Implementation of solar illumination system with three-stage charging and dimming control function

Phone: 91-9632839173

Implementation of Solar Illumination System with Three-Stage

Charging and Dimming Control Function

CONTENTS

1. INTRODUCTION

2. DESCRIPTION

3. BLOCK DIAGRAM

4. COMPONENTS LIST

5. SOFTWARES USED

6. ADVANTAGES

7. DISADVANTAGES

8. APPLICATIONS

E-mail: [email protected]; http://www.wavedigitech.com Phone: 91-9632839173

Phone: 91-9632839173

1. INTRODUCTION

Green energy includes solar energy, wind energy, tidal energy, hydro etc, which is widely used

and developed in recent years. Especially, Taiwan, which possesses subtropical climate, is very

suitable for the development of solar energy system. The application of solar energy is

more universal in daily now. In general, the solar power generation and solar illumination

system are more popular for people. With regard to solar illumination system, which can be

built while combined the charger and converter structure. It can charge the battery during the

day, while lighting the LED module at night. In recent year, many charge methods have been

widely used and discussed. For example constant current charging, constant voltage charging

and reflex charging, etc. Reflex charging needs large input power, constant current charging is

easily overcharge and constant voltage charging is unable to determine the charge current

during initial charge stage. So there are still some disadvantages and insufficient while use

unique charge method. In other sides, common linear dimming methods include constant

voltage dimming scheme and constant current dimming scheme.


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2. DESCRIPTION

In this project solar energy is used to charge the battery. Sometimes solar panel will not provide

enough voltage to charge battery due to insufficient sun light. So here a Buck Boost circuit is

used to boost the voltage to required level. A bulb or LED will be connected to battery as a

load, the battery supply is given to LED through another Buck Boost so that if battery voltage

reduces the intensity of light remains still due to constant voltage supplied by boost circuit.

3. BLOCK DIAGRAM

Fig.1 Block diagram

In figure it shows solar panel is used to convert solar energy into voltage. Voltage generated at

panel output will depend on the intensity of solar light. As the solar light is unpredictable so the

output at solar panel will vary. With this variation it is not possible to charge the battery so the

output of panel is fed to Buck Boost block where this block will supply constant required

voltage to battery. A load (LED) is driven by the battery through Buck Boost circuit. So that if

battery voltage reduces but the supply to the LED remains same.


SOLAR PANEL

BUCK BOOST

BATTERYRELAY

CONTROLLER

VOLTAGE DIVIDER

LED

VOLTAGE DIVIDER

BUCK BOOST

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If the panel voltage reduces in such a way that indicating that it is too dark than the LED

will turn ON where it is turned ON by activating relay by controller. As we need to measure

voltage which is normally higher than 5V this will be not tolerated by controller when ADC

input are fed so voltage dividers are used where this block will divide the voltage by 10 and

which will be sufficient to measure voltage.

4. COMPONENTS LIST

PIC18F458 Buck Boost Baterry-12V Voltage divider Power Supply Solar Panel ALCD

5. SOFTWARES USED

MPLAB PICkit-Microchip ORCAD

6. ADVANTAGES

Solar energy is used which is freely available Due voltage regulation by buck boost constant supply voltage is obtained Low cost

7. DISADVANTAGES

Current ratings will be lower

8. APPLICATIONS

Used in vehicles Used in street lights Used in traffic lights


Technology

Implementation of solar illumination system with three-stage charging and dimming control function