CN104569827A - Battery management system and operating method thereof - Google Patents

Abstract

The invention relates to a battery management system. The battery management system comprises a storage part, a first SOC speculative computation part, a SOH speculative computation part and a second SOC speculative computation part. The storage part is used for saving inputted voltage and current and saving OCV data mapping within the specified OCV range in accordance with SOC. The first ISOC speculative computation part is used for speculating a first SOC value by utilization of OCV data mapping in accordance with SOC on the condition that the current value is less than the critical current intensity and the voltage value exists in the pre-set specified range. The SOH speculative computation part is used for determining the condition that charging operation is performed by constant current and computing the battery speculative capacity in accordance with quantity of electric charge of the SOC rate of change and comparing speculative SOH value with the initial battery capacity. The second speculative computation part is saved on following conditions such as voltage value of a storage part out of the range of special voltage or current value of the storage part above the critical value. A second SOC value is speculated by utilization of accumulation of current value of battery speculative capacity. Speculation, computation, correction and hamming are carried out by means of two SOC ranges in order to reduce necessary time and cost.

Description

Battery management system and application method thereof

Technical field

The present invention relates to battery management system and application method thereof, the battery management system related in more detail and application method thereof are, perform and infer SOC (State Of Charge, charged state) and SOH (State Of Health, accumulator health degree).

Background technology

In general, electric automobile or mixed power electric car utilize the power supply being kept at battery to drive automobile in motorized motions pattern.

Further, electric automobile or mixed power electric car, by battery management system, can infer SOC (State Of Charge) and SOH (State Of Health).

By an example, in battery charging and discharging, measure the voltage of battery, infer at the open voltage of the battery of no load condition from the voltage measured, map the method for the SOC being equivalent to the open voltage inferred with reference to the SOC table by open voltage.

But, when carrying out the discharge and recharge of battery, there is very big-difference according to the voltage of IR pressure drop effect battery and virtual voltage, if therefore do not revise this error, then there is the shortcoming that can not obtain correct SOC.

For reference, IR pressure drop phenomena refers to that battery is connected to voltage phenomenon jumpy when load starts electric discharge or charges the battery from external power source.That is, when starting to discharge, cell voltage sharply declines, and when starting to charge, voltage sharply rises.

By another example, have the charging and discharging currents calculating battery to infer the method for the SOC of battery, its method is because continuing to be accumulated at the measuring error measured and occur in the process of electric current, the problem declined through there is SOC correctness along with the time.

On the other hand, except above-mentioned SOC, SOH is had as another parameter of display battery status.SOH is the parameter as quantitatively showing because of the battery capacity characteristic variations of aging (aging) effect, can know the degradation in capacity of battery is to what degree, if therefore know, SOH can replace battery at reasonable time point, according to the charge/discharge capacity of the term of life regulating cell of battery, overcharging and over-discharge can of battery can be prevented.

Be reflected in the internal resistance change of battery during the change of battery capacity characteristic, the therefore known internal resistance according to battery and temperature can infer SOH.That is, the internal resistance of battery and the battery capacity of each temperature is pressed by charge-discharge test measurement.

With the initial capacity of battery for the capacity relative of benchmark by measurement quantizes, and then can obtain to map tabling look-up of SOH, environment measurement battery internal resistance and the temperature of battery is used, if from the described SOH mapping and correspond to internal resistance and temperature that tables look-up, then SOH can be inferred in reality.

But, by the SOC estimation method of integrating electric current, by the SOC variable quantity inferred and the ratio showing the SOC variable quantity inferred with SOC-OCV, until the mutual relationship building hamming convergency value and battery capacity is tabled look-up, there is the problem needing long-time and expense.Especially, SOC is different according to the voltage properties of thermalization below 50, tables look-up will have a lot of error according to its SOC-OCV.

(prior art document)

(patent documentation)

Patent documentation KR10-2010-0019249A

Summary of the invention

(problem that will solve)

The object that the invention provides battery management system and application method thereof is, to improve existing SOC (State Of Charge) estimation method in software manner, and then reduces required time and expense when inferring, and can improve supposition correctness.

