In　order　to　solve　the　problem　of　insufficient　boost　capacity　of　high　boost　non-isolated　converters　required　in　renewable　energy　system,　a　soft-switched　high　voltage　gain　quasi-YZ　source　DC-DC　converter　is　proposed　based　on　the　advantages　of　Y　source　converter　and　quasi-Z　source　converter.　The　proposed　converter　can　not　only　improve　the　voltage　boost　capacity,　but　also　effectively　absorb　voltage　spikes　caused　by　leakage　inductor.　Furthermore,　the　application　of　synchronous　rectification　technique　enables　the　switches　and　diodes　to　operate　in　soft　switching　condition　and　improves　the　conversion　efficiency.　In　addition,　the　proposed　converter　has　continuous　input　current　and　low　current　ripple　due　to　the　single　inductor　connected　at　the　input　voltage.　Moreover,　it　has　the　advantages　of　low　switch　voltage　stress　and　common　ground　between　input　and　output　voltages.　First,　the　working　modes　and　steady　states　of　the　proposed　converter　are　analyzed.　Then,　efficiency　and　loss　distribution　are　calculated　quantitatively.　The　performance　of　the　proposed　converter　is　compared　with　other　converters,　and　the　design　requirements　are　defined.　Finally,　the　effectiveness　of　the　proposed　converter　is　verified　by　a　prototype　made　in　the　laboratory.　©2024　Chin.Soc.for　Elec.Eng.