Semi-digital SFVM-M3 control scheme for a two-phase interleaved TM boost PFC converter

This paper proposes a semi-digital synchronized-OFF voltage-mode Master-Made-Modulation (SFVM-M³) control scheme for a two-phase interleaved CCM/DCM transient-mode (TM) boost PFC converter. Synchronized-OFF operation can maintain the zero-current turn-on for both Master unit and Slave unit, whatever the mismatched inductances and synchronized signal. However, there is an existed current divergence issue in the boost inductor of the Slave unit by using conventional SFVM control. The SFVM-M³ is proposed to resolve the problem by applying the M³ signal, which can eliminate the phase error between Master unit and Slave unit cycle-by-cycle. The proposed scheme is implemented by a semi-digital controller in this paper, which the synchronized-OFF signal is generated by a fast analog circuit, and the SFVM-M³ control algorithm is designed in a digital signal processor dsPIC33FJ16GS504. The experimental results are given to verify the feasibility of the proposed semi-digital control scheme.