Introduction

The Solar Battery LED Streetlight Reference Design is an open platform designed for developing a solar-powered LED streetlight. This design implements a bi-directional synchronous buck/boost topology to lower the overall system cost by combining the solar charger buck topology with the LED driver boost topology. This design allows for quick implementation and tuning of solar panel and battery charge parameters to safely start the charging process. The goal of this reference design is to create a board that can be easily scaled up or down as needed, ranging from less than 20W to over 400W for both battery charging and LED driving functions.

The PCB includes numerous optional footprints for the input/output capacitors, MOSFETs and inductors. It also offers additional optional functions, such as dedicated battery and output load current/voltage/power metering (to implement fuel gauging), battery and board-level temperature monitoring and automatic cooling fan control. These functions can be added or removed based on the requirements of the end product. A relay is implemented to route the high side of the topology to either the solar input connection or the LED output connections. A second, optional relay routes between an external LED ballast versus the on-board ballast.

The firmware included with the design provides an open development platform that simplifies the implementation of the charging algorithm, safety features, LED driver functionality, I2C communication and power-point tracking algorithms. Each function is implemented as a state machine that is called from a simple main loop and can be updated or replaced as needed. The hardware is fully abstracted from the state machines, enabling easy configuration and hardware customization. A Windows®-based GUI provides complete configuration and control of the board through a single USB connection, with live numerical and graphical updates of all parameters throughout the charge and discharge cycles.

This document provides clear instructions for setting up the kit, including:

  1. Proper assembly and connection of system hardware
  2. Installation of the required PC-based GUI

This user guide also outlines the steps needed to configure a fully functional system for testing and evaluating the Solar Battery LED Streetlight Reference Design.