Performance Analysis of Photovoltaic Powered-LED via Step-Down Converter

Abstract

This article presents performance characteristics of Photovoltaic powered-LED via step-down converter for solar-based LED rural electrification.  Due to lack of electricity supply and maintenance of the existing street lighting system, photovoltaic-powered streetlight, is designed and operated completely independent of the power public utility. The proposed system is made up of a photovoltaic module, a closed loop step-down converter and LED lighting unit. Application of the step-down converter to transform a high level dc input voltage from PV module to a low level dc voltage needed for battery charging, a closed loop voltage feedback scheme was utilized to adjust the output of the system. The voltage regulation scheme is anticipated by utilizing PWM-based PI controller, which in turn adjusts the duty cycle of the PWM signal which regulated the triggering of power MOSFET to yield a constant output. The step-down converter, feedback circuit and LED light circuits were designed in MULTISIM SOFTWARE, simulated in MATLAB SOFTWARE and finally implemented on a Vero board. The implementation results for solar PV and step-down converter achieved in both software and hardware are presented here. A steady voltage of 15.85V was obtained at the output of the step-down converter.