Design Of High Power LED Driver

High power LED driver is the core of high power LED lamp, high efficiency is one of the development direction of LED driverHigh power LED driver was studied in this thesis, especially in the fields of active power factor correction (APFC) and LLC half-bridge resonant converter. APFC circuit was used to provide a stable voltage for LLC half-bridge resonant converter and reduce the interference of echo signal to the power grid; LLC half-bridge resonant converter was used to reduce the switching loss and improve the efficiency of LED driver.LLC half-bridge resonant converter was also studied, and the equivalent model was established with the fundamental harmonic approximation in this thesis. The resonant parameters were calculated by the design method which had been summarized by analyzing the influence of the parameters on the circuit performance. Correction of the resonant parameters was verified by simulating the soft switching waveform of LLC half-bridge resonant converter.According to the requirement of LLC half-bridge resonant converter, an integrated transformer was designed and realized, which integrated the parallel inductor and series inductor of LLC half-bridge resonant converter. The prototype was realized based on the achieved parameters, which included APFC circuit, LLC half-bridge resonant converter, auxiliary power supply circuit and electric current and voltage detection circuit. The thesis debugged the LED driver, and achieved satisfactory results.