CONTROL METHOD FOR CURRENT-TYPE THREE-PHASE INVERTER

摘要

PURPOSE:To suppress the pulsation of average torque by suitably increasing and decreasing the peak value of a conducting-width pulse current in a PWM system conducting pattern. CONSTITUTION:A control circuit 2 controls a power rectifier 1a for rectifying a commercial frequency input power and outputting a DC power and a power inverter 1c for converting said DC power into a three-phase AC power via DC intermediate reactor 1b and outputting said power to a three-phase induction machine system in the manner of successively increasing the peak value of a conducting-width pulse current between 0 deg. and pi/6 in a PWM conducting pattern for each half wave with each phase from the level of a certain peak value and successively decreasing said value from the level of a peak value, which is increased by 5pi/6 to pi, to the level of a certain peak value.