1. Authors: Jun-Young Lee, Eun-Woo Lee, and June-Seok Lee

2. Title: Design of L-Filter for Single-Phase Grid-Connected3-Level Flying Capacitor Totem-Pole PFC

3. Journal: The Transactions of the Korean Institute of Power Electronics

4. Vol/no/pp: Vol.30/no.6/pp:468-475

5. Date: Dec. 2025

: This study proposes a design method for the filter inductor of a single-phase grid-connected three-level flying capacitor totem-pole PFC (3-L FCTP). The grid-connected filter inductor is designed on the basis of the correlation among inductance value, switching ripple current, DC-link voltage, and grid voltage. Accordingly, the relationship between AC output voltage and grid voltage is analyzed, and the switching ripple current is calculated. In the 3-L FCTP, the output voltage is generated in three levels by the flying capacitor. Therefore, this study analyzes the relationship between the inductor voltage and current ripple by dividing the output voltage into two cases. Subsequently, the correlation among inductance value, switching ripple current, DC-link voltage, and grid voltage is derived. The filter inductance for the target current ripple ratio is calculated by considering other operating conditions (switching frequency, DC-link voltage, and grid voltage). The validity and usefulness of the proposed design method are verified through simulation and experiment.