Water electrolyser model
designing for hardware-inloop test setup
Joonas Koponen, Antti Kosonen
/ Topics of the presentation
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Electric conditioning of water electrolyser systems
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Specific energy consumption of water electrolyser systems
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Faraday efficiency
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Model designing for the HIL setup
/ Power-to-Hydrogen research focus at LUT
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Power electronics, control, and dynamics
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Electrical behavior of water electrolysers
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Influence of different current waveforms
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System energy efficiency in conversion
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Operation with renewable energy systems
/ Conversion structures based on natural commutation
Source: Ursúa, A, Sanchis, P, & Marroyo, L 2013, “Chapter 14 - Electric conditioning and efficiency of hydrogen production systems and their integration with renewable
energies”, in: Gandia, L, Arzamendi, G, & Diéguez, P (eds.), Renewable hydrogen technologies, Elsevier, Amsterdam.
/ Three-phase, full-wave rectifier
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Based on thyristors, and diodes in half-controlled rectifiers, which switch according to the line-frequency
Source: Mohan, N, Undeland, T, & Robbins, W 2003, Power electronics: converters, applications, and design, John Wiley & Sons, New Jersey.
/ DC-current and voltage waveforms (1/2)
/ DC-current and voltage waveforms (2/2)
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/ Current component amplitudes as a function of load
.
/ Influence of power supply, literature review
Source: Ursúa, A, Sanchis, P, & Marroyo, L 2013, “Chapter 14 - Electric conditioning and efficiency of hydrogen production systems and their integration with renewable
energies”, in: Gandia, L, Arzamendi, G, & Diéguez, P (eds.), Renewable hydrogen technologies, Elsevier, Amsterdam.
/ Efficiency of water electrolyser systems
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Specific energy consumption:
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Efficiency, HHV:
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Possible error from the assumption that all electrons effectively contribute to the water splitting
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reaction
Definition of Faraday efficiency, the ratio between the actual and theoretical amount of hydrogen
produced
/ Faraday efficiency, literature review
Source: Ulleberg, Ø 2003, “Modeling of advanced alkaline electrolyzers: a system simulation approach”, International Journal of Hydrogen
Energy, vol. 28, no. 1, pp. 21–33.
/ Electrical behaviour of an alkaline electrolyser cell
/ Model design for the HIL setup (1/2)
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Enable the emulation of main water electrolysis technologies
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Model the electrical characteristics of a cell stack
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Current and voltage waveforms, phase-shift
impedance
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Calculate the voltage level according to the input current
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Mimic the impedance of a water electrolyser
Structure of the HIL setup:
1.
AC/DC rectifier
2.
DC/DC buck converter
3.
DC/DC boost converter, the modelled water electrolyser
4.
DC/AC inverter
The effect of different waveforms on the cell
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Communication to the converters in the HIL setup t = 10 ms
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Limitation on the electrolyser’s voltage level update rate
/ Model design for the HIL setup (2/2)
Thank you!
Questions? Comments?