Improved Hydrogen-Production-Based Power Management Control of a Wind Turbine Conversion System Coupled with Multistack Proton Exchange Membrane Electrolyzers

Abstract

This paper deals with two main issues regarding the specific energy consumption in an electrolyzer (i.e., the Faraday efficiency and the converter topology). The first aspect is addressed using a multistack configuration of proton exchange membrane (PEM) electrolyzers supplied by a wind turbine conversion system (WTCS). This approach is based on the modeling of the wind turbine and the electrolyzers. The WTCS and the electrolyzers are interfaced through a stacked interleaved DC–DC buck converter (SIBC), due to its benefits for this application in terms of the output current ripple and reliability. This converter is controlled so that it can offer dynamic behavior that is faster than the wind turbine, avoiding overvoltage during transients, which could damage the PEM electrolyzers. The SIBC is designed to be connected in array configuration (i.e., parallel architecture), so that each converter operates at its maximum efficiency. To assess the performance of the power management strategy, experimental tests were carried out. The reported results demonstrate the correct behavior of the system during transient operation.

AC-DC Converters for Electrolyzer Applications: State of the Art and Future Challenges

“…The authors studied these issues considering the dynamic model of a PEM electrolyzers in [28]; different converter topologies and related control systems have been discussed in [18,29] and converters supplied by wind generators in [16,30].…”

“…Another interesting configuration consists of coupling a six-pulse diode bridge rectifier with a two-phase stacked interleaved buck converter (SIBC) as shown in Figure 15. It was first introduced in [16,18] to control the electrolyzer according to the available power from a wind turbine conversion system.…”

“…Since high-voltage are generated, thyristor-based rectifiers are particularly fit for alkaline electrolyzers requiring large currents. On the other hand, for chopper-rectifiers, the electrolyzer can be controlled through its voltage and current [15,16]. For small-scale electrolyzers [17], since the stack voltage range is quite small compared to the current range, it is interesting to control the current to enhance the management of the hydrogen flow rate and energy efficiency.…”

“…For low-and medium-power applications, diode rectifiers coupled with DC choppers (buck, interleaved buck converter, stacked interleaved buck converter) are the most suitable [15,16]. Power quality, energy efficiency, control, and reliability are not the only issues, but there is also the current ripple generated from rectifiers and DC choppers.…”

Faraday’s Efficiency Modeling of a Proton Exchange Membrane Electrolyzer Based on Experimental Data

“…Given that higher pressures lead up to the decrease of Faraday's efficiency and energy efficiency as well, the hydrogen pressure and membrane thickness are challenging issues and must be optimized to enhance the energy efficiency of the electrolyzer [31]. To optimize the Faraday's efficiency, some authors [32,33] have proposed to control power electronic converters connected to a PEM electrolyzer for specific operating conditions (i.e., stack voltage and current).…”