Abstract
This thesis presents the development of a home microgrid with multiple renewable sources and energy storage devices. Its 400V common DC bus voltage can be established by DC-DC and AC-DC interface converters from possible sources. The specific sources studied here include photovoltaic (PV) DC and AC sources. The PV source with nominal voltage of 48V is boosted to 400V using two interleaving boost DC/DC converters. As to the AC source, it is connected to the common DC bus via a properly designed Vienna three-phase switch-mode rectifier (SMR). The AC source can be the utility grid and permanent-magnet synchronous generator (PMSG). The developed energy storage system consists of a Li-ion battery bank, a super-capacitor bank and a flywheel, and the last one is substituted by an available reaction wheel owing to the lack of facility. Each storage device is interfaced to the 400V common DC bus by a bidirectional DC-DC converter. Through proper designs of power circuit and control scheme, the satisfactory charging and discharging control performances are achieved. In energy management control, the quick programmed energy support from the storage devices can be provided as the main source failure occurs. On the other hand, the established Vienna SMR can also be acted as a plug-in changer to charge the storage devices from the mains for the occurrence of long-term renewable energy exhaustion. To provide the commonly used AC sources for the home appliances, a single-phase three-wire (1P3W) inverter is developed to yield 220V/110V AC outputs from the 400V DC grid. An off-the-shelf three phase intelligent power module (IPM) is employed to form this 1P3W inverter, a master and a slave control schemes are proposed to handle the two output waveform regulation controls. While the outside two legs of IPM are arranged to produce the 220V-voltage output, the middle leg is in charge of regulating the balance of two 110V-voltage outputs. Good inverter sinusoidal output waveforms are preserved under unknown loads via the developed control technique. In the promotion of system miniaturization, only two IPMs are utilized to form the interfaced converters for the DC main source, the energy storage devices, and the 1P3W load inverter. Wherein the two interleaving DC/DC boost converters are constructed using the two brake legs in the employed IPMs. As to the three-phase Vienna SMR, the dedicated commercial power device is used to form its power circuit. In digital control affair, two digital signal processors (DSPs) are employed to realize all the control algorithms of the whole microgrid system, one for the SMR and the other one for all other power stages.