| Abstract |
This paper presents a high power factor high efficiency electronic ballast for high intensity
discharge lamp (HID). The complete electronic ballast consists of a power factor corrected rectifier, a
full-bridge inverter, and a resonant tank. The power factor pre-regulator generates a sinusoidal line
current in phase with line voltage to get the high power factor and to improve the power quality. The
phase-shift pulsewidth modulated scheme for full-bridge inverter is adopted to drive the metal halide
lamp. In this control scheme, the constant switching frequency with variable duty cycle is used for
dimming control. The series-resonant parallel-loaded circuit is used as a resonant tank. Finally,
experimental results of a 70W MHL hardware prototype are presented to verify the characteristics of
high power factor and dimming control of metal halide lamp (MHL). |
