Emi2

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EXPERT SYSTEMS AND SOLUTIONS
Project Center For Research in Power Electronics and Power Systems
IEEE 2010 , IEEE 2011 BASED PROJECTS FOR FINAL YEAR STUDENTS OF B.E
Email: expertsyssol@gmail.com,
Cell: +919952749533, +918608603634
www.researchprojects.info
OMR, CHENNAI
IEEE based Projects For
Final year students of B.E in
EEE, ECE, EIE,CSE
M.E (Power Systems)
M.E (Applied Electronics)
M.E (Power Electronics)
Ph.D Electrical and Electronics.
Training
Students can assemble their hardware in our Research labs. Experts will be guiding the projects.
EXPERT GUIDANCE IN POWER SYSTEMS POWER ELECTRONICS
We provide guidance and codes for the for the following power systems areas.
1. Deregulated Systems,
2. Wind power Generation and Grid connection
3. Unit commitment
4. Economic Dispatch using AI methods
5. Voltage stability
6. FLC Control
7. Transformer Fault Identifications
8. SCADA - Power system Automation

we provide guidance and codes for the for the following power Electronics areas.
1. Three phase inverter and converters
2. Buck Boost Converter
3. Matrix Converter
4. Inverter and converter topologies
5. Fuzzy based control of Electric Drives.
6. Optimal design of Electrical Machines
7. BLDC and SR motor Drives

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Emi2

  1. 1. EXPERT SYSTEMS AND SOLUTIONS Email: expertsyssol@gmail.com expertsyssol@yahoo.com Cell: 9952749533 www.researchprojects.info PAIYANOOR, OMR, CHENNAI Call For Research Projects Final year students of B.E in EEE, ECE, EI, M.E (Power Systems), M.E (Applied Electronics), M.E (Power Electronics) Ph.D Electrical and Electronics.Students can assemble their hardware in our Research labs. Experts will be guiding the projects. 1
  2. 2. BM 2203 - Sensors andMeasurmentG.ThiyagarajanBM 17REC/BME 2
  3. 3. Block diagram of a generalized instrumentation system Process or measurement Environmental medium effects (noise, Physical variable temperature etc) to be measured Observer Feedback signal for control Input signal Intermediate Modified Controller stage signal Primary stage Manipulation Detector-transducer Transduced & IndicatorSensing & conversion signal transmission Calibration Recorder Quantity signal presented to observer Calibration signal Final (output ) External source representing stage power known value of physical variable 3
  4. 4. The Bourdon Gauge 4
  5. 5. Block diagram of the pressure gauge based Physical variable on Bourdon tube to be measured Pressure Pressure (input) Displacement Intermediate stageDetector – transducer stage (transduced signal) Gearing arrangement thatBourdon tube amplifies the displacementPressure to mechanical signaldisplacement Pressure Amplified displacement (calibration) signal Final stage Calibration signal from Pointer and dial a source with known arrangement pressure values 5
  6. 6. A typical medical measurement system Outputs Signal Signal Data SensorMeasurand conditioning processing displays Feedback Data Data Effector storage communication 6
  7. 7. Feedback with and without clinician Patient InstrumentPatient Clinician Instrument 7
  8. 8. A patient monitors vital signs andnotify a clinician if abnormalities occur Abnormal Clinician readings Patient Instrument 8
  9. 9. Detailed generalized medical measurement system 9
  10. 10. Alternative operational modes Direct-indirect modes Sampling and continuous modes Generating and modulating sensors Analog and digital modes Real-time and delayed-time modes 10
  11. 11. Example to sampled dataLaboratory test Typical valueHemoglobin 13.5 to 18 g/dLHematocrit 40 to 54%Erythrocyte count 4.6 to 6.2 × 106/ µLLeukocyte count 4500 to 11000/ µL Neutrophil 35 to 71% Band 0 to 6% Lymphocyte 1 to 10%Differential count Monocyte 1 to 10% Eosinophil 0 to 4% Basophil 0 to 2% Complete blood count for a male subject. 11
  12. 12. Analog and digital signals Amplitude Amplitude Time TimeAnalog signals can have any Digital signals have a limitedamplitude value number of amplitude values 12
  13. 13. Continuous and discrete-time signals Amplitude Amplitude Time TimeContinuous signals have values Discrete-time signals are sampledat every instant of time periodically and do not provide values between these sampling times 13
  14. 14. Origins ofcommonbiological signal 14
