A Modular Self-Controlled Photovoltaic Charger With InterIntegrated Circuit ( $\hbox{I}^{2}\hbox{C}$) Interface

This paper presents a modular self-controlled photovoltaic (PV) charger with maximum power point tracking (MPPT) and pulse-charging schemes. The studied PV modules can be flexibly parallel connected through interleaved operation using an interintegrated circuit (I
²
C) interface. The MPPT control of PV panel is implemented by using a current-sensing technique with the on-state resistance of the power switch. Both an expensive hall-effect sensor and additional current-sensing resistor are not needed. A pulse-charging scheme without extra battery-current sensor is also designed to prolong the lifetime of the acid-lead battery. The operation principles and design considerations of the proposed PV charger are analyzed and discussed. A laboratory prototype is implemented and tested to verify its feasibility.