Advanced design of a low-cost electronic ballast with PFC for HPS lamps

In this paper, an advanced design of a low-cost electronic ballast with PFC for HPS lamps is presented. The inverter stage is based on LCC parallel-series inverter with resonant current mode control. This control method avoids the inverter handling any reactive energy, minimizing both switching and conduction losses. Also, the design performs a natural power control without exceeding the maximum power recommended by the lamp manufacturer. Also, since it is desirable to implement a low-cost power factor correction, a buck PFC is proposed. The ignition process is optimized because no additional elements are necessary to ignite the lamp providing low ignition current through the switches. The design has been realized for 70, 150 and 250 W HPS lamps. Computer simulation and experimental results have validated the design method proposed.