  15. 15. Medical measurement constraints Frequency,Measurement Range Method HzBlood flow 1 to 300 mL/s 0 to 20 Electromagnetic or ultrasonicBlood pressure 0 to 400 mmHg 0 to 50 Cuff or strain gageCardiac output 4 to 25 L/min 0 to 20 Fick, dye dilutionElectrocardiography 0.5 to 4 mV 0.05 to 150 Skin electrodesElectroencephalography 5 to 300 µ V 0.5 to 150 Scalp electrodesElectromyography 0.1 to 5 mV 0 to 10000 Needle electrodesElectroretinography 0 to 900 µ V 0 to 50 Contact lens electrodespH 3 to 13 pH units 0 to 1 pH electrodepCO2 40 to 100 mmHg 0 to 2 pCO2 electrodepO2 30 to 100 mmHg 0 to 2 pO2 electrodePneumotachography 0 to 600 L/min 0 to 40 Pneumotachometer 2 to 50Respiratory rate 0.1 to 10 Impedance breaths/minTemperature 32 to 40 ° C 0 to 0.1 15 Thermistor
  16. 16. Setting sensor specifications Specification Value – Pressure rangeSensor specifications for a blood pressure sensor aredetermined by a committee composed of individuals fromacademia, industry, hospitals, and government. 16
  17. 17. Specifications for ECG Specification Value Input signal dynamic range ±5 mV Dc offset voltage ±300 mV Slew rate 320 mV/s Frequency response 0.05 to 150 Hz Input impedance at 10 Hz 2.5 MΩ Dc lead current 0.1 µΑ Return time after lead switch 1s Overload voltage without damage 5000 V Risk current at 120 V 10 µΑSpecification values for an electrocardiograph are agreedupon by a committee. 17
  18. 18. Classification of biomedical instruments Quantity sensed: pressure, flow, temperature etc. Principle of transduction: resistive, inductive, capacitive, ultrasonic or electrochemical Organ system studied: cardiovascular, pulmonary, nervous, and endocrine systems. Clinical medical specialties: pediatrics, 18
  19. 19. Interfering and modifying inputsOriginal waveform An interfering input may shift A modifying the baseline input may change the gain 19
  20. 20. SimplifiedElectrocardiographic recording system 20
  21. 21. Compensation Techniques Inherent insensitivity Negative feedback Signal filtering Opposing inputs 21
  22. 22. Negative feedback ( xd − H f y )Gd = y yxd + ∑ Gd xd Gd = y (1 + H f Gd ) - Gd Hf y= xd 1 + H f Gd 22
  23. 23. Signal filteringSignals without noise are Interference superimposed on uncorrupted signals causes error. Frequency filters can be used to reduce noise and interference 23
  24. 24. Opposing inputs Differential amplifier: v0 = Gd(vA- vB) DC cancellation (bucking) A m p lit u d e D c o ffs e t T im e An input signal with dc offsetAn input signal without dcoffset 24
  25. 25. Generalized Static Characteristics Accuracy  Zero drift Precision and  Sensitivity drift reproducibility  Linearity Resolution  Input ranges Statistical control  Input impedance Static sensitivity 25
  26. 26. Data points with AccuracyAccuracy: closeness with which aninstrument reading approaches thetrue or accepted value of the variable(quantity) being measured. It isconsidered to be an indicator of thetotal error in the measurement without low accuracylooking into the sources of errors. true value − measured valueaccuracy = true valueAccuracy is often expressed in percentage 26 accuracy high
  27. 27. Precision Data points with1. A measure of the reproducibility of the measurements; i.e., given a fixed value of a variable, precision is a measure of the degree to which successive low precision measurements differ from one another. 2. Number of distinguishable alternatives. 2.434 V is more precise than 2.43 V. high precision 27
  28. 28. Resolution The smallest change in measured value to which the instrument will respond. Statistical control: random variations in measured quantities are tolerable, Coulter counter example 28
  29. 29. Tolerance Maximum deviation allowed from the conventional true value. It is not possible to built a perfect system or make an exact measurement. All devices deviate from their ideal (design) characteristics and all measurements include uncertainties (doubts). Hence, all devices include tolerances in their specifications. If the instrument is used for high- precision applications, the design tolerances must be small. However, if a low degree of accuracy is acceptable, it is not economical to use expensive sensors and precise sensing components 29
  30. 30. Static sensitivity Sensor Sensor signal signal Measurand MeasurandA low-sensitivity sensor has low A high sensitivity sensor hasgain high gain 30
  31. 31. Static sensitivity constant over a limited range n∑ xd y − (∑ xd )(∑ y ) (∑ y )(∑ xd ) − (∑ xd y )(∑ xd ) 2m= b= n ∑ x − ( ∑ xd ) 2 d 2 n ∑ xd − ( ∑ xd ) 2 2 31
  32. 32. Zero and sensitivity drifts 32
  33. 33. LinearityOutput Output Input InputA linear system fits the A nonlinear system does not fitequation y = mx + b. a straight line 33
