Power factor correction techniques used for fluorescent lamp ballasts

Various power factor correction techniques used in fluorescent lamp ballast are described. The basic circuit used to control the lamp voltage and current is the current-fed sine wave inverter. Numerous different passive power factor correction circuits were designed, built, and tested. A continuous duty boost converter was designed, built, and tested to make the comparisons. In all cases the wattage line power draw was greater than 300 W. The analytical methodology used to define power factor corrections was reevaluated. A newer version was derived, and a more accurate form of power factor derivation is presented which takes into account distortions of the AC line voltage. An attempt is made to explain the need for low-source impedance to make the correct measurements.<>