Patent ID: 8274246

Claim:
An AC motor control device comprising: an inverter control device having a current tracking PWM control circuit that generates PWM signals such that inverter output currents (id, iq) track PWM current references (id**, iq**), using results of comparison of said inverter output currents (id, iq) and said PWM current references (id**, iq**), in which, if current references (id*, iq*) exist, a result of adding said current reference (iq*) and a correction signal (iqC*), obtained by amplifying a deviation (iq*-iq) of said current reference (iq*) and said inverter output current (iq), is used as said PWM current reference (iq**) on a q axis side for performing current control, but, in respect of a d axis side, said current reference (id*) is used directly as said PWM current reference (id**) for performing current control; a flux weakening control circuit that amplifies a difference of said correction signal (iqC*) and a prescribed limiting value; and a limiter that applies limitation such that an output of said flux weakening control circuit cannot become negative, wherein vector control calculation is performed using a flux reference and torque reference, and a flux-based current reference (id*), torque-based current reference (iq*) and a slip angle θs are calculated, using a quantity obtained by subtracting a limiter output from a reinforcing flux reference as a new flux reference.