Battery aging state calculation method and system
View Patent ↗The present disclosure relates to a UPS battery aging state calculation method and system, and more specifically, to an aging state calculation method and system of a UPS battery for accurately calculating an aging state (i.e., State of Health (SOH)) of the UPS battery itself by repeatedly executing the charge and self-discharge of the UPS battery through a switch.
1. A method of calculating a State of Health (SOH) of a battery included in an Uninterruptible Power Supply (UPS), the method comprising:
controlling, by a control unit, repeated charge and discharge cycles of the battery, each charge and discharge cycle including a charge portion and a discharge portion;
for each charge and discharge cycle of the battery, measuring, by the control unit, each of a current, a voltage, and a temperature;
determining, by the control unit, whether the number of repeated charge and discharge cycles exceeds a predetermined value; and
continuing, by the control unit, the repeated charge and discharge cycles of the battery until the number of repeated charge and discharge cycles exceeds the predetermined value;
upon the number of charge and discharge cycles exceeding the predetermined value, calculating, by the control unit, the SOH of the battery based at least in part on (i) an initial battery capacity, (ii) a change amount of a State of Charge (SOC) of the battery during each charge portion or during each discharge portion of the repeated charge and discharge cycles, and (iii) a current amount accumulated during each charge portion or during each discharge portion of the repeated charge and discharge cycles.
2. The method of claim 1 , wherein controlling repeated charge and discharge cycles of the battery comprises:
controlling, by the control unit, charge of the battery during the charge portion until a full charge state is reached; and
controlling, by the control unit, discharge of the battery during the discharge portion in response to the battery being fully charged.
3. The method of claim 2 , wherein controlling charge of the battery during the charge portion until a full charge state is reached comprises:
controlling, by the control unit, a switch to supply current from a current supply unit to the battery;
calculating, by the control unit, a charge SOC based on the measured current, voltage, and temperature; and
comparing, by the control unit, the charge SOC to a full charge reference value.
4. The method of claim 3 , wherein controlling discharge of the battery during the discharge portion is initiated in response to the charge SOC being greater than the full charge reference value.
5. The method of claim 2 , wherein controlling discharge of the battery comprises:
controlling, by the control unit, a current supply switch to cut off current from the current supply to the battery when the battery is fully charged;
calculating, by the control unit, a discharge SOC based on the measured current, voltage, and temperature during discharge of the battery; and
comparing, by the control unit, the discharge SOC to a predetermined discharge reference value.
6. The method of claim 5 , wherein controlling discharge of the battery during the discharge portion further comprises:
determining that the discharge SOC is less than the predetermined discharge reference value;
in response to determining that the discharge SOC is less than the predetermined discharge reference value, accumulating one of a charged current or a discharged current.
7. The method of claim 1 , wherein either:
the SOH of the battery based at least in part on (i) an initial battery capacity, (ii) a change amount of a State of Charge (SOC) of the battery during each charge portion of the repeated charge and discharge cycles, and (iii) a current amount accumulated during each charge portion of the repeated charge and discharge cycles; or
the SOH of the battery based at least in part on (i) an initial battery capacity, (ii) a change amount of a State of Charge (SOC) of the battery during each discharge portion of the repeated charge and discharge cycles, and (iii) a current amount accumulated during each discharge portion of the repeated charge and discharge cycles.
8. The method of claim 7 , further comprising individually summing each charged current accumulated for each charge portion or individually summing each discharged current accumulated for each discharge portion, wherein the change amount of the State of Charge (SOC) during each charge portion of the repeated charge and discharge cycles is the summed charged currents, and wherein the change amount of the State of Charge (SOC) during each discharge portion of the repeated charge and discharge cycles is the summed discharged currents.