Single-Stage High-Power-Factor Electronic Ballast with Class E Inverter for Fluorescent Lamps
A single-stage high-power-factor electronic ballast with class E inverter is proposed for driving the fluorescent lamp. The circuit configuration is obtained from the integration of a buck-boost converter for power-factor- correction (PFC) and a class E resonant inverter for ballasting. The integrated ballast circuit requires only one active power switch and simple control. Operating the buck-boost converter in discontinuous conduction mode (DCM) at a fixed frequency, the electronic ballast can achieve nearly unity power factor. With pulse-width-modulation (PWM), the electronic ballast can provide an appropriate filament current for preheating, a high voltage for ignition, and then a desired lamp current for steady-state operation. An additional control circuit is included to eliminate the glow current during preheating stage.
The operation of the ballast-lamp circuit is analyzed by fundamental approximation. Computer simulations are made and design equations are derived on basis of the power-dependent resistance model of the fluorescent lamp. With carefully designed circuit parameters, the active power switch can be switched on at zero current to reduce the switching losses leading to a higher efficiency.
An experimental circuit designed for a PL-27W compact fluorescent lamp is built and tested to verify the computer simulations and analytical predictions. Experimental results show that satisfactory performances can be obtained on the proposed electronic ballast.
Advisor:Jiann-Fun Chen; Yu-Jen Lin; Tsorng-Jun Liang; Jen-Hao Teng; Chin-Sien Moo
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:fluorescent lamp class e resonant inverter electronic ballast power factor correction pfc
Date of Publication:06/11/2002