jeonju city, so there are enough places to install a large-scale solar power facilities with a large power generation capacity. Monthly solar power generation was the highest in April in both Jeonju city and Jinju city and the lowest in January. In particular, in December, Jinju city showed more solar power generation than Jeonju city because of the large amount of insolation, long sunshine hours, and few clouds.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1227-1234
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• 2015

The efficient electric power demand management in electric power supply industry is currently being changed by distributed generation. Meanwhile, small-scale distributed generation systems using renewable energy are being constructed worldwide. Several small-scale renewable distributed generation systems, which can supply electricity to the grid at peak load of the grid as per policy such as demand response programs, could help in the stability of the electric power demand management. In this case, the power quality of the small-scale renewable distributed generation system is more significant. Low prices of power semiconductors and multilevel inverters with high power quality have been recently investigated. However, the conventional multilevel inverter topology is unsuitable for the small-scale renewable distributed generation system, because the number of devices of such topology increases with increasing output voltage level. In this paper, a single-phase multilevel inverter based on H-bridge, with DC_Link divided by bi-directional switches, is proposed. The proposed topology has almost half the number of devices of the conventional multilevel inverter topology when these inverters have the same output voltage level. Double Fourier series solution is mainly used when comparing PWM output harmonic components of various inverter topologies. Harmonic components of the proposed multilevel inverter, which have been analyzed by double Fourier series, are compared with those of the conventional multilevel inverter. An inverter prototype is then developed to verify the validity of the theoretical analysis.

• Journal of Power Electronics
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• v.15 no.4
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• pp.899-909
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• 2015

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

• New & Renewable Energy
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• v.17 no.1
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• pp.61-75
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• 2021

Power generation using solar PV and wind power are more feasible to compete with fossil fuel power generation. However, residential acceptance is still a big challenge in the deployment of renewable energy. The Korean government has implemented various policies to support the development of renewable energy in which communities invest. However, there are very few cases of the commercial operation of community-invested renewable energy power plants. Renewable energy has attracted attention in the reduction of greenhouse gasses (GHG) effects and economic feasibility. However, it is also necessary to focus on socio-economic effects to overcome the economic recession while reducing greenhouse emissions. Community-invested renewable energy development projects can positively revitalize the local economy in many aspects, such as resident income, job creation, and the growth of local businesses. This study analyzes the local economic impact of renewable energy development projects on residents' income and job creation. It increased local companies' sales through community-invested development projects in Korea.

• Architectural research
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• v.18 no.2
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• pp.59-64
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• 2016

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings' energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.

• Proceedings of the KIEE Conference
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• summer
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• pp.704-706
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• 2004

The objective of this article is to provide the approach of improving trade system for activating the generation using renewable energy. The power trade system of our country is mandatory market, in which power generators fundamentally are to play. In this paper, several suggestions for power trading system of renewable energy will be showed.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.111-118
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• 2017

The increased diversity of different types of energy sources requires moving towards smart distribution networks. This paper proposes a probabilistic DG (distributed generation) units planning model to determine technology type, capacity and location of DG units while simultaneously allocating ESS (energy storage systems) based on pre-determined capacities. This problem is studied in a wind integrated power system considering loads, prices and wind power generation uncertainties. A suitable method for DG unit planning will reduce costs and improve reliability concerns. Objective function is a cost function that minimizes DG investment and operational cost, purchased energy costs from upstream networks, the defined cost to reliability index, energy losses and the investment and degradation costs of ESS. Electrical load is a time variable and the model simulates a typical radial network successfully. The proposed model was solved using the DICOPT solver under GAMS optimization software.