CN104833921A - Battery pack charge state calculating method and calculating device - Google Patents

Abstract

The invention provides a battery pack charge state calculating method. The battery pack charge state calculating method comprises the following steps: a current charge state and current test temperature of a battery unit of a battery pack can be acquired; current AC impedance and current compensation voltage can be acquired according to the current charge state, the current test temperature, a predetermined AC impedance relation table, and a predetermined compensation voltage relation table; the estimation voltage of the battery unit can be calculated according to the current charge state, the current AC impedance, and the current compensation voltage; the voltage difference between the estimation voltage and the test voltage; a corrected formula, which can be satisfied by the current charge state, the current AC impedance, and the current compensation voltage, can be acquired according to the voltage difference, and the corrected value can be acquired according to the corrected formula; and the charge state of the battery pack can be acquired according to the current charge state after the correction of the battery unit. The battery pack charge state calculating method is advantageous in that the accumulated errors can be reduced, and the calculating precision of the battery charge state can be improved. The invention also provides a battery pack charge state calculating device.

Description

The computing method of power brick state-of-charge and calculation element

Technical field

The present invention relates to technical field of vehicle, particularly a kind of computing method of power brick state-of-charge and calculation element.

Background technology

Lithium battery is power supply device conventional in electric vehicle, improve the state-of-charge (SOC of lithium battery, State ofCharge) estimation precision be a study hotspot of field of batteries, the precision of the SOC of lithium battery is for the control algolithm of motor vehicle driven by mixed power and the security of pure electric vehicle and economy important in inhibiting.The SOC estimation method of the lithium battery that current electric vehicle uses mainly comprises discharge test method, internal resistance method, open-circuit voltage method, load method, Ah counting method, neural network and Kalman filter method, wherein, Ah counting method estimates SOC by the integration of load current, is the evaluation method using maximum SOC in current electric vehicle.

But, Ah counting method is a kind of method of open-loop prediction, although the accurate estimation of electricity can be realized at short notice, but along with the increase of cumulative errors, estimation precision can become worse and worse, along with the change of the factors such as the increase of battery tenure of use, the change of environment for use, can there is corresponding change in battery parameter.Therefore, cause battery SOC estimation for the constant in the calculating formula of SOC estimation and the indefinite quantification of error inaccurate.

Summary of the invention

The present invention is intended to solve one of above-mentioned technical matters at least to a certain extent.For this reason, the present invention needs the computing method proposing a kind of power brick state-of-charge, and these computing method can reduce cumulative errors compared with ampere-hour computing method, improves the computational accuracy of battery charge state.

The present invention also proposes a kind of calculation element of power brick state-of-charge.

For solving the problem, one aspect of the present invention embodiment proposes a kind of computing method of power brick state-of-charge, and these computing method comprise: obtain the current state-of-charge of battery unit in power brick and current probe temperature; Current AC impedance and current bucking voltage is obtained according to described current state-of-charge and described current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table; The estimation voltage of described battery unit is calculated according to described current state-of-charge, described current AC impedance and described current bucking voltage; Calculate the voltage difference between the estimation voltage of described battery unit and test voltage; Obtain the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, and obtain the modified value of described current state-of-charge, described current AC impedance and described current bucking voltage according to described correction formula; According to described modified value, described current state-of-charge, described current AC impedance and described current bucking voltage are revised; And the state-of-charge of described power brick is obtained according to the described current state-of-charge after described battery unit correction.

According to the computing method of the power brick state-of-charge of the embodiment of the present invention, reasonably revised calculating the current state-of-charge obtained by the correction formula released, cumulative errors can be reduced compared with ampere-hour integration method, improve computational accuracy, in addition, compared with Kelman filtering method, calculated amount is little, more convenient.

In some embodiments of the invention, obtain the current state-of-charge of battery unit in power brick and current probe temperature, specifically comprise: the electric current and the probe temperature that obtained a upper moment, calculate described current state-of-charge according to default open-circuit voltage relation table and ampere-hour method; And detect described current probe temperature.

