LAUSR

The single-phase high frequency link (HFL) matrix-type DC-AC converter has been widely explored due to its high efficiency, light weight, and high power density, which offers galvanic isolation power conversion without bulky dc link capacitors and soft-switching operation. Different from traditional two-level DC-AC converters, the single-phase HFL matrix-type DC-AC converter has no double-line frequency ripple voltage on the DC side, but the ripple appears on the clamp capacitor, which has not yet been investigated in detail so far. In this paper, the mechanism of the double-line frequency ripple voltage of the clamp capacitor in the single-phase HFL matrix-type DC-AC converter is comprehensively explored, and a mathematical model of the HFL matrix-type DC-AC converter is established. To suppress the effect of the double-line frequency ripple voltage on the power quality and guarantee the good power quality of the AC side, a multi-resonant (MPR) controller is applied to reduce voltage harmonic distortions. A 20-kHz HFL matrix-type DC-AC converter prototype is built. Experimental results have verified the effectiveness of the analysis and applied control scheme.