Tuesday, June 1, 2010

Introduction

This is a solar tracking system which can be used as a power generating method from sunlight. This method of power generation is simple and is taken from natural resource. This needs only maximum sunlight to generate power. This project helps for power generation by setting the equipment to get maximum sunlight automatically. This system is tracking for maximum intensity of light. When there is decrease in intensity of light, this system automatically changes its direction to get maximum intensity of light.

We are using two sensors in two directions to sense the direction of maximum intensity of light. The difference between the outputs of the sensors is given to the micro-controller unit.

Here we are using the micro-controller for tracking and generating power from sunlight. It will process the input voltage from the oscillators circuit and control the direction in which the motor has to be rotated so that it will receive maximum intensity of light from the sun.



Applications of the Proposed Project

Solar energy refers primarily to the use of solar radiation for practical ends. However, all renewable energies, other than geothermal and tidal, derive their energy from the sun.
Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circula
te air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies. Solar tracking system will help us utilize every bit of solar energy in most efficient way.


Block Diagram of the Proposed System




Explanation of Each Component in Block Diagram

Microcontroller: - This is the heart of the circuit which performs all commanding and controlling operations. Microcontroller now days are becoming more popular because of several advantages over microprocessor. As it reduces the requirement of additional interfacing IC those are needed in microprocessor, the data which has to be read and controlled is directly fed to microcontroller and the software is designed in accordance with the requirement for controlling the circuit and action is taken by proper output device.

Sensors: - Here we would be using two LDR sensors in two different directions to sense the direction of maximum intensity of light. The difference between the outputs of the sensors is given to the microcontroller unit.


Oscillators:- Two oscillators would be used for generating square waves. The sensors are connected to these two oscillators which generate square pulses in accordance to the intensity of the light falling on the two sensors. The outputs of these two oscillators are given to the microcontroller for comparison.

Stepper Motor:- A uni-polar stepper motor is being used for rotation in one direction only. The stepper motor covers an angle of 1.8 degrees per step. The output of the microcontroller is given to this motor through motor driver circuit and hence the motor is rotated accordingly, pointing in the direction of maximum intensity of sunlight.

Motor Driver:- The uni-polar motor driver circuit is used for controlling the rotation of the stepper motor. This circuit has transistors in darlington pair with free-wheeling diodes.




Circuit Schematic




Simulation Results

The LDR sensors circuits simulation results on Livewire are shown below. It was noticed that when the intensity of light is maximum at the sensor the 555 oscillator gives no pulse at its output whereas if the intensity of light is decreased then it gives square pulses at its output which are to be compared by the micro-controller.

PCB's

The PCB of sensor's circuit is shown below
:



The PCB of generic board is shown below:


The PCB of motor driver circuit is shown below:


Mechanical Structure


Software Flowchart and Algorithm




Brief Description of Each Circuit Component


89C52:- Here microcontroller IC 89C52 used is a 40 pin IC consists of four ports which are used as an input and output port. This is the heart of the circuit which performs all commanding and controlling operations. Microcontroller now days are becoming more popular because of several advantages over microprocessor. As it reduces the requirement of additional interfacing IC those are needed in microprocessor, the data which has to be read and controlled is directly fed to microcontroller and the software is designed in accordance with the requirement for controlling the circuit and action is taken by proper output device.

LDRs:- For sensing the maximum intensity of light LDR sensors are used.
Here we would be using two LDR sensors in two different directions to sense the direction of maximum intensity of light. The difference between the outputs of the sensors is given to the microcontroller unit.

555:- For generating square pulses ICs 555 are used as oscillators.
Two oscillators would be used for generating square waves. The sensors are connected to these two oscillators which generate square pulses in accordance to the intensity of the light falling on the two sensors. The outputs of these two oscillators are given to the microcontroller for comparison.

Power Supply: - There are two power supply used to give power to the circuits. The first power supply is 5v regulated power supply it is used to supply power to microcontroller and sensing circuits. The second power supply is used to give the 5v power to motor.

Motor Driver:-
For configuration in darlington pair four TIP122 transistors and four 1N4110 diodes are being used in order to increase the current gain that is required to drive the stepper motor.

Problems Faced

Due to the constraint of resources, we were not able to get the system to generate power.

It was our first experience with PCB and soldering.

Faced difficulty in making the oscillators and sensors work.

Conclusion

The original purpose of this project is the power generation by setting the equipment to get maximum sunlight automatically.

Although due to resources constraints we just accomplished the tracking part of the system.


Video(s) and Picture(s)

The working of the generic board and motor driver circuit.

video
This video shows the working of the stepper motor.

Links


The poster pdf file can be downloaded from the link below:

http://rapidshare.com/files/396987665/solar_tracking_system.pdf.html



The poster photoshop psd file can be downloaded from the link below:

http://rapidshare.com/files/396988631/solar_tracking_system.psd.html


The code c file can be downloaded from the link below:

http://rapidshare.com/files/396989304/solar_track__2_.c.html


The code hex file can be downloaded from the link below:

http://rapidshare.com/files/396989507/solar_tracking.hex.html