Artur Blaszczyk

The intelligent battery charging system based on a photovoltaic panel

From early childhood interested in technology, especially electricity, electronics and computer science. My final year project mainly involved power electronics engineering and control system design integrated into one device by application of embedded system based on PIC18F microcontrollers. The concept presents a detailed step by step process of designing a power converter with an efficiency of 85-90%, the battery charger control system, system safety features such as overcurrent, overvoltage protection and finally sun tracking mechanism to optimize the system efficiency.

Finally, the system has been fully automated. In the difficult conditions caused by the Covid19 pandemic, I have supported my project with cheap and easy to access tools such as a basic multimeter, regulated power supplier and camera. The main inspiration for my project was to design and build a device/system which will be daily used by myself and reminding me the great time spend at the UoD. In the short future, I will continue to work and gather more experience as an electrical design engineer at Clayton Equipment Ltd.

My project with cheap and easy to access tools such as a basic multimeter, regulated power supplier and camera. The main inspiration for my project was to design and build a device/system which will be daily used by myself and reminding me the great time spend at the UoD. In the short future, I will continue to work and gather more experience as an electrical design engineer at Clayton Equipment Ltd.

Solar-powered lead-acid battery charging station

Project introduction

Renewable energy in recent years is becoming more popular and is replacing the energy sources provided by fossil fuels such as coal or gas. Currently, one of the most popular sources of renewable energy are photovoltaic panels. The project concentrated on the design of the complete system for storing energy produced by the PV. The crucial part of the system is a lead-acid battery charger and sun-tracking mechanism, allowing to recharge the battery daily from a free, renewable and green source of energy provided by the sun.

Aims and objectives

Regulated current and voltage output

The proportional-integral controller adjusts the output current and voltage based on an accurate feedback system. Sensors ACS712S, monitor output and input currents with a resolution of 10mA. The voltage feedback is provided by the acquisition system based on voltage dividers with an accuracy of 2mV. The converter can provide any output voltage between 12-14.5V rated at a maximum 2.5Amp, required to recharge 24Ah 12V battery with 87-90% efficiency.​

Battery charging process

The lead-acid battery charger uses the constant current constant voltage (CCCV) method. During the first stage, the charge voltage rises to a maximum limit of 2.4V per cell at the constant current. At the second stage, (topping charge) voltage is kept at a constant level of 2.4V per cell, and currents drop due to the battery's saturation. The topping charge stage is essential to keep the battery in good health. Finally, the float stage maintains the battery charge and prevents self-discharge.​

Other system features

Design of sun tracking mechanism

An 18V 50W solar panel supplies the battery charger. Nowadays, the market offers a wide range of inexpensive panels to be used in DIY and domestic projects. PV panel collects the radiation most efficiently when sun rays are hitting the panel surface perpendicularly. As the sun's angle changes during the day and year, optimal tilt can be provided by controlling an angle in a dual-axis direction. To improve the system's efficiency during continuous changes of sun location, the project involved a design of a sun tracker based on two servo motors and feedback control provided by an LDR array. The concept is blending electronic and mechanical engineering. The high torque required to adjust the solar panel position involved a simple spur gear assembly, reducing the servo motors current demand.

3D model of sun tracker assembly
3D model of sun tracker assembly

Sun tracker control system

The system has been based on two servo motors operating in continuous mode to provide motion for the mechanical assembly and an array of light-dependent resistors (LDR) to sense the current sun position required for PV adjustment. PIC182420 MCU has provided the device control system.

Download Artur's project overview poster (PDF) (this pdf document is not fully accessible but the contents within it can be viewed via the content on this page)

Gallery

  • Project Prototype Assembly
  • Another image of the Project Prototype Assembly
  • PCB Assembled
  • Prototype Testing in the garden
  • Final Prototype Assembled in the garden
Artur Blaszczyk headshot

Artur Blaszczyk
BEng (Hons) Electrical and Electronic Engineering

Currently I am working as an Electrical Design Engineer in the railway industry. My role involves the designs of electrical installations, 3D CAD modelling, programming PLC and also I am involved in testing and commissioning of completed goods.

Email
a.blaszczyk1@unimail.derby.ac.uk