Motor control device, electromechanical integrated unit, and electric vehicle system

A motor drive device comprising:

• a three-phase synchronous motor;
• a power converter connected to the three-phase motor, the power converter converts a DC voltage into a three-phase AC voltage to drive the three-phase synchronous motor;
• and
• a controller that is connected to the power converter and comprises a current command generation unit comprising a first current command generation unit, a second current command generation unit, and a current command selection unit, the current command generation unit configured to:
• acquire a magnet temperature of a rotor of the three-phase synchronous motor, a coil temperature of a stator of the three-phase synchronous motor, and a module temperature of the power converter,
• select, by the current command selection unit, a current command output calculated in advance from one of the first current command generation unit or the second current command generation unit based on the magnet temperature,
• output the current command output to drive of the three-phase synchronous motor by outputting a pulse width modulation signal to the power converter,
• wherein;
• when at least one of the acquired magnet temperature, coil temperature, and module temperature exceeds a predetermined temperature set to each thereof in advance, the output command from the second current command generation unit changes at least one of a current flowing through the three-phase synchronous motor based on the current command output from the second current command generation unit to change a ratio of the three-phase AC voltage to the DC voltage such that a voltage absolute value does not fall within a predetermined range, and a harmonic voltage twice a switching frequency of the power converter is reduced, and a switching frequency of the power converter.

A motor drive device comprising:

• a three-phase synchronous motor;
• a power converter connected to the three-phase motor, the power converter converts a DC voltage into a three-phase AC voltage to drive the three-phase synchronous motor;
• and
• a controller that is connected to the power converter and comprises a current command generation unit comprising a first current command generation unit, and a second current command generation unit, the current command generation unit configured to:
• acquire a magnet temperature from one of a temperature sensor that detects the magnet temperature or from a magnet temperature estimation unit that estimates the magnet temperature based on temperature dependency of an induced voltage of the three-phase synchronous motor,
• output the current command output from the first current command generation unit to drive of the three-phase synchronous motor by outputting a pulse width modulation signal to the power converter,
• wherein when a magnet temperature of a rotor of the three-phase synchronous motor exceeds a predetermined temperature, output the current command output from the second current command generation unit, that changes the three-phase AC voltage based on a ratio of the three-phase AC voltage to the DC voltage such that a voltage absolute value does not fall within a predetermined range, and a harmonic voltage twice a switching frequency of the power converter is reduced.