IMPLEMENTATION OF A PV LIGHTING SYSTEM BASED ON DC-DC CONVERTER WITH INTELLIGENT CONTROLLED APPROACH

摘要

This paper presents the design and implementation of a digital high performance photovoltaic lighting system based on a microcontroller. The proposed system consists of a photovoltaic module, a LED lighting module, a bidirectional buck-boost converter and a battery. HBLED with specific features of small size, long life and low power consumption will be choices of the light source of photovoltaic lighting system. In this paper, battery charging methods are analyzed first, and then, the control strategy and hardware implementation are proposed. The dimming control methods for LED are discussed and compared. The bi-directional buck-boost converter is the integration of a charger/discharger and a LED lightingmodule drive circuit, which can fulfill maximum power point tracking (MPPT), multi-stage current charging control and LED drive control. In addition, a microcontroller (PIC16F873) is used to realize the system controller. Finally, experimental results are provided to verify the theoretical analysis and design procedure of a digital controlled photovoltaic lighting system.