LAB MANUAL - vvitengineering

1 EE6411-ELECTRICAL MACHINES I1 VVIT DEPARTMENT OF EEED harmapuri 636 703 Regulation: 2013 & Semester: II Year / IVSemesterEE6411-ELECTRICAL MACHINESLABORATORY ILAB MANUALEE6411-ELECTRICAL MACHINES I2 VVIT DEPARTMENT OF EEEANNA UNIVERSITY-CHENNAI2013-REGULATIONEE6411- ELECTRICAL MACHINES LABORATORY ILIST OF circuitand load characteristics of DC shunt generator-critical resistance characteristics of DC compound generator with differential test on DC shunt and compound test on DC series s test and speed control of DC shunt s test on DC motor generator test on single-phase transformer and three phase circuit and short circuit tests on single phase Test and Sumpner stest on single phase of no-load losses in single phase of starters and 3-phase transformers connectionsTOTAL.

2 45 PERIODSEE6411-ELECTRICAL MACHINES I3 VVIT DEPARTMENT OF EEESAFETY PRECAUTIONSPRIMARY RULES: Do not make circuit changes orperform any wiring when power is on. When in doubt, turn power off. Assume that panel jacks on your bench are electrically live unless power is off. Be sure you understand the function and wiring of an instrument before using it in acircuit. Do not repeat the same mistake. Do not wear loose-fitting clothing or jewelry in the lab. Rings and necklaces are usuallyexcellent conductors in excellent contact with your skin. It is wise in electrical labs to wear pants rather than shorts or skirts. Tiesare alsodangerous. Powered equipment can be hot! Use caution when handling equipment after it has KEY PRECAUTIONS: Checkyourself with disconnect switches, especially those at your bench.

3 Work slowly and deliberately. Think as you act. Do your wiring, setup, and a careful circuit checkout before applying power. Use wires of appropriate length. Do not allow them to drape over your splices, which create live surfaces. When running a pair of wires to adjacentterminals, twist the wires together so they do not dangle. This also neatens your workand will save time. Keep your bench organized and neat. It should be clear of coats, extra books andpapers, and unused equipment. Use your bench. Avoid long connections by using the bench transfer wires. Pluginstruments into the bench, not into the wall. This gives you the protection of the benchswitches.

4 Do not touch anything if your hands are wet. The one-hand approach is safest. Do not pull wires out until youare absolutely sure that the circuit is completely can occur if an inductive load (motor or transformer) is disconnected MACHINES I4 VVIT DEPARTMENT OF EEEELECTRICAL MACHINESINTRODUCTION:The study of electric machinery and electromechanics offers a wide range ofopportunities in such diverse areas as manufacturing process control, control systems,electrical energy generation, electromechanical systems and actuators, electric and hybridtransportation, disk drives, electronic power conversion, and machinery and electromechanics provides an area for the generalist, in thatexpertise in electromagnetic field theory, circuit analysis, communication principles,information theory, electronics, computers, control systems, and energy areas must cometogether to create a complete working system.

5 The study of electric machinery is longestablished within electrical engineering. New technologies and materials, the economics ofenergy, the use of sophisticated computer hardware and software, and rapid advances inpower electronics for energy and motion control offer inviting topics for new :Ingeneral electrical machines is classified into twotypes, they are Motor GeneratorBoth Motorand generatorarethree types, Shunt Series CompoundShunt:Armature and fieldwindingare in parallel connectionSeries:Armature and fieldwindingare inseriesconnectionCompound:It is combination ofboth series and shunt engineering,electricmachineis a general term forelectricmotorsandelectric generators .

6 They areelectromechanicalenergy converters. Electric motor:It converts electrical energy intomechanical energy Electric generator:Itconverts mechanical energy to electrical energy Transformers:It is a static device, which is used to convert voltagEE6411-ELECTRICAL MACHINES I5 VVIT DEPARTMENT OF OF THE EXPERIMENTSIGNATUREOF THESTAFFREMARKS1 Load test on DC shunt motor2 Load test on DC series motor3 Speed control of DC shunt motor4 OCC & load test on separatelyexcited DC generator5 OCC & load test on self-excitedDC generator6 Load test on single phasetransformer7OC & SC test on single phasetransformer8 Swinburne s test9 Separation of iron losses in DCmachine10 Hopkinson s test11 Sumpner s test12 Study of three phase transformerconnections13 Load test on DCcompound motor14 Load test on DC compoundgeneratorEE6411-ELECTRICAL MACHINES I6 VVIT DEPARTMENT OF EEEAIM.

