The　traditional　two-stage　LED　driver　is　usually　used　in　the　small　and　medium　power　LED　drivers,　resulting　in　some　problems　such　as　large　in　size　and　high　in　cost,　and　a　large　conduction　loss　at　low　voltage　input,　etc.　To　solve　the　above　problems,　a　bridgeless　high　gain　single-stage　LED　driver　integrated　by　a　bridgeless　quadratic　Boost　PFC　circuit　and　DC-DC　LLC　circuit　was　proposed,　in　which　high　voltage　gain　and　soft　switching　can　be　realized,　a　set　of　control　circuit　is　needed　and　the　circuit　efficiency　can　be　improved.　Aiming　at　the　problem　that　the　DC　bus　voltage　variation　range　of　the　proposed　single-stage　circuit　needs　to　be　regulated,　the　APWM-PFM　hybrid　control　strategy　suitable　for　the　proposed　circuit　was　proposed　and　analyzed　and　the　hybrid　control　principle　and　the　control　process　were　analyzed　in　detail.　Finally,　computer　simulation　was　carried　out　and　a　200　W　experimental　prototype　was　built　up.　In　the　range　of　input　voltage　80　-　120　Vrms,　when　the　duty　cycle　is　0.　5,　the　maximum　voltage　gain　is　obtained　to　be　6.　7,　the　power　factor　value　of　the　prototype　can　be　achieved　to　be　higher　than　0.　990　in　all　line　voltage　ranges,　the　THD　can　be　reduced　to　be　lower　than　15%　and　the　DC　bus　voltage　is　regulated　to　be　under　700　V　to　equilibrate　the　line　characteristics　and　LLC　performance.　Under　full　load　condition,　the　prototype　efficiency　can　reach　up　to　93.　20%　when　the　input　voltage　is　110　Vrms.　Compared　with　the　traditional　two-stage　converter,　the　voltage　gain　is　increased　by　2.　21　times,　high　voltage　gain　and　soft　switching　are　achieved,　the　efficiency　under　low-voltage　input　condition　is　effectively　improved.　The　proposed　circuit　and　control　method　have　been　proved　to　be　effective　by　the　simulation　and　experimental　results.　©　2024　Editorial　Department　of　Electric　Machines　and　Control.　All　rights　reserved.