Controller of AC motor

A controller of an AC motor, the controller comprising:

• a d-axis voltage command section configured to generate a d-axis voltage command on a d axis of a d-q coordinate system, the d axis being parallel to a flux of the AC motor and orthogonal to a q axis of the d-q coordinate system;
• a d-axis non-interactive control section configured to remove, from the d-axis voltage command, an interference component resulting from a current on the q axis;
• a first current deviation arithmetic section configured to perform an arithmetic operation to obtain a q-axis current deviation between a current command on the q axis and the current on the q axis flowing through the AC motor;
• a q-axis integral control section configured to receive the q-axis current deviation and output an integral value of the q-axis current deviation;
• a q-axis voltage command section configured to generate a q-axis voltage command on the q axis based on the q-axis current deviation and configured to output the q-axis voltage command;
• a constant output control section configured to receive an amount equivalent to a voltage saturation on the q-axis by removing an induced voltage constant error and an amount equivalent to a voltage drop that is due to a coil resistance of the AC motor from an output of the q-axis integral control section, the constant output control section being configured to output a correction voltage command relative to the d-axis voltage command based on the amount equivalent to the voltage saturation on the q-axis;
• and
• a d-axis voltage command correction section configured to subtract the correction voltage command from the d-axis voltage command after the d-axis non-interactive control section has performed non-interactive control, so as to correct the d-axis voltage command.