CN102662148A - On-line feedback battery state of charge (SOC) predicting method - Google Patents

Abstract

The invention relates to the technical field of storage battery state of charge prediction, and discloses an on-line feedback battery state of charge (SOC) predicting method. According to the method, SOC valuation model parameters are corrected according to historical data in the on-line operating process of a storage battery. The influence of temperature, coulomb efficiency and self discharge on battery SOC is considered, basic operating parameters of the storage battery are only required to be monitored, related coefficients are corrected as long as conditions are met in the operating process of the battery, coefficient values are repeatedly corrected, and an SOC estimation result is close to a true value along time, so the accuracy is high and the storage battery SOC can be predicted on line.

Description

Online feedback formula accumulator SOC Forecasting Methodology

Technical field

(State of Charge, SOC) electric powder prediction are specifically related to a kind of online feedback formula accumulator SOC Forecasting Methodology to the present invention relates to the accumulator state-of-charge.

Background technology

The state-of-charge of accumulator (State of Charge; SOC) be used to describe the residual capacity of accumulator; Relatively more unified is from electric weight viewpoint definition SOC at present; It is defined as battery under certain discharge-rate, the ratio of rated capacity under residual capacity and the same terms, and it is the important parameter in the battery use.SOC can effectively learn the user mode of accumulator accurately, and the charge status of management of battery makes it balanced and prevent to overcharge, cross and put, and improves the serviceable life of battery pack; Can also reflect continual mileage more accurately for used for electric vehicle accumulator SOC, when the prompting human pilot charges or changes battery.Therefore, the estimation of SOC is a research focus of battery management.The Forecasting Methodology of SOC mainly contains following several kinds at present:

(1) infers the size of SOC according to the variation of inside battery parameter; Concentration of medium and SOC like lead-acid battery have the most directly relation; But battery can not reach balance all the time in charge and discharge process medium concentration; And lead-acid battery is because its sealing, makes this method be difficult to be applied to the online estimation of the SOC of battery;

(2) open-circuit voltage method is applied to the accumulator that inside reaches equilibrium state, and its open-circuit voltage and SOC have good mapping relations, but this method can not be used for online estimation;

(3) ampere-hour integral method; This is the more method of using at present; Simple, its basic thought is to become the discharge electricity amount under certain specific currents to the discharge electricity amount equivalence that different electric flows down, and judges SOC according to dump energy again; But discharge coefficient changes with the variation of several factors, is difficult to obtain stable exact value.In addition, in the ampere-hour integral method, how considering the problem of self-discharge of battery and efficiency for charge-discharge, how to correct because of error constantly accumulates, the problem of the final possibility of SOC estimated value substantial deviation actual value, is the difficult point place of improving the accuracy of ampere-hour integral method;

(4) internal resistance method; Set up the corresponding relation of the internal resistance of cell and SOC through test; Therefore need set up the internal resistance that model comes estimating battery, obtain SOC according to the internal resistance of calculating again, this method calculated amount is bigger; And need set up battery model, the accuracy of model must influence the estimation result's of SOC accuracy;

(5) Kalman filter method by a series of mathematical formulae recursive descriptions, comes the state of estimation procedure with a kind of computing method efficiently, and makes the estimation square error minimum.Its basic thought is: adopt the state-space model of signal and noise, utilize the estimated value of previous moment and the observed reading of now to upgrade the estimation to state variable, obtain the estimated value of present moment.This method need be set up battery model, and the foundation of equation and find the solution all complicatedly, is difficult to practical application.

