Abstract
Due to the limited space and noise considerations, a small-scale vertical wind power generation system (WPGS) is rather suitable for residential or other applications. However, for low cost purpose, it usually consists of a three-phase diode bridge cascading another DC converter for maximum power tracking control. Hence, the generator currents will contain harmonics which will result in additional mechanical stress, noise and losses. Therefore, the objective of this thesis is aiming at developing a novel single stage three-phase AC/DC converter to reduce the harmonics and noise as well as enhancing the efficiency. Basically, the major contributions of this thesis may be summarized as follows. First, a novel single-stage three-phase AC/DC converter is proposed for the small scale WPGS. This new topology requires only three active switches with common source terminal and are turned on/off simultaneously under discontinuous conduction mode to reduce the current THD. Besides, the stored energy of the leakage inductance can be recovered and the voltage stresses of the active switches are reduced by about 50%. Second, the corresponding mathematical model is derived for steady state characteristic analysis and parameter determination for converter design. Finally, a 200W prototype is implemented for verifying the validity of the proposed converter. It is seen that the resulting generator current THD can be reduced to below 5% and the efficiency is between 90% and 92% when the load is from 20W to 200W.