A single-stage ballast for HID lamps with a buck chopper integrated direct matrix converter

This paper proposes the combination of low frequency square waveform (LFSW) ballasts with AC/AC converter topologies as a new electronic ballast for high intensity discharge (HID) lamps. The proposed circuit is a buck integrated matrix converter to generate LFSW. The most prominent advantages of such an integration is the simplicity, cost and volume reduction as well as increased reliability due to the absence of DC link electrolytic capacitors. In addition, the double-loop control is adopted to the proposed ballast, with simple proportional controllers and a feed-forward path. Simulation results for a 125 W high pressure mercury vapor lamp confirm the theoretical achievements.