Design PV-fed LED streetlight using Soft-Switching bidirectional DC-DC converter with optimal flux control

Abstract

Today, solar energy is used for various applications such as photovoltaic-powered light emitting diodes (LEDs) streetlights. Such systems are composed of a photovoltaic (PV) panel, a battery storage, and an LED light integrated with often two power conversion systems along with independent controllers. In this paper, a single unified bidirectional boost converter is used to manage a PV-powered LED streetlight. A simple and useful soft-switching bidirectional boost converter is considered by incorporating an LC series resonant tank into the conventional version. Both buck and boost operations are supported by the proposed topology. The converter stores PV energy in battery by operating in buck mode during the day, and the battery supplies the LED light at night by operating in boost mode. The system is controlled in both cases through a suitable control strategy for regulating voltages at converter input and output ports, MPPT for the PV panel, SOC for the battery, and light control of the LED. Due to the relationships between photo, electricity, and thermal, LED lights can be supplied at an optimal voltage, where the maximum luminous flux is achieved. The technique, utilized in this paper, drives the LED streetlight to achieve optimal luminous flux by using photo-electro-thermal (PET) theory and heatsink characteristics. The obtained values for luminous flux for two simulated conditions are 1551 and 2187 lm, respectively. The proposed LED streetlight system is analyzed and simulated utilizing MATLAB/SIMULINK software.

Keywords

• Photovoltaic system
• PET theory
• Buck-boost converter
• LED streetlight
• Soft-Switching