Abstract
Wind energy and solar energy, due to their inexhaustible supply and environmentally clean characteristic, are probably two kinds of most potential renewable energy for recent development. In Taiwan area, the solar energy is quite rich during the day while the wind energy is usually available during the night. Hence, it is the main objective of this thesis to focus on the implementation of a photovoltaic (PV) and wind power hybrid generating system to enhance the utilization rate and efficiency of the system. Also, in order to reduce the installation cost, the concerned hybrid system is supposed to be connected to the grid system. Basically, the contributions of thesis may be summarized as follows. First, a new configuration of a grid connected PV and wind power hybrid generating system is proposed. Only two three-phase Insulated Gate Bipolar Transistor (IGBT) modules are required for implementing the ten active switches to achieve more compact volume and higher reliability. Second, the dc link voltage is stabilized by controlling the reactive power from the grid system and served as a basis for integrating the control of different renewable energy source. Third, by using the concept of conservation of energy, a dynamic model of the proposed hybrid generating system is derived and four control modes are defined to achieve the corresponding d-axis current commands for integrating into a total input command of the hybrid system. Since the real power control is independent of the reactive power control of the dc link voltage, fast response together with better power quality control can be achieved. Fourth, as far as the operation of the hybrid system is concerned, five operation modes, namely, the starting mode, normal operation mode, emergent control mode, power quality control mode and the shut down mode, are defined for convenient control and maintenance of the hybrid system. Finally, a prototype is constructed and experimental results are presented for verifying the feasibility of the proposed hybrid system.