2021 IEEE Applied Power Electronics Conference and Exposition (APEC) | 2021
A Constant Frequency Step-Up Resonant Converter With A Re-Structural Feature And A PWM-Controlled Voltage Multiplier
Abstract
This paper presents a new step up LLC resonant converter with re-structural feature that employs a novel pulse-width modulated (PWM) voltage multiplier. The proposed converter consists of a reconfigurable full-bridge to half-bridge inverter with fixed switching frequency at the input-side and a new PWM-controlled voltage multiplier rectifier at the output side. Wide voltage gain for different loading condition can be realized by adaptively changing the configuration at the input and controlling the duty ratio of the voltage multiplier in the output, with constant switching frequency. As a result, the circulating energy, and hence, the conduction losses of the LLC resonant tank are reduced. Zero voltage switching for all silicon carbide (SiC) switches and zero current switching for all the diodes are achieved for a wide range of voltage gain and loading conditions. Simulation and experimental results are provided on a laboratory scale 5kV, 4kW proof of concept prototype.