• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.74-81
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• 2006

In this study, on the basis of an analytic hierarchy process (AHP) method and through a questionnaire on subjective preference and importance, various power supply systems were comprehensively compared with multiple decision criteria such as environmental, social, healthy, and economic viewpoints and then overall priority was assessed. When a decision-making problem is modelled by a hierarchy structure, the AHP method is regarded as a useful tool for extracting subjective opinions via the aforementioned questionnaire. Here, the overall preferences were obtained by linearly aggregating weighting vector and preference matrix. The energy systems such as nuclear, coal, and LNG power plants were selected because they took share over 90% of domestic electricity supply in Korea. Furthermore, wind power and photovoltaic solar systems were included as representative renewable energy systems in Korea. According to the results of this demonstration study, the following comprehensive comparison indicators were yielded: 1) weighting factors for 4 types of main criteria as well as for 11 types of sub-criteria; 2) preference valuation for 7 types of energy systems under consideration; 3) overall score for each energy systems.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.41-53
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• 2017

This study focuses on the current state of Smart Grid policy in Japan and its problems while the interest in Smart Grid has been increasing since the March 2011 earthquake in East Japan. As a result of the analysis, Japan introduced the fixed price buying system of new and renewable energy in response to the power supply and demand problem caused by the 2011 earthquake in East Japan, and established a decentralized green electricity trading market in which electricity generated from new and renewable energy is traded Smart Grid-related projects were implemented as a solution to solve energy crisis and environmental problems at the same time. As a result, we achieved visible results such as suppressing peak power, reducing CO2 emissions, and securing stable supply and demand of energy using renewable energy sources. On the other hand, the improvement of current Smart Grid policy operation in Japan and the introduction of stabilization system of power system, promotion of international standards of domestic technology related to smart grid, and support for strengthening security of smart grid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.18-23
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• 2008

The electricity demand in Korea has rapidly increased along with a steady economic growth since 1970s. Therefore Korea has positively propelled not only SSM(Supply-Side Management) but also DSM(Demand-Side Management) activities to reduce investment cost of generating units and to save supply costs of electricity through the enhancement of whole national energy utilization efficiency. However study for rebate, which have influence on success or failure on DSM program, is not sufficient. This paper executed to modeling mathematically an amount of potential participants considering rebates, which have influence on penetration amounts for DSM program using by 'A Survey of End-User for Energy Efficiency Demand Side Management Programs'.

• Structural Engineering and Mechanics
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• v.84 no.2
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• pp.155-165
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• 2022

The use of electricity and communication between electronic devices is increasing daily, which makes the stability of electrical power supply vital. Since the 1990s, large earthquakes have occurred frequently causing considerable direct damage to electrical power facilities as well as secondary damage, such as difficulty in restoring functions due to the interruption of electric power supply. Therefore, it is very important to establish measures to protect electrical power facilities, such as transformers and switchboards, from earthquakes. In this study, a 154 kV transformer whose service life had expired was installed on the base fabricated by simulating the field conditions and conducting the shaking table tests. The dynamic characteristics and seismic behavior of the 154 kV transformer were analyzed through the resonance frequency search test and seismic simulation test that considers the front, rear, left, and right directions. Since the purpose of this study is to analyze the acceleration amplification in the bushing due to the acceleration amplification, the experimental results were analyzed focusing on the acceleration response and the converted acceleration amplification ratio rather than the failure due to the displacement response of the transformer. The seismic force amplification at the transformer bushing was evaluated by simulating the characteristics of electrical power facilities in South Korea, and compared with the IEC TS 61463 acceleration amplification factor. Finally, the amplification factor at zero period acceleration (ZPA) modified for each return period was summarized. The results of this study can be used as data to define the amplification factor at ZPA of the transformer bushing, simulating the characteristics of electrical power facilities in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.410-420
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• 2012

The heavy reliance on fossil fuels, especially oil and gas has triggered the global energy crisis. Continued use of petroleum fuels is now widely recognized as unsustainable because of their depleting supplies and degradation to the environment. To become less dependent on fossil fuels, current world is shifting paradigm in energy by developing alternative energy sources mainly through the utilization of renewable energy sources. In particular, bioenergy recovery from wastes with the help of microorganism is viewed as one of the promising ways to mitigate the current global warming crisis as well as to supply global energy. It has been proved that microorganism can generate power by converting organic matter into electricity using microbial fuel cells (MFCs). MFC is a bioelectrochemical device that employs microbes to generate electricity from bio-convertible substrate such as wastewaters including municipal solid waste, industrial, agriculture wastes, and sewage. Sustainability, carbon neutral and generation of renewable energy are some of the major features of MFCs. However, the MFC technology is confronted with a number of issues and challenges such as low power production, high electrode material cost and so on. This paper reviews the recent developments in MFC technology with due consideration of electrode materials used in MFCs. In addition, application of biocathodes in MFCs has been discussed.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.63-65
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• 2007

