A New Driving Compensation Strategy to Improve Current Symmetry of Integrated Buck-Boost-LLC Converter

The inherent characteristics of the integrated Buck-Boost-LLC converter lead to the asymmetry of its resonant tank voltage, which further leads to the asymmetry of the resonant current as well as the demagnetization of the transformer, which seriously affects the operation of the converter. In this paper, a drive compensation strategy is proposed to suppress the asymmetry of voltage and current. By compensating the drive signals, a balanced matching of the resonant tank voltage in each period is realized, which greatly suppresses the second harmonic component and significantly improves the asymmetry of the current, and the simulation results show that the proposed method can reduce the asymmetry of the current from 100% to 3.6% at most, which verifies the effectiveness of the proposed strategy.