Middle-stage current-fed high-frequency-link inverter (MSCF-HFLI)

This paper presents a new middle-stage current-fed high-frequency link inverter (MSCF-HFLI). The proposed inverter only contains one passive buffering energy element comparing with conventional resonant type HFLI, which at least has two passive buffering energy elements. The topology of the proposed inverter is given and the operational principle in a line-frequency cycle is analyzed, which is similar to that of Buck converter in current discontinuous conduction mode (DCM). The constraint relationship, which the proposed inverter must be obeyed, is derived. According to this mathematical relationship, a closed-loop control strategy is proposed for MSCF-HFLI. Experimental verifications are presented to verify the analysis.