# Different Subassemblies Of Ac And Dc Generator Engineering Essay

P1: Draw diagram and compose down the different subassemblies of AC and DC generator?

A.C. generator has spiral of wire traveling about into a magnetic field. With this assembly, a electromotive force is induced and this produce a current in a current

In a bike dynamo, a magnet turns inside a spiral of wire when the back wheel of the bike is turning.

AC Generator:

## P2: Describe the of AC and DC generator and explicate the difference between AC and DC generator-

Electricity is generated when a spiral of wire moves in a magnetic field. This is the footing of electricity generators.

Most electricity is made in power Stationss by firing fuels. Transformers are used in the National Grid to cut down energy losingss from the wires during transmittal.

## DC electricity:

Batteries produce direct current, or DC, electricity. The current flows in the same way all of the clip, as shown by this typical voltage-time graph.

## AC electricity:

Alternating current

Generators produce jumping current, or AC, electricity. The current contraries way on a regular basis, as shown by this typical voltage-time graph.

Mains electricity is AC. It has a frequence of 50Hz – 50 rhythms per second.

When a wire is moved in a magnetic field, the motion, magnetic field and current are all at right angles to each other. If the wire is moved in the opposite way, the induced current besides moves in the opposite way.

One side of a spiral in a generator moves up during one half-turn, and so down during the following half-turn. This means that, as a spiral is rotated in a magnetic field, the induced current contraries way every half-turn.

## Solar cells

Solar-powered ticket machine

Solar cells are devices that convert visible radiation energy straight into electrical energy. You may hold seen little solar cells in reckoners. Larger arrays of solar cells are used to power route marks in distant countries, and even larger arrays are used to power orbiters in orbit around Earth.

## Solar panels

Solar panels do non bring forth electricity, but instead they heat up H2O. They are frequently located on the roofs of edifices where they can have heat energy from the Sun. The diagram outlines how they work.

Cold H2O is pumped up to the solar panel, there it heats up and is transferred to a storage armored combat vehicle.

A pump pushes cold H2O from the storage armored combat vehicle through pipes in the solar panel. The H2O is heated by heat energy from the Sun and returns to the armored combat vehicle. In some systems, a conventional boiler may be used to increase the temperature of the H2O.

Solar energy is a renewable energy resource and there are no fuel costs. No harmful polluting gases are produced.

Solar cells are expensive and inefficient, so the cost of their electricity is high.

Solar panels may merely bring forth really hot H2O in really cheery climes, and in ice chest countries may necessitate to be supplemented with a conventional boiler.

Although warm H2O can be produced even on cloudy yearss, neither solar cells nor solar panels work at dark.

## Alkaline:

Long-life batteries giving up to six times the life of ordinary Zn C batteries.

Ideal for contraptions demanding a high current drain when being used on an intermittent or uninterrupted footing.

## Rechargeable Alkaline:

Offers the benefits of standard Alkaline cells but with rechargeable capableness.

Besides more good than NiMH cells due to ; 1.5v, ab initio to the full charged

Can be stored up to 7 old ages charged

Can be charged 50 times ( although a 500 times may be possible )

N.B. These batteries can merely be charged utilizing an Alkaline Battery Charger.

## Silver Oxide:

Silver oxide batteries have the most stable electromotive force features among all types of button-type batteries, every bit good as presenting the highest public presentation

Silver oxide batteries use silver oxide for the positive active stuff. The negative active stuff is zinc, and the electrolyte is potassium hydrated oxide

Because of the usage of these stuffs, the Ag oxide batteries have a higher operating electromotive force and an highly stable power supply. The nominal open-circuit electromotive force is 1.55 Vs

Silver oxide batteries are besides far superior in heavy drain utilizations and suited for the usage in cameras and exposure metres.

## Disposing:

These batteries should be recycled when disposing of them, ground being because of environmental issues. These batteries will non break up so this could consequence the environment

## Conductor:

Conductor makes the electric current flow freely. It is largely made out from Cu, holding high opposition to the flow of charge through them. Conductor involves the outer negatrons of the atoms are slackly bound and free to travel through the stuff. In a music director such as Cu negatrons are basically free and strongly drive each other. Simply stated, most metals are good electrical music directors, most non-metals are non. Metallic elements are besides by and large good heat music directors while non-metals are non.

