压缩机电机起动理论课件.pptVIP

MotorStartTheoryMotorStartTheory电机起动原理T-2005-11001MST1

MotorStartTheoryLowSlipvFullSlip低滑移与满滑移WhenapplyingACspeeddrivesthemotor‘slowslipperformancecharacteristicsareimportant.当使用AC速度驱动电机低滑移时，性能特征是十分重要的。Incontrast,whenapplyingsoftstartersthemotor‘sperformanceatalllevelsofslipisimportant.相反，当使用软起动器时，在满滑移水平下的电机性能是十分重要的。2

MotorStartTheoryMotorPerformance电机性能Amotor‘sstartperformancecharacteristicssetthelimitsofwhatcanbeachievedwitheitherafullvoltageorreducedvoltagestarter.电机起动性能规定使用全电压起动器或降压起动器能达到的极限值。Itisespeciallyimportanttoconsidermotorstartcharacteristicswhenseekingto:-Minimisestartcurrent-Maximisestarttorque当尝试以下方式时考虑电机起动特性尤其重要：-将起动电流降至最小-将起动扭矩增至最大3

MotorStartTheoryMotorPerformance电机性能Rotordesignaffectsstartingperformance.转子的设计影响起动性能。Statordesignaffectsfullspeedperformance.定子的设计影响全速性能。Theshape,positionandmaterialoftherotorbarsaffectthecurrentdrawnandtorqueproducedduringmotorstarting.转子杆的形状、位置和材料影响引入电流和电机起动时产生的扭矩。4

MotorStartTheoryTypicalMotorData典型电机数据SampleOfTypical110kWMotors%FLTorque(rpm)(amps)(%FLC)(%FLT)Ef’ncy@3xFLCAmotor‘sstartperformancecanbeidentifiedbyexaminingthemotordatasheet.电机起动性能可通过检查电机数据表得到确认。Thetabledetailsselectedperformancedataforarangeof110kWmotors.数据表详述了110kW电机系列选用的性能数据。5

MotorStartTheoryStartCurrent起动电流SampleOfTypical110kWMotors%FLTorque(rpm)(amps)(%FLC)(%FLT)Ef’ncy@3xFLCMaximummotorstartcurrentunderfullvoltagestartconditionsisdefinedbythemotor‘sLockedRotorCurrent(LRC).全电压起动条件下最大电机起动电流是由电机锁定转子电流（LRC）确定的。LRClevelsvaryconsiderablybetweenmotors.LRC等级在电机间有显著变化。Intheexample,MotorHwilldraw55%morecurrentatstartthanMotorE.在实例中，电机H引入的起动电流比电机E多55%。LRCrangesfrom550%to850%6

MotorStartTheoryStartTorque起动扭矩SampleOfTypical110kWMotors%FLTorque(rpm)(amps)(%FLC)(%FLT)Ef’ncy@3xFLCMotorstarttorqueperformanceisindicatedbythemotor‘sLockedRotorTorque(LRT)figure.电机起动扭矩性