An integrated solar controller synthesizing both battery charging and LED driving functions for off-grid lighting system is proposed. The BDC for the integrated solar controller with Sepic and Zeta modes improves the control flexibility of voltage level matching among solar PV panel, battery, and LED module.
Analysis shows that there is always a monotonic relationship between the operating voltage of PV panel and duty cycle of power switch regardless of inductor current continuous or discontinuous modes.
Either static or dynamic MPPT efficiency of the integrated solar controller in charging mode is quite good.
The digital hysteresis constant control of the integrated solar controller in driving mode is proposed and verified by experimental results.