Since September 2016, a team from the GREEN laboratory (Research Group in Electrical Energy of Nancy) has been created within the IUT of Longwy. The research activities of this team focus on the development of power converters for electrolyzers and on the energy management of multi-source systems composed of renewable energy sources (wind, photovoltaic), and hydrogen technologies (fuel cell and electrolyzer). These two research themes require skills in automatic control, particularly for control aspects and electrical fault tolerance (diagnosis, fault-tolerant controls). The IUT of Longwy is equipped with 3 renewable energy sources: a horizontal axis wind turbine, a vertical axis wind turbine, and photovoltaic panels. It is therefore natural that a collaboration around the use of hydrogen in the context of renewable energies and energy storage was initiated between this GREEN team and researchers from the CRAN located on the Longwy site: Hugues RAFARALAHY, Mohamed BOUTAYEB and Michel ZASADZINSKI for the CRAN and Damien Guilbert for the GREEN. The partners of this demonstrator dedicated to the use of hydrogen in the context of renewable energies and energy storage are the CRAN, the GREEN and the IUT Henri Poincaré de Longwy.
In the development of technological strategies to counteract global warming, it is important to develop solutions to store electrical energy and then distribute it according to needs, as this energy cannot be stored on the EDF network. Hydrogen represents an attractive and promising solution for storing and providing electrical energy already produced, hydrogen-based technologies are well suited to the modularity of renewable energy sources.
Currently, this collaboration focuses on the modeling and control of a power converter to power an electrolyzer within a hydrogen production chain based on a wind system. The main drawback of a wind system is its intermittent production of electrical energy due to weather conditions. To ensure good performance of the electrolyzer, the current or voltage at the output of the converter must be controlled to cope with the dynamics of the wind system. In particular, it was decided to control one of these two parameters at a specific operating point in order to optimize the overall efficiency of the system including the power converter and the electrolyzer. This operating point can be determined by conducting a thorough study of the energy efficiency of the power converter and the electrolyzer.
To test the developed control laws, a special experimental test bench has been made. The bench allows to emulate a wind system powering a proton exchange membrane electrolyzer. An article in the International Journal of Hydrogen Energy published in January 2021: R. Maamouri, D. GUILBERT, M. ZASADZINSKI, H. RAFARALAHY, "Proton exchange membrane water electrolysis: modeling for hydrogen flow rate control".
The next step in this collaboration will be to integrate a fuel cell into the hydrogen production chain containing the electrolyzer and to develop control laws taking into account the operating conditions of the fuel cell based on its hydrogen consumption, on the one hand, and the electrolyzer based on its hydrogen production, on the other.
This demonstrator currently consists of the following elements:
— a proton exchange membrane electrolyzer;
— an alkaline electrolyzer;
— a proton exchange membrane fuel cell;
— a control/command system consisting of a PC, a DSPACE rapid prototyping module equipped with a connector panel, Matlab/Simulink software;
— various measuring devices: ammeter clamps, voltage probes, digital oscilloscopes, ...