Inverter control device and AC motor control device using this inverter control device

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 inverter output currents (id, iq) and said PWM current references (id**, iq**), in which results of adding current references (id*, iq*) and correction signals (idC*, iqC*), obtained by amplifying respective deviations (id*-id), (iq*-iq) of said current references (id*, iq*) and said currents (id, iq), are used as said PWM current references (id**, iq**) for performing current control;
• a flux weakening control circuit that amplifies a difference of an absolute value 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.

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 an absolute value 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.

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 inverter output currents (id, iq) and PWM current references (id**, iq**), in which results of adding current references (id*, iq*) and correction signals (idC*, iqC*), obtained by amplifying respective deviations (id*-id), (iq*-iq) of said current references (id*, iq*) and said currents (id, iq), are used as said PWM current references (id**, iq**) for performing current control;
• a flux weakening control circuit that amplifies a difference of an absolute value 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.