Soft Transducer Materials For

Energy Conversion

CONTENTS

PropertiesPiezoelectricity

Pyroelectricity

Ferroelectricity

Conclusion

PIEZOELECTRICITY

What is piezoelectricity?

Response of applied mechanical stress on the material

Piezoelectricity

Mechanical Stress Electric Potential

A piezoelectric disk generates a voltage when deformed

MECHANISMIn the crystal +ve and –ve charges gets aligned symmetricallyso each of the side forms an electric dipole.when a mechanical Stress is applied this symmetry is disturbed and voltage is generated

Materials used in

piezoelectricityNatural crystals

Man-made crystalsMan-made ceramics

Lead free piezoceramics

Polymers

1. Natural crystals

1. Berlinite (AlPO4), a rare phosphate mineral that is structurally identical to quartz2. Cane sugar3. Quartz4. Rochelle salt5. Topaz6. Tourmaline-group minerals

crystals:-

1.quartz :- hexagonal structure, pure and contains traces of other elements Al3+,

fe3+,Ti4+,P5+, H+, Li+, Na+,

K+.

Density=2.65gm/cm3 Shows piezoelectric effect perpendicular to prism axis.

2]aluminium orthophosphate:-Rhombic crystal,Density: 2560 kg/m³Mol mass: 121,95 g/mol

[3]gallium orthophosphate:- colourless trigonal crystal system, similar structure to that of Quartz. It is not naturally found as the Quartz. Its piezoelectric effect is twice to that of Quartz

2.Ceramics

•Barium titanate (BaTiO3)—Barium titanate was the first piezoelectric ceramic discovered.•Lead titanate (PbTiO3)•Lead zirconate titanate •Potassium niobate (KNbO3)•Lithium niobate (LiNbO3)•Lithium tantalate (LiTaO3)•Sodium tungstate (Na2WO3)

3.man-made crystals

1.Gallium orthophosphate (GaPO4), a quartz analogic crystal2.Langasite (La3Ga5SiO14), a quartz analogic crystal

4.polymers

Polyvinylidene

fluoride (PVDF)Typical PVDF Applications

•Pressure Pick Ups: distribution of pressure on surfaces, accelerometers, keyboards.•Acoustic Components: microphones, ultrasonic detectors, hydrophones, sonar•Optical Devices: laser diameter measurement,

Applications

1.electric cigarette lighter2.Piezoelectric transformer3.Sensor4.Loudspeaker5.Microphone6.Inkjet printers7.DANCE FLOOR

Pyroelectricity

Temprature Variation Electric Potential

pyroelectric Materials

Single Crystal

Ceramics

Polymers

1. Single crystal

1. Triglycine Sulphate(TGS) or ((NH2 CH2COOH)3H2SO4)

TGS has been extensively studied forthermal imaging applications and is well known for its use in infrared detectors.

2 .LiTaO3 (Lithium Tantalate)

3. LiNbO3 (Lithium Niobate)4. Sr1-x BaxNb2O6 (Strontium Barium Niobate)

2. Ceramics

1. lead zirconium titanate (PZT)

2 . Mn-doped leadzirconate-lead-titanate-lead magnesium niobate (Pb(Mg1/3Nb2/3)O3-PbTiO3-PbZrO3)

3. Polymers

1. Ferroelectric poly(vinylidene fluoride) [p(VdF), PVDFor PVF2)]

Applications

1.Flame and Fire Detectors2.IR Detector3.Radiometers4.Thermometers5.Imaging

Ferroelectricity

1.Spontaneous Polarization 2.Reorientation of Polarization

FERROELECTIC MATERIALS

1.Tungston-Bronze group2.Oxygen Octahedral group

3.Pyroshlore group 4.Bismth-layer Structure group

FERROELECTIC MATERIALS

Oxygen Octahedral group

ABO3perovskite typeA=Pb2+ and La3+ ionsB=Zr4+ and Ti4+ ions

FERROELECTIC MATERIALS

Applications

1.Piezo- & Pyroelectricity2.Capacitor3.Ferroelctric Memory Technology4.FeFET

CONCLUSIONIt has very large importance in our daily life

as we have seen the electricity generation by soft transducer material is very easy and at

very low cost

BIBLIOGRAPHY1. http://www.imit.kth.se/info/SSD/KMF/2B1750/07_Pyro

.ppt2. http://www.ims.uconn.edu/~alpay/Courses/MMAT317/

Ferroelectrics3. http://

eng-sci.udmercy.edu/courses/e478/dass/courses/E452-SensorsActuators/projects/heat%20sensor.ppt

