Research on Interleaving Control Strategy on BFBIC-IPOS

Photovoltaic high voltage DC converters are difficult to match suitable power devices due to their high output voltage. In order to reduce the voltage stress of the power device, this paper adopts a Boost-based full-bridge boost isolation topology input parallel output series(BFBIC-IPOS) structure, and apply it to high-power, high-ratio photovoltaic high-voltage DC grid-connected converter. However, when the multi-module series, the phase and frequency of the PWM wave of each module have deviations due to the mismatch of the crystal oscillator frequency of the controller, causing a large output current ripple. In this paper, an interleaving control strategy is proposed to balance output voltage and suppress the output current ripple. Finally, according to the simulation results and experimental verification, we can obtain that the interleaved control can effectively reduce the output current ripple, and the ripple coefficient meets the requirements of high-power, high-transformation ratio HVDC converters.