A　nonlinear　pulse　width　modulation-controlled　single-phase　boost　mode　photovoltaic　grid-connected　inverter　with　limited　storage　inductance　current　is　proposed　in　this　paper.　The　circuit　topology,　control　strategy,　steady-state　principle　characteristic,　and　design　criterion　for　the　key　circuit　parameters　of　this　kind　of　inverter　are　investigated　in　depth,　and　important　conclusions　are　obtained.　The　inverter＇s　regenerating　energy　duty　ratio　1-D　which　decreases　with　the　decline　of　the　grid-connected　voltage　is　real　time　adapted　by　sampling　and　feeding　back　the　inverting　bridge　modulation　current,　and　the　average　value　of　the　modulation　current　in　each　switching　cycle　tracks　the　reference　sinusoidal　signal　to　get　high-quality　grid-connected　current.　The　active　control　of　the　energy　storage　inductance　current　and　the　balance　of　the　voltage　step-up　ratio　are　realized　by　adding　a　bypass　switch　connected　in　parallel　with　the　energy　storage　inductance　and　using　two　kinds　of　switching　pattern　namely　boost　pattern　and　freewheeling　pattern.　The　theoretical　analysis　and　experimental　results　of　the　1　kVA　110　VDC/220　V50　Hz　photovoltaic　grid-connected　inverter　prototype　show　that　it　has　the　advantages　such　as　single-stage　boost　conversion,　high　conversion　efficiency,　high　quality　of　grid-connected　current　waveform,　low　value　of　energy　storage　inductance,　simple　control,　etc.　©　1986-2012　IEEE.