Power　decoupling　is　always　a　strong　desire　for　single-phase　voltage　source　inverter　(VSI)　due　to　the　inherent　double-line　(2　omega)　frequency　ripple　caused　by　the　instantaneous　power　unbalance　between　dc-　and　ac-side.　The　existing　solutions　either　apply　a　large　capacitor　or　employ　a　small　power　converter　to　compensate　it,　which　inevitably　increases　the　system　cost　and　control　complexity.　To　overcome　these　drawbacks,　this　article　performs　the　transient　modeling　analysis　and　it　reveals　that　2　omega　frequency　power　component　in　the　converter　achieves　minimum　value　when　the　inductor　current　ripple　is　minimized.　A　novel　capacitors＇　voltage　ripple　complementary　control　algorithm　based　on　three-level　boost　fed　single-phase　VSI　is　proposed.　By　mitigating　the　2　omega　power　component　from　the　inductor　and　redistributing　the　stored　energy　between　two　intermediate　series-connected　capacitors,　the　oscillating　power　is　absorbed　with　notably　eliminated　input　current　ripple　and　significantly　reduced　dc-link　voltage　ripple.　Thus,　the　good　power　quality　of　both　dc-　and　ac-side　is　guaranteed.　Furthermore,　the　total　capacitance　requirement　is　minimized　under　the　given　dc-link　ripple　tolerance　without　any　more　electric　stress　increment　and　lifetime　reduction.　Simulation　and　experiment　results　verify　the　theoretical　analysis　and　proposed　control　method.　It　is　promising　in　applications,　where　both　input　current　ripple　is　strictly　limited　and　ac　output　voltage　quality　is　highly　required　with　small　dc-link　capacitance.