Abstract
With 700 V bus voltage in the SiC bidirectional LLC converters, high dv/dt is up to 35 kV/μs with 20 ns switching speed, which causes high common mode noise and poses serious challenge for synchronous rectification (SRs) control. A digital bidirectional SR online calculation control is proposed for 700 V high voltage at 300 kHz. It not only achieves bidirectional operation with high efficiency, but also applies to high voltage since it owns high immunity to the switching noise without any detection circuits. The mathematical model is built to calculate the SR conduction time online in the forward and reverse modes, and determine the SR turn off instant considering the switching frequency and load. The transformer dc bias is analyzed in the reverse mode. A 6.6-kW SiC bidirectional portable charger was built. The LLC efficiency of forward and reverse modes is improved by 0.3% and 0.2% over the conventional SR control at full load, respectively.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
