A single stage offline HB-LED driver with power factor correction for multi-color dynamic lighting systems

In this paper a single stage offline LED driver that can drive N-color HB-LED strings is presented. The proposed converter provides multiple current outputs for N-Color HB-LED strings from an AC input. The current outputs are independently controllable to obtain the desired Correlated Color Temperature (CCT) and high Color Rendering Index (CRI) for dynamic lighting systems. Hybrid Average Current Mode Control (HACMC) approach is used to realize multiple current outputs. HACMC is a combination of both the Average Current Mode Control (ACMC) and non-linear charge control. The proposed converter also provides Power Factor Correction (PFC) to the AC input mains. Simulation and experimental results of a high CRI multi-color LED lighting system with 110V AC input are presented.