• Journal of Sensor Science and Technology
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• v.29 no.1
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• pp.7-13
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• 2020

Dielectric capacitors are integral components in electronic devices that protect the electric circuit by providing modulated steady voltage. Explosive growth of the electric automobile market has resulted in an increasing demand for dielectric capacitors that can operate at temperatures as high as 400 ℃. To surpass the operation temperature limit of currently available commercial capacitors that operate in temperatures up to 125 ℃, Bi_1/2Na_1/2TiO₃ (BNT), which has a large temperature-insensitive dielectric response with a maximum dielectric permittivity temperature of 300 ℃, was selected. By introducing an intentional A-site cation deficiency and post-heat treatment, we successfully manage to control the dielectric properties of BNT to use it for high-temperature applications. The key feature of this new BNT is remarkable reduction in dielectric loss (0.36 to 0.018) at high temperature (300 ℃). Structural, dielectric, and electrical properties of this newly developed BNT were systematically investigated to understand the underlying mechanism.

• Explosives and Blasting
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• v.32 no.1
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• pp.23-30
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• 2014

The overall management for explosives in domestic and regulation for blasting is managed by the control Act of guns, sword, explosives etc. On the details for handling and method, delivery, storage, use and management for explosives and work safety for the accident prevention is recommended to the related business site through Standard safety work guideline of blasting which set by safety & health 27 Act handling. In this study, It reviews the standard safety work guideline of blasting notified by Ministry of employment & labor. We propose the new products introduced into domestic explosives market, definition of explosives word when the newest blasting technology is revised, emulsion explosives, bulk explosives and electronic detonators which increased in the latest. Indeed, We propose a typical handling method of non-electric detonator and electronic in order to make the renewed Standard safety work guideline of Blasting on work guideline.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.150-162
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• 2020

The proprietary post-combustion CO₂ solvent (KoSol) developed by the Korea Electric Power Research Institute (KEPRI) was applied at the Shanghai Shidongkou CO₂ Capture Pilot Plant (China Huaneng CERI, capacity: 120,000 ton CO₂/yr) of the China Huaneng Group (CHNG) for performance evaluation. The key results of the pilot test and data on the South Korean/Chinese electric power market were used to calculate the predicted cost of CO₂ avoided upon deployment of CO₂ capture technology in commercial-scale coal-fired power plants. Sensitivity analysis was performed for the key factors. It is estimated that, in the case of South Korea, the calculated cost of CO₂ avoided for an 960 MW ultra-supercritical (USC) coal-fired power plant is approximately 35~44 USD/tCO₂ (excluding CO₂ transportation and storage costs). Conversely, applying the same technology to a 1,000 MW USC coal-fired power plant in Shanghai, China, results in a slightly lower cost (32~42 USD/tCO₂). This study confirms the importance of international cooperation that takes into consideration the geographical locations and the performance of CO₂ capture technology for the involved countries in the process of advancing the economic efficiency of large-scale CCS technology aimed to reduce greenhouse gases

• Journal of Digital Convergence
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• v.11 no.11
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• pp.767-774
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• 2013

The electricity demand and supply could be off balance if several electric vehicles(EVs) were charged at the same time or at peak load times. Therefore, smart grids are necessary to flatten the EVs' electricity demand and to enable EVs to be used as distributed storage devices as electricity demand from EV-charging increases. There are still few quantitative studies on the impact of smart grids on managing EVs' electrical loads. In this study, we analyzed the quantitative impact of smart grids on managing EVs' electrical loads and suggested policy implications. As a result, it is identified that smart grids can manage effectively EVs' impact on electrical grids. The electricity market structure and regulatory framework should support the demonstration and commercialization of smart grid technologies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.347-353
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• 2017

In order to prohibit global warming, various kinds of regulatory policies have been established in the whole world. One example is the establishment of the Renewable Portfolio Standard. It requires the increased portion in energy production from renewable energy sources. The Republic of Korea adopted the act on the promotion of the development, use, and diffusion of new and renewable energy since 2012. However, in spite of the effort on the consideration of the renewable energy sources, it was reported the carbon intensity of electricity in Korea was not that low in 2015. Thus, it is required to examine the recent state of the utilization degree of the renewable energy sources in Korea. This paper analyzed the statistical data provided by Korea Power Exchange (KPX) to examine any problems and solutions for generating electricity from the renewable energy sources. We focused on the generation capacity provided by the power plants participated in the market, the electric power trading amount, and the utilization coefficient for 10 years. By analyzing the data, we provide an alternative to solve some imbalance among the factors contributing to renewable energy use.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1675-1681
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• 2017

