An Improved Three-Level LCC Converter with a Novel Control Strategy for High-Frequency High-Power-Density Capacitor-Charging Power Supplies

摘要

In this paper, the power factor concept of resonant converters is proposed and analyzed. A novel constant power factor control scheme for high-frequency high-power-density charging applications is proposed and studied. Based on this control scheme, the circulating energy of resonant converters is considerably reduced. Low switching losses are also achieved with very low turn off current. High efficiency can be obtained for high-frequency high- power (several kilowatts) charging applications. A 700kHz, 10kV three-level LCC resonant converter is designed to validate the proposed control scheme. The power density of 50W/inch~3 is achieved with over 88% efficiency at full load.