电机及其传动系统 原理、控制、建模和仿真课件：Principles of Direct Current Machines.pptx

PrinciplesofDirectCurrentMachines

Inductionofvoltageinadcmachine(1)ElementarystructureFluxlinkageandvoltage

Inductionofvoltageinadcmachine(2)ImprovedstructureFluxlinkageandvoltage

CommutationReversalofthecurrentthroughthearmaturecoilsDuringcommutationthecurrentthroughthecoilundergoingtheprocesswillreverseNeutralzoneThepresenceofaneutralzoneeasestheprocessEffectofinductanceofthecoilThecoilinductanceimpedestheprocess

InteractionofarmatureandfieldThemainfieldandarmaturefieldareperpendicularTheycreatethemostfavorableconditionforgenerationoftorqueArmaturecurrentandfieldintensitybothaffectthetorqueproduced

Dynamicmodelingofdcmachines(1)FieldcircuitArmaturecircuitMechanicalsubsystem

Dynamicmodelingofdcmachines(2)LinkingequationsLinearmagneticcoreDynamicequationsofthemachineWithoutfielddynamics(PMmachine)

Dynamicmodelingofdcmachines(3)

Example1(1)PMdcmachineemfconstantof0.8V/(rad/s)Armatureresistanceandinductance:0.25Wand0.02HDampingandmomentofinertia:0.05N.m/(rad/s)and2.0kg.m2200Vappliedtothearmatureterminalsatrestundernoloadfollowedbya40N.mstepchangeintheloadtorqueaftersixseconds

Example1(2)Transferfunction

Example1(3)ArmaturecurrentTF

Example2(1)Transferfunction

Example2(2)SteadystatelimitProportionalgain

SteadystateobservationsInsteadystateTherefore

AcombineddrivestrategyBeforethebasespeed:armaturevoltagecontrolBeyondthebasespeed:fieldweakening

ClosedloopspeedcontrolLimitsmustbeimposedtoensureproperoperationinsafeoperatingregions

Example(1)WiththelimitsWithoutthelimits

VariableSpeedDrivewithanInnerLoopCurrentControlTheinnercurrentcontrollooplimitsexcursionsofthearmaturecurrent