Single Stage High Brightness LED Driver with Improved Power Quality

A single switch single stage 24watt power supply is presented to run a light emitting diode (LED) load. In this power supply, the Zeta converter is used to operate in continuous conduction mode (CCM) for maintaining desired output voltage. A proportional integral (PI) controller is also proposed in the feedback to make system stable. The need of proposed controller is justified from stability analysis of the system with the help of small signal average modeling. A simulation model of the proposed LED driver is also carried out in MATLAB/SIMLINK using sim-power toolbox environment for a universal ac input mains. The results confirm a constant current of 0.4amp at output with improved power quality parameters such as total harmonic distortion (THD) and power factor (PF). All outcomes lie under the limit of IEC 61000-3-2 standards that verifies the theoretical analysis. (paper)