Use the SOC estimation that is based on the ampere-hour integral method the most widely at present.Publication number is that the one Chinese patent application " assay method of battery charge state " of CN101359036A adopts basic ampere-hour method to add correction function φ (t) to estimate SOC, as shown in the formula:

$\mathrm{SOC}\left(t\right)=\frac{C_0-\underset{0}{\overset{t}{\∫}}i\left(\mathrm{\τ}\right)\mathrm{d\τ}}{C_n}+\mathrm{\φ}\left(t\right)$

Wherein, the mensuration of correction factor φ (t) adopts following method: use formula

Calculate the SOC theoretical value SOC in a plurality of moment _Reason, x representes a moment in a plurality of moment, the SOC actual value SOC that records in these a plurality of moment _Real, adopt least square method to calculate then and be used to express SOC _ReasonAnd SOC _RealDifference and concern correction function φ (t) between used a plurality of moment.

This method relies on electrical quantity measurement arrangement and confirms initial capacity C ₀, accumulator dump energy or electric quantity change amount, i.e. the SOC actual value SOC in described a plurality of moment _RealAcquisition and degree of accuracy all depend on the electrical quantity measurement arrangement that adds;

Publication number is one Chinese patent application " evaluation method of a kind of automobile batteries SOC " the application open-circuit voltage of CN102162836 and the initial capacity that historical results is confirmed battery; With ampere-hour integral method estimation SOC; Consideration influences all kinds of factors of SOC proofreaies and correct SOC, and the compensation correction Consideration comprises:

1, efficiency for charge-discharge according to the Peukert experimental formula, adopts look-up table that the SOC that different electric flows down is revised;

2, temperature is gathered a large amount of experimental datas and is obtained the battery temperature coefficient in advance;

3, the consistance situation of battery is provided with a plurality of points of battery otherness, according to different discrepancys SOC is revised;

4, the self discharge of battery is pre-estimated the self discharge situation of accumulator through a large amount of experimental techniques, proofreaies and correct through the data lookup table method;

5, aging, SOC _Age=(SOC-A _F)/(1-A _F), SOC _AgeBe the SOC value behind the compensation of ageing, A _FBe senescence-factor.

Directly putting SOC numerical value when battery is full of electricity is 100%, and when utilizing the open-circuit voltage method to obtain SOC, if the battery context temperature surpasses battery operated ultimate temperature, this moment, SOC was 0, and cut off charging and discharging circuit with the protection battery.But coefficient is through the acquisition of tabling look-up, can not be with changes such as serviceable life of battery, degree of agings, and along with the coefficient of its acquisition of accumulation of time can not truly reflect battery the present situation, the accuracy meeting is affected; And the acquisition of data need be done a large amount of experiments in the table, and different with kind, the combined method of electric battery, and data all will be done experiment again and draw, and are difficult to realize.

Patented claim " Method for Measuring SOC of a Battery in a BatteryManagement System and the Apparatus Thereof " is used for the method for open-circuit voltage-ampere-hour integration equally and asks SOC; Its open-circuit voltage is tried to achieve through building circuit model, and the shortcoming of this method is that the battery capacity estimation for accuracy depends on the precision of battery model.

To sum up, existing ampere-hour integration modification method perhaps depends on external device (ED), perhaps needs a large amount of experimental data form the basis, complex equipments, and coefficient can not be realized adaptively correcting.

Summary of the invention

The technical matters that (one) will solve

The technical matters that the present invention will solve is: how to improve accumulator SOC prediction accuracy.

(2) technical scheme

For solving the problems of the technologies described above, the invention provides a kind of online feedback formula accumulator SOC Forecasting Methodology, may further comprise the steps:

S1, with the duty of accumulator be divided into be full of leave standstill, put leave standstill, common leaving standstill and four kinds of common operations, and the initialization state of putting accumulator is common operation, said be full of to leave standstill refer to that accumulator reaches the floating charge condition and keeps more than a period of time; Put to leave standstill and referred to that accumulator reaches the discharge lower limit and keeps more than a period of time; Common leaving standstill refers to charging current less than certain value, do not satisfy the floating charge condition and keeps more than a period of time, and perhaps, discharge current is less than certain value, do not satisfy the discharge lower limit and keeps more than a period of time; More than state beyond three kinds of states be common operation;

S2, collection battery tension U, electric current I, temperature T get into step S3 then;

