The Research Of A Novel High Efficiency PFC Circuit Based On One Cycle Control

As a major measure to reduce harmonic pollution and improve power quality, Active Power Factor Correction (APFC) has being concerned by people all over the world and becoming the popular area. In this thesis, a novel high efficiency PFC circuit based on One Cycle Control (OCC) has been researched, which improved many flaws in traditional PFC circuit widely used now.Topology of the traditional PFC circuit is Boost circuit with Rectifier Bridge, which have a larger conduction loss. So this thesis compared and analyses two novel high efficiency PFC circuit topology derived by Boost circuit, especially analyses the common mode interference in each circuit, and then chose the Bridgeless Boost circuit with one single inductance as the PFC circuit topology in this thesis.Direct current control strategy with multiplier is widely used in PFC circuit, which has a complicated structure and poor interference immunity. So the One Cycle Control has been introduced in the PFC circuit in the thesis. Its control principle and performance advantage has been analyzed. According to comparative study on control characteristics of OCC used in PFC circuit at different mode of inductor current, decided the specific structure of control circuit.This thesis combined the novel topology and the novel control strategy (OCC) mentioned above to get a simple, efficient PFC circuit with ideal correction effectiveness. According to the analysis, this PFC circuit has many special properties such as good interference immunity and the capability of continual Power Factor Correction. Computer simulation has verified the theoretical analysis and the effectiveness of the control strategy.The current detecting circuit of this PFC scheme would be more complex than traditional PFC circuit because of its unique topology and require of control. For that, the thesis designed a new detecting circuit used hall current sensor and absolute circuit, which achieved accurate and reliable detection of current.Finally, a 400W novel high efficiency PFC circuit based on OCC has been manufactured to verify the analysis above. The experimental tests and results indicated that the PFC circuit designed in this thesis can achieve the function of active power factor well and possesses more advantages than traditional PFC circuit.