7 To conduct load test on motor and to obtain performance characteristicsAPPARATUS (0-300)V12 AmmeterMC(0-20)A13 Rheostat230 ,000 RPM1 FUSE RATING:125% of rated currentPRECAUTIONS: The motor field rheostat should be kept at minimum resistance position. The motor shouldbe started at no load condition. The motor should be cooled by circulating water throughout the as per the circuit the the motor using three point the field rheostat till themotor reaches its rated down the no load reading of voltmeter, ammeter, speed and springbalance load in steps and note down the corresponding reading till the ratedcurrent is reached rated 1 LOAD TEST ON SHUNT MOTORDATE:EE6411-ELECTRICAL MACHINES I7 VVIT DEPARTMENT OF EEECIRCUIT DIAGRAM( LOADTEST ON DC SHUNT MOTOR):EE6411-ELECTRICAL MACHINES I8 VVIT DEPARTMENT OF EEETABULATION:(LOAD TEST ON SHUNTMOTOR) ~S2 KgSpeedNrpmTorqueTNmInputpowerPiwattsOut putPowerPmwattsEfficiency %S1 KgS2 KgEE6411-ELECTRICAL MACHINES I9 VVIT DEPARTMENT OF EEEMODEL GRAPHS.

8 Speed N (rpm)Torque T (Nm)Efficiency %NT y3y2y1 Output Power (Watts)Speed N (rpm)yxTorque T(Nm)EE6411-ELECTRICAL MACHINES I10 VVIT DEPARTMENT OF EEEFORMULAE: Torque(T)= (s1 s2)R Output power=2 NT/60 Input power=V*IWhere, gravity constantR=radius of brake drumN=speed in RPMRESULT:Thus the load test on DCshunt motor was performed and the performancegraphswere ,% =output power/input power * 100EE6411-ELECTRICAL MACHINES I11 VVIT DEPARTMENT OF 2 LOAD TEST ON SERIES MOTORDATE:AIM:To conduct load test on series motor and to obtain performancecharacteristicsAPPARATUS (0-300)V12 AmmeterMC(0-20)A13 TachometerDigital60,000 RPM1 FUSE RATING:125% of rated currentPRECAUTIONS: The motor field rheostat should be kept at minimumresistance position.

9 The motor should be started at no load condition. The motor should be cooled by circulating water throughout the as per the circuit the the motor using three the field rheostat till the motor reaches its rated down the no load reading of voltmeter, ammeter, speed and springbalance load in steps and note down the corresponding reading till the ratedcurrent is reachedrated MACHINES I12 VVIT DEPARTMENT OF EEECIRCUIT DIAGRAM( LOAD TEST ON DC SERIES MOTOR):EE6411-ELECTRICAL MACHINES I13 VVIT DEPARTMENT OF EEETABULATION(LOAD TEST ON DC SERIES MOTOR) ~S2 KgSpeedNrpmTorqueTNmInputpowerPiwattsOut putPowerPmwattsEfficiency %S1 KgS2 KgEE6411-ELECTRICAL MACHINES I14 VVIT DEPARTMENT OF EEEMODEL GRAPHS:Speed N (rpm)Torque T (Nm)Efficiency %NT y3y2y1 Output Power (Watts)Speed N (rpm)yxTorque T (Nm)EE6411-ELECTRICAL MACHINES I15 VVIT DEPARTMENT OF EEEFORMULAE: Torque(T)= (s1 s2)R Output power=2 NT/60 Input power=V*IWhere, gravity constantR=radius of brake drumN=speed in RPMRESULT:Thus the load test on DCseriesmotor was performed and the performancegraphs were ,% =output power/input power * 100EE6411-ELECTRICAL MACHINES I16 VVIT DEPARTMENT OF 3 SPEED CONTROL OF DC SHUNT MOTORDATE:AIM:To control thespeed of DC shunt motor byArmature control methodandField control methodAPPARATUS (0-300)V12 AmmeterMC(0-20)A13 Rheostat1250 ,50 RATING:40% of rated currentPRECAUTIONS.

10 Armature rheostat must be kept at maximum resistance position. Field rheostat should be kept at minimum resistance minimum :ARMATURE CONTROL per the circuit the DPST the motor using three point keeping the field current(If) as constant value, adjust the armaturerheostat and note down the corresponding armature voltage and the step four till the motor reaches the rated MACHINES I17 VVIT DEPARTMENT OF EEEFLUX CONTROL as per the circuit the DPST the motor using three point keeping the armature voltage as constant value, adjust the field rheostatandnote down corresponding field current and motor the step four till the motor reaches the rated speedEE6411-ELECTRICAL MACHINES I18 VVIT DEPARTMENT OF EEECIRCUIT DIAGRAM(SPEED CONTROL DC SHUNT MOTOR).