4. http://bayes.wustl.edu/etj/articles/ferroelectricity.pdf5. http://eng.sut.ac.th/ceramic/old/images_news/217.pdf6. http://

butane.chem.illinois.edu/murphycj/chem204spring2011/handouts/FerroelectricReview.pdf

7. http://theory.caltech.edu/~politzer/supplements/ferroelectricity.pdf

8. http://r8---sn-o097zuel.c.youtube.com/videoplayback?algorithm=throttle-factor&burst

9. http://www.lboro.ac.uk/research/iemrc/documents/EventsDocuments/2012%20conference/presentations/whatmore.pdf

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Insulators for overhead transmission line

Types of insulators

1. Sackle type-Used in 230v-440v, Dumpy shape2.Pin type-For 11 kv-33kv, small & cheap.3.Strain type-Above 33kv, used in vertical plane. 4.Suspension type-Above 33kv, used in horizontal plane

Characteristics of insulatorsThere should be not any pores or air space.There should not be any impurities.There should be perfectly homogeneous material.Leakage current should be minimum. Insulators should be able to withstand over voltage and normal working voltage.It should be mechanically strong to bear the conductor load.

Underground transmission lines

It can assists the transmission of power across:•Densely populated urban areas •Areas where land is unavailable or planning consent is difficult .•Rivers and other natural obstacles •Land with outstanding natural or environmental heritage. •Areas of significant or prestigious infrastructural development.

It can assists the transmission of power across:•Densely populated urban areas. •Areas where land is unavailable or planning consent is difficult .•Rivers and other natural obstacles •Land with outstanding natural or environmental heritage. •Areas of significant or prestigious infrastructural development.

Cross-section of Underground transmission lines

Transmission line parameters

R=resistance per unit lengthL=Inductance per unit length G=conductance per unit length C=Capacitance per unit length

Transmission line equations

For harmonic variation

V(z, t)=v e^(-αz)cos(wt-βz)I(z, t)=I e^(- αz)cos(wt-βz)

For harmonic variationV(z, t)=V’ e^(-αz)cos(wt-

βz)I(z, t)=I’ e^(- αz)cos(wt-

βz)

WhereV=voltage across z-axisI=current across z-axisV’=maximum voltageI’=maximum current

α= Attenuation factorβ= phase factor

Loss in transmissi

on line

Lossless transmissi

on line

Conditions for lossless line

1.Resistance=o

2.Attenuation factor(α)=03.Conductance=infinity4.Characteristic impedence=√(L/C)

ELECTRIC POWER

DISTRIBUTION

TWO TYPES OF DISTRIBUTION

SYSTEMS

1. High voltage or Primary distribution systems.

2. Low voltage or Secondary distribution systems.

PRIMARY DISTRIBUTION SYSTEMS

A 3-phase 3-wire system. Operates at voltages such as 3.3,6.6,11 kV or higher even some what

higher than 230 V.A primary distribution line is used Called

FEEDER. Each feeder can carry a load of 1-2 MVA.

33/11 kV substations – Load requirement order of 5 MVA. No of feeders required 3-4.

For the Load exceeding 8 MVA the secondary transmission is carried out at 66 kV. So as to

reduce the line losses, and therefore secondary substations are 66/11 kV.

66/11 kV substations –Load requirement order of 8 MVA. No of feeders required 6-8.

