Synchronous machine control device, synchronous machine control method, and electric vehicle

A synchronous machine control device configured to drive and control a synchronous machine, the synchronous machine control device comprising:

• a first magnetic flux command computation unit that generates a first magnetic flux command value from a current command value for the synchronous machine;
• a magnetic flux estimation unit that acquires a magnetic flux estimation value from an actual current flowing through the synchronous machine;
• a second magnetic flux command computation unit that calculates a difference between the first magnetic flux command value and the magnetic flux estimation value, and generates a second magnetic flux command value by proportional-integral control;
• a voltage vector computation unit that generates a voltage command value including a coaxial voltage command value and an orthogonal axis voltage command value based on the second magnetic flux command value;
• a voltage limitation unit that limits the coaxial voltage command value in preference to the orthogonal axis voltage command value to prevent the voltage command value from exceeding a predetermined voltage limit value;
• and
• a correction amount calculation unit that calculates an amount of correction of a magnetic flux command value for correcting the second magnetic flux command value based on limitation of voltage determined by the voltage limitation unit,
• the second magnetic flux command computation unit being configured to correct the second magnetic flux command value by the proportional-integral control based on the amount of correction of a magnetic flux command value.

A synchronous machine control method that is for driving and controlling a synchronous machine, the method comprising:

• calculating a difference between a current command value for the synchronous machine and an actual current flowing through the synchronous machine and generating a current command value by proportional-integral control;
• generating a voltage command value including a coaxial voltage command value and an orthogonal axis voltage command value based on the generated current command value;
• limiting the coaxial voltage command value in preference to the orthogonal axis voltage command value to prevent the voltage command value from exceeding a predetermined voltage limit value;
• calculating the amount of correction of a current command value for correcting the current command value based on the limitation;
• and
• correcting an integrator coaxially applied to the proportional-integral control based on the amount of correction of a current command value, the amount corresponding to an excess of a coaxial component in an excess of voltage exceeding the voltage limit value due to the limitation.