A　novel　three-phase　Boost　mode　photovoltaic　(PV)　grid-connected　inverter　was　proposed.　The　topology,　two-loop　modified　zone　SPWM　control　strategy,　low　frequency　mode,　suppression　of　the　energy　storage　switch　turn-off　voltage　spike,　high　frequency　switching　process,　maximum　power　point　tracking　(MPPT)　of　PV　cells　and　design　criteria　of　key　circuit　parameters　were　deeply　investigated,　and　important　conclusions　were　obtained.　The　circuit　topology　is　a　cascade　of　the　input　filter　capacitance,　the　center-tapped　energy　storage　inductance,　three-phase　inverting　bridge　and　three-phase　output　filter,　and　there　is　an　energy　storage　switch　connected　between　the　center　tap　of　the　energy　storage　inductance　and　the　negative　end　of　the　input　source;　the　control　strategy　is　that　three-phase　grid　voltage　is　divided　by　60°　to　guarantee　the　operating　mechanism　of　the　current　converter　is　satisfied　in　every　switching　period.　The　experimental　results　of　the　designed　and　developed　3kW　96VDC/380V　50Hz　3φAC　inverter　have　shown　that　this　kind　of　inverter　has　the　excellent　performances　such　as　high　voltage　transmission　ratio,　high　power　density,　high　conversion　efficiency,　small　the　storage　inductance　and　output　filter,　and　high　quality　grid-connected　current,　which　has　important　application　prospect　in　single-stage　three-phase　low-voltage　grid-connected　inverting　fields.　©　2017　Chin.　Soc.　for　Elec.　Eng.