Research on a novel constant power control strategy for single-stage PFC LED driver

As some research results show, LED lighting has an obvious luminous flux decrease with LED´s junction temperature increasing. The constant power control strategy is suitable to achieve constant luminous flux when junction temperature varies. This paper puts forward a kind of constant power control strategy based on multiplier and establishes its small-signal model. Considering its characteristics of low cost and high efficiency, integrated single-stage PFC circuit is widely applied in the medium and small power LED drive power supply. The paper adopts Buck-Flyback working in Transition Mode(TM) to realize constant power control with control chip L6562. At last, the simulation and experiment were set up to verify the theoretical analysis.