A　novel　two　modes　controlled　combined　set-up　inverter　topology　with　wide　range　varied　input　voltage,　and　two　modes　control　strategy　of　output　voltage　instantaneous　value　feedback　with　input　voltage　feedforward　are　proposed.　The　circuit　topology,　control　strategy,　characteristic　of　steady　principle　and　design　criteria　for　the　key　circuit　parameters　are　deeply　analyzed,　and　important　conclusions　are　obtained.　The　circuit　topology　is　constituted　of　＂T＂　type　network　and　Buck　type　inverting　bridge,　in　which　the　＂T＂　network　is　equivalent　to　a　Buck-Boost　DC　converter.　By　setting　the　saturation　point　and　zero-cross　point　of　duty　cycle　in　the　two　modes　as　switching　points,　the　two　modes　achieve　smooth　transition.　Experimental　results　of　a　500VA　100-200VDC/220V50Hz　AC　inverter　prototype　show　that　the　proposed　inverter　has　the　advantages　of　wide　range　of　input　voltage,　bidirectional　power　flow,　boost　capacity,　high　conversion　efficiency,　high　quality　of　output　waveform　and　so　on,　which　can　be　widely　used　in　the　boost　inversion　of　wide　range　varied　input　voltage.　©　2018　Chin.　Soc.　for　Elec.　Eng.