• 전기의세계
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• v.16 no.1
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• pp.19-28
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• 1967

Indigenous energy resources available in Korea are limited to the three major resources such as Korean anthracite, hydraulic potential and wood and straws. As reported in various reports concerning energy problem in Korea, unfortunately these three major resources are not only poor in quality but also limited in quantity. The amount of energy to be imported, which will be increased at a considerably high rate by years due to the shortage in the supply by domertic sources against the demand, is studied in the view-pint of sound and logical energy dependence upon the external sources. What would occur, if the imported energy would be exclusively limited to an energy source only, has an enough reason to be paid a significant consideration. As a result, the feasibility is discarded in favour of nuclear power plants after an extensive prospect for electric power development plan covering more than coming thirty years, i.e., up to the year of 2,000 A.D. In briefing, this paper indicates that a measures to accomodate as large amount of nuclear power plants as possible in the electric power system is not only inevitable for a sound solution of the severe energy problem with which Korea is to be confronted but also leads to the national benefit.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1416-1417
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• 2007

The high frequency pulsed power system is widely available for use in high frequency generator applications. We designed and fabricated our own high frequency pulsed power system to obtain very sort pulse width and high peak value and investigated microbe removal characteristics using it. This paper introduces a simple high voltage high frequency pulsed power system for removing various bacteria caused by dirty water. This system include power supply circuit, switching MOSFET, and flyback converter. We can also control the switching using a PIC one chip microprocessor. As a result, we can obtain good removing characteristics of various bacteria by adjusting the charging voltage, the pulse repetition rate and the electrical field inducing time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.113-114
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• 2023

As the available resources are gradually depleted, interest in renewable energy is increasing. Various energy harvesting technologies are emerging, and energy harvesting using solar, solar, and wind power is used in the highest range. Depending on the abnormal climate, solar heat and solar power differ in energy harvest, but the wind is fixed compared to the sun. Therefore, it was intended to maximize the effect of energy harvesting by using the venturi effect, which has a change in wind speed according to the turbine used for wind power generation and wind pressure. Therefore, in this paper, we want to see the difference in the amount of power generated by the turbine after increasing the wind speed using the venturi effect.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.124.2-124.2
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• 2010

Generally, a coolant of the nuclear power plant is manufactured by electrolyzing the sea water near the plant for making the sodium hypochlorite(NaOCl), which is used for sterilizing the bacteria and the shellfishes sticking to the drains or the pumps at the outlet of the cooling system due to $8-10^{\circ}C$ warmer temperature than the inlet sea water. During manufacturing the sodium hypochlorite, the hydrogen with the high purity is also produced at the anode side of the electrolyzer. This paper describes a novel power plant system combined with the polymer electrolyte membrane(PEM) fuel cell, the wasted hydrogen from the sea water electrolyzer and the wasted heat of the nuclear power plant. The present status over the exhausted hydrogen at twenty nuclear power plants in Korea was investigated in this study, from which an available power generation is estimated. Furthermore, the economic feasibility of the PEM fuel cell power plant is also evaluated by a current regulations over the power production and exchange using a renewable energy shown in Korea Power Exchange(KRX).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.27-31
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• 1996

In this paper, The SSPA(Solid State Power Amplifier) is 100 watts amplifier which is used with C-Band Satellite communication Up-Link frequency, 5.875 ∼6.425 GHz. SSPA requires more output power than is available from a single GaAs FET with result it is necessary to combine the output of many device. To achieve a high power, it is important to make a good N-way power divider which has a small different phase, good combining efficiency and high power handling capability. The reliability of Power GaAs FET decrease with increasing junction temperature, power amplifier in general dissipate amount of power. It is important to provide them with a heatsink and a temperature compensation circuit to dispose of the unwanted heat. To compensate temperature, Using PIN diode attenuator, it is enable to get a precision gain control. The output power of the SSPA is more than 100 watt with which the TWTA (Traveling-Wave Tube Amplifier) can be replaced. Each stage was measured by the Network analyzer PH8510C, Power meter Booton 42BD, The gain is more than 53 dB, flatness is less than 1.5 dB.

