week 8

Block Diagram

above is the block diagram of solar system.

 referring to above, the operation of solar system can be shown as in the block diagram of PV system. The input and output are determine.Solar module is used to generate electricity from sunlight. When electricity is generated, the control unit will take part. Its function is to switch the loads manually or automatically, protect the batteries and wiring, monitor the performance of the system and give warnings when faults happen in the system. Some simpler system may not have control unit. The rechargeable batteries are connected directly to the solar module.

The rechargeable batteries are used to store electricity for later use at night and during cloudy periods. Normally, twelve-volt (12V) Lead-acid batteries, similar to the ones in cars and trucks, are used.

The distribution of electricity is direct current (DC) 12-24V. It is much less dangerous than mains voltages, which is 100-240V. Besides, its wiring is less complicated. Finally, the generated electricity can be connected to the electrical appliances. These appliances normally work in DC. They may need adaptor and inverter if work in AC.

above is the block diagram of wind energy system

A hydro power station uses potential energy of water at high level for generating electrical energy.

This power station is generally located in hilly areas where dams can be built conveniently and large water reservoirs can be obtained. This kind of power station can be used to produce large amounts of electrical energy. In most countries these power stations are used as peak load power stations. This is because they can be started and stopped easily and fast.

The water from the dam is lead to the water turbine through the penstock. Here the hydraulic energy of water is converted to rotational mechanical energy by the turbine. The turbine is connected to the generator through the turbine shaft and hence mechanical energy is converted into electrical energy by the generator.

above is the block diagramm of wind energy

When the wind strikes the rotor blades, blades start to rotating. Rotor is directly connected to high speed gearbox. Gearbox converts the rotor rotation into high

speed which rotates the electrical generator. An exciter is needed to give the required excitation to the coil so that it can generate required voltage. The exciter current is controlled by a turbine controller which senses the wind speed based on that it calculate the power what we can achieve at that particular wind speed.

Then output voltage of electrical generator is given to a rectifier and rectifier output is given to line Converter unit to stabilise the output ac that is feed to the grid by a high voltage transformer. An extra units is used to give the power to internal auxiliaries of wind turbine (like motor, battery etc.), this is called Internal Supply unit