As recently the demand on electric power has been increasing, the requirement of power supply reliability has been increased. Accordingly, the number of HVDC transmission systems in the world has been steadily increased, which have been installed in the power system to transmit a large capacity power to the long distant and interconnect the power grid between different countries. etc. #1 HVDC Transmission System was installed between Haenam and Jeju island in 1998, which is the first HVDC system furnished in korea. and has been operated until now. Before #1 HVDC Transmission System being installed, the power system of the Jeju Island is a isolated power system from that of Korea mainland. After the construction of #1 HVDC the system has made the Jeju power system more reliable and also been able to supply the mainland power, which was cheaper than that of Jeju island, to Jeju island. The construction of additional HVDC transmission system between mainland and the Jeju Island has been currently underway to cope with recent changes of the power market of the Jeju island, for examples the increase of power demand and the capacity of wind power generation. etc. #2 HVDC Transmission System construction was completed in 2012. #3 HVDC Transmission System will be also installed according to the plan. If all goes as planned, the Jeju power system will be operated with Multi-Infeed HVDC system connected to mainland power system. So the additional studies are needed in order to maintain the stability of the Jeju power system and get the efficiency of the Multi-Infeed HVDC system. Therefore, in this paper, the optimal operation strategies of the Multi-Infeed HVDC system between the mainland of Korea and the Jeju are suggested to ensure the stability of the power system in Jeju Island when the Multi-Infeed HVDC system is operated between two power system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.9
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• pp.82-87
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• 2008

Faster, safer and cheaper mailing of the postal matter is essential for surviving in the competitive market of home-delivery service. In the past, the domestic delivery business has been nu by only a few number of companies. But more and more number of companies including medium size ones are participating in the business, and the competition is getting severe. This paper proposes a method to select the optimal location of mail distribution centers that minimally connect the local mail centers of some major cities in Korea using the Steiner Tree theory, which is about connecting a finite number of points with a minimal length of paths and has been used in the distribution system optimization and optimal routing of the transmission lines of the electric power system. By using Steiner Tree theory in finding the best location of the postal delivery hub, we may expect the reduction of transportation cost and the increase of profit, resulting in acquiring the superior position in the competitive delivery business. It is expected that we may use the Steiner Tree theory in finding the best location of the electric power substation for the nott higher EHV(extreme high voltage) transmission network.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.91-97
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• 2021

ISO/IEC 15118 is an international communication standard for EV(electric vehicle)'s V2G implementation. In the charging/discharging control of an EV based on a communication protocol, there is inevitably a time delay when charging/discharging occurs, and the delay may limit in supplying power flexibility. In this paper, we implemented an ISO/IEC 15118-based V2G emulator and measured the charge/discharge response characteristics. As a result, the time delay appeared as 0.12ms. Accordingly, the power flexibility markets that EV can participate in under the current standard were explored.

• Journal of Korea Trade
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• v.27 no.4
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• pp.77-100
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• 2023

Purpose - Using the Model of Goal-Directed Behavior (MGB), this study identifies the critical factors that influence consumer intention to purchase an electric vehicle (EV). This study also provides differentiated policy implications to the Korean and Chinese governments and EV-related companies for the expansion of the EV market in both countries by comparing consumers' perceptions of EV purchase intentions. Design/methodology - Our extended MGB model adds to the standard model consideration of financial incentives, perceived risks, and environmental concerns. An online survey was conducted of Korean and Chinese consumers. Based on the collected responses, all tested hypotheses were verified using PLS-SEM (Partial Least Squares-Structural Equation Modeling). Differences in the path analysis results between Korea and China were compared and verified using Henseler's MGA (multi-group analysis), the parametric test, and the Welch-Satterthwaite test. Findings - The most critical factor that influences the intent to purchase an EV in consumers from both countries is personal desire. PBC and SN were identified as the critical factors that respectively increase personal desire in Korea and China. In addition, in Korea, among the three factors EC, FIP, and PR, environmental concerns were found to have the most significant impact on attitudes and purchase intention. In contrast, in China, economic factors (specifically financial incentives) had greater importance than environmental issues. Originality/value - This study has academic contributions in that it presents a new research model that includes financial incentive policies, environmental concerns, and perceived risk variables based on the MGB to explore consumers' purchase intentions. This study can also make a practical contribution in that it provides some meaningful implications to the governments and EV-related companies of both countries based on the differences in the analysis results of the Korean and Chinese markets.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.2
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• pp.91-99
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• 2023

Participation in power trading using surplus power is considered a business model active in the domestic energy trade market, but it is limited only if the legal requirements according to the type, capacity, and use of the facilities to be applied for are satisfied. The hydrogen residential demonstration model presented in this paper includes solar power, energy storage system (ESS), fuel cell, and water electrolysis facilities in electrical facilities for private use with low-voltage power receiving system. The concept of operations strategy for this model focuses on securing the energy self-sufficiency ratio of the entire system, securing economic feasibility through the optimal operation module installed in the energy management system (EMS), and securing the stability of the internal power balancing issue during the stand-alone mode. An electric facility configuration method of a hydrogen residential complex demonstrated to achieve this operational goal has a structure in which individual energy sources are electrically connected to the main bus, and ESS is also directly connected to the main bus instead of a renewable connection type to perform charging/discharging operation for energy balancing management in the complex. If surplus power exists after scheduling, participation in power trading through reverse transmission parallel operation can be considered to solve the energy balancing problem and ensure profitability. Consequentially, this paper reviews the legal regulations on participation in electric power trading using surplus power from hydrogen residential models that can produce and consume power, gas, and thermal energy including hybrid distributed power sources, and suggests action plans.