## Insulator:

Insulator does non flux freely similar music director does, most non-metallic solids are good dielectrics. Most atoms hold on to their negatrons tightly and are dielectrics. Insulators offer big sum of opposition to the flow of electric current.

## Semi-conductor:

Is an component which neither is a good music director or a good dielectric, but instead lies someplace in between the two. Characterized by a valency shell incorporating four voters. Silicon, Ge and C are the semi-conductors most often used in electronics.

## Electric resistance:

Resistance controls the flow of current and is identified in ohms. Electrical electric resistance is a measuring of how robustly a material resist the flow of current. A high electric resistance show a stuff does n’t freely allows the motion of electrical whereas low electric resistance shows a stuff that readily allows the motion of electrical charge.

## Tensile Strength:

Is a strict belongings of the stuff is the maximal sum of tensile emphasis that it can be subjected to before failure. . It is an intensive belongings of the stuff, which non merely depends on the type of stuff but besides the readying of the specimen and the temperature of the trial. The definition of failure can change harmonizing to stuff type and design methodological analysis

## Geothermal energy

You should be able to sketch how electricity is generated from geothermic energy.

## Volcanic countries

Several types of stone contain radioactive substances such as U. Radioactive decay of these substances releases heat energy, which warms up the stones. In volcanic countries, the stones may heat H2O so that it rises to the surface of course as hot H2O and steam. Here the steam can be used to drive turbines and electricity generators. This type of geothermic power station exists in topographic points such as Iceland, California and Italy.

## Hot stones

In some topographic points, the stones are hot, but no hot H2O or steam rises to the surface. In this state of affairs, deep Wellss can be drilled down to the hot stones and cold H2O pumped down. The H2O runs through breaks in the stones and is heated up. It returns to the surface as hot H2O and steam, where its energy can be used to drive turbines and electricity generators. The diagram below shows how this works.

## Step-up Transformer:

Step-Up Transformers are one of the truly common and critical electrical tools used in power transmittal and modification.A They are normally the first major transformer in a transmittal system and are frequently used in assorted signifiers throughout the system.

## Step-down Transformer:

Step down transformers are designed to cut down electrical electromotive force. Their primary electromotive force is greater than their secondary electromotive force. This sort of transformer “ stairss down ” the electromotive force applied to it. For case, a measure down transformer is needed to utilize a 110v merchandise in a state with a 240v supply.

## Wind Power

Wind power generators are seldom seen in isolation as they are usually put together in groups organizing air current farms. This is the most efficient manner of bring forthing electricity from the air current and feeding it into the national power grid. Single generators are usually much smaller and used on farms or in distant countries where it is non possible to overseas telegram electricity from the national grid. Wind farms tend to be located in the countryside were they are off from towns and people. Many people believe that these big constructions spoil the expression and piece of the countryside. Wind generators create a batch of noise. It is said that each one is every bit loud as a auto engine running at 70 MPH.

Some engineers and scientists believe the reply is to site big air current generators at sea. The noise they produce will non be heard and if sited stat mis manner from the seashore they will non even be seen. However, they are much more dearly-won to turn up and keep in the sea. Besides, the salt in sea H2O means that the stuffs used to do them hold to be specially treated so that they are protected. This increases there overall cost of industry and installing significantly. However, this may be the hereafter for the big scale production of electricity through air current powered turbines.

## Wave Power

The power of the moving ridges can be used to bring forth electricity. Most systems concentrate on making electricity straight from the force of H2O. However, an ‘Oscillating Water Column ‘ plants as the moving ridge enters the lower chamber, it forces air into the upper chamber and this causes the turbines to revolve. The advantage of this type of system is that the propellors are out of the sea H2O which means they are non affected by the salty H2O.

The PENDULUM device is another electricity bring forthing device that utilises the power of moving ridges, as the moving ridge hits the pendulum it is forced backwards and so returns to its original place until the following moving ridge hits. This motion forces hydraulic inclines backwards and forwards which drive particular turbines and produces electricity.