The duty of S3, judgement accumulator leaves standstill if be full of, and then gets into step S4, leaves standstill if put, and then gets into step S5, if common leaving standstill then gets into step S6, if common operation then gets into step S7;

S4, refresh state-of-charge SOC, get into step S8 then;

S5, refresh SOC, get into step S9 then;

S6, common time of repose timing is begun, refresh SOC, judge U and U ₀If whether difference satisfy, then proofreaies and correct self discharge coefficient greater than set-point, gets into step S10 then, and wherein U is the current time magnitude of voltage, U ₀For getting into the common magnitude of voltage constantly that leaves standstill;

S7, refresh SOC, get into step S11 then;

S8, carry out first state exchange and judge, return step S2 then;

S9, carry out second state exchange and judge, return step S2 then;

S10, carry out third state conversion and judge, return step S2 then;

S11, carry out four condition conversion and judge, return step S2 then.

Preferably; The step that refreshes SOC among step S4, S5, S6, the S7 comprises the steps: to judge that whether common time of repose is greater than set-point t5; If satisfy, then with current magnitude of voltage as open-circuit voltage values, refresh battery initial capacity value SOC according to following formula (1) ₀, calculate SOC then, if do not satisfy, directly calculate SOC

SOC ₀＝f(OCV) (1)。

Preferably, among step S4, S5, S6, the S7, calculate SOC according to the SOC appraising model, said SOC appraising model is shown in formula (2):

$\mathrm{SOC}={\mathrm{SOC}}_0-\left[\underset{t1}{\overset{t}{\&Integral;}}{K}_1{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00001619791300011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{Idt}\right]/C_B-\underset{t1}{\overset{t}{\&Integral;}}{k}_{\mathrm{dis}}\mathrm{dt}---\left(2\right)$

Wherein, K ₁Be enclosed pasture efficiency factor, K ₂Be temperature coefficient; K ₁Representative is under standard temperature, with normalized current I _BThe electric weight Q that emits _IBWith the electric weight Q that emits with different discharge current I _IRatio, K ₂Representative is at standard temperature T _BThe capacity Q of following accumulator _TBCapacity Q with accumulator under temperature T _TRatio, k _DisBe self discharge coefficient, C _BBe the rated capacity of accumulator, t1, t represent constantly different.

Preferably, the determination methods of the judgement of first state exchange described in the step S8 is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, judge whether to satisfy electric current simultaneously less than set-point I ₁, voltage is less than set-point U ₁And the retention time is greater than set-point t ₄,, then put common static condition and record magnitude of voltage U this moment if satisfy ₀With moment this moment t ₀

Preferably, the determination methods of the judgement of second state exchange described in the step S9 is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃,, then put common running status if satisfy.

Preferably, the determination methods of the judgement of second state exchange described in the step S10 is following: judge that battery current is less than set-point I ₁And voltage reaches sparking voltage value lower limit and retention time greater than set-point t ₄, if satisfy, then put static condition, timing finishes, and judges that simultaneously whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, timing finishes.

Preferably, the determination methods of the judgement of second state exchange described in the step S11 is following:

121, judge that whether battery current I is less than I ₁And the retention time is greater than t ₂,, then get into step 122 if satisfy;

122, judge whether battery tension reaches the float charge voltage value,, get into step 123, otherwise get into step 124 if satisfy;

123, make SOC=100%, SOC ₀=100%, get into step 125;

124, judge whether battery tension reaches the discharge lower limit,, then get into step 128,, then get into step 129 if do not satisfy if satisfy;

125, judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 126, if do not satisfy, then get into step 127;

126, put and be full of static condition;

127, correction is waited to revise an enclosed pasture efficient related coefficient n, is waited to revise temperature coefficient k _T, get into step 126;

128, make SOC=0%, SOC ₀=0%, get into step 1210;

129, put common static condition, record magnitude of voltage U this moment ₀With moment this moment t ₀

1210, judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 1211, if do not satisfy, then get into step 1212;

1211, put static condition;

1212, correction coefficient n, k _T, get into step 1211.

