To　develop　a　novel　hybrid　energy　system　for　urban　rail　power　supply　within　a　dc　converter,　we　propose　a　multi-level　three-port　LCC　resonant　converter　capable　of　operating　in　multiple　modes.　The　converter　integrates　a　five-level　hybrid　I-bridge　(HI-B),　a　three-level　I-bridge　(I-B),　and　a　voltage　multiplier　circuit,　all　of　which　are　connected　to　an　LCC　resonant　tank　to　establish　common,　auxiliary,　and　backup　mode　for　energy　transmission.　Voltage　boost　and　energy　storage　functions　are　realized　by　building　the　impedance　model,　which　is　also　employed　to　derive　power　flow　analysis　for　establishing　a　hybrid　control　strategy　concerning　switching　frequency　and　phase　shift　angle.　Then,　the　application　of　the　hybrid　control　strategy　to　the　converter　enables　the　supercapacitor　to　operate　in　both　constant　current　(CC)　and　constant　voltage　(CV)　modes.　The　design　of　parameters　and　the　control　strategy　among　three　ports　under　the　condition　of　realizing　zero-voltage　switching　(ZVS)　are　analyzed　emphatically.　Finally,　according　to　the　simulation　and　prototype　experimental　results,　it　can　be　shown　that　the　performance　of　the　converter　is　close　to　the　theoretical　analysis　in　each　mode.　©　2015　IEEE.