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Properties Piezoelectricity Pyroelectricity Ferroelectricity Conclusion.

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Presentation on theme: "Properties Piezoelectricity Pyroelectricity Ferroelectricity Conclusion."— Presentation transcript:

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2 Properties Piezoelectricity Pyroelectricity Ferroelectricity Conclusion

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4  Response of applied mechanical stress on the material

5 Mechanical Stress Electric Potential

6 A piezoelectric disk generates a voltage when deformed

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

9 Natural crystals Man-made crystals Man-made ceramics Lead free piezoceramics Polymers

10 1. Natural crystals 1. Berlinite (AlPO 4 ), a rare phosphate mineral that is structurally identical to quartzBerlinitephosphatemineralquartz 2. Cane sugarCane sugar 3. QuartzQuartz 4. Rochelle saltRochelle salt 5. TopazTopaz 6. Tourmaline-group mineralsTourmaline-group minerals

11 crystals:- 1. quartz :- hexagonal structure, pure and contains traces of other elements Al 3 +, fe 3+, Ti 4+, P 5+, H +, Li +, Na +, K +. Density=2.65gm/cm3 Shows piezoelectric effect perpendicular to prism axis. crystals:- 1. quartz :- hexagonal structure, pure and contains traces of other elements Al 3 +, fe 3+, Ti 4+, P 5+, H +, Li +, Na +, K +. Density=2.65gm/cm3 Shows piezoelectric effect perpendicular to prism axis.

12 2]aluminium orthophosphate :- Rhombic crystal, Density: 2560 kg/m³ Mol mass: 121,95 g/mol

13 [3] gallium orthophosph ate:- 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

14 2.Ceramics Barium titanate (BaTiO 3 )—Barium titanate was the first piezoelectric ceramic discovered.Barium titanate Lead titanate (PbTiO 3 )Lead titanate Lead zirconate titanate Potassium niobate (KNbO 3 )Potassium niobate Lithium niobate (LiNbO 3 )Lithium niobate Lithium tantalate (LiTaO 3 )Lithium tantalate Sodium tungstate (Na 2 WO 3 )Sodium tungstate

15 3.man-made crystals 1.Gallium orthophosphate (GaPO 4 ), a quartz analogic crystalGallium orthophosphate 2.Langasite (La 3 Ga 5 SiO 14 ), a quartz analogic crystalLangasite 1.Gallium orthophosphate (GaPO 4 ), a quartz analogic crystalGallium orthophosphate 2.Langasite (La 3 Ga 5 SiO 14 ), a quartz analogic crystalLangasite

16 4.polymers Polyvinylidene fluoride 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, 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,

17 Applications 1.electric cigarette lighterlighter 2.Piezoelectric transformer 3.Sensor 4.Loudspeaker 5.Microphone 6.Inkjet printers 7.DANCE FLOOR

18 Temprature Variation Electric Potential

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20 Single Crystal Ceramics Polymers

21 1. Single crystal 1. Triglycine Sulphate (TGS) or ((NH2 CH2COOH)3H2SO4 ) TGS has been extensively studied for thermal 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)

22 2. Ceramics 1. lead zirconium titanate (PZT) 2. Mn-doped lead zirconate-lead-titanate-lead magnesium niobate (Pb(Mg1/3Nb2/3)O3-PbTiO3-PbZrO3)

23 3. Polymers 1. Ferroelectric poly(vinylidene fluoride) [p(VdF), PVDF or PVF2)]

24 Applications 1.Flame and Fire Detectors 2.IR Detector 3.Radiometers 4.Thermometers 5.Imaging

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29 1.Spontaneous Polarization 2.Reorientation of Polarization

30 1.Tungston-Bronze group 2.Oxygen Octahedral group 3.Pyroshlore group 4.Bismth-layer Structure group

31 FERROELECTIC MATERIALS Oxygen Octahedral group ABO 3 perovskite type A=Pb2+ and La3+ ions B= Zr4+ and Ti4+ ions

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33 Applications 1.Piezo- & Pyroelectricity 2.Capacitor 3.Ferroelctric Memory Technology 4.FeFET

