THREE-PHASE PWM INVERTER WITH SPEED CONTROL AND LOAD COMPENSATION FOR ANINDUCTION MOTOR

摘要

ABSTRACTAccording to the present invention, thereis provided a harmonically suppressed driver for athree phase full bridge pulse width modulated (PWM)inverter, for driving an AC motor. The drivergenerates three phase PWM waveforms for operating amotor in a speed range of from approximately 240 to4000 rpm. Below 1800 rpm, voltage reduction isimplemented by phase shifting in order to maintainconstant volt-sec operation and prevent armature fluxsaturation. Additional load dependent fluxcompensation is achieved by measuring motor speed,calculating the slip and providing compensation atlarge slips.