Preferably, correction coefficient n, k in the step 127 and 1212 _TStep be specially: battery gets into first to be full of and leaves standstill or when having put static condition, be designated as t ₀₀Constantly, correspondingly put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, leave standstill or when having put static condition, be designated as t when getting into once more to be full of ₁₁Constantly, correspondingly put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, then calculate the A value in the formula (7):

$\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{I_i}{I_B}\right)}^{n-1}\&CenterDot;\frac{1}{1+k_T(T_i-20)}\&CenterDot;I_i\&CenterDot;\mathrm{\&Delta;t}=A---\left(7\right)$

A is the determined value of calculating, and wherein gets

Known n ∈ [1.15,1.42], k _T∈ [0.006,0.008] gets minimum value in the n span, substitution formula (7) is obtained k _T, if k _TIn span, then refresh n, k _T, if k _TNot in span, then minimum n value is added fixed step size and take off a n value, substitution formula (7) is obtained k again _T, repeat said process, up to getting suitable k _TOr the n value is got maximal value.

Preferably, in the step of said correction self discharge coefficient by formula (8) refresh k _DisValue:

$k_{\mathrm{dis}}=\frac{f\left(U_0\right)-f\left(U\right)}{t-t_0}---\left(8\right)$

Wherein, U is current magnitude of voltage, and t is the current time, U ₀Magnitude of voltage during for common the leaving standstill of firm entering, t ₀Time during for common the leaving standstill of firm entering.

(3) beneficial effect

Method of the present invention utilizes historical data to carry out the correction of SOC appraising model parameter in accumulator on-line operation process, and this method has been considered the influence to battery SOC of temperature, enclosed pasture efficient, self discharge; Only need the basic operating conditions of monitoring accumulator, just revise related coefficient as long as in the battery operation process, satisfy condition, repeatedly the correction coefficient value; Accumulation along with the time; The estimation result of SOC can be more near true value, so accuracy is high, can realize on-line prediction accumulator SOC.

Description of drawings

Fig. 1 is the method flow diagram of the embodiment of the invention;

Fig. 2 is for calculating the SOC process flow diagram;

Fig. 3 judges 1 process flow diagram for state exchange;

Fig. 4 judges 2 process flow diagrams for state exchange;

Fig. 5 judges 3 process flow diagrams for state exchange;

Fig. 6 judges 4 process flow diagrams for state exchange;

Fig. 7 is the correction coefficient process flow diagram.

Embodiment

Below in conjunction with accompanying drawing and embodiment, specific embodiments of the invention is done further explain.Following examples are used to explain the present invention, but are not used for limiting scope of the present invention.

The present invention utilizes historical data to carry out the correction of SOC appraising model parameter; In the accumulator on-line operation process; The electric current of all cells of timing acquiring (I), voltage (U), temperature data such as (T) and storage; And with the accumulator operational process be divided into be full of leave standstill, put leave standstill, common leaving standstill and four kinds of duties of common operation, be full of to leave standstill and refer to that accumulator reaches the floating charge condition and keeps more than a period of time; Put to leave standstill and referred to that accumulator reaches the discharge lower limit and keeps more than a period of time; Common leaving standstill refers to charging current less than certain value, do not satisfy the floating charge condition and keeps more than a period of time, and perhaps, discharge current is less than certain value, do not satisfy the discharge lower limit and keeps more than a period of time.In the present embodiment, be full of to leave standstill and refer to that battery reaches and be full of (SOC=100% this moment) and remain full of a period of time, put to leave standstill and refer to that battery reaches and put (SOC=0% this moment) and maintenance has been put a period of time, during common leaving standstill, 0%＜SOC＜100%.System's beginning that powers on, putting original state is common operation, initialization SOC, after this substitution SOC appraising model parameter initial value changes circular flow over to.In the circular flow process,, realize the conversion of battery management system duty through analyzing operating condition and data variation.Wherein,

Under common running status, refresh the SOC value according to the SOC appraising model, be full of the condition of leaving standstill if satisfy, then put SOC=SOC ₀=100%, SOC ₀Be the initial capacity value of accumulator, SOC is the current capability value of accumulator, and puts duty and leave standstill for being full of; Put the condition of leaving standstill if satisfy, then put SOC=SOC ₀=0%, and put duty and leave standstill for having put; If satisfy the common condition that leaves standstill, then putting duty is common leaving standstill.