(means of dealing with problems)

For the feature of the battery management system according to the present invention one side reaching described object is, comprising: sensor part, the magnitude of voltage of its induced cell and current value;

Storage part, it preserves voltage and the current value of induction, and preserves the OCV data-mapping by SOC (State Of Charge, charged state) in specific OCV (the Open Circuit Voltage) interval set in advance; 1SOC speculative computation portion, if within the magnitude of voltage of described induction meets the particular voltage range set in advance, the current value of described induction is less than critical electric current value, then infers 1SOC value by the OCV data-mapping of SOC described in its utilization; And 2SOC speculative computation portion, within the satisfied particular voltage range set in advance of magnitude of voltage of described induction, or the current value of described induction is greater than critical electric current value, then it infers 2SOC value according to current value of integrating induction.

In addition, this battery management system also comprises controller portion, it, with at the interval setting described 1SOC value or described 2SOC value in advance, obtains the data point in the number set in advance, utilizes hamming to infer the final SOC value of corresponding described 1SOC value or described 2SOC value.

In addition, this battery management system also can comprise SOH speculative computation portion, if perform charging with steady current, then its calculating is according to the quantity of electric charge of SOC rate of change and then the supposition capacity calculating battery, comparatively infers SOH (State Of Health) value with initial cell volume ratio.

In addition, after predetermined time period asks described battery supposition capacity with the rate of change of SOC and the quantity of electric charge, described SOH value is calculated divided by described initial cell capacity percent.

In addition, the current value inputted during the integration unit interval infers described 2SOC value divided by integral battery door capacity.

Described 2SOC value can be calculated according to mathematical expression 1.

Mathematical expression 1: $\mathrm{SOC}\left(n\right)=\mathrm{SOC}(n-1)+\frac{{\∫}_{n-1}^n\mathrm{I\; dt}}{C}$

(here, SOC (n-1): n-1 order 2SOC value, SOC (n): n order 2SOC value, I: electric current (A), t: time (s), C: battery capacity (Ah)).

Described final SOC value, according in described data point, (mathematical expression 2 that a, b, c, d, proportion e) being multiplied by each are averaging calculates described final SOC value.

Mathematical expression 2:

Final SOC value=1/16*a+4/16*b+6/16*c+4/16*d+1/16*e

＝0.0625(a+e)+0.25(b+d)+0.375c

In addition, the described OCV pressing SOC (Stat Of Charge), if SOC is predetermined above, it has not by the specific eigenvalue that temperature and thermalization affect.

In addition, according to the battery calculated in described SOH speculative computation portion, 2SOC speculative computation portion infers that capacity considers battery thermalization, infer described 2SOC.

For the feature of the application method reaching the battery management system according to another side of the present invention of described object is, comprising: sensing step, the magnitude of voltage of induced cell and current value; Preserve step, the voltage of induction and current value are kept at storage part, and preserve the OCV data-mapping by SOC (Stat Of Charge) in specific OCV (the Open Circuit Voltage) interval set in advance; The step of speculative computation 1SOC, if within the magnitude of voltage of described induction meets the particular voltage range set in advance, the current value of described induction is less than critical electric current value, then infers 1SOC value by the OCV data-mapping of SOC described in utilizing; And the step of speculative computation 2SOC, if within the magnitude of voltage of described induction does not meet the particular voltage range set in advance, or the current value of described induction is greater than critical electric current value, then infer 2SOC value according to the current value of integrating induction.

In addition, the application method of this battery management system also comprises the step inferring final SOC value, with at the interval setting described 1SOC value or described 2SOC value in advance, obtain the data point in the number set in advance, utilize hamming to infer the step of the final SOC value of corresponding described 1SOC value or described 2SOC value.

In addition, the application method of this battery management system also comprises the step of speculative computation SOH, if perform charging with steady current, then calculate the quantity of electric charge according to SOC rate of change and then calculating battery supposition capacity, comparatively infer SOH (State Of Health) value with initial cell volume ratio.

In addition, ask described battery to infer capacity at predetermined time period with the rate of change of SOC and the quantity of electric charge, calculate described SOH value divided by described initial cell capacity percent.

In addition, according to described calculating, the step of described calculating supposition 2SOC, infers that the battery that the step of SOH calculates infers that capacity considers battery thermalization, infers described 2SOC.

