Method and apparatus for monitoring secondary power device, and electronic system including the apparatus

1. A method of monitoring a secondary power device, the method comprising:

charging, by a charging unit, the secondary power device including at least one capacitor, by supplying power from the charging unit to the secondary power device;

setting, by a calibration unit, a first reference parameter in a first calibration interval by using a voltage of the at least one capacitor;

setting, by the calibration unit, a second reference parameter in a second calibration interval by using the voltage of the at least one capacitor and the first reference parameter;

setting, by a level setting unit, a reference level for checking a state of the secondary power device, by using the second reference parameter; and

monitoring, by a monitoring unit, the state of the secondary power device by using the reference level.

2. The method of claim 1 , wherein the voltage of the at least one capacitor ripples between a local maximum value and a local minimum value via a charging operation of the charging unit,

wherein the setting of the first reference parameter comprises:

detecting a maximum value of the voltage of the at least one capacitor in the first calibration interval;

detecting a minimum value of the voltage of the at least one capacitor in the first calibration interval; and

setting an average of the maximum value and the minimum value as the first reference parameter.

3. The method of claim 2 , wherein the setting of the second reference parameter comprises:

classifying, in the second calibration interval, the voltage of the at least one capacitor into high state intervals and low state intervals by using the first reference parameter;

detecting, in the second calibration interval, first local maximum values in the high state intervals and calculating a first average value which is an average of the first local maximum values;

detecting, in the second calibration interval, first local minimum values in the low state intervals and calculating a second average value which is an average of the first local minimum values; and

setting an average of the first average value and the second average value as the second reference parameter.

4. The method of claim 3 , further comprising extracting each of the first local maximum values from each of the high state intervals via a first comparison logic, and

extracting each of the first local minimum values each of the low state intervals via a second comparison logic.

5. The method of claim 3 , wherein setting of the reference level comprises setting a range of ±Δ about a central value which is set to the second reference parameter as the reference level.

6. The method of claim 5 , wherein Δ is set to a fixed value or a percentage (%) with respect to a difference between the first average value and the second average value.

7. The method of claim 1 , further comprising:

measuring a discharging time of the at least one capacitor by using the reference level; and

comparing the discharging time with a set reference time to determine whether the secondary power device is operating abnormally.

8. The method of claim 7 , further comprising:

obtaining an average discharging time by measuring and averaging a plurality of discharging times of the at least one capacitor; and

comparing the average discharging time with the reference time to determine whether the secondary power device is operating abnormally.

9. The method of claim 1 , wherein the reference level is calibrated by repeatedly performing operations from the setting of the first reference parameter to the setting of the reference level for a set period, or

the reference level is calibrated in real time by using the voltage of the at least one capacitor detected after the setting of the second reference parameter, in resetting of the second reference parameter and resetting of the reference level.

10. The method of claim 1 , wherein setting of the reference level comprises setting a range of ±Δ about a central value which is set to the second reference parameter as the reference level.

11. The method of claim 10 , further comprising:

measuring a discharging time from the voltage of the at least one capacitor corresponding to the second reference parameter +Δ, to a voltage of the at least one capacitor corresponding to the second reference parameter −Δ; and

comparing the discharging time with a set reference time to determine whether the secondary power device is operating abnormally.

12. A method of monitoring a secondary power device, the method comprising:

charging, by a charging unit, the secondary power device including at least one capacitor, by supplying power from the charging unit to the secondary power device;

setting, by a calibration unit, a first reference parameter in a first calibration interval, by using a voltage of the at least one capacitor, wherein the voltage ripples between a local maximum value and a local minimum value;

setting, by the calibration unit, a second reference parameter in a second calibration interval, by using the voltage of the at least one capacitor and the first reference parameter;

setting, by a level setting unit, a reference level to a range of ±Δ about a central value which is set to the second reference parameter; and

monitoring, by a monitoring unit, a state of the secondary power device by using the reference level,

wherein operations from the setting of the first reference parameter to the setting of the reference level are repeated for a set period.

13. The method of claim 12 , further comprising:

setting the first reference parameter to an average of a maximum value and a minimum value of the voltage of the at least one capacitor in the first calibration;

classifying the voltage of the at least one capacitor in the second calibration interval into high state intervals and low state intervals by using the first reference parameter;

detecting first local maximum values from the high state intervals;

calculating a first average value as an average of the first local maximum values;

detecting first local minimum values from the low state intervals;

calculating a second average value as an average of the first local minimum values; and

setting an average of the first average value and the second average value as the second reference parameter.

14. The method of claim 13 , wherein Δ is set to a fixed value or as a percentage (%) with respect to a difference between the first average value and the second average value.

15. The method of claim 12 , further comprising:

measuring a discharging time from the voltage of the at least one capacitor corresponding to the second reference parameter +Δ, to a voltage of the at least one capacitor corresponding to the second reference parameter −Δ; and

comparing the discharging time with a set reference time to determine whether the secondary power device is operating abnormally.

16. A method, comprising:

charging, by a charging unit, a secondary power device;

in a first interval, measuring a capacitor voltage of the secondary power device;

detecting first local minimum values and first local maximum values of the measured capacitor voltage in the first interval;

setting a first reference parameter based on detected local minimum values and local maximum values;

in a second interval, measuring the capacitor voltage of the secondary power device;

setting a second reference parameter based on values of the measured capacitor voltage in the second interval together with the first reference parameter;

setting a reference level as a range centered about a voltage set to the second reference parameter;

in a third interval, measuring the capacitor voltage of the secondary power device;

measuring a discharging time of the capacitor voltage in the third interval by using the measured capacitor voltage in the third interval and the reference level; and

comparing the discharging time with a set reference time to determine whether the secondary power device is operating abnormally.

17. The method of claim 16 , wherein setting a second reference parameter based on values of the measured capacitor voltage in the second interval together with the first reference parameter comprises:

classifying, in the second interval, the measured capacitor voltage into high state intervals and low state intervals using the first reference parameter;

detecting, in the second interval, second local maximum values in the high state intervals and calculating a first average value which is an average of the second local maximum values;

detecting, in the second interval, second local minimum values in the low state intervals and calculating a second average value which is an average of the second local minimum values; and

setting an average of the first average value and the second average value as the second reference parameter.

18. The method of claim 17 , wherein each of the first local maximum values is extracted from each of the high state intervals via comparison logic, and

wherein each of the first local minimum values is extracted from each of the low state intervals via comparison logic.

19. The method of claim 17 , wherein the range is ±A, and wherein Δ is set to a percentage (%) with respect to a difference between the first average value and the second average value.

20. The method of claim 16 , wherein the range is ±Δ, and wherein Δ is set to a fixed value.