A compact single-stage converter for emergency lighting applications

This paper presents a compact single-stage converter for emergency lighting applications. The converter is derived by integrating a bi-directional flyback converter and a hay-bridge series-resonant parallel-loaded inverter, which can fulfill the functions of battery charging, discharging and lamp ballasting. Unlike conventional approaches, the rectified and filtered input voltage is directly added on the battery voltage in the proposed system, which can simplify the circuit configuration. Derivation and operating principle of the proposed converter is first presented and an application to emergency lighting is then developed. Hardware measurements have verified its feasibility. The proposed single-stage converter has the unique features of simple configuration, ease in combining with the existing lighting future and dimming capability, and it can be readily further integrated with a boost or a buck-boost converter to achieve power factor correction.