LED Power Factor and Quality Factor

Abstract

This paper presents the LED power factor and quality factor simply characterized from the available terminal average current, average voltage, and RMS current to evaluate the electric power quality of LEDs. The LED average power is composed of the bandgap power and the resistive power due to the forward voltage and equivalent series resistor in the LED approximate linear circuit, respectively. The forward voltage and equivalent series resistor are characterized from the available terminal average current, average voltage, and RMS current to calculate the bandgap power and the resistive power. The LED power factor and quality factor are calculated from the bandgap power, resistive power and average power to evaluate the electric power quality of LEDs. Using a single-branch LED approximate linear circuit and a high-order LED piecewise linear circuit, two verification examples, respectively, are demonstrated to calculate their LED power factor and quality factor.