• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.100-103
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• 1997

Korea Electric Power Corporation (KEPCO) started a fuel cell project to develop alternative sources of electric power because of the rapid increase in power demand and global environmental problems. For the development of a molten carbonate fuel cell (MCFC), KEPCO started the project in 1993 to develop a 2 kW MCFC system and finished it at the end of 1996. In this project, $ASPEN^+$ was utilized to design the 2 kW MCFC generation system. Based on this simulation, a power generation system was designed and installed for operation and a long term test of internally manifolded 2 kW class MCFC stack. This stack has 20 cells with an effective electrode area of $1000\;cm^2$. It was run at 0.84 V and $150\;mA/cm^2$ and was operated for more than 3,250 hours continuously. This paper describes the system configuration and its control and measurement units. An analysis of the stack performance, the effect of gas utilization ratio, and the stack performance requirements are also discussed.

• Journal of the Korea Safety Management & Science
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• v.11 no.1
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• pp.43-49
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• 2009

This study set three kinds of situation and observed the various states such as carbonization by experimenting damages by fire of electric iron. The results of this study are as follows: The fire did not occurred when the unpowered iron over mattress and cotton shirts was com busted completely by external flame because the temperature of surface of soleplate and mattress did not reach the minimum ignition energy and when the powered electric iron over mattress and cotton shirts was left for an hour with its temperature dial set to high because the temperature of combustibles did not reach the minimum ignition energy. The fire occurred when the electric iron in which the outer box, bi-metal switch, and temperature fuse were removed over mattress and cotton shirts was powered by through heater terminal, and then the electric iron, mattress, and cotton shirts were combusted by the fallen combustibles because the temperature of combustibles reached to the minimum ignition energy with the help of active transfer of heat.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.277-279
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• 2005

The imbalance of energy demand and supply caused by rapid industrialization around the world and the associated environmental issues require and alternative energy source with possible renewable fuels. Political instability and depletion of cruel oils are other factors that cause fluctuation of oil price. Securing a new alternative energy source for the next century became an urgent issue that our nation is confronting with. As a matter of fact, the fuel cell technology can be widely used as next generation energy regardless of regions and climate. Specially, the ability of expansion and quick installation enable one to apply it for distributed power, where the technology is already gaining remarkable attentions for the application. Particularly, leading industrialized nations are focusing on the PEM fuel dell with anticipation that this technology will find their place of applications in the vehicles and homes. In this study, demonstrate the multi physics modeling of a proton exchange membrane(PEM) fuel cell with interdigitated flow field design. The model uses current balances, mass balance(Maxwell-Stefan diffusion for reactant, water and nitrogen gas) and momentum balance(gas flow) to simulate the PEM fuel cell behavior.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.9-13
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• 2015

Energy storage systems (ESS) can be used to provide frequency regulation services in a power system to replace traditional frequency regulation power plants. Battery ESS, in particular, can provide "fast-responding frequency regulation," wherein the facility can respond immediately and accurately to the frequency regulation signal sent by the system operator. This paper presents the development and the trial run results of a frequency regulation control system that uses large-scale ESS for use in a large power system. The control system was developed initially for the 4 MW ESS demonstration facility in Jocheon Jeju Island, and was further developed for use in the 28 MW ESS facility at the Seo-Anseong substation and the 24 MW ESS facility at the Shin-Yongin substation to provide frequency regulation services within mainland Korea. The ESS facility in Seo-Anseong substation responds to a sudden drop in frequency via governor-free control, while the ESS facility in Shin-Yongin responds via automatic generator control (AGC).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.10-17
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• 2014

The Jeju Special Self-Government Provincial Government has made the plan penetrating gradually electric vehicles(EVs) in the Jeju Special Self-Government Province(Jejudo). However the effects of EVs penetration on the electrical grid of the Jejudo is not reported. In this paper the yearly electric energy consumed by the EVs was calculated and the effects of the EV penetration on the peak power of the grid were analyzed in the Jejudo for the future 10 years, and we hope that our study results will help the governors realize the EVs penetration plan in the Jejudo. The calculation results show that the rate of the electric energy used by the EVs will become to 2.9% at its maximum at the 2017 year when the penetration rate of EVs in passenger cars becomes 10%, and the rate of the electric energy consumed by the EVs will become to 9.4% at its maximum at the 2020 year when the penetration rate of EVs in passenger cars becomes 30%. The concepts of smart-charging capacity and 100%-valley-filling charging capacity of the grid were defined and calculated for the Jeju Grid, and the grid was analyzed to have the sufficient EV charging capacity until the 2022 year.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.519-524
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• 1999

