This　paper　proposes　a　three-phase　quasi-Z-source　grid-connected　inverter　with　strong　boost　ability　and　three　kinds　of　simple　boost　modified　space　vector　modulation　(SVM)　strategies.　Two　existing　kinds　of　modified　SVMs　were　used　as　the　simple　boost　modulation.　The　characteristics　of　the　inverter　with　five　kinds　of　simple　boost　modified　SVM　strategies　were　deeply　investigated　and　compared,　including　the　switching　losses　of　the　inverter　bridge　and　the　impedance　network　diode,　the　loss　of　the　energy　storage　inductor,　the　current　ripples　of　the　energy　storage　inductor　and　the　filter　inductor,　and　total　harmonic　distortion　(THD)　of　output　grid-connected　current.　It　is　concluded　that　the　overall　performance　of　the　inverter　is　the　best　with　the　simple　boost　modified　SVM　that　has　four　shoot-through　segments　between　active　vectors　and　traditional　zero　vectors.　The　quasi-Z-source　grid-connected　inverter　is　composed　of　a　large　boost　ratio　quasi-Z-source　impedance　network　and　a　three-phase　inverter.　The　simple　boost　modified　SVM　strategy　has　many　advantages,　such　as　fully　utilizing　zero　vector　action　time,　low　switching　loss　and　voltage　stress,　strong　boost　capability.　The　feasibility　of　the　inverter　and　the　correction　of　theory　analysis　were　verified　by　the　experiments.　It　lays　a　key　technical　foundation　on　new　energy　grid-connected　power　generation　systems　such　as　photovoltaic,　wind.　©　2018,　Electrical　Technology　Press　Co.　Ltd.　All　right　reserved.