Performance Evaluation of Single Stage Three Level Resonant AC/DC Converter Topologies

In this paper the performance of different three-level resonant converters is studied for single stage power factor correction operation. These converters are suitable for higher power ranges than the available single stage converters due to their high efficiency and reduced component stresses. All converters presented here are characterized by their ability to regulate the output voltage as well as the dc-bus voltage. This leads to obtaining lower voltage stresses, wide input voltage range, higher output power applications and improved efficiencies compared to existing single stage topologies. Due to the availability of more degrees of freedom in the presented converters, two types of control strategies can be used for this purpose: variable-frequency-PWM control and variable-frequency-phase-shift control. Three resonant converters were studied in this paper; where their performances as well as the applicability of the aforementioned control methods for each converter is compared. A 2.3 kW, 48 V converter with input voltage range of (90-265 Vrms) is used to study the performance of each case