In some embodiments of the invention, the described estimation voltage calculating described battery unit according to described current state-of-charge, described current AC impedance and described current bucking voltage, specifically comprise: according to described current state-of-charge, current probe temperature and described default open-circuit voltage relation table, by interpolation calculation current open circuit voltage; And the estimation voltage of described battery unit is calculated according to described current open circuit voltage, described current AC impedance and described current bucking voltage, wherein, described estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

In some embodiments of the invention, obtain the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, wherein, described correction formula is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU},$ Wherein, $A=[\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{\∂U_{\mathrm{off}}}],$

Wherein, be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential, Δ SOC be calculate described current state-of-charge and actual state-of-charge between difference, Δ R be calculate described current AC impedance and practical impedance between difference, Δ U _offfor calculate bucking voltage and actual bucking voltage between difference, Δ U be calculate described voltage difference.

In addition, in some embodiments of the invention, above-mentioned computing method also comprise: the health status calculating described battery unit according to the impedance of the described current AC impedance after described battery unit correction and described current bucking voltage and described battery unit end of life and bucking voltage; And the health status of described power brick is calculated according to the Data distribution8 of the health status of described battery unit.

The computing method of the embodiment of the present invention calculate the battery unit in power brick and minimum series unit, can the health status of battery unit in Real-Time Monitoring power brick, Rational Maintenance can be carried out to power brick according to the health status of battery unit, facilitate the management of power brick, and then improve the performance of whole-control system.

For solving the problem, another aspect of the present invention embodiment proposes a kind of calculation element of power brick state-of-charge, this calculation element comprises: acquisition module, for obtaining the current state-of-charge of battery unit in power brick and current probe temperature, and obtain current AC impedance and current bucking voltage according to described current state-of-charge and described current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table, correcting module, described correcting module is according to described current state-of-charge, described current AC impedance and described current bucking voltage calculate the estimation voltage of described battery unit, and the voltage difference calculated between the estimation voltage of described battery unit and test voltage, and obtain described current state-of-charge according to described voltage difference, the correction formula that described current AC impedance and described current bucking voltage meet, and obtain described current state-of-charge according to described correction formula, the modified value of described current AC impedance and described current bucking voltage, according to described modified value to described current state-of-charge, described current AC impedance and described current bucking voltage are revised, state-of-charge computing module, for obtaining the state-of-charge of described power brick according to the described current state-of-charge after described battery unit correction.

According to the calculation element of the power brick state-of-charge of the embodiment of the present invention, there is self-recision function, reasonably revised calculating the current state-of-charge obtained according to correction formula by correcting module, and then the state-of-charge of power brick is obtained according to the state-of-charge after battery unit correction, can cumulative errors be reduced compared with ampere-hour integration method, improve computational accuracy, in addition, compared with Kelman filtering method, the calculated amount of this calculation element is little, more convenient.

In some embodiments of the invention, described acquisition module, also for obtaining electric current and the probe temperature in a upper moment, calculating described current state-of-charge according to default open-circuit voltage relation table and ampere-hour method, and detecting described current probe temperature.

In some embodiments of the invention, described correcting module is also for according to described current state-of-charge, current probe temperature and described default open-circuit voltage relation table, by interpolation calculation current open circuit voltage, and the estimation voltage of described battery unit is calculated according to described current open circuit voltage, described current AC impedance and described current bucking voltage, wherein, described estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

Further, in some embodiments of the invention, described correcting module obtains the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, and wherein, described correction formula is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU},$ Wherein, $A=[\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{\∂U_{\mathrm{off}}}],$

Wherein, be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential, Δ SOC be calculate described current state-of-charge and actual state-of-charge between difference, Δ R be calculate described current AC impedance and practical impedance between difference, Δ U _offfor calculate bucking voltage and actual bucking voltage between difference, Δ U be calculate described voltage difference.

In addition, in some embodiments of the invention, described calculation element also comprises: health status computing module, for calculating the health status of described battery unit according to the impedance of the described current AC impedance after described battery unit correction and described current bucking voltage and described battery unit end of life and bucking voltage, and calculate the health status of described power brick according to the Data distribution8 of the health status of described battery unit.

The calculation element of the embodiment of the present invention calculates the battery unit in power brick and minimum series unit, can the health status of battery unit in Real-Time Monitoring power brick, the health status of battery unit is calculated by healthy computing module, and then Rational Maintenance can be carried out according to the health status of battery unit to power brick, facilitate the management of power brick, and then improve the performance of whole-control system.

