The invention patent “A Control Method for a Three-Level Converter and Related Components” applied for by the ZJU-PMIC team was granted authorization by the China National Intellectual Property Administration on March 3, 2026, demonstrating the ZJU-PMIC team’s independent innovation capability in the field of power electronics technology.
This patent mainly addresses the control challenges of three-level converters and proposes a self-voltage-balancing topology based on flying-capacitor three-level (FC-3L) technology and its control method.
This scheme cleverly introduces a set of auxiliary clamping diodes on the basis of the traditional FC-3L circuit. By adjusting the duty cycle of the switches, the flying capacitor voltage is dynamically clamped to the midpoint of the bus voltage, thereby achieving excellent natural voltage balancing under open-loop conditions.
Clamping mechanism under asynchronous duty cycle control
As the most commonly used multilevel converter today, the three-level converter offers low voltage stress on switching devices and small output voltage harmonics. At the same time, an increased number of levels helps reduce the volume of magnetic components and improve the power density of prototypes. This scheme fully leverages the advantages of three-level converters and provides a technical path for the design of high-efficiency, miniaturized power electronic converters.
Three-level hybrid clamping Buck prototype
The patent was filed on October 17, 2022, and incorporated into the PMIC patent pool, open for general licensing to member units that remained active in 2022. Patent summary: A Control Method for a Three-Level Converter and Related Components – PMIC
This patented technology has been applied to the PMIC research project **”Research on 240W High-Efficiency High-Density PD Adapter.”** Project result summary: Design and Verification of a 240W High-Efficiency High-Power-Density PD Adapter (June 2024) – PMIC
To learn more about the technical reports related to this project, members can log in and access: Special Topic: A Control Method for a Three-Level Converter and Related Components – PMIC