## Hydroelectricity

Hydro power is an alternate manner of bring forthing electricity from the power produced by H2O under force per unit area. A typical apparatus requires the building of a dike. This would be situated at the caput of a vale. Behind the dike, H2O is allowed to construct up organizing a big, deep lake. The deeper and larger the lake, the greater the potency of bring forthing big sums of electricity. A typical dike may take old ages to build and be 1000000s of dollars / euros and accordingly a dike must remain bring forthing electricity for many old ages ( possibly even decennaries ) – in order to bring forth electricity productively. The Hoover Dam in the USA was opened in 1936 and is an first-class illustration of this type of dike.

The lake behind the dike contains 1000000s of gallons of H2O and it is the pressure/weight from the ‘head ‘ of H2O that is used to drive turbines bring forthing electricity. The H2O is release through penstock Gatess good below the H2O line. The weight of the H2O above forces H2O through the penstock Gatess at high velocity. This velocity drives the turbines round bring forthing big sums of electricity. The diagram below shows how electricity is produced.

## Piezo-electric actuators

Piezo-electric actuators work in two ways ; they either produce motion in response to an applied electromotive force or they produce a electromotive force in response to an applied force per unit area. Piezo-electric actuators are used in salutations cards that play melodies when opened. They produce a sound from an electrical signal as a consequence of the card being opened.

When piezo-electric transducers are used as detectors they are capable of picking up little signals that can so be amplified and processed. They are used in a broad assortment of applications including burglar dismaies. The transducer produces a electromotive force in response to a loud sound, such as a breakage window, or to a motion such as steping on a mat or step pace.

The transducers are made from minerals, ceramics or polymers. The piezo-electric movie is bonded to a basal stuff one time coated with a metallic movie and contacts are so attached. In some instances amplifier circuits are built in to the whole transducer but in most illustrations they are left like the illustrations below.

The electromotive force generated as a consequence of the stuff being deformed is sufficient plenty to illume an LED as shown below

## M1: Compare and contrast the characteristics of three premier energy beginnings that are in general usage for the production of electricity by automatically driving an electromagnetic generator. Explain in item advantages and disadvantages of three electrical beginning of energy e.g. atomic, thermic and steam turbine?

Nuclear:

There is approximately 0 emanation, which means it produces electricity without pollution.

Does n’t take fossil fuels which is acquiring more & A ; more expensive

They can be sited about anyplace unlike oil which is largely imported

A batch of energy from a individual power works

The advantage is a clean combustion fuel that can supply energy for 100s of stat mis at a clip.

More expensive to construct

Waste merchandise is harmful and need to be carefully stored for long clip

Produce radioactive waste which needs to be contained carefully

Nuclear power workss can be unsafe to its milieus and employees. There has been a instance where a works has gone through a meltdown and as a consequence left people dead and its milieus destroyed.

Thermal:

Thermal energy is the easiest to happen and make.

Geothermal energy is a renewable energy resource and there are no fuel costs.

No harmful polluting gases are produced

It is necessary in some state of affairss ( for illustration, chemical procedures where molecular gesture is necessary

Most parts of the universe do non hold suited countries where geothermic energy can be exploited.

Hydroelectricity:

Once a dike is constructed, electricity can be produced at a changeless rate.

If electricity is non needed, the penstock Gatess can be shut, halting electricity coevals. The H2O can be saved for usage another clip when electricity demand is high.

Dams are designed to last many decennaries and so can lend to the coevals of electricity for many old ages / decennaries.

The lake ‘s H2O can be used for irrigation intents.

The physique up of H2O in the lake means that energy can be stored until needed, when the H2O is released to bring forth electricity.

When in usage, electricity produced by dam systems does non bring forth green house gases. They do non foul the ambiance.

Dams are highly expensive to construct and must be built to a really high criterion.

The high cost of dam building means that they must run for many decennaries to go profitable.

The implosion therapy of big countries of land agencies that the natural environment is destroyed.

Peoples populating in small towns and towns that are in the vale to be flooded, must travel out. This means that they lose their farms and concerns. In some states, people are forcibly removed so that hydro-power strategies can travel in front.

The edifice of big dikes can do serious geological harm. For illustration, the edifice of the Hoover Dam in the USA triggered a figure of earth temblors and has depressed the Earth ‘s surface at its location.

