Method and apparatus for estimating state of charge of lithium iron phosphate battery

1 . A computer-implemented method for controlling a state of charge of a lithium iron phosphate battery, the method comprising:

providing a lithium iron phosphate battery;

with a voltage sensor, a temperature sensor and a current sensor coupled to the lithium iron phosphate battery and to a computer, acquiring the temperature of the current time period and an SOC-OCV curve under the current of the current time period;

with the computer, determining, on the basis of the state of charge of the SOC-OCV curve, a correction point of the SOC-OCV curve; and

with the computer, correcting, on the basis of a combination of at least one temperature and at least one current, the SOC-OCV curve at the correction point, and updating the SOC-OCV curve; and

with the computer, estimating a state of charge of the lithium iron phosphate battery by determining a SOC value corresponding to a current voltage in the updated SOC-OCV curve; and with the computer, controlling a change of the state of charge of the lithium iron phosphate battery as a function of the estimated state of charge;

wherein the determining, on the basis of the state of charge of the SOC-OCV curve, a correction point of the SOC-OCV curve comprises:

with the computer, differentiating the SOC-OCV curve to determine a voltage differentiation curve; and

with the computer, determining, on the basis of a voltage differentiation peak of the voltage differentiation curve in a preset state of charge interval, the correction point.

2 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 1 , wherein the acquiring the temperature of the current time period and an SOC-OCV curve under the current of the current time period comprises:

acquiring the temperature of the current time period and the voltage of the current time period under the current of the current time period;

filtering the current of the current time period and the voltage of the current time period, and determining the current and voltage after noise reduction; and

determining, on the basis of the current and voltage after noise reduction, the SOC-OCV curve.

3 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 2 , wherein the filtering the current of the current time period and the voltage of the current time period, and determining the current and voltage after noise reduction comprises:

acquiring current of at least the previous time period and voltage of at least the previous time period;

fusing the current of the current time period and the current of at least the previous time period to determine the current after noise reduction; and

fusing the voltage of the current time period and the voltage of at least the previous time period to determine the voltage after noise reduction.

4 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 1 , wherein the differentiating the SOC-OCV curve to determine a voltage differentiation curve comprises:

acquiring a fixed voltage increment and a time increment corresponding to the fixed voltage increment; and

differentiating, on the basis of the fixed voltage increment and the time increment, the SOC-OCV curve to determine the voltage differentiation curve.

5 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 1 , wherein the preset state of charge interval comprises a first state of charge interval under a first platform area, the correction point comprises a first correction point, and the first platform area is a continuous area with a voltage differentiation value in the voltage differentiation curve less than a first preset value; and the determining, on the basis of the voltage differentiation peak of the voltage differentiation curve in a preset state of charge interval, the correction point comprises:

determining, on the basis of the position of a first voltage differentiation peak in the first state of charge interval, the first correction point in the first state of charge interval.

6 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 5 , wherein the correcting, on the basis of a combination of at least one temperature and at least one current, the SOC-OCV curve at the correction point, and updating the SOC-OCV curve comprises:

calibrating, on the basis of the combination of at least one temperature and at least one current, a first correction value of the SOC-OCV curve at the first correction point; and

updating, on the basis of the first correction value, the SOC-OCV curve.

7 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 5 , wherein the preset state of charge interval comprises a second state of charge interval between the first platform area and a second platform area, the correction point comprises a second correction point, and the second platform area is a continuous area with a voltage differentiation value in the voltage differentiation curve less than a second preset value; and the determining, on the basis of the voltage differentiation peak of the voltage differentiation curve in a preset state of charge interval, the correction point comprises:

determining, on the basis of the position of the second voltage differentiation peak in the second state of charge interval, the second correction point in the second state of charge interval.

8 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 7 , wherein the correcting, on the basis of a combination of at least one temperature and at least one current, the SOC-OCV curve at the correction point, and updating the SOC-OCV curve comprises:

calibrating, on the basis of the combination of at least one temperature and at least one current, a second correction value of the SOC-OCV curve at the second correction point; and

updating, on the basis of the second correction value, the SOC-OCV curve.

9 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 1 , further comprising:

determining, on the basis of the temperature of the current time period and the current of the current time period, an SOC value corresponding to the current voltage in the updated SOC-OCV curve.

10 . An electronic device, a memory and a processor, wherein the memory is configured to store computer programs which can run in a processor, and the processor executes the programs to implement the method according to claim 1 .

11 . A non-transitory computer-readable storage medium, on which a computer program is stored, wherein the computer program is executed by a processor to implement the method according to claim 1 .

12 . A computer implemented method for controlling a state of charge of a lithium iron phosphate battery, the method comprising:

providing a lithium iron phosphate battery;

with a voltage sensor, a temperature sensor and a current sensor coupled to the lithium iron phosphate battery and to a computer, acquiring the temperature of the current time period and an SOC-OCV curve under the current of the current time period;

with the computer, determining, on the basis of the state of charge of the SOC-OCV curve, a correction point of the SOC-OCV curve;

with the computer, correcting, on the basis of a combination of at least one temperature and at least one current, the SOC-OCV curve at the correction point, and updating the SOC-OCV curve; and

with the computer, estimating a state of charge of the lithium iron phosphate battery by determining a SOC value corresponding to a current voltage in the updated SOC-OCV curve; and with the computer, controlling a change of the state of charge of the lithium iron phosphate battery as a function of the estimated state of charge;

wherein the acquiring the temperature of the current time period and an SOC-OCV curve under the current of the current time period comprises:

with the voltage sensor, temperature sensor and current sensor, acquiring the temperature of the current time period and the voltage of the current time period under the current of the current time period;

with the computer, filtering the current of the current time period and the voltage of the current time period, and determining the current and voltage after noise reduction; and

with the computer, determining, on the basis of the current and voltage after noise reduction, the SOC-OCV curve.

13 . The method for controlling a state of charge of a lithium iron phosphate battery according to claim 12 , wherein the filtering the current of the current time period and the voltage of the current time period, and determining the current and voltage after noise reduction comprises:

acquiring current of at least the previous time period and voltage of at least the previous time period;

fusing the current of the current time period and the current of at least the previous time period to determine the current after noise reduction; and

fusing the voltage of the current time period and the voltage of at least the previous time period to determine the voltage after noise reduction.