  34. 34. Calibration for linearity Output Output Input Input The one-point calibration may The two-point calibration may miss nonlinearity also miss nonlinearityMeasuring instruments should be calibrated against astandard that has an accuracy 3 to 10 times better than thedesired calibration accuracy 34
  35. 35. Hysteresis Sensor s ig n a l M e a s u ra n dA hysteresis loop. The output curve obtained when increasing themeasurand is different from the output obtained when decreasingthe measurand. 35
  36. 36. Independentnonlinearity 36
  37. 37. ObjectivesAt the end of this chapter, the studentsshould be able to: describe the principle of operation ofvarious sensors and transducers; namely.. Resistive Position Transducers. Capacitive Transducers Inductive Transducers 37
  38. 38. Introduction Sensors and transducers are classifiedaccording to;  the physical property that they use (piezoelectric, photovoltaic, etc.)  the function that they perform (measurement of length, temperature, etc.). Since energy conversion is an essentialcharacteristic of the sensing process, the variousforms of energy should be considered. 38
  39. 39. Introduction There are 3 basic types of transducers namely self-generating, modulating, and modifyingtransducers.The self-generating type (thermocouples,piezoelectric, photovoltaic) does not require theapplication of external energy. 39
  40. 40. Introduction Modulating transducers (photoconductivecells, thermistors, resistive displacement devices) dorequire a source of energy. For example, a thermocouple is self-generating, producing a change in resistance in response to a temperature difference, whereas a photoconductive cell is modulating because it requires energy. The modifying transducer (elastic beams,diaphragms) is characterized by the same form ofenergy at the input and output. The energy form onboth sides of a modifier is electrical. 40
  41. 41. Definition The words sensor and transducer areboth widely used in the description ofmeasurement systems. The former is popular in the USAwhereas the latter has been used in Europefor many years. The word sensor is derivedfrom entire meaning to perceive andtransducer is from transducer meaning tolead across. 41
  42. 42. Definition A dictionary definition of sensor is `a device that detects a change in a physicalstimulus and turns it into a signal which canbe measured or recorded; The corresponding definition oftransducer is a device that transfers energyfrom one system to another in the same or inthe different form. 42
  43. 43. Features of SensorsThe desirable features of sensors are:1. accuracy - closeness to "true" value of variable; accuracy = actual value - sensed value;2. precision - little or no random variability in measured variable3. operating range - wide operating range; accurate and precise over entire sensing range4. calibration - easy to calibrate; no "drift" - tendency for sensor to lose accuracy over time.5. reliability - no failures6. cost and ease of operation - purchase price, cost of installation and operation 43
  44. 44. Sensors TypesA list of physical properties, and sensors tomeasure them is given below: 44
  45. 45. Sensors Types 45
  46. 46. Common SensorsListed below are some examples of commontransducers and sensors that we may encounter: Ammeter - meter to indicate electrical current. Potentiometer - instrument used to measurevoltage. Strain Gage - used to indicate torque, force,pressure, and other variables. Output is change inresistance due to strain, which can be converted intovoltage. Thermistor - Also called a resistance thermometer;an instrument used to measure temperature. Theoperation is based on change in resistance as afunction of temperature. 46
  47. 47. Sensors Types• There are several transducers that will be examined further in terms of their principles of operations.• Those include :1. Resistive Position Transducers2. Strain Gauges3. Capacitive Transducers4. Inductive Transducers5. And a lot more… 47
  48. 48. Resistive Position Transducers• The principle of the resistive position transduceris that the measured quantity causes a resistancechange in the sensing element.• A common requirement in industrialmeasurement and control work is to be able to sensethe position of an object, or the distance it hasmoved.• One type of displacement transducer uses aresistance element with a sliding contact linked to theobject being monitored.• Thus the resistance between the slider and oneend of the resistance element depends on theposition of the object. 48
  49. 49. Resistive Position Transducers• The output voltage depends on the wiper position and therefore is a function of the shaft position.• In figure below, the output voltage Eout is a fraction of ET, depending on the position of the wiper.• The element is considered perfectly linear if the resistance of the transducer is distributeduniformly along the length of travel of wiper. Eout R2 = ET R1 + R2 49
