This　paper　proposes　a　novel　Y-Sepic　high　boost　DC-DC　converter,　which　is　characterized　by　high　voltage　gain,　continuous　input　current,　low　voltage　stress　of　the　switch　and　diodes,　and　high　efficiency.　The　proposed　converter　is　obtained　by　hybridizing　the　Y-source　and　Sepic　converters.　With　the　coupled　inductor　turns　ratio　introduced　in　the　converter,　the　circuit　can　operate　in　an　appropriate　duty　cycle　D　while　maintaining　high　voltage　gain.　The　working　states　of　the　proposed　converter　are　discussed.　Then,　the　voltage　and　current　stresses　of　components　are　deduced.　The　device　design　considerations　have　been　presented.　The　power　losses　and　efficiency　are　calculated.　The　derivation　of　the　real　voltage　gain　and　the　voltage　gain　in　DCM　have　been　performed.　Besides,　a　small　signal　analysis　and　comparisons　with　other　topologies　have　been　conducted.　Finally,　a　prototype　made　in　the　laboratory　verifies　the　effectiveness　of　the　proposed　converter.　The　efficiency　is　94.6%　when　the　output　power　reaches　300　W.　©　2025　John　Wiley　&　Sons　Ltd.