Electrical Insulation for Rotating Machines: Design, Evaluation, Aging, Testing, and Repair

678 Pages·2014·8.34 MB·English

by  Greg Stone

ELECTRICAL INSULATION
FOR ROTATING MACHINES
IEEE Press
445 Hoes Lane
Piscataway, NJ 08854
IEEE Press Editorial Board
Tariq Samad, Editor in Chief
George W. Arnold Mary Lanzerotti Linda Shafer
Dmitry Goldgof Pui-In Mak MengChu Zhou
Ekram Hossain Ray Perez George Zobrist
Kenneth Moore, Director of IEEE Book and Information Services (BIS)
ELECTRICAL INSULATION
FOR ROTATING MACHINES
Design, Evaluation, Aging, Testing,
and Repair
Second Edition
GREG C. STONE
IAN CULBERT
EDWARD A. BOULTER
HUSSEIN DHIRANI
Copyright©2014byTheInstituteofElectricalandElectronicsEngineers,Inc.
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Electricalinsulationforrotatingmachines:design,evaluation,aging,testing,andrepair/GregC.Stone,
IanCulbert,EdwardA.Boulter,HusseinDhirani.–Secondedition.
pagescm
Includesbibliographicalreferencesandindex.
ISBN978-1-118-05706-3(cloth:alk.paper)1. Electricinsulatorsandinsulation.2. Electric
machinery–Windings.3. Electricmotors.4. Electricmachinery–Protection.I.Stone,GregC.,editor.
II.Culbert,Ian,editor.III.Boulter,EdwardA.,editor.IV.Dhirani,Hussein,editor.
TK3401.E4242014
621.31′042–dc23
2014021677
PrintedintheUnitedStatesofAmerica
10987654321
CONTENTS
PREFACE xix
CHAPTER1 ROTATINGMACHINEINSULATIONSYSTEMS 1
1.1 TypesofRotatingMachines 1
1.1.1 ACMotors 2
1.1.2 SynchronousGenerators 4
1.1.3 InductionGenerators 6
1.1.4 PermanentMagnet(PM)SynchronousMotorsandGenerators 7
1.1.5 ClassificationbyCooling 7
1.2 WindingComponents 9
1.2.1 StatorWinding 9
1.2.2 InsulatedRotorWindings 10
1.2.3 SquirrelCageInductionMotorRotorWindings 11
1.3 TypesofStatorWindingConstruction 11
1.3.1 Random-WoundStators 12
1.3.2 Form-WoundStators—CoilType 12
1.3.3 Form-WoundStators—RoebelBarType 13
1.4 Form-WoundStatorWindingInsulationSystemFeatures 14
1.4.1 StrandInsulation 14
1.4.2 TurnInsulation 17
1.4.3 GroundwallInsulation 19
1.4.4 GroundwallPartialDischargeSuppression 21
1.4.5 GroundwallStressReliefCoatingsforConventionalStators 24
1.4.6 SurfaceStressReliefCoatingsforInverter-FedStators 27
1.4.7 ConductorShields 29
1.4.8 MechanicalSupportintheSlot 30
1.4.9 MechanicalSupportintheEndwinding 32
1.4.10 TranspositionInsulation 34
1.5 Random-WoundStatorWindingInsulationSystemFeatures 36
1.5.1 PartialDischargeSuppressioninInverter-FedRandomWindings 37
1.6 RotorWindingInsulationSystemComponents 38
1.6.1 SalientPoleRotor 40
1.6.2 RoundRotors 41
1.6.3 InductionMachineWoundRotors 43
References 45
CHAPTER2 EVALUATINGINSULATIONMATERIALSANDSYSTEMS 47
2.1 AgingStresses 49
2.1.1 ThermalStress 49
v
vi CONTENTS
2.1.2 ElectricalStress 50
2.1.3 AmbientStress(Factors) 52
2.1.4 MechanicalStress 53
2.1.5 RadiationStress 54
2.1.6 MultipleStresses 54
2.2 PrinciplesofAcceleratedAgingTests 54
2.2.1 CandidateandReferenceMaterials/Systems 55
2.2.2 StatisticalVariation 55
2.2.3 FailureIndicators 61
2.3 ThermalEnduranceTests 62
2.3.1 BasicPrinciples 62
2.3.2 ThermalIdentificationandClassification 63
2.3.3 InsulatingMaterialThermalAgingTestStandards 64
2.3.4 InsulationSystemThermalAgingTestStandards 64
2.3.5 FutureTrends 67
2.4 ElectricalEnduranceTests 67
2.4.1 ProprietaryTestsforForm-WoundCoils 68
2.4.2 StandardizedACVoltageEnduranceTestMethodsforForm-Wound
Coils/Bars 69
2.4.3 VoltageEnduranceTestsforInverter-FedWindings 70
2.5 ThermalCyclingTests 71
2.5.1 IEEEThermalCyclingTest 72
2.5.2 IECThermalCyclingTest 73
2.6 NuclearEnvironmentalQualificationTests 74
2.6.1 EnvironmentalQualification(EQ)byTesting 75
2.6.2 EnvironmentalQualificationbyAnalysis 76
2.6.3 EnvironmentalQualificationbyaCombinationofTestingand
Analysis 77
2.7 MultifactorStressTesting 77
2.8 MaterialPropertyTests 78
References 80
CHAPTER3 HISTORICALDEVELOPMENTOFINSULATIONMATERIALS
ANDSYSTEMS 83
