Comparison of the Variable-Frequency and Phase-Shift Control Based on the Three-Level Resonant Converter

The three-level resonant converter achieves soft-switching to lower the power loss and can be utilized in applications with high input voltages. Variable-frequency control is popularly used because of its gain characteristic, while phase-shift control can also be used because of the three-level structure. This paper presents a comparison of the two different control strategies based on the three-level resonant converter. The resonant converter with two control strategies should achieve voltage stability on the foundation of soft-switching. The feasibility of the two control strategies can be verified, and the theoretical analysis was conducted in the simulation results.