The aspect that the present invention adds and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.

Accompanying drawing explanation

The present invention above-mentioned and/or additional aspect and advantage will become obvious and easy understand from the following description of the accompanying drawings of embodiments, wherein:

Fig. 1 is the process flow diagram of the computing method of power brick state-of-charge according to an embodiment of the invention;

Fig. 2 is the schematic diagram of the computing method middle impedance deviation of power brick state-of-charge according to a specific embodiment of the present invention;

Fig. 3 is the process flow diagram of the computing method of power brick state-of-charge according to another embodiment of the invention;

Fig. 4 is the block diagram of the calculation element of power brick state-of-charge according to an embodiment of the invention; And

Fig. 5 is the block diagram of the calculation element of power brick state-of-charge according to another embodiment of the invention.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Being exemplary below by the embodiment be described with reference to the drawings, only for explaining the present invention, and can not limitation of the present invention being interpreted as.

Disclosing hereafter provides many different embodiments or example is used for realizing different structure of the present invention.Of the present invention open in order to simplify, hereinafter the parts of specific examples and setting are described.Certainly, they are only example, and object does not lie in restriction the present invention.In addition, the present invention can in different example repeat reference numerals and/or letter.This repetition is to simplify and clearly object, itself does not indicate the relation between discussed various embodiment and/or setting.In addition, the various specific technique that the invention provides and the example of material, but those of ordinary skill in the art can recognize the property of can be applicable to of other techniques and/or the use of other materials.In addition, fisrt feature described below second feature it " on " structure can comprise the embodiment that the first and second features are formed as directly contact, also can comprise other feature and be formed in embodiment between the first and second features, such first and second features may not be direct contacts.

In describing the invention, it should be noted that, unless otherwise prescribed and limit, term " installation ", " being connected ", " connection " should be interpreted broadly, such as, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be directly be connected, also indirectly can be connected by intermediary, for the ordinary skill in the art, the concrete meaning of above-mentioned term can be understood as the case may be.

With reference to description below and accompanying drawing, these and other aspects of embodiments of the invention will be known.Describe at these and in accompanying drawing, specifically disclose some particular implementation in embodiments of the invention, representing some modes of the principle implementing embodiments of the invention, but should be appreciated that the scope of embodiments of the invention is not limited.On the contrary, embodiments of the invention comprise fall into attached claims spirit and intension within the scope of all changes, amendment and equivalent.

Computing method and the calculation element of the battery charge state proposed according to the embodiment of the present invention are described with reference to the accompanying drawings.

First the computing method of the power brick state-of-charge of the embodiment of the present invention are described.Fig. 1 is the process flow diagram of the computing method of power brick state-of-charge according to the embodiment of the present invention, and as shown in Figure 1, the computing method of the power brick state-of-charge of the embodiment of the present invention comprise the following steps;

S1, obtains the current state-of-charge of battery unit in power brick and current probe temperature.

Wherein, in power brick, battery unit can refer to minimum series unit battery in power brick.

Particularly, obtained electric current and the probe temperature in a upper moment, and calculated current state-of-charge according to default open-circuit voltage relation table and ampere-hour method, and detect current probe temperature.Such as, can by the measuring current of previous moment t and probe temperature as input, utilize open-circuit voltage and ampere-hour integral method to coordinate the current state-of-charge calculating current time t+1, current state-of-charge can be designated as SOC ₁.It should be noted that, default open-circuit voltage relation table can be obtained in early stage by carrying out performance test to battery unit.Such as, under different temperatures T, the different state-of-charge SOC and open-circuit voltage U of battery unit in test battery bag _ocvrelation, obtain default open-circuit voltage relation table U _ocv=f (SOC, T).

S2, obtains current AC impedance and current bucking voltage according to current state-of-charge and current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table.

Wherein, default AC impedance relation table and predesigned compensation voltage relationship table can be obtained by carrying out performance test to battery unit.Particularly, HPPC (Hybrid Pulse Power Characteristic, mixed pulses power test) can be carried out to battery unit in power brick, and calculate the AC impedance R of battery under different state-of-charge SOC and different temperatures T and bucking voltage U _off, thus obtain default AC impedance relation table R=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T).

