Project Ppt1

BY:

ANAND NAGARAJAN YUVRAJ RATHOD SAGAR TANMANE

INTRODUCTION • Oil, coal, gas and such other forms of nonrenewable energy are fast depleting. • And hence we need to go for renewable sources of energy like Sun, Wind, Biomass etc. • Due to the growing demand for clean sources of energy, the manufacture of solar cells and photovoltaic arrays has expanded dramatically in recent years.

Photovoltaics

The sun provides almost infinite solar energy that can be converted into electric energy usable for all. The technology is photovoltaic which converts light into electricity. .

Due to the growing environmental issues and awareness raised, there is an inevitable need for alternative energies other than fossil fuels that almost always emit greenhouse gases or other air polluting substances that are hazardous to the environment and atmosphere – ozone layer. Thus, the research and studies devoted to the manufacturing of solar cells have increased during the recent years.

Difficulties in capturing this vast solar energy • Large panels and large area required. • Installations are very costly. • The source has low power density (300 W/m2 to 1 KW/m2). • And climatic conditions are not always favorable throughout the year.

So our task is to capture this superabundant and & free resource to fuel our planet... Thus efforts are being made all over the world to search for a viable solution to all above problems.

Existing systems, technology and methods available for Solar energy conversion are:

A simple PV system

Drawbacks of the simple PV system Output voltage and current are continuously changing throughout the day because of : 1)

Unavailability of constant solar irradiance throughout the day, since sun is available to us only during daytime and not available during night time.

2)

Still another is the cloud covering over areas on earth that further lessens the intensity of the incoming rays.

Problems associated with 1.Solar Tracking System • By adding a solar tracking system to your solar panels, you are adding moving parts and gears which will require regular maintenance and repair or replacement of broken parts • 1/3rd of total energy is used up by the tracking system itself..

2. Battery

chargers

• For small systems, workable energymanagement schemes usually include a rechargeable battery and battery charger. A shortcoming of this solution is that ordinary battery chargers, even efficient ones, do an imperfect job of squeezing the last milli-watt from sustainable sources over realistic combinations of ambient and battery conditions.

BLOCK DIAGRAM

Maximum Power Point Tracker (MPPT) • A new feature is showing up in charge controllers. It's called maximum power point tracking (MPPT). It extracts additional power from your PV array, under certain conditions. This article explains the process by a mechanical analogy. • The function of a MPPT is analogous to the transmission in a car. When the transmission is in the wrong gear, the wheels do not receive maximum power. That's because the engine is running either slower or faster than its ideal speed range. The purpose of the transmission is to couple the engine to the wheels, in a way that lets the engine run in a favorable speed range in spite of varying acceleration and terrain.

• Let's compare a PV module to a car engine. Its voltage is analogous to engine speed. Its ideal voltage is that at which it can put out maximum power. This is called its maximum power point. (It's also called peak power voltage, abbreviated Vpp). Vpp varies with sunlight intensity and with solar cell temperature. The voltage of the battery is analogous to the speed of the car's wheels. It varies with battery state of charge, and with the loads on the system (any appliances and lights that may be on). For a 12V system, it varies from about 11 to 14.5V. • In order to charge a battery (increase its voltage), the PV module must apply a voltage that is higher than that of the battery. If the PV module's Vpp is just slightly below the battery voltage, then the current drops nearly to zero (like an engine turning slower than the wheels). So, to play it safe, typical PV modules are made with a Vpp of around 17V when measured at a cell temperature of 25°C. They do that because it will drop to around 15V on a very hot day. However, on a very cold day, it can rise to 18V!

• What happens when the Vpp is much higher than the voltage of the battery? The module voltage is dragged down to a lower-than-ideal voltage. Traditional charge controllers transfer the PV current directly to the battery, giving you NO benefit from this added potential. • Now, let's make one more analogy. The car's transmission varies the ratio between speed and torque. At low gear, the speed of the wheels is reduced and the torque is increased, right? Likewise, the MPPT varies the ratio between the voltage and current delivered to the battery, in order to deliver maximum power. If there is excess voltage available from the PV, then it converts that to additional current to the battery. Furthermore, it is like an automatic transmission. As the Vpp of the PV array varies with temperature and other conditions, it "tracks" this variance and adjusts the ratio accordingly. Thus it is called a Maximum Power Point Tracker.

• What advantage does MPPT give in the real world? That depends on your array, your climate, and your seasonal load pattern. It gives you an effective current boost only when the Vpp is more than about 1V higher than the battery voltage. In hot weather, this may not be the case unless the batteries are low in charge. In cold weather however, the Vpp can rise to 18V. If your energy use is greatest in the winter (typical in most homes) and you have cold winter weather, then you can gain a substantial boost in energy when you need it the most!

•

The maximum power point (MPP) of a photovoltaic (PV) array is an essential part of a PV system. Many MPP tracking (MPPT) methods have been developed and implemented. In fact, so many methods have been developed that it is very difficult to adequately determine which method is most appropriate. • In this project we propose to design simulate / implement a system that would remain stable at MPP (avoid oscillations) under varying conditions.

Future Scope We will be connecting an inverter to convert the obtained DC voltage to AC. This will enable us to run even the AC loads.

Let’s make our future brighter and secure it for our Future generations......

Thank you......