Analysis to Input Current Zero Crossing Distortion of Bridgeless Rectifier Operating under Different Power Factors

摘要

The principles and operating characteristics of bridgeless rectifiers under different power factors are discussed with emphasis on analyzing the input current distortion. Firstly, two driving modes are analyzed and compared. Based on the results of comparison it is concluded that the complementary drive mode is a better choice in terms of reducing the current distortion when bridgeless rectifier operates on non-unity power factor. Then, the mechanism causing input current zero-crossing distortion is analyzed. The input current during the distortion is expressed by the piecewise function when a bridgeless rectifier operates under complementary drive mode. Based on the piecewise function, the harmonic analysis is performed. Besides, the relationships between the input current Total Harmonic Distortion (THD) and the filtering inductance, the input current amplitude and the power factor angle are also investigated, which is useful when designing bridgeless rectifiers and selecting the corresponding parameters. Finally, the accuracy of the theoretical analysis is verified through the simulation and experiment.