Abstract
This thesis develops the plug-in energy support systems for a wind switched- reluctance generator (SRG) based DC micro-grid. The auxiliary energy support from the accessible AC or DC sources can be achieved as the energy deficiencies of wind source and storage devices occur. First, an available wind SRG based micro-grid is redesigned and employed as the studied platform. It is equipped with a hybrid energy storage system consisting of a flywheel, a lead-acid battery bank and a super-capacitor bank. The common DC bus voltage of micro-grid is established by the SRG via an interleaved boost DC/DC converter. Thanks to the interleaving approach, the well-regulated DC bus voltage with lower ripple and fault-tolerance is preserved. For performing experimental test, a three-phase load inverter is established. The balanced three-phase voltages with good waveform and dynamic response characteristics are obtained by applying the designed space-vector PWM switching and dynamic control schemes. In the hybrid energy storage system, while the super-capacitor bank is directly connected across the SRG output, the battery and the switched-reluctance motor (SRM) driven flywheel are respectively interfaced to the common DC bus via a bilateral buck/boost-buck/boost DC/DC converter and an one-leg bilateral buck-boost DC/DC converter. In the developed single-phase AC source plug-in energy support systems (ESSs), two schematics are proposed: (i) Single-phase SMR based ESS: an external SMR is added to excite the 400V micro-grid bus from the mains; and (ii) Single-phase buck and buck-boost SMR based ESSs: only a full-bridge diode rectifier and an AC-side low-pass filter are externally added. A buck SMR or a buck-boost SMR is formed using the embedded power devices to dedicatedly charge the flywheel and battery bank. As to the three-phase AC source plug-in ESS, an extra three-phase Vienna SMR is equipped. Through proper arrangement and control, the micro-grid can be supported auxiliary energy from three-phase AC, single-phase AC or DC source.