Multifunctional Solar Tracking System using AT8952

With  the  alarming  rate  of  depletion  of  the  major  energy  resources worldwide,  it  has  become  an  urgent  necessity  to  seek  for  renewable  energy resources  that  will  power  the  future. In  this  context  we  have  concentrated  our focus  on  the  research  of renewable energy. Among these renewable energy resources solar energy is one of a kind. Solar  power  (photovoltaic)  systems  are  a  sustainable way  to  convert  the  energy  of  the  sun  into  electricity.  The expected lifetime of a system is 25-30 years.

With  all  the  above  information,  the  rapid  depletion  of  the  natural resources of  the  world,  we  would  soon  meet  a  great demand  for  alternative source of energy. In the very near future, experts are predicting that we will be bound to move to renewable sources of energy, solar being one of them. As long as our earth exists, the sun is there to give us unlimited solar energy.  It is completely up to us how we are going to utilize this abandoned energy.  Every  hour,  sun  gives  the  same  amount  of energy to  the  world  that  the whole world uses in an entire year.

By considering all the above things and the environmental friendliness, economically  sound  and  the  ease  of  implementation, we  thought  of  working  on  it as  we  believe  that  in  the  near  future,  our  country  along  with  the  whole  world will be benefited from this source of renewable energy.

Multifunctional Solar Tracking System
Multifunctional Solar Tracking System

1. PROBLEM STATEMENT

As we can see, there are many problems that occur in the previous type of solar tracking system. The problem that we can see here is the solar panel that is fixed in position. Because of this problem, the power that can be generated is low.  The second problem is the price for the solar tracking system is very expensive for the family that use more power than usual because they need to install more than one solar  panel to produce enough power. So,  this  project  is  to  fix  the  problem  that  occurs  here. This solar tracking system can detect a 180 degree of rotation. So, the solar panel that can be generating here is very high compare to when the solar panel can only stay in one direction. So, the families don’t have to install more than one solar panel to generate enough power.  One solar panel is enough to produce a lot of power.

2. PROJECT SCOPE

This project is focused to design and build the prototype of solar tracking system that would be a starting point to build the realistic solar tracking system. Therefore, this prototype will cover the scope as followed.

  • Using microcontroller (AT89S52).
  • Using gear motor.
  • Using two Light Dependant Resistors (LDRs) as sensors.
  • Using an Inverter to run the load in the absence of the mains.
  • Using a Solar battery to store the output power from the solar panel.

The Block diagram of “MULTIFUNCTIONAL SOLAR TRACKING SYSTEM” has shown below.

Multifunctional Solar Tracking System Block Diagram
Multifunctional Solar Tracking System Block Diagram

The design has been organized in six modules. They are

  • Power supply
  • Light dependant resistor
  • Microcontroller
  • Solar panels
  • Gear motor
  • Inverter

3. POWER SUPPLY

In-order to work with any components basic requirement is power supply. In this section required voltage level is 5V DC power supply. The block diagram of a typical power supply is shown below.

Block diagram of Power Supply
Block diagram of Power Supply

4. LIGHT DEPENDENT RESISTOR

Light sensors are components of circuits that are able to measure light and increase or decrease their resistance accordingly. Resistance refers to the amount of electrical current or voltage that is held back by a certain part of the circuit, in this case because of a component called a Resistor. Compared to most resistors which have a set resistance and therefore resist a specified amount of electrical current through a circuit, this one is a bit more advanced with its resistance able to be altered under varying brightness’s of light, hence being referred to as a variable resistor. It is a bilateral device, which means this conducts in both directions in same fashion.

5. MICROCONTROLLER 89S52

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8Kbytes of in-system programmable Flash memory. This device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the  industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable  Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly flexible and cost-effective solution to many embedded control applications.

6. SOLAR POWER FUNDAMENTALS

Below figure shows a simple model of a PV cell. Rs is the series resistance associated with connecting to the active portion of a cell or module consisting of a series of equivalent cells. Rp is parallel leakage resistance and is typically large, > 100kΩ in most modern PV cells. This component can be neglected in many applications except for low light conditions.

Simplified circuit of a solar cell
Simplified circuit of a solar cell

The amazing thing about solar power is that all the electricity is generated from the material of the solar panels and the energy from the sun. The solar panels are mainly made out of semiconductor material, Silicon being the most abundantly used semiconductor. The benefit of using semiconductor material is largely due to the ability of being able to control its conductivity whereas insulators and conductors cannot be altered. The electrons of the semiconductor material can be located in one of two different bands: the conduction band or the valence band. The valence band is initially full with all the electrons that the material contains. When the energy from sunlight, known as photons, strikes the electrons in the semiconductor, some of these electrons will acquire enough energy to leave the valence band and enter the conduction band. When this occurs, the electrons in the conduction band begin to move creating electricity. As soon as the electron leaves the valence band, a positively charged hole will remain in the location the electron departed. When this occurs, the valence band is no longer full and can also play a role in the current flow. This process basically describes how Photovoltaic (PV) systems function. However, PV systems further enhance the rate at which the electrons are sent into the conduction band through the process of doping.

7. GEAR MOTOR

Gear Motor Gear motors are widely used in modern systems due to their high performance, long service life, and low purchase and maintenance costs. Product development has made it possible to achieve high operating pressures, excellent volumetric and mechanical efficiency, and lower noise levels. The geared instrument dc motor is ideally suited to a wide range of applications requiring a combination of low speed operation and small unit size. The integral iron core dc motor provides smooth operation and a bidirectional variable speed capability while the gear head utilizes a multistage metal spur gear train rated for a working torque up to 0.2 Nm.

8. INVERTER

The method by which dc power from the PV array is converted to ac power is known as inversion. Other than for use in small off-grid systems and small solar gadgets, using straight dc power from a PV array, module or cell is not very practical. Although many things in our homes and businesses use dc power, large loads and our electrical power infrastructure are based on ac power. This dates back to the early days of Edison versus Tesla when ac won out over dc as a means of electrical power distribution. The CD 4047 is the major element in the inverting principle. The CD4047 is capable of operating in either the monostable or astable

Circuit diagrams, source codes and project photos are give in next pages.

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