A single stage electronic ballast family for high pressure sodium lamps

In the recent years many authors [1-4] are working to obtain single stage HPF electronic ballast for fluorescent and HID lamps to achieve cost reduction and to comply with international standard requirements. Usually to obtain HPF in electronic ballast for high pressure sodium lamps a Power Factor Corrector (PFC) is used between the mains and the electronic ballast [5]. In this paper will be reported the study and implementation of two single stage high power factor (HPF) electronic ballasts for high pressure sodium (HPS) lamps using a LCC filter, one using a half-bridge inverter and the second one using a full-bridge inverter. The main idea in this work is to present two simple electronic ballasts topologies with HPF for HPS lamps working with a 220 V-RMS mains voltage. Design criteria, simulation and experimental results will be also presented. These topologies present some drawbacks like moderate THD, lamp power limitation once the converter works as a Buck inverter and it is not an ideal PFC. PF around .95 are easily obtained. This paper intends to warn other researchers about these structures limitation, but may be an interesting option for some applications.