Abstract: To eliminate the impact on the lifetime of LED drivers due to electrolytic capacitors, technologies of electrolytic capacitor-less LED drivers are quite important. In this paper, the principle of electrolytic capacitor-less LED driver topologies is explained based on the power flow of three-port converters（TPC）. And combined and integrated TPC topologies based on Flyback converters are consequently derived, from which the integrated topologies is realized by integrating the paralleled sub-circuits of the combined type. The main circuit control strategy of the proposed TPC topology is then addressed following the analysis of operating principles, as well as the control circuit. Finally, experiments of a 13.5W prototype help to verify the correctness and feasibility of the TPC LED driver.