Microcontroller–Based Modified SEPIC Converter for Driving Lamp with Power Factor Correction

A methodological study of electronic ballast for electrode less lamps including design and development issues is presented in this paper. The ballast is intended to feed a 300 W ultra violet lamp at 100 kHz with dimming feature. The proposed topology is composed of a Single-Ended Primary Inductance Converter (SEPIC), used as power factor correction (PFC) stage, integrated with a resonant half-bridge inverter, used as lamp power control (PC) stage. The integration of both stages is proposed in this paper, in order to reduce the number of active switches, as well as to simplify the required driving and control circuitry for this application. The implemented topology attained very high power factor (0.9982), and low line current total harmonic distortion (THD) (1.86%), without using electromagnetic interference (EMI) filter, while the measured efficiency was 90% at nominal lamp power.