A Novel Scalable Multilevel PFC Rectifier Based on Full Binary-Tree Structure

This paper presents a novel scalable multilevel power factor correction (PFC) rectifier topology, termed the multilevel topology based on the full binary tree (MT-FBT). Through the utilization of new clamping units (NCUs), the MT-FBT constructs the multilevel network by successively binary partitioning the root node and extending it with branch nodes. Therefore, more voltage levels can be obtained due to a multiplying effect. Moreover, a computationally efficient carrier-overlapping pulse-width modulation (COPWM) strategy has also been employed to maintain the voltage balance of the DC-link capacitors. A four-level implementation is presented to demonstrate the operation principle, modulation method, and control scheme of the proposed topology. Finally, experimental results from a 1 kW prototype confirm that the MT-FBT meets the design criteria for both steady-state and dynamic performance.