AC rotating electric machine control device

1. A control device for an AC rotating electric machine, comprising:

temperature detection circuitry configured to detect a temperature of a protection part, the temperature increasing in proportion to an increase in a temperature of a switching device of a power conversion circuit connected to the AC rotating electric machine;

maximum current adjustment circuitry configured to adjust a maximum current of the AC rotating electric machine so as to prevent the temperature of the protection part detected by the temperature detection circuitry from exceeding a set temperature set in advance;

allowable torque calculation circuitry configured to calculate an allowable torque based on the maximum current adjusted by the maximum current adjustment circuitry;

torque command adjustment circuitry configured to adjust a torque command value directed to the AC rotating electric machine based on the allowable torque;

upper limit number-of-rotation calculation circuitry configured to calculate an upper-limit number of rotations of the AC rotating electric machine based on the maximum current adjusted by the maximum current adjustment circuitry; and

number-of-rotation adjustment circuitry configured to adjust the number of rotations of the AC rotating electric machine based on the upper-limit number of rotations.

2. The control device for an AC rotating electric machine according to claim 1 , further comprising:

a DC power source;

voltage detection circuitry configured to detect a DC voltage of the DC power source; and

electric angular speed detection circuitry configured to detect an electric angular speed of the AC rotating electric machine,

wherein the allowable torque calculation circuitry is configured to:

calculate a maximum voltage based on the DC voltage of the DC power source and on a maximum modulation factor set in advance;

calculate a maximum interlinkage magnetic flux based on the maximum voltage and on the electric angular speed; and

calculate the allowable torque based on the maximum interlinkage magnetic flux and on the maximum current adjusted by the maximum current adjustment circuitry.

3. The control device for an AC rotating electric machine according to claim 1 , further comprising:

a DC power source; and

voltage detection circuitry configured to detect a DC voltage of the DC power source,

wherein the upper limit number-of-rotation calculation circuitry is configured to:

calculate a maximum voltage based on the DC voltage of the DC power source and on a maximum modulation factor set in advance; and

calculate the upper-limit number of rotations based on the maximum voltage and on the maximum current adjusted by the maximum current adjustment circuitry.

4. The control device for an AC rotating electric machine according to claim 1 , wherein the number-of-rotation adjustment circuitry is configured to:

compare the number of rotations and the upper-limit number of rotations with each other; and

adjust the number of rotations of the AC rotating electric machine by outputting a gear shift control command for changing to gear shift control when the number of rotations is equal to or higher than the upper-limit number of rotations.

5. The control device for an AC rotating electric machine according to claim 1 , wherein the number-of-rotation adjustment circuitry is configured to:

compare the number of rotations and the upper-limit number of rotations with each other; and

adjust the number of rotations of the AC rotating electric machine by outputting a brake control command for performing brake control when the number of rotations is equal to or higher than the upper-limit number of rotations.

6. The control device for an AC rotating electric machine according to claim 1 , wherein the number-of-rotation adjustment circuitry is configured to:

compare the number of rotations and the upper-limit number of rotations with each other; and

adjust the number of rotations of the AC rotating electric machine by outputting a fuel injection control command for stopping a fuel injection when the number of rotations is equal to or higher than the upper-limit number of rotations.

7. The control device for an AC rotating electric machine according to claim 1 , wherein the number-of-rotation adjustment circuitry is configured to:

compare the number of rotations and the upper-limit number of rotations with each other; and

output, when the number of rotations is equal to or higher than the upper-limit number of rotations, a torque control command value for setting a torque command value to 0 to the torque command adjustment circuitry.

8. The control device for an AC rotating electric machine according to claim 1 , wherein the torque command adjustment circuitry is configured to adjust the torque command value by:

setting, when the number of rotations is lower than the upper-limit number of rotations and the torque command value is higher than an upper limit value of the allowable torque, the torque command value to the upper limit value of the allowable torque;

setting, when the number of rotations is lower than the upper-limit number of rotations and the torque command value is lower than a lower limit value of the allowable torque, the torque command value to the lower limit value of the allowable torque; and

keeping the torque command value unchanged when the number of rotations is lower than the upper-limit number of rotations and the torque command value is equal to or lower than the upper limit value of the allowable torque and is equal to or higher than the lower limit value of the allowable torque.

9. The control device for an AC rotating electric machine according to claim 1 , wherein the maximum current adjustment circuitry is configured to:

select, when two or more of the protection parts are provided, a protection part in which an absolute value of a temperature deviation between the detected temperature of the protection part and the set temperature is largest; and

adjust the maximum current of the AC rotating electric machine so as to prevent the temperature of the selected protection part from exceeding the set temperature set in advance.