Dams built barricading the advancement of a river in one state normally means that the H2O supply from the same river in the undermentioned state is out of their control. This can take to serious jobs between neighboring states.

Differences:

There are many differences between atomic, thermic and hydro-electricity. These three types of energy production have different ways of bring forthing energy ( electricity ) . There is besides the cost of doing the generator in order to bring forth energy, hydro-electricity is much more expensive compared to atomic. There is besides the waste that the generators produces e.g. Nuclear produces harmful substances that need to be dispose or shops whereas hydroelectricity does non merchandise and waste.

Similarities:

One of the chief similarities between atomic, thermic and hydro-electricity is that there are all beginnings of renewable energy. These types of energy beginnings have different ways of bring forthing energy but produces renewable energy.

## M2: Explain the grounds for the usage of a scope of electromotive forces in an electricity supply system. In electricity supply systems from point of coevals to distributions there are many different types of electromotive force are being used explicate what the importance of these types of electromotive forces is?

When generators supply electrical energy is uses step-up transformer that can travel up to 25,000V so electricity can be supplied to far distance to every places and concerns. The power station distributes electricity

## D1: Justify the usage of different energy beginnings, including fuels and renewable beginnings, to supply a state ‘s electricity supply

In different countries around the universe there are different environments to be considered when utilizing different types of energy beginnings. In topographic points such as South Africa, it is excessively expensive to provide fuel energy to topographic points like the small towns. Alternatively in these kinds of topographic points, they use renewable beginnings of energy such as solar energy. This is a good benefit for the people who live in such an environment because it stays cheery most of the clip, the energy is supplied invariably. Not merely that, but after puting up the supply the energy is so free.

But in topographic points such as the UK it is different. Right now the chief supply of energy beginnings is from fuels. The ground being is because it is much cheaper at the minute. Another ground is utilizing solar energy is non a sufficient plenty because of deficiency of Sun. But the UK will utilize air current power which will be topographic point into the sea. Constructing these large air current turbines is expensive but it could supply adequate energy for a metropolis etc.

But utilizing fuel to make electrical energy harms the environment. Creating energy utilizing fuels harms the environment such as doing holes in the o-zone bed. There are advantages on utilizing fuel energy such as big sums of electricity can be generated in one topographic point utilizing coal, reasonably cheaply. But there are more disadvantages such as fuels causes pollution, firing any fossil fuel produces C dioxide, which contributes to the nursery consequence, warming the Earth and besides fuels are non-renewable so one time the fuel is burn that is it, there is no more.

With renewable energy the lone autumn back about it is the fact that it is most of the clip expensive to put up. But when setted up, the energy is perfectly free. The chief benefit of renewable energy is that it does non do pollution which fuel does.

## With the mention to healthcare magnetic resonance imagination ( MRI ) scanners, runing theater uninterruptible power supplies ( UPS ) .

CNC:

There are many machine-controlled procedures such as CNC. A CNC ( Computer Numeric Controls ) milling machine uses CAD/CAM cutter waies to cut away metal blocks into the assorted parts of an injection cast and so add the pits and ouster pin holes. This produces anything from CPU ‘s to motherboards. The great thing about this engineering is that there are many benefits such as

Rapid fabrication

Can be easy to plan utilizing package

Magnetic resonance imaging:

MRI is a particular radiology technique designed to image internal constructions of the organic structure utilizing magnetic attraction, wireless moving ridges, and a computing machine to bring forth the images of organic structure constructions. MRI creates better images than a CT scan or X-ray, because it can demo both healthy and morbid tissues. MRI is ideal for:

Diagnosing multiple induration ( MS )

Diagnosing tumours of the pituitary secretory organ and encephalon

Diagnosing infections in the encephalon, spinal column or articulations

Visualizing lacerate ligaments in the carpus, articulatio genus and mortise joint

Visualizing shoulder hurts

Diagnosing tendinitis

Measuring multitudes in the soft tissues of the organic structure

Measuring bone tumours, cysts and pouching or herniated phonograph record in the spinal column

Diagnosing shots in their earliest phases

UPS:

UPS is chiefly used as a backup power beginning for computing machines and computing machine webs to see ongoing operation in the event of a power failure. Sophisticated units besides have power conditioning and power monitoring characteristics.