  50. 50. Resistive Position TransducersExample 1An RPT with a shaft stroke of 5.5 inches is applied inthe circuit as below. The total resistance of thepotentiometer is 4.7kΩ. The applied voltage isET= 3V.When the wiper is 0.9 in. from B, what is Eout? 50
  51. 51. Strain Gauges• The Strain Gauge is an example of a passivetransducer that uses electrical resistance variationin wires to sense the strain produced by a force onthe wire.• It is a very versatile detector and transducer for measuring weight, pressure, mechanical force or displacement. 51
  52. 52. Strain GaugesThe construction of a bonded strain gauge shows afine wire looped back and forth on a mounting plate,which is usually cemented to the element thatundergoing stress. 52
  53. 53. Strain Gauges• For many common materials, there is a constant ratio between stress and strain.• Stress is defined as the internal force per unitarea.• F S= S – Stress (kg/m2) F – Force (kg) A A - Area (m2)• The constant of proportionality between stressand strain for the curve is known as the modulus ofelasticity of the materials, E or Young’s Modulus. 53
  54. 54. Capacitive Transducers• The capacitance of a parallel plate is givenby: kAε k= dielectric constant C= o A= area of the plate εo=8.854x10-12 F/m d d= plate spacing• Since the capacitance in inverselyproportional to the spacing of the parallelplates, any variations in d will cause a variationin capacitance. 54
  55. 55. Capacitive Transducers• Some examples of capacitive transducers 55
  56. 56. Capacitive TransducersExample 2:An electrode-diaphragm pressure transducer hasplates whose area is 5x10-3 m2 and distancebetween plates is 1x10-3.Calculate its capacitance if it measures airpressure with k=1. 56
  57. 57. Inductive Transducers• Inductive Transducers may be either the self-generating or the passive type transducers.• In the Self-Generating IT, it utilises the basicelectrical generator principle that when there isrelative motion between conductor and magneticfield, a voltage is induced in the conductor.• An example of this is Tachometer that directlyconverts speeds or velocity into an electricalsignal. 57
  58. 58. Tachometers• Examples of a Common Tachometer 58
  59. 59. Linear VariableDifferential Transformer (LVDT)• Passive inductive transducers require an external source of power.• The Differential transformer is a passive inductive transformer, well known as Linear VariableDifferential Transformer (LVDT).• It consists basically of a primary winding and two secondly windings, wound over a hollow tube and positioned so that the primary is between two of its secondaries. 59
  60. 60. Linear VariableDifferential Transformer (LVDT)• Some examples of LVDTs. 60
  61. 61. Linear VariableDifferential Transformer (LVDT)• An example of LVDT electrical wiring. 61
  62. 62. Linear VariableDifferential Transformer (LVDT)• An iron core slides within the tube and thereforeaffects the magnetic coupling between the primaryand two secondaries.• When the core is in the centre , the voltageinduced in the two secondaries is equal.• When the core is moved in one direction of centre,the voltage induced in one winding is increased andthat in the other is decreased. Movement in theopposite direction reverse this effects. 62
  63. 63. Linear VariableDifferential Transformer (LVDT)•In next figure, the windingis connected ‘series opposing’-that is the polarities of V1and V2 oppose each otheras we trace through the circuitfrom terminal A to B.•Consequently, when the coreis in the center so that V1=V2,there is no voltage output,Vo = 0V. 63
  64. 64. Linear VariableDifferential Transformer (LVDT)• When the core is away from S1, V1 is greater thanV2 and the output voltage will have the polarity of V1.• When the core is away from S2, V2 is greater thanV1 and the output voltage will have the polarity of V2.• That is the output of ac voltage inverts as the corepasses the center position.• The farther the core moves from the centre, thegreater the difference in value between V1 and V2,and consequently the greater the value of Vo. 64
  65. 65. Linear VariableDifferential Transformer (LVDT)• Thus, the amplitude of Vo is a function of distancethe core has moved. If the core is attached to amoving object, the LVDT output voltage can be ameasure of the position of the object.• The farther the core moves from the centre, thegreater the difference in value between V1 and V2,and consequently the greater the value of Vo. 65