Thus, according to current state-of-charge SOC ₁with current probe temperature T ₁and relation table R=f (SOC, T) and U _off=f (SOC, T), utilizes the current AC impedance of interpolation calculation and current bucking voltage, can be designated as R respectively ₁and U _{off_1}.

In addition, it should be noted that, bucking voltage is caused by the polarization of battery and electrochemical reaction.

S3, calculates the estimation voltage of described battery unit according to current state-of-charge, current AC impedance and current bucking voltage.

Particularly, according to current state-of-charge SOC ₁with current probe temperature T ₁and relation table U _ocv=f (SOC, T), utilizes interpolation calculation current open circuit voltage, can be designated as U _{oCV_1}, and then the estimation voltage of battery unit is calculated according to current open circuit voltage, current AC impedance and current bucking voltage, wherein, estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}(1)

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

S4, calculates the voltage difference between the estimation voltage of battery unit and test voltage.

Such as, test voltage is labeled as U _test, by the estimated voltage U of battery unit _{est_1}compare the difference Δ U obtaining estimation voltage and test voltage:

ΔU＝U _{est_1}-U _test(2)

Be illustrated in figure 2 the schematic diagram of the impedance deviation according to a specific embodiment of the present invention, wherein, solid line is estimation voltage, and dotted line is test voltage.

S5, obtains the satisfied correction formula of current state-of-charge, current AC impedance and current bucking voltage according to voltage difference, and obtains the modified value of current state-of-charge, current AC impedance and current bucking voltage according to correction formula.

Suppose that the difference between current state-of-charge and the state-of-charge of reality is Δ SOC, the difference between current AC impedance and actual AC impedance is Δ R, and the difference between current bucking voltage and actual bucking voltage is Δ U _off, then have following formula to set up according to formula (1) and (2):

$(\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{\∂U_{\mathrm{off}}})\×{(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\mathrm{\ΔU}---\left(3\right)$

Wherein: be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential.

Further, can be by be labeled as A, be described below in detail the computation process of A.

First, at current state-of-charge SOC ₁near get two point (SOC ₁+ δ SOC) and (SOC ₁-δ SOC), according to default open-circuit voltage relation table U _ocv=f (SOC, T) can calculate these 2 corresponding open-circuit voltage U1 and U2 respectively, and wherein, δ SOC is a less value, suggestion get (0 0.01] in some values, then thus, can obtain value.

Then, calculate value.Due to, I × Δ R=Δ U, therefore

Finally, calculate value.Due to Δ U _off=Δ U; Therefore,

Thus, in acquisition with value after, obtain current state-of-charge, current AC impedance and current bucking voltage meet correction formula, i.e. Δ SOC, Δ R and Δ U _offthe correction formula met is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU}---\left(4\right)$

Wherein, above formula (4) can be derived by formula (3).

And then modified value and Δ SOC, Δ R and the Δ U of current state-of-charge, current AC impedance and current bucking voltage can be obtained according to formula (4) _off.

S6, revises current state-of-charge, current AC impedance and current bucking voltage according to modified value.

Obtain Δ SOC, Δ R and Δ U _off, afterwards, according to Δ SOC, Δ R and Δ U _offcan revise current state-of-charge, current AC impedance and current bucking voltage respectively, concrete formula is as follows:

$\left\{\begin{array}{c}{\mathrm{SOC}}_{\mathrm{est}}={\mathrm{SOC}}_1+\mathrm{\ΔSOC}\\ R_{\mathrm{est}}=R_1+\mathrm{\ΔR}\\ U_{\mathrm{off}\_\mathrm{est}}=U_{\mathrm{off}\_1}+\mathrm{\Δ}{U}_{\mathrm{off}}\end{array}\right.$ Wherein, R _est, U _{off_est}and SOC _estcurrent AC impedance after being respectively correction, current bucking voltage and current state-of-charge.

S7, obtains the state-of-charge of power brick according to the current state-of-charge after battery unit correction.

Such as, can the mean value of current state-of-charge after the correction of power taking pool unit as the state-of-charge of power brick.

