Digital control applied to single-stage high-power-factor EFL ballast with burst-mode dimming

This paper presents the analysis, design and simulation of a digital control strategy for an electronic ballast to supply a 100 W high frequency Electrodeless Fluorescent Lamp (EFL). The electronic topology consists of a single-stage SEPIC power-factor converter associated with a half-bridge asymmetric LCC resonant inverter. In this configuration, the dimming capability based on a low-frequency burst-mode modulation is proposed. The presented digital control is composed of two main strategies: 1) voltage feedback loop for input grid disturbance and lamp parametric variations, 2) and a hysteretic power control loop to maintain a stable lamp power on each operating point. In this initial paper version, simulation results are included to demonstrate the digital control performance.