Hybrid-input power supply with PFC (power factor corrector) and MPPT (maximum power point tracking) features for battery charging and HB-LED driving

In this paper, a MSEBC (modified-SEPIC embedded-boost converter) is proposed, which can deal with either utility power or PV (photovoltaic) power to serve as HB-LED (High-Brightness Light-Emitting-Diode) driver and battery charger. While connected to utility, the proposed converter can perform PFC (power factor corrector) for universal line input. Once power failure occurs, it can draw energy from PV panel with MPPT (maximum power point tracking). Even if there is no utility power and PV energy, the MSEBC still can power on HB-LED from battery bank to achieve uninterruptable lighting feature. The topology of MSEBC is mainly derived from SEPIC-type converter as well as an embedded boost converter to develop a single-stage configuration, instead of multi-stage or two-stage type. Even though it only has single stage, both functions of HB-LED driving and battery charging still can be accomplished. In the MSEBC, a coupled inductor is adopted to replace the second inductor of traditional SEPIC and the chock of boost converter. A microprocessor-based controller is developed to accomplish all converter functions. A prototype, which have the functions of dealing with universal line input 85 ∼ 265 Vrms, performing power factor correction, tracking maximum power for PV panel, lighting HB-LED, and charging/discharging battery, is carried out. Key measurements have verified the feasibility, functionality, and validity.