In addition, in an embodiment of the present invention, on the basis calculating power brick state-of-charge, health status SOH (the State of Health of power brick can also be calculated further, health status), to facilitate, power brick reasonably safeguarded, manage, and then improve the performance of whole-control system, below the health status calculating power brick is described.

Particularly, as shown in Figure 3, above-mentioned computing method comprise further:

S8, calculates the health status of battery unit according to the impedance of the current AC impedance after battery unit correction and current bucking voltage and battery unit end of life and bucking voltage.

Wherein, the impedance of battery unit end of life and bucking voltage, such as, be labeled as R _endand U _{off_end}, this value is generally consulted to determine by battery supplier and application vendor.Particularly, the health status of following formulae discovery battery unit can be utilized:

$\mathrm{SOH}=\min (1-\frac{R_{\mathrm{est}}}{R_{\mathrm{end}}},1-\frac{U_{\mathrm{off}\_\mathrm{est}}}{U_{\mathrm{off}\_\mathrm{end}}}).$

S9, calculates the health status of power brick according to the Data distribution8 of the health status of battery unit.

Particularly, the Data distribution8 of the health status of battery unit is analyzed, according to the Data distribution8 of the health status of battery unit, carries out the health status of statistical computation power brick, and the health status of the highest and minimum battery unit is identified, facilitate the maintenance of power brick.

In sum, according to the computing method of the power brick state-of-charge of the embodiment of the present invention, reasonably revised calculating the current state-of-charge obtained by the correction formula released, cumulative errors can be reduced compared with ampere-hour integration method, improve computational accuracy, in addition, compared with Kelman filtering method, calculated amount is little, more convenient.In addition, the computing method of the embodiment of the present invention calculate the battery unit in power brick and minimum series unit, can the health status of battery unit in Real-Time Monitoring power brick, Rational Maintenance can be carried out to power brick according to the health status of battery unit, facilitate the management of power brick, and then improve the performance of whole-control system.

The calculation element describing the power brick state-of-charge of embodiment according to a further aspect in the invention is with reference to the accompanying drawings described.

Fig. 4 is the block diagram of the calculation element of power brick state-of-charge according to an embodiment of the invention.As shown in Figure 4, the calculation element 100 of the power brick state-of-charge of the embodiment of the present invention comprises acquisition module 10, correcting module 20 and state-of-charge computing module 30.

Acquisition module 10 for obtaining the current state-of-charge of battery unit in power brick and current probe temperature, and obtains current AC impedance and current bucking voltage according to current state-of-charge and current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table.Wherein, in power brick, battery unit can refer to minimum series unit battery in power brick.

Particularly, acquisition module 10 obtained electric current and the probe temperature in a upper moment, calculates current state-of-charge, and detect current probe temperature according to default open-circuit voltage relation table and ampere-hour method.Such as, can by the measuring current of previous moment t and probe temperature as input, acquisition module 10 utilizes open-circuit voltage and ampere-hour integral method to coordinate the current state-of-charge calculating current time t+1, and current state-of-charge can be designated as SOC ₁.It should be noted that, in early stage by carrying out performance test to battery unit, default open-circuit voltage relation table can be obtained, such as, under different temperatures T, the different state-of-charge SOC and open-circuit voltage U of battery unit in test battery bag _ocvrelation, obtain default open-circuit voltage relation table U _ocv=f (SOC, T).

By carrying out performance test to battery unit, default AC impedance relation table and predesigned compensation voltage relationship table also can be obtained.Particularly, HPPC (Hybrid Pulse Power Characteristic, mixed pulses power test) can be carried out to battery unit in power brick, and calculate the AC impedance R of battery under different state-of-charge SOC and different temperatures T and bucking voltage U _off, thus obtain default AC impedance relation table R=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T).

Thus, according to current state-of-charge SOC ₁with current probe temperature T ₁and relation table R=f (SOC, T) and U _off=f (SOC, T), utilizes the current AC impedance of interpolation calculation and current bucking voltage, can be designated as R respectively ₁and U _{off_1}.In addition, it should be noted that, bucking voltage is caused by the polarization of battery and electrochemical reaction.

