Control device for controlling an output voltage of a power converter

1. A control device for a power converter that controls an output voltage of the power converter, the control device being configured to:

generate a reference voltage command value based on a deviation between a first current command value and a second current actual value or the first current command value;

generate a d-axis reference correction term based on a deviation between a d-axis current command value and a d-axis current actual value;

generate a q-axis reference correction term based on a deviation between a q-axis current command value and a q-axis current actual value;

generate a limit value for limiting the output voltage based on the d-axis reference correction term and the q-axis reference correction term;

generate a d-axis limited voltage command value obtained by limiting the d-axis reference correction term based on the limit value;

generate a q-axis limited voltage command value obtained by limiting the q-axis reference correction term based on the limit value;

generate a d-axis correction term by subtracting the d-axis limited voltage command value from the d-axis reference correction term;

generate a q-axis correction term by subtracting the q-axis limited voltage command value from the q-axis reference correction term;

generate a limited voltage value based on the d-axis correction term, a d-axis AC voltage actual value of the power converter, the q-axis correction term, and a q-axis AC voltage actual value of the power converter; and

generate a voltage command value by adding the reference voltage command value and the limited voltage value.

2. The control device for a power converter according to claim 1 , wherein

the output voltage is a voltage value of a three phase component or a two phase component, and

the first current command value is a current value of a three phase component or a two phase component, and

the second current actual value is a current value of a three phase component or a two phase component, and

the limited voltage value is a voltage value of three phase component or two phase component, and

the reference voltage command value is a voltage value of three phase component or two phase component.

3. The control device for a power converter according to claim 1 , wherein

the first current command value is a current command value obtained by coordinate conversion of the d-axis current command value and the q-axis current command value into three phase components.

4. The control device for a power converter according to claim 1 , wherein

the d-axis reference correction term is an estimated value of a reference voltage command value of a d-axis component obtained when the reference voltage command value is coordinate-converted into dq component, and

the q-axis reference correction term is an estimated value of a reference voltage command value of a q-axis component obtained when the reference voltage command value is coordinate-converted into dq component.

5. The control device for a power converter according to claim 1 , wherein

in a process of generating the limit value, the control device is configured to:

generate a square root of a sum of a square of the d-axis reference correction term and a square of the q-axis reference correction term;

calculate a ratio value of the square root to a reference absolute value by dividing the square root by the reference absolute value; and

determine the limit value according to the ratio value.

6. The control device for a power converter according to claim 1 , wherein

in a process of generating the limit value, the control device is configured to:

generate a square root of a sum of a square of a d-axis low-frequency component reference correction term obtained by applying a low pass filter to the d-axis reference correction term and a square of a q-axis low-frequency component reference correction term obtained by applying a low pass filter to the q-axis reference correction term;

calculate a ratio value of the square root to a reference absolute value by dividing the square root by the reference absolute value; and

determine the limit value according to the ratio value.

7. He control device for a power converter according to claim 1 , wherein

in a process of generating the limited voltage value, the control device is configured to:

generate a first voltage by subtracting the d-axis correction term from the d-axis AC voltage actual value;

generate a second voltage by subtracting the q-axis correction term from the q-axis AC voltage actual value; and

generate the limited voltage value obtained by coordinate-converting the first voltage and the second voltage into three phase component.

8. The control device for a power converter according to claim 1 , wherein

in a process of generating the limited voltage value, the control device is configured to:

generate an AC voltage actual value of a d-axis frequency component by applying a low pass filter to the d-axis AC voltage actual value;

generate an AC voltage actual value of a q-axis frequency component by applying a low pass filter to the q-axis AC voltage actual value;

generate a first voltage by subtracting the d-axis correction term from the AC voltage actual value of a d-axis frequency component;

generate a second voltage by subtracting the q-axis correction term from the AC voltage actual value of the q-axis frequency component, and

generate the limited voltage value obtained by coordinate-converting the first voltage and the second voltage into three phase component.

9. The control device for a power converter according to claim 1 , wherein

the control device includes a first processor and a second processor,

the first processor is a processor having a shorter operation cycle than the second processor,

the first processor is configured to execute:

a process of generating the reference voltage command value; and

a process of generating the voltage command value, the second processor is configured to execute:

a process of generating the d-axis reference correction term;

a process of generating the q-axis reference correction term;

a process of generating the limit value;

a process of generating the d-axis limited voltage command value; and

a process of generating the q-axis limited voltage command value.

10. A control device for a power converter that controls an output voltage of the power converter, the control device being configured to:

generate a reference voltage command value based on a deviation between a first current command value and a second current actual value or the first current command value;

generate a first estimated voltage of a d-axis component based on a deviation between a d-axis current command value and a d-axis current actual value;

generate a first estimated voltage of a q-axis component based on a deviation between a q-axis current command value and a q-axis current actual value;

generate a first limit value for limiting the output voltage based on the first estimated voltage of the d-axis component and the first estimated voltage of the q-axis component;

generate a first limited voltage command value of the d-axis component obtained by limiting the first estimated voltage of the d-axis component based on the first limit value;

generate a first limited voltage command value of the q-axis component obtained by limiting the first estimated voltage of the q-axis component based on the first limit value;

generate a second limit voltage command value of the d-axis component based on the first limited voltage command value of the d-axis component and a d-axis AC voltage actual value;

generate a second limited voltage command value of the q-axis component based on the first limited voltage command value of the q-axis component and a q-axis AC voltage actual value;

generate a second limit value for limiting the output voltage based on the second limit voltage command value of the d-axis component and the second limit voltage command value of the q-axis component;

generate a third limited voltage command value of the d-axis component obtained by limiting the second limited voltage command value of the d-axis component based on the second limit value;

generate a third limited voltage command value of the q-axis component by limiting the second limited voltage command value of the q-axis component based on the second limit value;

generate a second estimated voltage of the d-axis component based on the first estimated voltage of the d-axis component and the d-axis AC voltage actual value;

generate a second estimated voltage of the q-axis component based on the first estimated voltage of the q-axis component and the q-axis AC voltage actual value;

generate a d-axis differential voltage command value by subtracting the second estimated voltage of the d-axis component from the third limited voltage command value of the d-axis component;

generate a q-axis differential voltage command value by subtracting the second estimated voltage of the q-axis component from the third limited voltage command value of the q-axis component;

generate a limited voltage value based on the d-axis AC voltage actual value, the d-axis differential voltage command value, the q-axis AC voltage actual value, and the q-axis differential voltage command value; and

generate a voltage command value by adding the reference voltage command value and the limited voltage value.