3.1 NaturalMaterialsforForm-WoundStatorCoils 84
3.2 EarlySyntheticsforForm-WoundStatorCoils 86
3.3 PlasticFilmsandNon-Wovens 89
3.4 LiquidSyntheticResins 90
3.4.1 Polyesters 90
3.4.2 Epoxides(EpoxyResins) 92
3.5 Mica 95
3.5.1 MicaSplittings 95
3.5.2 MicaPaper 96
3.5.3 MicaBackingMaterials 98
3.6 GlassFibers 99
3.7 Laminates 100
3.8 EvolutionofWireandStrandInsulations 101
3.9 ManufactureofRandom-WoundStatorCoils 102
3.10 ManufactureofForm-WoundCoilsandBars 103
CONTENTS vii
3.10.1 EarlySystems 103
3.10.2 AsphalticMicaSystems 103
3.10.3 IndividualCoilandBarThermosetSystems 104
3.10.4 GlobalVPISystems 105
3.11 WireTranspositionInsulation 106
3.12 MethodsofTapingStatorGroundwallInsulation 107
3.13 InsulatingLiners,Separators,andSleeving 109
3.13.1 Random-WoundStators 109
3.13.2 Rotors 110
References 110
CHAPTER4 STATORWINDINGINSULATIONSYSTEMSINCURRENTUSE 111
4.1 ConsolidationofMajorManufacturers 114
4.2 DescriptionofMajorTrademarkedForm-WoundStatorInsulationSystems 115
4.2.1 WestinghouseElectricCo.:ThermalasticTM 115
4.2.2 GeneralElectric:MicapalsIandIITM,EpoxyMicaMatTM,MicapalHTTM,
andHydromatTM 116
4.2.3 Alsthom,GECAlsthom,andAlstomPower:lsotenaxTM,ResithermTM,
ResiflexTM,ResivacTM,andDuritenaxTM 117
4.2.4 SiemensAG,KWU:MicalasticTM 118
4.2.5 BrownBoveri,ASEA,ABB,andAlstomPower:MicadurTM,Micadur
CompactTM,MicapacTM,andMicarexTM 119
4.2.6 ToshibaCorporation:TosrichTMandTostightTM 120
4.2.7 MitsubishiElectricCorporation 121
4.2.8 Hitachi,Ltd.:Hi-ResinTM,Hi-MoldTM,andSuperHi-ResinTM 121
4.2.9 DongfangElectricMachinery 122
4.2.10 HarbinElectricCorporation(HEC) 122
4.2.11 ShanghaiElectricMachinery 122
4.2.12 JinanPowerEquipment:ResithermTM,MicadurTM,andMicadur
CompactTM 123
4.2.13 SummaryofPresent-DayInsulationSystems 123
4.3 RecentDevelopmentsforForm-WoundInsulationSystems 123
4.3.1 ReducingGroundwallThermalImpedance 124
4.3.2 IncreasingElectricStress 125
4.3.3 EnvironmentalIssues 126
4.4 Random-WoundStatorInsulationSystems 127
4.4.1 MagnetWireInsulation 127
4.4.2 PhaseandGroundInsulation 127
4.4.3 VarnishTreatmentandImpregnation 128
References 129
CHAPTER5 ROTORWINDINGINSULATIONSYSTEMS 133
5.1 RotorSlotandTurnInsulation 134
5.2 CollectorInsulation 136
5.3 EndWindingInsulationandBlocking 136
5.4 RetainingRingInsulation 137
5.5 Direct-CooledRotorInsulation 138
5.6 WoundRotors 139
viii CONTENTS
5.7 SuperconductingSychronousRotors 140
References 141
CHAPTER6 ROTORANDSTATORLAMINATEDCORES 143
6.1 MagneticMaterials 143
6.1.1 MagneticFields 143
6.1.2 Ferromagnetism 143
6.1.3 MagnetizationSaturationCurve 144
6.1.4 FerromagneticMaterials 144
6.1.5 Permeability 145
6.1.6 HysteresisLoss 145
6.1.7 EddyCurrentLoss 146
6.1.8 OtherFactorsAffectingCoreLoss 146
6.1.9 EffectofDirectionoftheGrain 148
6.1.10 EffectofTemperature 148
6.1.11 EffectofHeatTreatment 148
6.1.12 EffectofImpuritiesandAlloyingElements 148
6.1.13 Silicon/AluminumSteels 149
6.2 Mill-AppliedInsulation 149
6.3 LaminationPunchingandLaserCutting 150
6.4 AnnealingandBurrRemoval 151
6.5 EnamelingorFilmCoatings 151
6.6 StatorandRotorCoreConstruction 152
6.6.1 StatorCoreConstruction:General 152
6.6.2 HydrogeneratorandLargeMotorStatorCoreAssembly
andSupport 153
6.6.3 TurbogeneratorStatorCoreAssemblyandSupport 154
6.6.4 SmallerMotorandGeneratorStatorCores 155
6.6.5 RotorCoreConstruction 155
References 157
CHAPTER7 GENERALPRINCIPLESOFWINDINGFAILURE,REPAIRAND
REWINDING 159
7.1 FailureProcesses 159
7.1.1 RelativeFailureRatesofComponents 161
7.1.2 FactorsAffectingFailureMechanismPredominance 162
7.2 FactorsAffectingRepairDecisions 164
7.3 RapidRepairofLocalizedStatorWindingDamage 165
7.4 CuttingoutStatorCoilsAfterFailure 166
7.5 Bar/CoilReplacementandHalfCoilSplice 167
7.6 Rewinding 168
References 169
CHAPTER8 STATORFAILUREMECHANISMSANDREPAIR 171
8.1 ThermalDeterioration 171
8.1.1 GeneralProcess 171
8.1.2 RootCauses 174