(effect of invention)

Identical therewith, even if the present invention considers that thermalization proceeds to a certain degree on battery behavior, the this point that electromotive force can not change is played in predetermined charge state, the hamming revised through 2 kinds of speculative computations at specific SOC (Stage Of Charge) interval band is suitable for when charging, infer final charged state and thermalization state, and then inferring time required on SOC and expense compared to existing reduction, and supposition correctness can be improved.

Accompanying drawing explanation

Fig. 1 is the block diagram of battery management system according to an embodiment of the invention.

Fig. 2 is the OCV by SOC (Open CircuitVoltage) schematic diagram according to the capacity thermalization obtained by experiment.

Fig. 3 is according to one embodiment of the invention, in order to the drawing of the final SOC value inferring battery management system is described.

Fig. 4 is according to one embodiment of the invention, in order to the process flow diagram of the action of battery management system is described.

(description of reference numerals)

10: sensor part 11: voltage sensor

12: current sensor 30: storage part

40: the 1SOC speculative computation portion 50: the 2SOC speculative computation portions

60:SOH speculative computation portion 70: controller portion

Specific embodiment mode

As follows the present invention is described with reference to accompanying drawing, here by omit repeatedly explanation, to the unnecessary detailed description making the unclear known function of main points of the present invention and formation.Example of the present invention provides to give the explanation the present invention in the industry cycle having the technician of average knowledge more complete, therefore in order to explanation definitely can exaggerate the shape of the key element being shown in drawing and size etc.

Fig. 1 is the block diagram of battery management system according to an embodiment of the invention.With reference to Fig. 1, sensor part 10, storage part 30,1SOC speculative computation portion 40, SOH speculative computation portion 60,2SOC speculative computation portion 50, controller portion 70 can be comprised according to the battery management system of the present embodiment.

Storage part 30, according to the sensor part 10 in order to respond to voltage and the electric current inputted from high-voltage battery (B), can perform the function of magnitude of voltage that preservation inputs respectively and current value.Sensor part 10, is made up of voltage sensor 11 and current sensor 12.

At storage part 30, save at the interval OCV by SOC (the Open Circuit Voltage) data-mapping of specific OCV (Open Circuit Voltage) in advance.

1SOC speculative computation portion 40, judging that the current value being kept at storage part 30 is less than critical electric current value, the magnitude of voltage preserved is present in the situation in the particular range that in advance sets, utilize be kept at storage part 30 can infer 1SOC value by the OCV data-mapping of SOC.

SOH speculative computation portion 60, is judging with the situation of steady current craspedodrome charging, calculates the quantity of electric charge according to SOC rate of change and then calculating battery supposition capacity, compares can infer SOH (State Of Health) value S220 with initial capacity.

Utilization asks the capacity of present battery can infer SOH (State Of Health) value with the quantity of electric charge ratio changed according to predetermined time period SOC after inferring SOC value by the OCV data-mapping conversion SOC (State Of Charge) of SOC.

2SOC speculative computation portion 50, be not stored in the particular voltage range in advance set at the magnitude of voltage being kept at storage part 30, or the current value being kept at storage part 30 is the situation more than the critical electric current value set in advance, utilize the battery calculated according to SOH speculative computation portion 60 to infer capacity, measuring electric current according to integrating can infer 2SOC value.

Controller portion 70, to be set in the interval of the 1SOC value inferred in 1SOC speculative computation portion 40 or the 2SOC value inferred in 2SOC speculative computation portion 50 (such as in advance, 1 second interval) obtain 5 data points, utilize hamming can infer the final SOC value of corresponding 1SOC value or 2SOC value.

In addition, controller portion 70, with in interval acquiring 5 data points setting the SOH value inferred according to SOH speculative computation portion 60 in advance, utilizes hamming can infer final SOH value.

Controller portion 70, can the in-built function final SOC value of such as above-mentioned supposition and final SOH value being shown to user.

Following, 1SOC speculative computation portion 40, SOH speculative computation portion 60 and 2SOC speculative computation portion 50 are specifically described.

1SOC speculative computation portion 40, to carry out charge or discharge below critical low current during vehicle operating, with OCV, the voltage measured during by voltage between given zone, carries out identifying that the OCV data-mapping be applicable to by SOC can infer 1SOC value.

