Granted Patent B2

US 8,283,900 · App. 12/615,888 · Granted Oct 9, 2012

Assignee: GM Global Technologies Operations LLC

Abstract

Claims (82)

1. A method for controlling a boost converter having a duty cycle, the method comprising the steps of:

obtaining a boost ratio of the boost converter;

obtaining an existing value of the duty cycle;

receiving an electric current command for the boost converter;

measuring a source current for the boost converter; and

regulating the duty cycle as a function of the electric current command, the boost ratio, and the source current, subject to:

a first minimum limit and a first maximum limit if the existing value of the duty cycle is greater than or equal to a first predetermined threshold, the electric current command and the source current are less than a second predetermined threshold apart, or both; and

a second minimum limit and a second maximum limit if the existing value of the duty cycle is less than the first predetermined threshold and the electric current command and the source current are at least the second predetermined threshold apart.

2. The method of claim 1 , further comprising the steps of:

calculating an input voltage of the boost converter; and

calculating an output voltage of the boost converter;

wherein the step of obtaining the boost ratio comprises the step of obtaining the boost ratio of the boost converter using the input voltage and the output voltage of the boost converter.

3. The method of claim 1 , further comprising the step of:

calculating a maximum duty cycle that requires duty adjustment given the boost ratio, to thereby obtain the second predetermined threshold.

4. The method of claim 1 , further comprising the step of:

obtaining an existing value of the duty cycle;

wherein the step of regulating the duty cycle comprises the step of regulating the duty cycle as the function of the electric current command, the source current, and the boost ratio, subject to:

the first minimum limit and the first maximum limit if the existing value of the duty cycle is greater than or equal to a second predetermined threshold; and

the second minimum limit and the second maximum if the existing value of the duty cycle is less than the second predetermined threshold.

5. The method of claim 1 , further comprising the step of:

obtaining an existing value of the duty cycle, wherein:

the first minimum and maximum limits are independent of the existing value of the duty cycle; and

the second minimum and maximum limits are dependent upon the existing value of the duty cycle.

6. The method of claim 5 , wherein the second minimum limit is equal to the second maximum limit.

7. The method of claim 6 , further comprising the steps of:

adding a first predetermined value to the existing value of the duty cycle, to thereby calculate the second minimum limit and the second maximum limit, if the rapid change in duty cycle is required above the predetermined threshold; and

subtracting a second predetermined value from the existing value of the duty cycle, to thereby calculate the second minimum limit and the second maximum limit, if the rapid change in duty cycle is not required.

8. A method for controlling a boost converter having a duty cycle, the method comprising the steps of:

receiving an electric current command for the boost converter;

measuring a source current for the boost converter;

determining a boost ratio for the boost converter;

determining an existing value of the duty cycle;

regulating the duty cycle as a function of the electric current command, the source current, and the boost ratio if the existing value of the duty cycle is greater than or equal to a first predetermined value, a difference between the electric current command and the source current is less than a second predetermined value, or both;

forcing the duty cycle to a first fixed value if the existing value of the duty cycle is greater than or equal to a first predetermined value, the difference between the electric current command and the source current is less than the second predetermined value, or both; and

forcing the duty cycle to a second fixed value if the existing value of the duty cycle is less than the first predetermined value, the difference between the electric current command and the source current is greater than or equal to the second predetermined value, and the source current is greater than or equal to the electric current command, the second fixed value being equal to the existing value of the duty cycle minus the constant, wherein:

the first fixed value is equal to the existing value of the duty cycle plus a first constant; and

the second fixed value is equal to the existing value of the duty cycle minus a second constant.

9. The method of claim 8 , wherein the first constant is equal to the second constant.

10. A system for controlling a boost converter having a duty cycle, the system comprising:

a first sensor configured to measure a source current of the boost converter;

a second sensor configured to measure an input voltage of the boost converter;

a third sensor configured to measure an output voltage of the boost converter; and

a processor coupled to the first sensor, the second sensor, and the third sensor and configured to:

receive an electric current command;

obtain an existing value of the duty cycle;

calculate a boost ratio using the input voltage and the output voltage; and

regulate the duty cycle as a function of the electric current command, the boost ratio, and the source current, subject to:

a first minimum limit and a first maximum limit if the existing value of the duty cycle is greater than or equal to a first predetermined threshold, the electric current command and the source current are less than a second predetermined threshold apart, or both; and

a second minimum limit and a second maximum limit if the existing value of the duty cycle is less than the first predetermined threshold and the electric current command and the source current are at least the second predetermined threshold apart.

11. The system of claim 10 , wherein the processor is further configured to calculate a maximum duty cycle that requires duty adjustment given the boost ratio, to thereby obtain the second predetermined threshold.

12. The system of claim 10 , wherein:

the first minimum and maximum limits are independent of the existing value of the duty cycle; and

the second minimum and maximum limits are dependent upon the existing value of the duty cycle.

13. The system of claim 10 , wherein the second minimum limit is equal to the second maximum limit.

14. The system of claim 10 , wherein the processor is further configured to:

add a first predetermined value to the existing value of the duty cycle, to thereby calculate the second minimum limit and the second maximum limit, if the rapid change in duty cycle is required above the predetermined threshold; and

subtract a second predetermined value from the existing value of the duty cycle, to thereby calculate the second minimum limit and the second maximum limit, if the rapid change in duty cycle is not required.

15. A system for controlling a boost converter having a duty cycle, the system comprising:

a first sensor configured to measure a source current of the boost converter;

a second sensor configured to measure an input voltage of the boost converter;

a third sensor configured to measure an output voltage of the boost converter; and

a processor coupled to the first sensor, the second sensor, and the third sensor and configured to:

receive an electric current command;

obtain an existing value of the duty cycle;

calculate a boost ratio using the input voltage and the output voltage; and

regulate the duty cycle as a function of the electric current command, the boost ratio, and the source current, subject to:

a first minimum limit and a first maximum limit if a rapid change in duty cycle is required above a predetermined threshold; and

a second minimum limit and a second maximum limit if the rapid change in duty cycle is not required,

wherein:

the first minimum and maximum limits are independent of the existing value of the duty cycle; and

the second minimum and maximum limits are dependent upon the existing value of the duty cycle.

16. A system for controlling a boost converter having a duty cycle, the system comprising:

a first sensor configured to measure a source current of the boost converter;

a second sensor configured to measure an input voltage of the boost converter;

a third sensor configured to measure an output voltage of the boost converter; and

a processor coupled to the first sensor, the second sensor, and the third sensor and configured to:

receive an electric current command;

calculate a boost ratio using the input voltage and the output voltage; and

regulate the duty cycle as a function of the electric current command, the boost ratio, and the source current, subject to:

a first minimum limit and a first maximum limit if a rapid change in duty cycle is required above a predetermined threshold; and

a second minimum limit and a second maximum limit if the rapid change in duty cycle is not required;

wherein the second minimum limit is equal to the second maximum limit.

Assignments (8)

Continuity (1)