And then correcting module 20 calculates the estimation voltage of battery unit according to current state-of-charge, current AC impedance and current bucking voltage.Particularly, correcting module 20 is according to current state-of-charge SOC ₁with current probe temperature T ₁and relation table U _ocv=f (SOC, T), utilizes interpolation calculation current open circuit voltage, can be designated as U _{ocv_1}, and then the estimation voltage of battery unit is calculated according to current open circuit voltage, current AC impedance and current bucking voltage, wherein, estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}(1)

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

Correcting module 20 calculates the voltage difference between the estimation voltage of battery unit and test voltage, and such as, test voltage is labeled as U _test, by the estimated voltage U of battery unit _{est_1}compare the difference Δ U obtaining estimation voltage and test voltage:

ΔU＝U _{est_1}-U _test(2)，

Be illustrated in figure 2 the schematic diagram of the impedance deviation according to a specific embodiment of the present invention, wherein, solid line is estimation voltage, and dotted line is test voltage.

Further, correcting module 20 obtains the satisfied correction formula of current state-of-charge, current AC impedance and current bucking voltage according to voltage difference, and the modified value of current state-of-charge, current AC impedance and current bucking voltage is obtained according to correction formula, below the computation process of modified value is described.

Suppose that the difference between current state-of-charge and the state-of-charge of reality is Δ SOC, the difference between current AC impedance and actual AC impedance is Δ R, and the difference between current bucking voltage and actual bucking voltage is Δ U _off, then have following formula to set up according to formula (1) and (2):

$(\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{\∂U_{\mathrm{off}}})\×{(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\mathrm{\ΔU}---\left(3\right)$

Wherein: be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential.

Further, can be by be labeled as A, be described below in detail the computation process of A.

First, at current state-of-charge SOC ₁near get two point (SOC ₁+ δ SOC) and (SOC ₁-δ SOC), according to default open-circuit voltage relation table U _ocv=f (SOC, T) can calculate these 2 corresponding open-circuit voltage U1 and U2 respectively, and wherein, δ SOC is a less value, suggestion get (0 0.01] in some values, then thus, can obtain value.

Then, calculate value.Due to, I × Δ R=Δ U, therefore

Finally, calculate value.Due to Δ U _off=Δ U; Therefore,

Thus, in acquisition with value after, obtain current state-of-charge, current AC impedance and current bucking voltage meet correction formula, i.e. Δ SOC, Δ R and Δ U _offthe correction formula met is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},\mathrm{\Δ}{U}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU}---\left(4\right)$

Wherein, above formula (4) can be derived by formula (3).

And then correcting module 20 can obtain modified value and Δ SOC, Δ R and the Δ U of current state-of-charge, current AC impedance and current bucking voltage according to formula (4) _off.

And then correcting module 20 is revised current state-of-charge, current AC impedance and current bucking voltage according to modified value.Particularly, Δ SOC, Δ R and Δ U is obtained _off, afterwards, correcting module 20 is according to Δ SOC, Δ R and Δ U _offcan revise current state-of-charge, current AC impedance and current bucking voltage respectively, concrete formula is as follows:

$\left\{\begin{array}{c}{\mathrm{SOC}}_{\mathrm{est}}={\mathrm{SOC}}_1+\mathrm{\ΔSOC}\\ R_{\mathrm{est}}=R_1+\mathrm{\ΔR}\\ U_{\mathrm{off}\_\mathrm{est}}=U_{\mathrm{off}\_1}+\mathrm{\Δ}{U}_{\mathrm{off}}\end{array}\right.$ Wherein, R _est, U _{off_est}and SOC _estcurrent AC impedance after being respectively correction, current bucking voltage and current state-of-charge.

After being revised current state-of-charge, current AC impedance and current bucking voltage by correcting module 20, and then state-of-charge computing module 30 obtains the state-of-charge of power brick according to the current state-of-charge after battery unit correction.Such as, state-of-charge computing module 30 can the mean value of current state-of-charge after the correction of power taking pool unit as the state-of-charge of power brick.

In addition, in an embodiment of the present invention, on the basis calculating power brick state-of-charge, health status SOH (the State of Health of power brick can also be calculated further, health status), to facilitate, power brick reasonably safeguarded, manage, and then improve the performance of whole-control system.