Namely, 1SOC speculative computation portion 40, the magnitude of voltage measured is in the particular voltage range in advance set, and the current value of measurement is less than the situation at the critical electric current value set in advance, and what it was applicable to be kept at storage part 30 can infer 1SOC value by the OCV data-mapping of SOC.

For the high-voltage battery of electric vehicle, be subject to term of life and the very large impact of temperature carry out thermalization but according to the active volume of thermalization degree reduction battery, but the intrinsic OCV value of battery does not affect by temperature and thermalization in particular battery charged state (SOC) interval and has specific eigenvalue.

Fig. 2 is the capacity thermalization according to obtaining by experiment, by the OCV schematic diagram of SOC.With reference to Fig. 2, according to the interval of capacity thermalization at more than SOC60%, can confirm electric battery by the OCV value of SOC be do not have vicissitudinous, for consistent.

SOH speculative computation portion 60 performs charging with steady current, in specific SOC interval, at this moment carry out the situation of the state of charging, and calculates according to the quantity of electric charge of SOC rate of change and then can calculate battery specified vol, comparing can infer SOH value with initial capacity.

Infer that the formula of battery capacity is as mathematical expression 1.

[mathematical expression 1]

$C^{\′}=\frac{\underset{k=n1}{\overset{n2}{\mathrm{\Σ}}}i\left(k\right)\mathrm{\ΔT}}{\mathrm{SOC}\left(n2\right)-\mathrm{SOC}\left(n1\right)}$

SOH value is the thermalization degree shown battery meter, predetermined time period with the rate of change of SOC and the quantity of electric charge ask battery infer capacity (C') after get percent divided by initial capacity C and can calculate SOH value.As mathematical expression 2 can calculate SOH value.

[mathematical expression 2]

$\mathrm{SOH}=\frac{C^{\′}}{C}\×100$

2SOC speculative computation portion 50, infers capacity based on the battery calculated according to SOH speculative computation portion 60, can infer 2SOC value.That is, 2SOC speculative computation portion 50 is by considering can calculate 2SOC value by the integrating of the current value that the reservoir portion 30 of battery thermalization is preserved.

2SOC speculative computation portion 50, according to the current value inputted during the integration unit interval divided by integral battery door capacity, can unit of account time durations variation 2SOC value.That is, if as mathematical expression 3 adds instantaneous variation SOC value n-1 SOC (n-1), then the 2SOC value of n time can be inferred.

(mathematical expression 3)

$\mathrm{SOC}\left(n\right)=\mathrm{SOC}(n-1)+\frac{{\∫}_{n-1}^n\mathrm{I\; dt}}{C}$

(here, I: electric current (A), t: time (s), C: battery capacity (Ah))

2SOC speculative computation portion 50, utilizes the battery calculated according to SOH speculative computation portion 60 to infer that capacity infers 2SOC value, therefore can consider battery capacity thermalization in supposition 2SOC value.

Controller portion 70, with the data point in the number set in advance, obtains according to the 1SOC value of 1SOC speculative computation portion 40 supposition or is applicable to hamming according to the 2SOC value that 2SOC speculative computation portion 50 is inferred, and then can infer final SOC value.

Controller portion 70, obtain the 1SOC value inferred according to 1SOC speculative computation portion 40 or the 2SOC value inferred according to 2SOC speculative computation portion 50 with 5 data points, applicable hamming can infer final SOC value.

As data point (a, b, c, d, hamming e) that Fig. 3 is 5.As mathematical expression 4,5 SOC data points inferred, (a, b, c, d, proportion e) being multiplied by each are averaging and finally can infer final SOC value.

[mathematical expression 4]

Final SOC value=1/16*a+4/16*b+6/16*c+4/16*d+1/16*e

＝0.0625(a+e)+0.25(b+d)+0.375c

Below, with reference to Fig. 4, the application method of battery management system is according to an embodiment of the invention described.

Battery management system, according in order to the voltage sensor 11 of induced voltage and electric current and current sensor 12, measures the magnitude of voltage and current value S110 that input respectively.

Battery management system, the magnitude of voltage S120 within the particular voltage range in advance set measured, the current value measured is less than the situation S130 at the critical electric current value set in advance, is applicable to infer 1SOC value S140 what set in advance by the OCV data-mapping of SOC.

