Ανάπτυξη Δυναμικού Μοντέλου Κυψέλης Καυσίμου Μεμβράνης Ανταλλαγής Πρωτονίων (PEMFC) και πειραματική επιβεβαίωση για βελτιστοποίηση της απόδοσης σε εφαρμογές ηλεκτροκίνησης

Abstract

The purpose of this thesis is the study of fuel cells as an alternative electric energy storage device. It overviews the theoretical background of this technology and the respective electrical equivalent circuits. Particular emphasis is given to fuel cells of proton exchange membrane type (PEM Fuel Cells), which are of particular interest because of their high power density, high efficiency, small start-up time and low operating temperatures. Because of these characteristics, PEM fuel cells are likely to play an important role not only in the transportation sector but also in many other applications in the near future. In a first step a functional description and representation of PEM Fuel Cells is undertaken and an equivalent electrical model for PEM fuel cells is developed concerning both steady state and dynamic behavior under load variations. This model can be used in state estimators for sensor-less control applications. It can also be implemented in the design of power electric drives for transportation systems. Finally, experimental validation is performed in the proton exchange membrane fuel cell stack of 500W used in the research prototype vehicle “Prometheus” developed by the respective team of the Laboratory of Electrical Machines and Power Electronics of NTUA.