Be full of under the static condition, refreshing the SOC value; Putting under the static condition, refreshing the SOC value; Under common static condition, register system is in the common time of leaving standstill, and refreshes the SOC value, when satisfying the condition of proofreading and correct the self discharge coefficient, proofreaies and correct the self discharge coefficient.

The process that refreshes SOC comprises, judges the common time of leaving standstill of accumulator, if greater than preset time, then measures the magnitude of voltage of accumulator this moment, as open-circuit voltage OCV (Open CircuitVoltage), according to the given SOC of system ₀Obtain SOC with the corresponding relation function f of OCV ₀, refresh initial capacity SOC ₀, calculate SOC according to the SOC appraising model then;

Satisfy to be full of in system and leave standstill conditioned disjunction and put when leaving standstill condition, satisfy certain condition and just revise enclosed pasture efficiency factor and temperature coefficient in the ampere-hour integration.

Referring to Fig. 1, the method for the embodiment of the invention comprises the steps:

1) beginning

2) initialization SOC is enclosed pasture efficient related coefficient, temperature coefficient, self discharge coefficient initialize, and the initial launch state of putting accumulator is common operation;

3) gather battery tension U, electric current I, temperature T, get into step 4;

4) duty of judgement accumulator leaves standstill if be full of, and then gets into step 5, leaves standstill if put, and then gets into step 6, if common leaving standstill then gets into step 7, if common operation then gets into step 8;

5) refresh SOC, get into step 9;

6) refresh SOC, get into step 10;

7) get into common time of repose timing and begin, refresh SOC, judge U and U ₀(U is magnitude of voltage this moment, U to difference greater than set-point ₀For just getting into the common magnitude of voltage constantly that leaves standstill), if satisfy, then proofread and correct the self discharge coefficient.Get into step 11;

8) refresh SOC, get into step 12;

9) state exchange judges 1, returns step 3;

10) state exchange judges 2, returns step 3;

11) state exchange judges 3, returns step 3;

12) state exchange judges 4, returns step 3;

Further, refresh SOC in the step 5,6,7,8 and comprise following process, shown in accompanying drawing 2: whether judge common time of repose greater than set-point t5, if satisfy, then with the cell voltage of this moment as open-circuit voltage values, according to formula (1)

SOC ₀＝f(OCV) (1)

Refresh initial capacity SOC ₀, press the SOC appraising model then and calculate SOC, if do not satisfy, directly press the SOC appraising model and calculate SOC; F (OCV) expression is the function of parameter with OCV.

Further, said formula (1) is obtained by experiment, under standard temperature, discharges with normalized current; Write down some open-circuit voltage values, calculate corresponding some SOC values with the ampere-hour integral method, application of mathematical method is obtained the relation function f of SOC and OCV again; For example, can adopt least square method.The funtcional relationship that obtains is deposited in the database of system, in the estimation process, obtain SOC according to detected open-circuit voltage values OCV by system ₀

Further, said SOC appraising model is shown in formula (2):

$\mathrm{SOC}={\mathrm{SOC}}_0-\left[\underset{t1}{\overset{t}{\&Integral;}}{K}_1{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA00001619791300011.png"\; state="\{\{state\}\}">K</figure-callout>}}_2\mathrm{Idt}\right]/C_B-\underset{t1}{\overset{t}{\&Integral;}}{k}_{\mathrm{dis}}\mathrm{dt}---\left(2\right)$