Battery management system, after beginning control flow of the present invention, judge the situation S210 performing charging with steady current, namely within specific SOC scope, carry out the situation of the state of charging, calculate the quantity of electric charge according to SOC rate of change and then calculating battery supposition capacity, comparatively can infer SOH (State Of Health) value S220 with initial cell volume ratio.Mathematical expression 1 described above and mathematical expression 2 can perform the supposition of SOH value.

Battery management system, the magnitude of voltage measured is not present in S120 in the particular voltage range in advance set, or measurement current value is the situation S130 more than the critical electric current value set in advance, utilize the battery calculated according to S220 step to infer capacity, the integrating according to measuring electric current infers 2SOC value S150.The supposition of 2SOC value can be performed according to above-mentioned mathematical expression 3.

That is, the current value inputted during the unit interval according to integration, divided by integral battery door capacity, can ask 2SOC value according to calculating the SOC value changed during the unit interval.

Battery management system, to set the interval according to the 1SOC value or 2SOC value performing S140 step or the supposition of S150 step in advance, obtain the data point in advance set, utilize hamming to infer the final SOC value S160 of corresponding 1SOC value or 2SOC value.

Battery management system, with at the interval setting the SOH value inferred according to S220 step in advance, obtains the data point in advance set, utilizes hamming to infer final SOH value S230.Battery management system, shows the final SOC value of supposition and final SOH value S300 to user.

Identical therewith, according to battery management system and the application method thereof of the present embodiment, even if thermalization proceeds to a certain degree on battery behavior, in view of playing the indeclinable this point of electromotive force in predetermined charge state, the hamming revised through 2 kinds of speculative computations in particular range SOC (Stage Of Charge) scope is suitable for when charging, infer final charged state and thermalization state, and then reduce required time and expense when inferring SOC compared to existing, and supposition correctness can be improved.

Battery management system and application method thereof according to an embodiment of the invention, is not restricted in the formation of the embodiment of above-mentioned explanation and method, according to user need optionally combine all or part of that form embodiment.

Basis described above describes the present invention as the specific item of concrete inscape etc. and the embodiment of restriction and drawing, but this only provides to more contribute to understanding the present invention, the present invention is not restricted to described embodiment, and the technician that the field belonging to the present invention has usual knowledge can carry out various amendment and distortion from this record.

Claims (18)

1. a battery management system, is characterized in that, comprising:

Sensor part, the magnitude of voltage of its induced cell and current value;

Storage part, it preserves voltage and the current value of induction, and preserves the OCV data-mapping pressing SOC (State Of Charge, charged state) in specific OCV (Open Circuit Voltage, the open-circuit voltage) interval set in advance;

1SOC speculative computation portion, if within the magnitude of voltage of described induction meets the particular voltage range set in advance, the current value of described induction is less than critical electric current value, then its utilization infers 1SOC value by the OCV data-mapping of described SOC; And

2SOC speculative computation portion, within the satisfied particular voltage range set in advance of magnitude of voltage of described induction, or the current value of described induction is greater than critical electric current value, then it infers 2SOC value according to current value of integrating induction.

2. battery management system according to claim 1, is characterized in that, also comprises:

Controller portion, it, with at the interval setting described 1SOC value or described 2SOC value in advance, obtains the data point in the number set in advance, utilizes hamming to infer the final SOC value of corresponding described 1SOC value or described 2SOC value.

3. battery management system according to claim 1, is characterized in that, also comprises:

SOH speculative computation portion, if perform charging with steady current, then its calculating is according to the quantity of electric charge of SOC rate of change and then the supposition capacity calculating battery, comparatively infers SOH (State Of Health, accumulator health degree) value with initial cell volume ratio.

4. battery management system according to claim 3, is characterized in that,

Described SOH value, after predetermined time period asks described battery supposition capacity with the rate of change of SOC and the quantity of electric charge, calculates described SOH value divided by described initial cell capacity percent.

5. battery management system according to claim 1, is characterized in that,

Described 2SOC value, the current value inputted during the integration unit interval infers described 2SOC value divided by integral battery door capacity.

