Simulation, design, and control of stand-alone integrated wind-hydrogen power systems

Concerns about the environmental impact of carbon-based power production systems have drawn attention to clean renewable and alternative sources of energy. One of the sources of energy being harnessed is wind. A major challenge for wind turbines is matching the wind power supply curve with the time-dependant power demand of the load. In order to solve the problem, energy storage must be used in conjunction with the wind turbines. Gaseous hydrogen, despite of its low volumetric energy density, remains the favored method to store electric power for specific applications. Electrochemical devices such as proton exchange membrane (PEM) fuel cells and electrolyzers facilitate the use of hydrogen as an energy carrier and storage medium. Integration of the wind turbine with electrolyzer, fuel cell, load, and other devices is complicated. Since the input and output power of each device in the system are not regulated, the design and control of suitable power electronics based regulators are necessary. The output voltage of a PEM fuel cell stack for instance is uncontrolled DC voltage, which fluctuates with load variations. This unregulated DC voltage needs to be converted to a controlled DC voltage before feeding it to the inverter. DC/AC inverted power is required to supply an AC load. Design and control of power converters and inverters are necessary not only to regulate the electric power but also to improve the overall efficiency of the system. This research is aimed at addressing and studying the feasibility of stand-alone integrated wind-to-hydrogen power systems to bring emission free and reliable power towards commercial viability. Dynamic simulation of a fuel cell and an electrolysis stack will be compared with experimental results.;Electrochemical impedance spectroscopy (EIS) will be utilized to understand the electrical behavior of fuel cells and electrolyzers and will be used to extract the parameters of these devices for precise and realistic simulation studies. The system dynamics will be based on experimental data collected in the UND Hydrogen Laboratory. Controls and simulations will be implemented in a combined Matlab/Simulink/PSIM simulation environment.