• Journal of Environmental Impact Assessment
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• v.30 no.6
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• pp.339-354
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• 2021

The purpose of this study is to provide valuable information and data by analyzing the environmental status and potential forrenewable energy projects (or plans) based on environmental assessment (EA) data, so that more objective and scientific environmental assessments can be conducted. The study also suggests regional directions that could satisfy the goals of nature conservation and renewable energy. Based on the analysis of EA data that was conducted up until June 2019, the study analyzed the size, location and characteristics of both onshore wind power and onshore photovoltaic. The environmentally available potential by region was also derived by considering the main constraints and requirements related to the potential siting ofrenewable energy projects at the EA. Based on EA data, 63 out of 80 (79%) onshore wind power projects are shown to be located in mountainous areas. For onshore photovoltaic projects, a total of 7,363 projects were subjected to environmental assessment over the country. The environmentally potential area for onshore wind power, considering all the environmental regulatory factors, is 2,440 km². For onshore photovoltaic, the environmentally available area estimated as idle farmland is 2,877 km². The distribution and characteristics of the environmentally available potential of the region may be the most important factor that local governments should bear in mind in terms of promoting renewable energy development projects in the region. Based on the results of this study, even if we consider the national energy plan including the expected future increase, as well as environmental goals and socio-economic acceptance through an environmental assessment, the available resources forrenewable energy projects are not insufficient. It is possible to examine the adequacy of the target distribution rate of renewable energy sources by region taking into consideration the quantitative and scientific results such as the environmentally available potential data derived from this study.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.529-536
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• 2013

Lack of proper amount of sun lights and wind strength which are major factors of solar power and wind power system may cause poor electric power generation and decrease the lifetime of batteries that are major energy saving units. Because the PCS, which is essential in solar and wind power system, for small power generation system has been rarely developed an efficient and stable PCS for small power generation system is highly required. In this paper, we design a new constant current/constant voltage type hybrid PCS by which stand alone/grid connected operation with commercial power system is available and implement the designed PCS as a protype for performance verification.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1110-1122
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• 2018

This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.3810-3830
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• 2015

In this paper, we investigate the differential game theoretic approach for distributed dynamic cooperative power control in cognitive radio ad hoc networks (CRANETs). First, a payoff function is defined by taking into consideration the tradeoff between the stock of accumulated power interference to the primary networks and the dynamic regulation of the transmit power of secondary users (SUs). Specifically, the payoff function not only reflects the tradeoff between the requirement for quickly finding the stable available spectrum opportunities and the need for better channel conditions, but also reveals the impact of the differentiated types of data traffic on the demand of transmission quality. Then the dynamic power control problem is modeled as a differential game model. Moreover, we convert the differential game model into a dynamic programming problem to obtain a set of optimal strategies of SUs under the condition of the grand coalition. A distributed dynamic cooperative power control algorithm is developed to dynamically adjust the transmit power of SUs under grand coalition. Finally, numerical results are presented to demonstrate the effectiveness of the proposed algorithm for efficient power control in CRANETs.

• Journal of Power Electronics
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• v.19 no.1
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• pp.220-233
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• 2019

This work aims to study and analyze the various operating modes of universal power converter which is powered by solar and thermoelectric generators. The proposed converter is operated in a DC-DC (buck or boost mode) and DC-AC (single phase) inverter with high efficiency. DC power sources, such as solar photovoltaic (SPV) panels, thermoelectric generators (TEGs), and Li-ion battery, are selected as input to the proposed converter according to the nominal output voltage available/generated by these sources. The mode of selection and output power regulation are achieved via control of the metal-oxide semiconductor field-effect transistor (MOSFET) switches in the converter through the modified stepped perturb and observe (MSPO) algorithm. The MSPO duty cycle control algorithm effectively converts the unregulated DC power from the SPV/TEG into regulated DC for storing energy in a Li-ion battery or directly driving a DC load. In this work, the proposed power sources and converter are mathematically modelled using the Scilab-Xcos Simulink tool. The hardware prototype is designed for 200 W rating with a dsPIC30F4011 digital controller. The various output parameters, such as voltage ripple, current ripple, switching losses, and converter efficiency, are analyzed, and the proposed converter with a control circuit operates the converter closely at 97% efficiency.