  66. 66. Linear VariableDifferential Transformer (LVDT)Among the advantages of LVDT are as follows:• It produces a higher output voltages for smallchanges in core position.• Low cost• Solid and robust -capable of working in a widevariety of environments.• No permanent damage to the LVDT ifmeasurements exceed the designed range. 66
  67. 67. Linear VariableDifferential Transformer (LVDT)Example 3: An ac LVDT has the following data; input 6.3V, output 5.2V, range ±0.50 cm. Determine:a) Plot of output voltage versus core position for a core movement going from +0.45cm to -0.03cm?b) The output voltage when the core is -0.35cm from the center?c) The core movement from center when the output voltage is -3V?d) The plot of core position versus output voltages varying from +4V to -2.5V. 67
  68. 68. Piezoelectric Transducers• When a mechanical pressure is applied to acrystal of a Rochelle salt, quartz, or tourmaline type, adisplacement of the crystals that will produce apotential difference will occur.• This property is used in piezo-electric transducers; where acrystal is placed between a solidbase and force-summing element,as shown below: 68
  69. 69. Piezoelectric Transducers• When externally force is applied to the plates, astress will be produced in the upper part of the crystal.• This deformation will produce a potentialdifference at the surface of the crystal. This producesan electromotive force across the crystal proportionalto the magnitude of the applied pressure. This effect iscalled piezoelectric effects.•• The induced charge on the crystal is proportionalto the impressed force and given by: Q = dF; where d = piezoelectric constant. 69
  70. 70. Temperature Transducers• The temperature transducers can be divided into four main categories: o Resistance Temperature Detectors (RTD) o Thermocouples o Thermistors o Ultrasonic transducers 70
  71. 71. Resistance Temperature Detectors (RTDs)• Detectors of resistance temperaturescommonly employ platinum, nickel, orresistance wire elements, whose resistancevariation with temperature has a high intrinsicaccuracy.• They available in many configurations andsizes and as shielded and open units for bothimmersion and surface applications. 71
  72. 72. Resistance Temperature Detectors (RTDs)• Some examples of RTDs are as follows: 72
  73. 73. Resistance Temperature Detectors (RTDs)• The relationship between temperature andresistance of conductors can be calculated fromthis equation: R = Ro (1 + α∆T ) where;R= resistance of the conductor at temp t (oC)Ro=resistance at the reference temp.α= temperature coefficient of resistance∆= difference between operating and reference temp. 73
  74. 74. Resistance Temperature Detectors (RTDs)Example:A platinum resistance thermometer has aresistance of 220Ω at 20oC. Calculate theresistance at 50oC?Given that α20oC=0.00392. 74
  75. 75. Thermocouples• A thermocouple is a sensor for measuringtemperature. It consists of two dissimilar / differentmetals, joined together at one end, which produce asmall unique voltage at a given temperature. Thisvoltage is measured and interpreted by thethermocouple.•The magnitude of this voltage depends on thematerials used for the wires and the amount oftemperatures difference between the joined end andthe other ends. 75
  76. 76. Thermocouples• Some examples of the thermocouples are asfollows: 76
  77. 77. Thermocouples• Common commercially availablethermocouples are specified by ISA(Instrument Society of America) types.• Type E, J, K, and T are base-metalthermocouples and can be used up to about1000°C (1832°F).• Type S, R, and B are noble-metalthermocouples and can be used up to about2000°C (3632°F). 77
  78. 78. Thermocouples• The following table provides a summary of basicthermocouple properties. 78
  79. 79. Thermocouples•Calibration curves for several commerciallyavailable thermocouples is as below: 79
  80. 80. Thermocouples• The magnitude of thermal emf depends on thewire materials used and on the temperature differencebetween the junctions.• The effective emf of the thermocouple is given as: E = c(T1 − T2 ) + k (T − T ) 1 2 2 2•Where; c and k – constant of the thermocouple materials T1 - temperature of the ‘hot’ junction. T2 - temperature of the ‘cold’ or ‘reference’ junction. 80
  81. 81. ThermocouplesExampleDuring experiment with a copper- costantanthermocouple, it was found thatc= 3.75x10-2 mV/oC and k = 4.50x10-5 mV/oC. IfT1= 100oC and the cold junction T2 is keptin the ice, compute the resultant electromotiveforce, emf? 81

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