A　circuit　configuration　and　circuit　topological　family　of　unidirectional　buck　dc-dc　converter　mode　photovoltaic　gridconnected　inverters　with　high　frequency　link　(HFL)　are　proposed　in　this　paper.　Its　circuit　configuration　is　composed　of　the　photovoltaic　(PV)　array,　the　unidirectional　isolated　buck　dcdc　converter　and　polarity　reversal　inverting　bridge.　The　circuit　topology,　the　maximum　power　point　tracking　(MPPT)　methods,　dual-loop　PWM　control　strategy　with　the　input　voltage　as　outer　loop　and　the　output　current　as　inner　loop,　and　design　criteria　for　the　key　circuit　parameters　are　deeply　investigated.　Taking　pushpull　forward　mode　topology　as　an　example,　make　the　photovoltaic　power　generation　experiment　on　the　unidirectional　buck　dc-dc　converter　mode　photovoltaic　grid-connected　inverter　system　with　high　frequency　link.　The　simulation　and　experiment　results　have　shown　that　this　kind　of　inverter　have　the　advantages　such　as　high　frequency　(HF)　electrical　isolation,　quasi　single-stage　power　conversion,　accurate　MPPT,　low　voltage　stress　and　ZVZCS　of　the　power　switches　in　the　polarity　reversal　inverting　bridge,　high　conversion　efficiency,　high　quality　grid-connected　current　etc.　©　2013　IEEE.