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.