K wherein ₁Be enclosed pasture efficiency factor, K ₂Be temperature coefficient; K ₁Representative is under standard temperature, with normalized current I _BThe electric weight Q that emits _IBWith the electric weight Q that emits with different discharge current I _IRatio, K ₂Representative is at standard temperature T _BThe capacity Q of following accumulator _TBCapacity Q with accumulator under temperature T _TRatio, k _DisBe self discharge coefficient, C _BBe the rated capacity of accumulator, t1, t represent constantly different, I _BKind, manufacturer according to battery decide.Further;

is according to Peukert equation well-known to those skilled in the art, shown in (3):

I ⁿ·t＝K (3)

Be out of shape I ^N-1It=K, i.e. I ^N-1Q=K, Q is an accumulator capacity, then has

N is for waiting to revise enclosed pasture efficient related coefficient;

Experimental formula (4) according to known application temperature correction the most widely:

Q _T＝Q _TB·[1+k _T·(T-T _B)] (4)

Then have

Wherein TB is a standard temperature, for example gets 20 ℃, k _TBe temperature coefficient to be revised; Put in order formula (5):

$\mathrm{SOC}={\mathrm{SOC}}_0-[\underset{t1}{\overset{t}{\&Integral;}}{\left(\frac{I}{I_B}\right)}^{n-1}\&CenterDot;\frac{1}{1+k_T\&CenterDot;(T-20)}\&CenterDot;I\&CenterDot;\mathrm{dt}]/C_B-\underset{t1}{\overset{t}{\&Integral;}}{k}_{\mathrm{dis}}\mathrm{dt}---\left(5\right)$

If the Δ t of per interval of system refreshes U, I, T, then formula (5) can be expressed as formula (6):

$\mathrm{SOC}={\mathrm{SOC}}_0-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{I_i}{I_B}\right)}^{n-1}\&CenterDot;\frac{1}{1+k_T\&CenterDot;(T_i-20)}\&CenterDot;I_i\&CenterDot;\mathrm{\&Delta;t}/C_B-{\mathrm{\&Sigma;k}}_{\mathrm{dis}}\&CenterDot;\mathrm{\&Delta;t}---\left(6\right)$

Wherein

I _i, T _iBe electric current, the temperature that at every turn newly collects.

Further, state exchange described in the step 9 judges 1, and referring to shown in Figure 3, determination methods is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, judge whether to satisfy electric current simultaneously less than set-point I ₁, voltage is less than set-point U ₁And the retention time is greater than set-point t ₄,, then put common static condition and record magnitude of voltage U this moment if satisfy ₀With moment this moment t ₀

Further, state exchange described in the step 10 judges 2, and referring to shown in Figure 4, determination methods is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃,, then put common running status if satisfy;

Further, state exchange described in the step 11 judges 3, and referring to shown in Figure 5, determination methods is following: judge that battery current is less than set-point I ₁And voltage reaches sparking voltage value lower limit and retention time greater than set-point t ₄, if satisfy, then put static condition, timing finishes, and judges that simultaneously whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, timing finishes;

Further, state exchange described in the step 12 judges 4, and referring to shown in Figure 6, determination methods is following:

121) judge that whether battery current I is less than I ₁And the retention time is greater than t ₂,, then get into step 122 if satisfy;

122) judge whether battery tension reaches the float charge voltage value,, get into step 123, otherwise get into step 124 if satisfy;

123) make SOC=100%, SOC ₀=100%, get into step 125;

124) judge whether battery tension reaches the discharge lower limit,, then get into step 128,, then get into step 129 if do not satisfy if satisfy;

125) judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 126, if do not satisfy, then get into step 127;

126) put and be full of static condition;

127) correction coefficient n, k _T, get into step 126;

128) make SOC=0%, SOC ₀=0%, get into step 1210;

129) put common static condition, record magnitude of voltage U this moment ₀With moment this moment t ₀

1210) judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 1211, if do not satisfy, then get into step 1212;

1211) put static condition;

1212) correction coefficient n, k _T, get into step 1211;

