Abstract
Due to less limitation of space and noise problems, vertical small-scale wind power generation systems are becoming more and more popular distributed clean energy sources in residential areas. In order to further increase the overall system efficiency and decrease the cost, many efforts are made to improve the converter efficiency as well as the corresponding maximum power point tracking control. Hence, the major motivation of this thesis is focused on the above two issues. Basically, the major contributions of this thesis may be summarized as follows. First, a novel single-stage boost-buck AC/DC converter is proposed to integrate with the brushless DC generator (BLDCG) to achieve more flexible control and improve the converter efficiency. Second, the mathematical models of the proposed BLDCG and converter are derived for convenient closed loop control design. Also, synchronous rectification control and a novel generator current commutation ripple reduction control are integrated at the same time to enhance the system performance. Third, a novel maximum power point tracking control is proposed for extracting more wind power while the wind speed is changing dynamically. Finally, a 200W rating vertical BLDC wind power system is constructed for testing the effectiveness of the proposed control. Experimental results show that a maximum converter efficiency of 95.1% can be achieved and the efficiency remains above 90% as the load is varied from 20W to 200W.