As　the　fourth　generation　lighting　source,　the　Lighting　Emitting　Diode　(LED)　has　gradually　replaced　conventional　sources　of　light　in　various　lighting　fields　due　to　its　excellent　qualities　in　luminous　efficiency,　Service　life,　environmental　protection,　and　production　cost.　Designing　an　LED　driving　power　supply　with　a　long　service　life,　low　device　cost,　high　efficiency,　and　high　reliability　is　urgent.This　paper　proposes　a　two-switch　electrolytic　capacitor-less　LED　driving　circuit　topology,　which　integrates　the　auxiliary　energy　storage　circuit　into　the　flyback　Converter　to　suppress　low-frequency　ripples　of　the　Output　current　and　remove　the　electrolytic　capacitor　in　the　LED　driving　power　supply.　This　circuit　only　contains　two　Switches　and　two　diodes　by　sharing　power　Switches　and　energy　storage　components,　reducing　circuit　cost　and　improving　the　efficiency　of　the　LED　driving　power　supply.　The　auxiliary　energy　storage　capacitor　for　balancing　the　input　and　Output　ripple　power　difference　is　isolated　from　the　LED　load.　Thus,　the　energy　storage　capacitance　can　be　reduced　by　increasing　the　energy　storage　capacitor＇s　average　voltage　or　ripple　value.　The　maximum　capacitor　value　used　in　the　entire　LED　driving　power　supply　is　reduced　to　6.8uF,　and　the　electrolytic　capacitor　is　replaced　by　the　film　capacitor　with　smaller　capacitance　and　longer　life,　which　improves　the　service　life　and　reliability　of　the　LED　driving　power　supply.　Moreover,　the　auxiliary　circuit　without　additional　structures　absorbs　the　voltage　spike　caused　by　the　leakage　inductance　of　its　energy　storage　capacitor,　reducing　the　voltage　stress　of　the　switch　and　enabling　a　wide　AC　input　voltage　ränge.A　control　strategy　for　ripple　suppression　and　minimum　energy　storage　capacitor　voltage　is　proposed.　According　to　the　relationship　among　the　duty　cycle　of　each　switch,　the　auxiliary　energy　storage　capacitor　voltage,　the　Output　current,　and　the　changing　rules　of　the　working　duty　cycle　are　obtained　under　the　conditions　that　the　two　switches　turn　off　at　the　same　time　when　charging　the　auxiliary　energy　storage　capacitor　and　turn　on　at　the　same　time　when　discharging.　The　low-frequency　ripple　of　the　Output　current　is　suppressed　by　Controlling　the　minimum　value　of　the　auxiliary　energy　storage　capacitor　voltage,　and　the　efficiency　of　the　LED　driving　power　supply　is　further　improved.Based　on　the　working　principle　of　the　circuit,　the　critical　parameter　design　method　is　given,　the　selection　principles　of　the　energy　storage　capacitor　value　are　determined,　and　the　corresponding　control　strategy　is　proposed.　Finally,　a　35　W　principle　prototype　is　built.　The　results　show　that　when　the　auxiliary　energy　storage　capacitor　and　Output　filter　capacitor　are　both　6.8　uE,　the　Output　current　ripple　of　the　prototype　is　less　than　10%　in　the　AC　input　voltage　ränge　of　90~264　V,　the　maximum　efficiency　reaches　87.8%,　and　the　circuit　power　factors　are　higher　than　0.95.　The　proposed　circuit　topology　and　control　strategy　achieve　electrolytic　capacitor-less,　Output　current　ripple　suppression,　high　power　factor,　and　wide　AC　input　voltage　ränge,　which　eliminates　the　impact　of　the　electrolytic　capacitor　on　the　Service　life　of　the　LED　driving　power　supply.　©　2024　China　Machine　Press.　All　rights　reserved.