34 It 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

35 1.http://www.imit.kth.se/info/SSD/KMF/2B1750/07_Pyro.ppthttp://www.imit.kth.se/info/SSD/KMF/2B1750/07_Pyro.ppt 2.http://www.ims.uconn.edu/~alpay/Courses/MMAT317/Ferroele ctricshttp://www.ims.uconn.edu/~alpay/Courses/MMAT317/Ferroele ctrics 3.http://eng-sci.udmercy.edu/courses/e478/dass/courses/E452- SensorsActuators/projects/heat%20sensor.ppthttp://eng-sci.udmercy.edu/courses/e478/dass/courses/E452- SensorsActuators/projects/heat%20sensor.ppt 4.http://bayes.wustl.edu/etj/articles/ferroelectricity.pdfhttp://bayes.wustl.edu/etj/articles/ferroelectricity.pdf 5.http://eng.sut.ac.th/ceramic/old/images_news/217.pdfhttp://eng.sut.ac.th/ceramic/old/images_news/217.pdf 6.http://butane.chem.illinois.edu/murphycj/chem204spring2011/ handouts/FerroelectricReview.pdfhttp://butane.chem.illinois.edu/murphycj/chem204spring2011/ handouts/FerroelectricReview.pdf 7.http://theory.caltech.edu/~politzer/supplements/ferroelectricit y.pdfhttp://theory.caltech.edu/~politzer/supplements/ferroelectricit y.pdf 8.http://r8---sn- o097zuel.c.youtube.com/videoplayback?algorithm=throttle- factor&bursthttp://r8---sn- o097zuel.c.youtube.com/videoplayback?algorithm=throttle- factor&burst 9.http://www.lboro.ac.uk/research/iemrc/documents/EventsDoc uments/2012%20conference/presentations/whatmore.pdfhttp://www.lboro.ac.uk/research/iemrc/documents/EventsDoc uments/2012%20conference/presentations/whatmore.pdf

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40 Types of insulators 1. Sackle type-Used in 230v-440v, Dumpy shape 2.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

41 Characteristics of insulators  There 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.  There 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.

42 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.

43 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.

44 Cross-section of Underground transmission lines

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47  For harmonic variation  V(z, t)=v e^(-αz)cos(wt-βz)  I(z, t)=I e^(- αz)cos(wt-βz)  For harmonic variation  V(z, t)=v e^(-αz)cos(wt-βz)  I(z, t)=I e^(- αz)cos(wt-βz)

48  For harmonic variation  V(z, t)=V’ e^(-αz)cos(wt-βz)  I(z, t)=I’ e^(- αz)cos(wt-βz) Where V=voltage across z-axis I=current across z-axis V’=maximum voltage I’=maximum current α= Attenuation factor β= phase factor  For harmonic variation  V(z, t)=V’ e^(-αz)cos(wt-βz)  I(z, t)=I’ e^(- αz)cos(wt-βz) Where V=voltage across z-axis I=current across z-axis V’=maximum voltage I’=maximum current α= Attenuation factor β= phase factor

49 Loss in transmission line

50 Lossless transmission line

51 Conditions for lossless line 1. Resistance=o 2. Attenuation factor(α)=0 3. Conductance=infinity 4. Characteristic impedence=√(L/C)

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53 1. High voltage or Primary distribution systems. 2. Low voltage or Secondary distribution systems.

54 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.

55 Feeders are of 4 types 1. Radial Feeders. 2. Parallel Feeders. 3. Loop Feeders. 4. Inter connected.

56 Radiates 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.

57 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.

58 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.

59 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.

60 In this system distribution occurs in 2 way 1. 3-phase 4-wire distribution. 2. Single-phase 2-wire distribution.

61 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}

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

63 Secondary distribution system can be classified as 1. Radial System 2. Open loop System 3. Network distribution system

64 In 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.

65 In 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.

66 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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70 THANK YOU THANK YOU

71 ANY QUERIES ?


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