FEEDERSFeeders are of 4 types

1. Radial Feeders.2. Parallel Feeders.

3. Loop Feeders.4. Inter connected.

RADIAL FEEDERSRadiates from the secondary substation and branches into distribution transformer connected (11 kV/415 kV) sub feeders and laterals. Advantageous for supplying

power to heavy industrial load near the secondary substation, isolated loads such as tube wells and areas

of low load density such as villages.Drawbacks:

1.When a fault occurs at any point on the feeder supply to all consumer beyond the fault point towards the tail

end gets interrupted.2. In case of increase in load demand , the length of the

feeder has to be extend and may results in a greater voltage drop. It may cause the voltage towards the tail

end to reach a value below the permissible value.

PARALLEL FEEDERS

In this system 2 radial feeders originating from the same or different secondary substation are run in parallel. Each feeder though capable of supplying the entire load, shares the total load equally in normal conditions. As in case of fault on one feeder, the total load can be supplied by the healthy feeder. Interruption of supply is only for the time duration i.e. taken in transferring the load from the faulty feeder to the healthy one either by manual or by automatic switches. Such a system is used when the continuity of supply is of greater importance.

LOOP FEEDERS

In a loop feeder system 2 or more radial feeders originating from the same or different secondary substations are laid on different routes of load areas. The arrangement having the ends of 2 feeders tied together through normally open switching devices is known as open loop system while the arrangement having the ends of 2 feeders tied together through normally closed switching devices is called ring main feeder or the ring loop. This system is most reliable for continuity of supply and gives better voltage regulation and less power losses.The use of this system is prohibitive on account of very large investment involved.

INTER-CONNECTED NETWORK SYSTEM

When the feeder ring main is energized from 2 or more than two generating stations or substation and it is called the Inter connected network system. Because of inter connected feeders, power can be supplied to all the distribution transformers even though a part of network may be out of service such a system is employed in large metropolitan cities where continuity of the supply is more important.

SECONDARY DISTRIBUTION

SYSTEM

In this system distribution occurs in 2 way

1. 3-phase 4-wire distribution.2. Single-phase 2-wire

distribution.

3-PHASE 4-WIRE DISTRIBUTION SYSTEM

Transformer substation contains (1) High voltage switch gears and bus bars and (2) Low voltage fuses

or Links.High or extra high voltage feeder cable supplies to primary from the generating station. Low voltage bass bars are distinguished by their colour RED,

YELLOW, BLUE for phases and BLACK for the neutral. The local 4-wire distributors are connected

in parallel to the bus bars through the fuses or links.Domestic and other low consumers -> 2 wire service

cables.Larger Non domestic consumers -> 4 wire service

{230 V single phase for lightning , 400 V 3-phase for power}

SINGLE PHASE 2-WIRE DISTRIBUTION SYSTEM

Employed for supplying purely domestic loads. These are connected to single phase & neutral at the sub station bus bars.

CLASSIFICATIONSecondary distribution system

can be classified as

1. Radial System2. Open loop System

3. Network distribution system

RADIAL SYSTEMIn this system the low voltage distributors

radiate out from the distribution transformer and run through the areas of supply. A simplest

less expensive system.DRAWBACKS :

1. The end of the distributor nearest to the supply end would be heavily loaded.

2. The consumers at the furthest end of the distributor would be subjected to serious

voltage fluctuations with the variation in load.3. Fault on a distributor can affect a lots of

consumer.

OPEN LOOP SYSTEMIn this system 2 low voltage distributors take off from the same distribution transformer and run in different directions and so supply in different areas. The far ends of the 2 distributors are tied together by a normally open switching device. In the case of a fault on one line, the load can be supplied though partially from the other line. Thus in this system the reliability of supply is improved and cost is increased marginally in comparison to the previous one.

NETWORK DISTRIBUTION SYSTEM

It consisting of a number of interconnected distributing lines is supplied from 2 or more

distribution transformers operating in parallel.

It is an advantageous system because in case of one transformer fails load can be supplied

by other one. Such a system is used in High load density

METROPOLITAN areas.

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