The　matrix-type　ac-dc　dual-active-bridge　(DAB)　converter　is　a　promising　topology　for　single-stage　ac-dc　power　conversion,　recognized　for　its　high　power　density,　reliability,　and　efficiency.　This　converter　uses　small　capacitance　for　the　ac-side　filter,　typically　ranging　from　a　few　to　a　dozen　microfarads,　to　achieve　a　high　power-factor　(PF)　and　optimize　both　power　density　and　cost.　However,　the　relatively　small　ac-side　capacitance　can　cause　noticeable　capacitor　voltage　ripple　during　the　switching　cycle.　This　article　presents　a　time-domain　steady-state　model　to　accurately　characterize　the　steady-state　behavior　of　the　converter.　The　analysis　reveals　that　the　ac-side　capacitor　voltage　ripple　can　substantially　impact　the　performance　of　the　converter,　particularly　by　causing　the　front-end　circuit　to　lose　zero　voltage　switching　(ZVS),　thereby　reducing　efficiency　and　worsening　electromagnetic　interference　(EMI)　issues.　The　steady-state　model　is　then　used　in　an　optimized　modulation　strategy　to　determine　the　optimal　control　variables　to　ensure　ZVS　operation,　realize　power　factor　correction　(PFC),　and　enhance　efficiency.　Simulation　and　experimental　results　demonstrate　the　theoretical　analysis　and　validate　the　findings.　Specifically,　using　the　proposed　modulation　method,　compared　to　the　modulation　method　that　does　not　account　for　the　ac-side　capacitor　voltage　ripple,　the　efficiency　at　light-load　and　heavy-load　conditions　can　be　improved　by　over　11.21%　and　2.66%,　respectively.　　©　IEEE.　1986-2012　IEEE.