6. battery management system according to claim 5, is characterized in that,

Described 2SOC value, calculates described 2SOC value according to mathematical expression 1,

Mathematical expression 1: $\mathrm{SOC}\left(n\right)=\mathrm{SOC}(n-1)+\frac{{\∫}_{n-1}^n\mathrm{I\; dt}}{C}$

(here, SOC (n-1): n-1 order 2SOC value, SOC (n): n order 2SOC value, I: electric current (A), t: time (s), C: battery capacity (Ah)).

7. battery management system according to claim 2, is characterized in that,

Described final SOC value, according to described data point (mathematical expression 2 that a, b, c, d, proportion e) being multiplied by each are averaging, calculates described final SOC value,

Mathematical expression 2:

Final SOC value=1/16*a+4/16*b+6/16*c+4/16*d+1/16*e

＝0.0625(a+e)+0.25(b+d)+0.375c

8. battery management system according to claim 2, is characterized in that,

The described OCV pressing SOC (Stat Of Charge), if SOC is predetermined above, it has not by the specific eigenvalue that temperature and thermalization affect.

9. battery management system according to claim 3, is characterized in that,

Described 2SOC speculative computation portion, according to the battery calculated in described SOH speculative computation portion, it infers that capacity considers battery thermalization, infer described 2SOC.

10. an application method for battery management system, is characterized in that, comprising:

Sensing step, the magnitude of voltage of induced cell and current value;

Preserve step, the voltage of induction and current value are kept at storage part, and preserve the OCV data-mapping by SOC (Stat Of Charge) in specific OCV (the Open Circuit Voltage) interval set in advance;

The step of speculative computation 1SOC, if within the magnitude of voltage of described induction meets the particular voltage range set in advance, the current value of described induction is less than critical electric current value, then infers 1SOC value by the OCV data-mapping of SOC described in utilizing; And

The step of speculative computation 2SOC, if within the magnitude of voltage of described induction does not meet the particular voltage range set in advance, or the current value of described induction is greater than critical electric current value, then infer 2SOC value according to the current value of integrating induction.

The application method of 11. battery management systems according to claim 10, is characterized in that, also comprise:

Infer the step of final SOC value, with at the interval setting described 1SOC value or described 2SOC value in advance, obtain the data point in the number set in advance, utilize hamming to infer the step of the final SOC value of corresponding described 1SOC value or described 2SOC value.

The application method of 12. battery management systems according to claim 10, is characterized in that, also comprise:

The step of speculative computation SOH, if perform charging with steady current, then calculates the quantity of electric charge according to SOC rate of change and then calculating battery supposition capacity, comparatively infers SOH (State Of Health) value with initial cell volume ratio.

The application method of 13. battery management systems according to claim 10, is characterized in that,

Described SOH value, asks described battery to infer capacity at predetermined time period with the rate of change of SOC and the quantity of electric charge, calculates described SOH value divided by described initial cell capacity percent.

The application method of 14. battery management systems according to claim 10, is characterized in that,

Described 2SOC value, according to the current value inputted during the integration unit interval divided by integral battery door capacity, infers described 2SOC value.

The application method of 15. battery management systems according to claim 14, is characterized in that,

Described 2SOC value, can calculate described 2SOC value according to mathematical expression 1,

Mathematical expression 1: $\mathrm{SOC}\left(n\right)=\mathrm{SOC}(n-1)+\frac{{\∫}_{n-1}^n\mathrm{I\; dt}}{C}$

(here, SOC (n-1): n-1 order 2SOC value, SOC (n): n order 2SOC value, I: electric current (A), t: time (s), C: battery capacity (Ah)).

The application method of 16. battery management systems according to claim 11, is characterized in that,

Described final SOC value, according to described data point (mathematical expression 2 that a, b, c, d, proportion e) being multiplied by each are averaging calculates described final SOC value,

Mathematical expression 2:

Final SOC value=1/16*a+4/16*b+6/16*c+4/16*d+1/16*e

＝0.0625(a+e)+0.25(b+d)+0.375c

The application method of 17. battery management systems according to claim 11, is characterized in that,

The described OCV pressing SOC (Stat Of Charge), if SOC is predetermined above, it has not by the specific eigenvalue that temperature and thermalization affect.

The application method of 18. battery management systems according to claim 12, is characterized in that,

According to described calculating, the step of described calculating supposition 2SOC, infers that the battery that the step of SOH calculates infers that capacity considers battery thermalization, infers described 2SOC.