Byoung-Seoup Lee, “저가형 전해조 장치와 DC-DC 컨버터를 이용한 수소발생시스템,” 아주대학교 공학박사 학위 논문, 2016. > Paper

An electrololysis system separates water molecules into hydrogen and oxygen, which are one of chemical reactions. It consist of an

electrolyzer and a power supply system. To generate the chemical reaction in electrolyzer, dc-power should be supplied to

electrolyzer. In this paper, low cost electrolyzer and the power supply for supplying dc-voltage to electrolyzer is proposed. The

proposed alkaline electrolyzer is composed of stacks, steam separators, a water storage tank and pumps. A cell consist of SUS sheet,

polymer separator, gasket and nickel electrode. Porous nickel foam is compressed and sintered to produce porous nickel electrode,

which is electro-catalytic layer and flow route of produced gas and electrolyte mixture. A cell is piled up several times to produce

Stack. Electrolyte with KOH solution entering the stack branch with anode and cathode path, dc-power supplied to stack, the stack

generate hydrogen and oxygen with electrochemical reaction. The proposed power supply system consists of a diode rectifier, a full-

bridge DC-DC converter, a transformer, and an output filter. Firstly, the electrical characteristic of electrolyzer is analyzed. Secondly,

this paper introduces the design process of the power supply system for achieving small size. This includes the proper switching

device, switching frequency selection method, design method of high frequency transformer and output filter. Finally, a hybrid voltage

and current control methods for the dc power supply system are proposed. The simulations and experiments are carried out to verify

the performance and effectiveness of the proposed power supply system with small size for electrolyzer.