A unified control strategy for improved performance of Totem-Pole Power Factor Correction Boost Converter

The Totem-Pole Power Factor Correction (TP-PFC) boost converter is gaining popularity due to its bridgeless topology for rectification purpose. The performance of such converter is affected by numerous factors as reported in the literature. In this work, a new control strategy for the improved performance of the TP-PFC boost converter is proposed with a focus on the following issues. The occurrence of current spike at the zero-crossing of input current is eliminated by introducing a dead-zone. The mixed conduction mode operation of the TP-PFC is avoided at light load conditions using a variable switching frequency scheme, which also improves the THD. Further, the response of the slow DC voltage control loop affects the dynamic response of the converter. The occurrence of a transient condition is detected in this work, and the voltage controller parameters are modified to speed up the voltage response. Thus, a unified controller combining all the above aspects has been developed, and the working of the proposed control strategy is verified through extensive simulation. The improved performance is also validated against that of the conventional control strategy.