Abstract
In this thesis, a switched-reluctance generator (SRG) based DC micro-grid is established. It is equipped with a hybrid energy storage system composed of a flywheel and a lead-acid battery bank. The plug-in energy support through SRG power circuit from the utility grid is also implemented. The developed SRG is interfaced to the micro-grid common DC bus via an interleaved boost DC/DC converter. Well regulated DC bus voltage is obtained under varying shaft driving speeds and load conditions by properly treating the related key issues, such as power circuit design, robust voltage control, voltage command setting and commutation shift, etc. Also, lower input current ripples and higher reliability are preserved since the interleaving technique. To evaluate the established DC micro-grid experimentally, a three-phase load inverter with proper control is established. Good AC voltage waveform and dynamic response characteristics are achieved under linear and nonlinear load. In the developed hybrid energy storage system, the battery bank is interfaced to the common DC bus through a bilateral buck/boost DC/DC converter. Good charging and discharging characteristics are achieved through properly designing the power circuit and controllers. As to the switched-reluctance motor driven flywheel, the proposed bilateral boost/boost DC/DC converter is employed as its interface. Several discharging performance improvement approaches are proposed and comparatively evaluated. In the developed plug-in energy support mechanism, a single phase interleaved boost switched-mode rectifier is formed using the original SRG system components. The energy support from the mains to the micro-grid with good line drawn power quality is achieved.