• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.552-559
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• 2015

Hydrogen is commonly used in many industrial field. However, hydrogen should be filled in a high pressure container to use it. Therefore, many researches have been conducted about an electrolyzer. The operating principle of the electrolyzer is that the electrolyzer can separate water molecules into hydrogen and oxygen. To use the electrolyzer, a power conversion system is needed because the current of the electrolyzer increases exponentially depending on the voltage of the electrolyzer. Thus, this paper proposes the power conversion system for the electrolyzer using a full-bridge DC-DC converter topology.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1994-2000
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• 2008

The output power of photovoltaic(PV) generation system is strongly affected by weather conditions. To make up for the defect of solar energy, energy storages such as battery and electrolyzer are usually integrated with photovoltaic cell. This paper focuses on the way to store energy surplus with battery and electrolyzer and to provide energy with battery. Photovoltaic generation system is modeled with PV cell, DC/DC converter, DC/AC inverter, battery and electrolyzer. The operation algorithm to regulate PV output power with battery and electrolyzer is suggested. The simulation results show that battery and electrolyzer effectively cooperate with each other to compensate the fluctuation of PV generation system.

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.302-307
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• 2021

Polymer electrolyte membrane (PEM) electrolyzer or alkaline electrolyzer is required to produce green hydrogen using renewable energy such as wind and/or solar power. PEM and alkaline electrolyzer differ in many ways, instantly basic materials, system configuration, and operation characteristics are different. Building an optimal water hydrolysis system by closely grasping the characteristics of each type of electrolyzer is of great help in building a safe hydrogen ecosystem as well as the efficiency of green hydrogen production. In this study, the basic operation characteristics of a kW class alkaline water electrolyzer we developed, and water electrolysis efficiency are described. Finally, a brief overview of the characteristics of PEM and alkaline electrolyzer for large-capacity green hydrogen production system will be outlined.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.76-80
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• 1991

This paper presents a merit of feedforward Dyamic Matrix Control(DMC) for electrolyzer process. The electrolyzer consists of anode part and cathode part that are separated by ion membrane. As the electolyzer process consumes a large amount of electricity, electric power change is inevitable in order to take advantage of the cheaper electricity during night. But the electric power change makes the electrolyzer control difficult because the electric power change affect the dynamics of the process. Feedforward DMC treats the electric power change as a load disturbance and gives the weighting value to the disturbance prediction part in the DMC algorithm. Feedforward DC shows better regulation performance than PID control and feedforward-feedback control for electrolyzer process.

• 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).

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.190-197
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• 2024

A commercial PbO₂ mesh cylinder electrode was utilized as the anode for the electrochemical degradation of the textile effluent after the biological treatment with the titanium cylinder as the cathode in a self-made tube electrolyzer. The electrochemical performances of the PbO₂ electrode in tube electrolyzer under different initial pH, electrolyte flow rates, current densities and times of the electrochemical degradation were investigated. The experimental results illustrated that the PbO₂ electrode can reduce the chemical oxygen demand (COD) of the textile effluent from 94.0 mg L^-1 to 65.0 mg L^-1 with the current efficiency of 88.3%, the energy consumption of 27.7 kWh kg^-1 (per kilogram of degraded COD) and the carbon emissions of 18.0 kg CO₂ kg^-1 (per kilogram of degraded COD) under the optimal operating conditions. In addition, the COD of the textile effluent could be reduced from 94.0 mg L^-1 to 22.0 mg L^-1 after the fifth electrochemical degradation. Therefore, PbO₂ mesh cylinder electrode in the tube cylinder was promising for the electrochemical degradation of the textile effluent.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.383-386
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• 2007

This paper describes the design and integration of the wind- fuel cell hybrid system. The hybrid system components included a wind turbine, an electrolyzer (for generation of H2), a PEMFC (Proton Exchange Membrane Fuel Cell), storage system and BOP (Balance of Plant) system. The energy input is entirely provided by a wind turbine. A DC-DC converter controls the power input to the electrolyzer, which produces hydrogen and oxygen form water. The hydrogen used the fuel for the PEMFC. The hydrogen is compressed and stored in high pressure tank by hydrogen gas booster system.

• Proceedings of the KIEE Conference
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• 2007.11c
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• pp.187-190
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• 2007

To improve the power factor and reduce the harmonic contents of the system, the design of tunned filters for six-pulse thyrister converter which is used by electrolyzer system is discussed in this paper. Tunned filters are added to high-power rectifiers to keep the line current distortion within allowable limits and to improve the rectifier power factor. For electrolyzer system, the design procedure of tunned filters of AC 14.4kV power system are proposed by dynamic simulation. It is shown that these harmonic filters can meet most operational requirments. The the proposed design procedure is verified with the simulation and experimental results.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.226-234
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• 2018

Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1130-1131
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• 2008

현재는 화석연료에서 신재생에너지로 에너지 패러다임이 변화하고 있는 시점이며, 신재생에너지를 보다 효율적으로 운영하여 효율성을 높이기 위해 많은 연구가 이루어지고 있다. 전기 에너지는 생산과 동시에 소비해야 한다는 특성을 가지고 있으며, 그 중 태양광 발전과 같은 신재생에너지원은 기후요인에 의해 출력이 결정되기 때문에 수요전력보다 공급전력이 많아 잉여전력이 생기거나 공급전력보다 수요전력이 많아 부족전력이 발생하여 전력품질을 악화시킬 수 있다는 단점이 있다. 본 논문에서는 이런 태양광 발전의 단점을 보완하기 위해서는 잉여전력이 발생한 경우는 Battery와 Electrolyzer를 이용하여 에너지를 저장하고 부족전력이 발생한 경우는 Battery를 이용하여 보상하는 방법을 제안하였다.