Recently with increase consumption of electric power, the scale of the electric system becomes bigger and complex. Then, it is increasing the hardship in the operation of electric system and the continuance of stability. Especially, as the differences between demand and supply in electric power keeping low frequency oscillating attenuation from electric power have been very important in the continuance part of stability. The more control time of electricity system is getting faster with digitalization the more stability of electricity system is getting worse. As solutions of these problems, by establishing Power System Stabilizing Controller putting PSS output signal and putting damping to vibration of the rotor at generators's AVR in area where is oscillated, We are willing to contribute the electricity system by holding in generator output vibration.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1415-1422
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• 2018

In Korea, prior to 2011, the electric reserve margin followed the probabilistic reliability view and the planning reserve margin had been operated at about 15% based on the assumption that power outage was permitted within 0.5 days a year. However, after experiencing the shortage of the electric generation capacity in Sept. 15, 2011, the planning reserve margin was selected as 22% to improve the reliability of the electric supply. In this paper, using panel data of 28 OECD countries over the period 2000-2014 we attempted to empirically examine the linkage between reserve margin, electricity tariffs, renewable energy share, GDP per capita, and summer / winter peak-to-peak ratios. As a result, all four independent variables have been significant for the electric reserve margin, and in particular, we found that countries with similar peaks in winter and summer have operated 4.3% higher reserve margin than countries experiencing only summer peak.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.261-265
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• 2008

To solve the lack of housing, our country has supplied an enormous volume of apartments, and these days it occupies 75% of our buildings. As apartments occupy most of our housings, the rate of energy usage from them are also high. On this, setting apartment energy reduction as a target, by researching the actual conditions of energy consumption and drawing a basis data, we can apply this as a way of saving energy, rationalization of the scale of energy supply facilities and a standard when planning facilities. To grasp the present condition of energy usage of the urban rental apartment, this research analysed the use of electricity, gas and water monthly and annually of a rental apartment that is located in Daegu. The results showed that in 2003 the electricity usage was 1,198MWh but 1,315MWh in 2007, which means 9% of electricity usage increases every year. The average of water usage was $85,072m^2$ per year and they used $604.2MJ/m^2$ Typical energy consumption unit on $74.4m^2$ of area and $448.8MJ/m^2$ on $105.8m^2$. By showing the usage of energy and water of the urban rental apartment, understanding the tendency and preparing an Typical energy consumption unit standard through this research, apartments should use energy more efficiently.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.329-330
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• 2006

The research and development of an actuator are accelerating in the robotics industry. The electricity polymer and SMA actuator are designed simply and are produced a lot of forces per unit volume. Their motions are similar to human's motion, But the repeatability of the electricity polymer actuator is lower. The reaction velocity of the SMA actuator is slow and the travel is short. In this paper, the dynamic characteristic of the segmented SMA is studied. The SMA wire is divided by using the Thermo-electric module(TEM) to control each of segments independently. The MOSFET circuit is used to supply constant currents fer the Thermo-electric module(TEM). The hysteresis and displacement of the SMA wire according to load are measured.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.749-763
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• 2022

The fulcrum of economic development is a sustainable supply of electricity. Nigeria is plagued with blackouts, with one of the lowest per capita electricity consumption in the world (circa. 120 kWh per capita). Hence, policies have been instigated to integrate electricity generation from nuclear power plants (NPP) on or before 2027. However, a critical requirement for NPP generation is the implementation of robust human resource development (HRD) programs. This paper presents the perspective of Nigeria in assessing human resources needs over the entire NPP lifecycle following the milestone approach and employing the IAEA's Nuclear Power Human Resource (NPHR) modeling tool. Three workforce organizations are in focus including the owner/operator, regulators, and construction workers following three decades timeframe (2015-2045). The results indicate that for the study period, a maximum of approximately 9045 personnel (73% construction workers, 24% owner/operator, and 3% regulators) should be directly involved in the NPP program just before the commissioning of the third NPP in 2033. However, this number decreases by about 73% (2465 personnel including 94% operator and 6% regulator) at the end of the study timeframe. The results can potentially provide clarity and guidance in HRD decision-making programs.