Further, correction coefficient n, k described in the step 127 and 1212 _T, referring to shown in Figure 7, comprise following process: system gets into first to be full of and leaves standstill or when having put static condition, be designated as t ₀₀Constantly, put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, leave standstill or when having put static condition, be designated as t when system gets into to be full of once more ₁₁Constantly, put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, then can calculate the A value in the formula (7):

$\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{I_i}{I_B}\right)}^{n-1}\&CenterDot;\frac{1}{1+k_T(T_i-20)}\&CenterDot;I_i\&CenterDot;\mathrm{\&Delta;t}=A---\left(7\right)$

A is the determined value of calculating, and wherein gets

Known n ∈ [1.15,1.42], k _T∈ [0.006,0.008] gets minimum value in the n span, substitution formula (7) is obtained k _T, if k _TIn span, then refresh n, k _T, if k _TNot in span, then minimum n value is added fixed step size and take off a n value, fixed step size can set up on their own, and substitution formula (7) is obtained k again _T, repeat said process, up to get the kT that satisfies span or, the n value is got maximal value.

Further, in the step of said correction self discharge coefficient by formula (8) refresh k _DisValue:

$k_{\mathrm{dis}}=\frac{f\left(U_0\right)-f\left(U\right)}{t-t_0}---\left(8\right)$

Wherein, the function of open-circuit voltage and SOC corresponding relation in the f () representation formula (1), U is current magnitude of voltage, t is the current time, U ₀Magnitude of voltage during for common the leaving standstill of firm entering, t ₀Time during for common the leaving standstill of firm entering.

The above only is a preferred implementation of the present invention; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from know-why of the present invention; Can also make some improvement and modification, these improve and modification also should be regarded as protection scope of the present invention.

Claims (9)

1. an online feedback formula accumulator SOC Forecasting Methodology is characterized in that, may further comprise the steps:

S1, with the duty of accumulator be divided into be full of leave standstill, put leave standstill, common leaving standstill and four kinds of common operations, and the initialization state of putting accumulator is common operation, said be full of to leave standstill refer to that accumulator reaches the floating charge condition and keeps more than a period of time; Put to leave standstill and referred to that accumulator reaches the discharge lower limit and keeps more than a period of time; Common leaving standstill refers to charging current less than certain value, do not satisfy the floating charge condition and keeps more than a period of time, and perhaps, discharge current is less than certain value, do not satisfy the discharge lower limit and keeps more than a period of time; More than state beyond three kinds of states be common operation;

S2, collection battery tension U, electric current I, temperature T get into step S3 then;

The duty of S3, judgement accumulator leaves standstill if be full of, and then gets into step S4, leaves standstill if put, and then gets into step S5, if common leaving standstill then gets into step S6, if common operation then gets into step S7;

S4, refresh state-of-charge SOC, get into step S8 then;

S5, refresh SOC, get into step S9 then;

S6, common time of repose timing is begun, refresh SOC, judge U and U ₀If whether difference satisfy, then proofreaies and correct self discharge coefficient greater than set-point, gets into step S10 then, and wherein U is the current time magnitude of voltage, U ₀For getting into the common magnitude of voltage constantly that leaves standstill;

S7, refresh SOC, get into step S11 then;

S8, carry out first state exchange and judge, return step S2 then;

S9, carry out second state exchange and judge, return step S2 then;

S10, carry out third state conversion and judge, return step S2 then;

S11, carry out four condition conversion and judge, return step S2 then.

