• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.3
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• pp.246-254
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• 2018

In this study, we developed a thermoelectric generation system for coastal fishing boats that allows for a high-density arrangement of thermoelectric modules, verified the improvement in performance by conducting comparative analysis between field test results and results from previous studies. The developed thermoelectric generation system was installed in a 3-ton gill-netter to analyze the engine revolutions per minute and energy production per day for each fishing process over a period of 20 days. From the experimental results, the maximum electric energy generated was 207.1 Wh, the minimum was 53.93 Wh and the average electric energy was 129.98 Wh. In accordance with the increasing of the engine r.p.m., the maximum electric production was 183 W at 1,500 r.p.m. It was approximately 80.5% of designed capacity, 227.2 W. Considering the result in the earlier research was 50.7% of designed capacity, 115.8 W. It was improved by 30% compared to the earlier one. The fishing operation was classified as departure, fishing and arrival. From the result on production analysis of electric energy, the composition of energy was 63% in fishing, 19.5% in departure and 17.5% in arrival. The electric energy production per unit hour was 42.8% in arrival, 32.9% in departure and 24.3% in fishing.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.61-67
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• 2006

The use of the wind energy resource is a rapidly growing area world-wide. The number of installed units is continuously increasing, and therefore, it is important to respect and to deal with the impact of wind power generation system. From the view of an electric grid utility, there is a major problem with the impact of the wind system on the voltage of the electric grid, to which a turbine is connected. In this paper, it is investigated the voltage impact and transient state analysis on distribution line, with which wind power generation system is connected. Connections of wind power system usually occur to voltage drop due to reactive power absorption and sometime result in higher than nominal voltage.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.104-107
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contact-less power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.265-273
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• 2017

Recently the Paris Climate Change Accord has been officially put into effect, making global efforts to implement Greenhouse Gas (GHG) reductions, and also International environmental regulations in the automotive sector will be further strengthened. The electric vehicle, which minimizes the particulate matter generated by existing internal combustion engine automobiles, is evaluated as a representative eco-friendly automobile. However, charging the battery of an electric vehicle is not fully environment-friendly if it is fueled by electricity that is being generated by fossil fuels as an energy source. The energy generated by the photovoltaic power generation system, which is an infinite clean energy, can be used to charge an electric vehicle's battery. Currently, shortage of charging facilities, time of charging, and high battery prices are the problem of activating the supply of electric vehicles. This study is to build a conjunction between the EVBSS (Electric Vehicle Battery Supply System) and ESS (Energy Storage System), which can quickly supply the photovoltaic charged battery to the required demand. If the charged battery in the Battery Swapping Station (BSS) is swapped swiftly, it will dramatically shorten the waiting time for charging the battery. As a result, if the battery is rented when it is needed, electric vehicles can be sold without the cost of a battery, which accounts for a large portion of the total cost, then the supply of electric vehicles are expected to expand. Furthermore, it will be an important alternative to maneuver climate change by minimizing GHG emissions from internal combustion engine vehicles.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.354-356
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• 2000

This paper describes the strategy of a daily optimal operational scheduling on cogeneration systems with each other generation mode. The cogeneration systems consists of three generators. auxiiiary devices which are three auxiliary boilers, two waste boilers and three sludge incinerators. One unit that using the back pressure turbin generates the electrical and the thermal energy. The other two units that using the extraction condensing turbine generate the energy. Auxiliary devices operate to supplement the thermal energy to the thermal load with three units. The cogeneration system has a large capacity which is able to supply enough the thermal energy to the thermal load, however the electric power generated is insufficient to satisfy the electrical load. Therefore the insufficient electric energy is supplemented by buying electrical energy from the utility. Simulation was carried out using optimization toolbox. The result reveals that the proposed modeling and strategy can be effectively applied to cogeneration systems with each other generation mode.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.151-156
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• 2000

A vibration in a high-speed machine may lead to machinery malfunction and even catastrophic failure. So solving the vibration problem is a fundamental requirement for the stability of the high-speed machine. The flywheel energy storage system using superconducting magnetic bearings is a device to store electrical energy as rotational kinetic energy by motor and to convert it to electrical by generator when necessary. The high-speed rotating flywheel has large amplitude at a critical speed. And it has an unstable behavior by the electric torque at the first stage of the energy generation. In this paper, the stability analysis is performed with an analytical model and equations of motion-which is considered the effect of the electric torque-to identify the stable driving condition and the dynamic behavior.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.174-182
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contactless power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1248-1252
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• 1999

To provide electricity power of good quality, it is essential to establish generation of electricity plan in electric power system based on accurate power-demand prediction and cope with changes of power-need fluctuating constantly. The role of hydraulic-power generation of electricity in electric power system is of importance because responding to electric power-demand counts or reservoir-type hydraulic-power generation of electricity which is designed for additional load in electric power system. So hydraulic-power generation of electricity must have fast start reserve. But the amount of water, resources of reservoir-type hydraulic-power generation of electricity is restricted and multi-used, so the scheduling of management by exact forecasting the amount of water is critical. That is why efficient hydraulic-power generation of electricity makes a main role on pumping up the utility of energy and water resource. This thesis introduced the example of optimal generation of electricity plan establishment which is used in managing reservoir-type hydraulic-power generation of electricity.

• Current Photovoltaic Research
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• v.6 no.4
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• pp.124-132
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• 2018

The Korean electric power supply plan was prepared by greatly enhancing the environmental and safety with considering the economical efficiency of the electric equipment, the impact on the environment and the public safety. As a result, the fossil energy-based power generation sector is accelerating the paradigm shift to eco-friendly energy such as solar power and wind. Also the solar power industry is expected to grow into a super large-sized industry by converging the energy storage and electric vehicle industry. Generally, a levelized cost of electricity (LCOE) is used to calculate the power generation cost for different generation power generation efficiency, operating cost, and life span. In this paper, we have studied the future research and development direction of photovoltaic technology development for the era of massive utilization of photovoltaic solar power, and have studied the LCOE of major countries including China, USA, Germany, Japan and Korea. Finally we have reviewed USA and Japan research programs to reduce the LCOE.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.343-347
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• 2019

When referring to weight, volume, and efficiency, a SuperConducting Synchronous Generator (SCSG) is definitely superior to conventional generators as a large-scale wind power generation system. The SCSG is connected to a full power converter that transmits the energy from the SCSG to the power grid. To reduce the current stress and system cost, the SCSG which has nine-phase armature windings with three converters is used. This paper deals with a comparative analysis of 10 MW superconducting wind power generators with three-phase and nine-phase armature windings. The stator windings of SCSGs are of various types. Using the finite element method, SCSGs are analyzed and compared in terms of the weight and volume of SCSGs, the total length of the superconducting wire, harmonics, torque performance, and efficiency. The analyzed results will be effectively utilized to design large-scale superconducting generators for wind power generation systems.