A Variable Frequency ZVS Control of a Three-level Buck without Zero Crossing Detection for Wide-Range Output Voltage Battery Chargers

In this paper, a variable frequency soft-switching control for a three-level half bridge (TLHB) buck converter is proposed to achieve wide-range output battery charging function without losing zero voltage switching (ZVS) or high efficiency. The adopted variable frequency triangle-current-modulation (TCM) is based on dc measurement and average-model calculation, thus able to realize ZVS operation fully digitally without current zero-crossing-detection (ZCD) circuits. A top-level average current or output voltage feedback controller further ensures the desired power or output voltage regulation. Experimental results from a GaN based TLHB prototype have shown the reliable TCM control and smooth transition of ZVS operation through the charging procedure.

[1]  J. W. Kolar,et al.  Optimal design of a 5kW/dm3 / 98.3% efficient TCM resonant transition single-phase PFC rectifier , 2010, The 2010 International Power Electronics Conference - ECCE ASIA -.

[2]  Dushan Boroyevich,et al.  Variable frequency and constant frequency modulation techniques for GaN based MHz H-bridge PFC , 2015, 2015 IEEE Applied Power Electronics Conference and Exposition (APEC).

[3]  Xinbo Ruan,et al.  Soft-switching PWM three-level converters , 2001 .

[4]  Daniel Costinett,et al.  A High-Efficiency GaN-Based Single-Stage 6.78 MHz Transmitter for Wireless Power Transfer Applications , 2019, IEEE Transactions on Power Electronics.

[5]  C. W. Tipton,et al.  A Fault Detection and Protection Scheme for Three-Level DC–DC Converters Based on Monitoring Flying Capacitor Voltage , 2012, IEEE Transactions on Power Electronics.

[6]  J. W. Kolar,et al.  Comparative evaluation of a Triangular Current Mode (TCM) and Clamp-Switch TCM DC-DC boost converter , 2016, 2016 IEEE Energy Conversion Congress and Exposition (ECCE).

[7]  Bo Liu,et al.  Capacitor-Clamped, Three-level GaN-Based DC–DC Converter With Dual Voltage Outputs for Battery Charger Applications , 2016, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[8]  Xinbo Ruan,et al.  Fundamental Considerations of Three-Level DC–DC Converters: Topologies, Analyses, and Control , 2008, IEEE Transactions on Circuits and Systems I: Regular Papers.

[9]  J. W. Kolar,et al.  Interleaved Triangular Current Mode (TCM) resonant transition, single phase PFC rectifier with high efficiency and high power density , 2010, The 2010 International Power Electronics Conference - ECCE ASIA -.

[10]  Fred C. Lee,et al.  A zero-voltage and zero-current switching three-level DC/DC converter , 2002 .

[11]  Young-Jin Woo,et al.  A zero current detector with low negative inductor current using forced freewheel switch operation in synchronous DC-DC converter , 2014, 2014 IEEE Fifth International Conference on Communications and Electronics (ICCE).

[12]  Fred C. Lee,et al.  Design of GaN-based MHz totem-pole PFC rectifier , 2015, 2015 IEEE Energy Conversion Congress and Exposition (ECCE).