Model-based control design for H2 purity regulation in high-pressure alkaline electrolyzers

This paper proposes two control strategies that mitigate the cross contamination of H and O in a high-pressure alkaline electrolyzer, which consequently increases the supplied gases purity: one based on a decoupled PI scheme and the other based on optimal control tools. In order to reduce the diffus...

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Detalles Bibliográficos
Autores: David, Martín, Bianchi, Fernando D., Ocampo-Martínez, Carlos, Sánchez-Peña, Ricardo S.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/261232
Acceso en línea:http://hdl.handle.net/10261/261232
Access Level:acceso abierto
Palabra clave:Hydrogen
Alkaline electrolysis
Multivariable control
H1 optimal control
Descripción
Sumario:This paper proposes two control strategies that mitigate the cross contamination of H and O in a high-pressure alkaline electrolyzer, which consequently increases the supplied gases purity: one based on a decoupled PI scheme and the other based on optimal control tools. In order to reduce the diffusion of gases through the membrane, the controllers establish the opening of two outlet valves based on the pressure of the system and the difference in liquid level between both separation chambers. Therefore, two multiple input - multiple output controllers are designed here. For this purpose, a high-fidelity model previously developed was simplified in order to obtain a control-oriented model. The proposed controllers were evaluated in simulation using the high-fidelity nonlinear model in a wide operating range, which resulted in less than 1% impurity of gases.