Fuel cell simulator system

Abstract

Applied research and development of Fuel Cell (FC) power electronics is currently expensive and difficult to carry out due to high cost and lack of flexibility of FC stacks. Flexible affordable FC simulators are required to assist the development and testing of FC power electronics. Using FC simulators results in significant cost, space, and time reductions. It also provides a solution for safety standards problems and overcome the major issue of power sizing in FC stacks. A FC simulator can be constructed using a power converter that follows a reference signal generated by a FC model. The output voltage of the power converter is then controlled to behave according to the FC output characteristics. This thesis describes in detail the development of two different FC simulator systems namely, a stand-alone FC simulator based on an empirical model and a low cost Digital Signal Processor (DSP), and real-time FC simulator based on a small single cell. A special fast dynamics power converter for FC simulators is designed, taking into consideration the dynamic requirements to successfully reproduce the behavior of a FC. A control scheme based on switching surface control is investigated to achieve near time optimal response in the converter. Laboratory prototypes of the two systems are implemented and investigated. It is shown that the first system provides the advantages of eliminating the dependence upon a computer, communication cards, and licensed software, thus resulting in a small low-cost system suitable for laboratory operation. The second system overcomes modeling drawbacks and expands the features of the existing designs by replacing the computer model of the FC with an actual small single FC. Experimental and simulation results are provided in the thesis to confirm the behavior of the simulators.