this paper proposes the operation algorithm of 1MW class Battery Energy Storage System(BESS) installed at the extra-high voltage customer. The objective of the proposed algorithm is to reduce electric charges during the operation of the BESS interconnected to power system. This paper simulates the electric charges in 1998 considering Season and Time of Use Rate and Power Factor in the assumption that electricity demand in 1998 is the same amount of that in 1997 and shows the saving of about 40 million won in the total electric charges. The results comparing the real electric charges of June. July and August in 1997 with that in 1998 show that the implementation of the proposed algorithm could significantly reduce electric charges during the operation the BESS.

• 전기의세계
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• v.17 no.2
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• pp.6-10
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• 1968

The conversive limitation of electric energy for the thyristor inverter is analysed under the boundary conditions which the term of a negative inverse voltage is longer than that of the turn off time of the thyristor under commutation. It is clear that the maximum electric energy conversion is affected by the turn off time of the thyristor, the reactance of a commutation reactor, the capacity of a commutation condenser and the voltage of Direct current source. It is useful for design the thyrister invertor and the motor speed control to apply the above conclusion.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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• pp.169-177
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• 2014

Operation and control system has been installed and tested to use energy storage system(ESS) for frequency regulation at 4MW class of ESS demonstration facility installed at Jeju island, Korea in 2013. Simulation tests were performed by programing language C# for power system of Jeju island to develop control algorithm. Site simulation tests were performed in control system itself without connecting power system and energy storage system. Control algorithm was coded, modified and tested to load to controller and communication system and human-machine interface were developed and tested in the process of simulation tests. After similar results to that of simulation tests by programing language were obtained, power system and energy storage system demonstration facility were connected to control system by communication system. Energy storage system for frequency regulation was tested for actual frequency and simulation frequency. The site tests showed the similar results to that of simulation tests and the control systems is possible to be operated for frequency regulation. Faster response of energy storage system for frequency regulation, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. It is expected that more studies for time-reduction and time-delay elements can make less capacity of energy storage system cover more role of frequency regulation of power plants.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1625-1636
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• 2017

A power electronic transformer (PET) based on the cascaded H-bridge (CHB) and the isolated bidirectional DC/DC converter (IBDC) is capable of accommodating a large scale battery energy storage system (BESS) in the medium-voltage grid, and is referred to as a power electronic transformer based battery energy storage system (PET-BESS). This paper investigates the PET-BESS and proposes a coordinative control strategy for it. In the proposed method, the CHB controls the power flow and the battery state-of-charge (SOC) balancing, while the IBDC maintains the dc-link voltages with feedforward implementation of the power reference and the switch status of the CHB. State-feedback and linear quadratic Riccati (LQR) methods have been adopted in the CHB to control the grid current, active power and reactive power. A hybrid PWM modulating method is utilized to achieve SOC balancing, where battery SOC sorting is involved. The feedforward path of the power reference and the CHB switch status substantially reduces the dc-link voltage fluctuations under dynamic power variations. The effectiveness of the proposed control has been verified both by simulation and experimental results. The performance of the PET-BESS under bidirectional power flow has been improved, and the battery SOC values have been adjusted to converge.

• Journal of information and communication convergence engineering
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• v.2 no.4
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• pp.243-246
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• 2004

Currently, advanced countries invest lots of efforts to develop improvement of electric power production and supply, confronting environmental problems and new energy development. They set up long term plan focusing on electric power transmission infrastructure construction technology, establishment of the customer care service network using electric technologies, improvement of economic productivity by innovative electric technology, prevention of global warming gas and clean and efficient energy use etc. Comparing to those countries, the level of technologies that we have are in behind and moreover, technological resources are limited. Therefore, Korea is required to reconsider efficient distribution of R&D investment by concentrating on limited R&D resources to important technologies which could be stepping stone to gain competitive advantage. It can be done through comparative analysis of electric technologies among advanced countries and analysis of electric technology development policy.