SOLAR BASED POWER GENERATION WITH

AGRICULTURAL PUMP

ABSTRACT

In this project we use the solar energy for generation of electrical energy, by using the Solar cells.

The solar cells receive the solar energy. The solar cells operate on the photo electric energy by using

solar cells principle. The energy from the cells is stored to a battery through the

battery charger circuit. This circuit will maintain the charging conditions of the

battery. The stored energy is utilized by using the inverters to switch

ON the PUMP. The sensors are provided to sense the wetness of the soil, if

the wetness is less the pump will be automatically switched ON.

BLOCK DIAGRAM

230V,50HZ

CHARGE CONTROL

LOAD (PUMP)

ON/OFFSOLAR CELL

16V,5W

WET\DRY

12V

WATER OUT

UNIT

SUN

WATER IN

CIRCUIT

INVERTER

BATTERY

SWITCH

DETECTOR

SOLARCELL

A PN junction is formed from a piece of semiconductor by diffusing p type materials to one half side and N type materials to other half side.

It consists of both types of semiconductor materials. The N type layer is situated towards the sunlight. As N type layer is thin, light can penetrate through it. The energy of the sunlight will create free electron in the N type material and

holes in the p type material. This condition built up the voltage with in the crystal. Because the ELECTRONS will travel to the +ve region and the HOLES will

travel to the –ve region. This conduction ability is one of the main technical goals in fabricating solar

cells.

INVERTER- POWER DRIVE SECTION

When the point A is in ‘1’ state the series of transistors connected to its emitter will conduct and thus the current will be flow from middle of winding to one end causing 12V drop across that winding.

So, the voltage output will be present at the secondary of this step up transformer is 230V (Positive Half).

When the point B is in ‘1’ state the series of transistors connected to its emitter will conduct and thus the current will be flow from middle of winding to another end causing 12V drop across that winding.

So, the voltage output will be present at the secondary of this step up transformer is 230V (Negative Half).

Like this the continuous voltage will be available in 230V, quasi sine wave format.

This voltage will be connected to the pump circuit.

WET/DRY DETECTOR

Thermistors (Thermally sensitive resistors) are solid state, electronic devices which detect thermal environmental changes for use in WET\DRY DETECTOR.

The sensing sensor is thermistor. The thermistor used in the comparator

circuit is a negative temperature coefficient (NTC) type.

A NTC exhibits decreasing electrical resistance with increase in environmental temperature and increasing electrical resistance with decreasing temperature.

Relays are switching devices. Switching devices are the heart of

industrial electronic systems. When a relay is energized or activated, contacts are made or broken.

They are used to control ac or dc power.

They are used to control the sequence of events in the operation of a system such as an electronic heater, counter, welding circuits, and X-ray equipment, measuring systems, alarm systems and telephony.

Electromagnetic relays are forms of electromagnets in which the coil current produces a magnetic effect.

It pulls or pushes flat soft iron armatures or strips carrying relay contacts.

Several relay contact can be operated to get several possible ON/OFF combinations.

Fin