Single-stage converters for photovoltaic powered lighting systems with MPPT and charging features

This paper proposes single-stage power converters (SSCs) for application in photovoltaic powered lighting systems. The synchronous switch technique is employed to synthesize the SSCs which can fulfill maximum power point tracking, battery charging, discharging and lamp ballasting features. Several typical SSCs are discussed in the paper. One of the proposed SSCs, which is the integration of a buck-boost charger/discharger and a class-D series resonant parallel loaded inverter, is analyzed and designed. Both pulse-width modulation and variable-frequency controls are used to govern the system. The controller is implemented on a single-chip microprocessor. Simulated and experimental results of the proposed system for driving sixteen GE TBX 26 W fluorescent lamps are used to verify the theoretical prediction and feasibility. The proposed system has the merits of lower cost, more compact size and possibly achieving higher reliability over conventional systems.