2. the method for claim 1; It is characterized in that; The step that refreshes SOC among step S4, S5, S6, the S7 comprises the steps: to judge that whether common time of repose is greater than set-point t5; If satisfy, then with current magnitude of voltage as open-circuit voltage values, refresh battery initial capacity value SOC according to following formula (1) ₀, calculate SOC then, if do not satisfy, directly calculate SOC

SOC ₀＝f(OCV) (1)。

3. method as claimed in claim 2 is characterized in that, among step S4, S5, S6, the S7, calculates SOC according to the SOC appraising model, and said SOC appraising model is shown in formula (2):

Wherein, K ₁Be enclosed pasture efficiency factor, K ₂Be temperature coefficient; K ₁Representative is under standard temperature, with normalized current I _BThe electric weight Q that emits _IBWith the electric weight Q that emits with different discharge current I _IRatio, K ₂Representative is at standard temperature T _BThe capacity Q of following accumulator _TBCapacity Q with accumulator under temperature T _TRatio, k _DisBe self discharge coefficient, C _BBe the rated capacity of accumulator, t1, t represent constantly different.

4. the method for claim 1 is characterized in that, the determination methods that first state exchange described in the step S8 is judged is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, judge whether to satisfy electric current simultaneously less than set-point I ₁, voltage is less than set-point U ₁And the retention time is greater than set-point t ₄,, then put common static condition and record magnitude of voltage U this moment if satisfy ₀With moment this moment t ₀

5. the method for claim 1 is characterized in that, the determination methods that second state exchange described in the step S9 is judged is following: judge that whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃,, then put common running status if satisfy.

6. the method for claim 1 is characterized in that, the determination methods that second state exchange described in the step S10 is judged is following: judge that battery current is less than set-point I ₁And voltage reaches sparking voltage value lower limit and retention time greater than set-point t ₄, if satisfy, then put static condition, timing finishes, and judges that simultaneously whether battery current is greater than set-point I ₂And the retention time is greater than set-point t ₃, if satisfy, then put common running status, timing finishes.

7. method as claimed in claim 2 is characterized in that, the determination methods that second state exchange described in the step S11 is judged is following:

121, judge that whether battery current I is less than I ₁And the retention time is greater than t ₂,, then get into step 122 if satisfy;

122, judge whether battery tension reaches the float charge voltage value,, get into step 123, otherwise get into step 124 if satisfy;

123, make SOC=100%, SOC ₀=100%, get into step 125;

124, judge whether battery tension reaches the discharge lower limit,, then get into step 128,, then get into step 129 if do not satisfy if satisfy;

125, judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 126, if do not satisfy, then get into step 127;

126, put and be full of static condition;

127, correction is waited to revise an enclosed pasture efficient related coefficient n, is waited to revise temperature coefficient k _T, get into step 126;

128, make SOC=0%, SOC ₀=0%, get into step 1210;

129, put common static condition, record magnitude of voltage U this moment ₀With moment this moment t ₀

1210, judge whether to satisfy I less than I for the first time ₁And the retention time is greater than t ₂, if satisfy, then get into step 1211, if do not satisfy, then get into step 1212;

1211, put static condition;

1212, correction coefficient n, k _T, get into step 1211.

8. method as claimed in claim 7 is characterized in that, correction coefficient n, k in the step 127 and 1212 _TStep be specially: battery gets into first to be full of and leaves standstill or when having put static condition, be designated as t ₀₀Constantly, correspondingly put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, leave standstill or when having put static condition, be designated as t when getting into once more to be full of ₁₁Constantly, correspondingly put SOC=SOC ₀=100% or put SOC=SOC ₀=0%, then calculate the A value in the formula (7):

A is the determined value of calculating, and wherein gets

Known n ∈ [1.15,1.42], k _T∈ [0.006,0.008] gets minimum value in the n span, substitution formula (7) is obtained k _T, if k _TIn span, then refresh n, k _T, if k _TNot in span, then minimum n value is added fixed step size and take off a n value, substitution formula (7) is obtained k again _T, repeat said process, up to getting the k that satisfies span _TOr the n value is got maximal value.

9. method as claimed in claim 3 is characterized in that, in the step of said correction self discharge coefficient by formula (8) refresh k _DisValue:

Wherein, U is current magnitude of voltage, and t is the current time, U ₀Magnitude of voltage when getting into common leaving standstill, t ₀Zero-time when getting into common leaving standstill.

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