11. The control device for a power converter according to claim 10 , wherein

the output voltage is a voltage value of a three phase component or a two phase component, and

the first current command value is a current value of a three phase component or a two phase component, and

the second current actual value is a voltage value of a three phase component or a two phase component, and

the limited voltage value is a voltage value of three phase component or two phase component, and

the reference voltage command value is a voltage value of three phase component or two phase component.

12. The control device for a power converter according to claim 10 , wherein

the first current command value is a current command value obtained by coordinate conversion of the d-axis current command value and the q-axis current command value into three phase component.

13. The control device for a power converter according to claim 10 , wherein

the first estimated voltage of the d-axis component is an estimated value of a reference voltage command value of the d-axis component obtained when the reference voltage command value is coordinate-converted into dq component, and

the first estimated voltage of the q-axis component is an estimated value of a reference voltage command value of the q-axis component obtained when the reference voltage command value is coordinate-converted into dq component.

14. The control device for a power converter according to claim 10 , wherein

in a process of generating the first limit value, the control device is configured to:

generate a square root of a sum of a square of the first estimated voltage of the d-axis component and a square of the first estimated voltage of the q-axis component;

calculate a ratio value of the square root to a reference absolute value by dividing the square root by the reference absolute value; and

determine the first limit value according to the ratio value.

15. The control device for a power converter according to claim 10 , wherein

in a process of generating the second limit value, the control device is configured to:

generate a square root of a sum of a square of the second limit voltage command value of the d-axis component and a square of the second limit voltage command value of the q-axis component;

calculate a ratio value of the square root to a reference absolute value by dividing the square root by the reference absolute value; and

determine the second limit value according to the ratio value.

16. The control device for a power converter according to claim 10 , wherein

in a process of generating the first limit value, the control device is configured to:

generate a square root of a sum of a square of an estimated voltage of a d-axis low-frequency element obtained by applying a low pass filter to the first estimated voltage of the d-axis element and a square of an estimated voltage of a q-axis low-frequency element obtained by applying a low pass filter to the first estimated voltage of the q-axis element;

calculate a ratio value of the square root to a reference absolute value by dividing the square root by the reference absolute value; and

determine the first limit value according to the ratio value.

17. The control device for a power converter according to claim 10 , wherein

in a process of generating the limited voltage value, the control device is configured to:

generate a first voltage by subtracting the d-axis AC voltage actual value from the d-axis differential voltage command value;

generate a second voltage by subtracting the q-axis AC voltage actual value from the q-axis differential voltage command value;

generate the limited voltage value obtained by coordinate-converting the first voltage and the second voltage into three phase component.

18. The control device for a power converter according to claim 10 , wherein

in a process of generating the limited voltage value, the control device is configured to:

generate an AC voltage actual value of a d-axis frequency component by applying a low pass filter to the d-axis AC voltage actual value;

generating an AC voltage actual value of q-axis frequency component by applying a low pass filter to the q-axis AC voltage actual value;

generate a first voltage by subtracting the AC voltage actual value of the d-axis frequency component from the d-axis differential voltage command value;

generate a second voltage by subtracting the AC voltage actual value of the q-axis frequency component from the q-axis differential voltage command value; and

generate the limited voltage value obtained by coordinate-converting the first voltage and the second voltage into three phase component.

19. The control device for a power converter according to claim 10 , wherein

the second limit voltage command value of the d-axis component is a voltage value obtained by adding the first limited voltage command value of the d-axis component and the d-axis AC voltage actual value, and

the second limit voltage command value of the q-axis component is a voltage value obtained by adding the first limited voltage command value of the q-axis component and the q-axis AC voltage actual value, and

the second estimated voltage of the d-axis component is a voltage value obtained by adding the first estimated voltage of the d-axis component and the d-axis AC voltage actual value, and

the second estimated voltage of the q-axis component is a voltage value obtained by adding the first estimated voltage of the q-axis component and the q-axis AC voltage actual value.

20. The control device for a power converter according to claim 10 , wherein

the second limit voltage command value is a voltage value obtained by adding the first limited voltage command value and an AC voltage actual value of a d-axis frequency component obtained by applying a low pass filter to the d-axis AC voltage actual value, and

the second limit voltage command value of a q-axis element is a voltage value obtained by adding the first limited voltage command value of the q-axis element and an AC voltage actual value of the q-axis element obtained by applying a low pass filter to the q-axis AC voltage actual value of the q-axis element, and

the second estimated voltage of a d-axis element is a voltage value obtained by adding the first estimated voltage of the d-axis element and the AC voltage actual value of a d-axis AC voltage obtained by applying a low pass filter to the d-axis AC voltage actual value, and

the second estimated voltage of the q-axis element is a voltage value obtained by adding the first estimated voltage of the q-axis element and the AC voltage actual value of a q-axis AC voltage obtained by applying a low pass filter to the q-axis AC voltage actual value.