In one embodiment of the invention, as shown in Figure 5, above-mentioned calculation element 100 can also comprise health status computing module 40, health status computing module 40 for calculating the health status of battery unit according to the impedance of the current AC impedance after battery unit correction and current bucking voltage and battery unit end of life and bucking voltage, and then calculates the health status of power brick according to the Data distribution8 of the health status of battery unit.

Wherein, impedance during battery unit end of life and bucking voltage, such as, be labeled as R _endand U _{off_end}, generally consulted to determine by battery supplier and application vendor.Particularly, health status computing module 40 can utilize the health status of following formulae discovery battery unit:

and then the Data distribution8 of the health status of healthy computing module 40 pairs of battery units is analyzed, and the Data distribution8 of health status according to battery unit, carry out the health status of statistical computation power brick, and the health status of the highest and minimum battery unit is identified, facilitate the maintenance of power brick.

According to the calculation element of the power brick state-of-charge of the embodiment of the present invention, there is self-recision function, reasonably revised calculating the current state-of-charge obtained according to correction formula by correcting module, and then the state-of-charge of power brick is obtained according to the state-of-charge after battery unit correction, can cumulative errors be reduced compared with ampere-hour integration method, improve computational accuracy, in addition, compared with Kelman filtering method, the calculated amount of this calculation element is little, more convenient.In addition, the calculation element of the embodiment of the present invention calculates the battery unit in power brick and minimum series unit, can the health status of battery unit in Real-Time Monitoring power brick, the health status of battery unit is calculated by healthy computing module, and then Rational Maintenance can be carried out according to the health status of battery unit to power brick, facilitate the management of power brick, and then improve the performance of whole-control system.

Describe and can be understood in process flow diagram or in this any process otherwise described or method, represent and comprise one or more for realizing the module of the code of the executable instruction of the step of specific logical function or process, fragment or part, and the scope of the preferred embodiment of the present invention comprises other realization, wherein can not according to order that is shown or that discuss, comprise according to involved function by the mode while of basic or by contrary order, carry out n-back test, this should understand by embodiments of the invention person of ordinary skill in the field.

In flow charts represent or in this logic otherwise described and/or step, such as, the sequencing list of the executable instruction for realizing logic function can be considered to, may be embodied in any computer-readable medium, for instruction execution system, device or equipment (as computer based system, comprise the system of processor or other can from instruction execution system, device or equipment instruction fetch and perform the system of instruction) use, or to use in conjunction with these instruction execution systems, device or equipment.With regard to this instructions, " computer-readable medium " can be anyly can to comprise, store, communicate, propagate or transmission procedure for instruction execution system, device or equipment or the device that uses in conjunction with these instruction execution systems, device or equipment.The example more specifically (non-exhaustive list) of computer-readable medium comprises following: the electrical connection section (electronic installation) with one or more wiring, portable computer diskette box (magnetic device), random access memory (RAM), ROM (read-only memory) (ROM), erasablely edit ROM (read-only memory) (EPROM or flash memory), fiber device, and portable optic disk ROM (read-only memory) (CDROM).In addition, computer-readable medium can be even paper or other suitable media that can print described program thereon, because can such as by carrying out optical scanning to paper or other media, then carry out editing, decipher or carry out process with other suitable methods if desired and electronically obtain described program, be then stored in computer memory.

Should be appreciated that each several part of the present invention can realize with hardware, software, firmware or their combination.In the above-described embodiment, multiple step or method can with to store in memory and the software performed by suitable instruction execution system or firmware realize.Such as, if realized with hardware, the same in another embodiment, can realize by any one in following technology well known in the art or their combination: the discrete logic with the logic gates for realizing logic function to data-signal, there is the special IC of suitable combinational logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) etc.

Those skilled in the art are appreciated that realizing all or part of step that above-described embodiment method carries is that the hardware that can carry out instruction relevant by program completes, described program can be stored in a kind of computer-readable recording medium, this program perform time, step comprising embodiment of the method one or a combination set of.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing module, also can be that the independent physics of unit exists, also can be integrated in a module by two or more unit.Above-mentioned integrated module both can adopt the form of hardware to realize, and the form of software function module also can be adopted to realize.If described integrated module using the form of software function module realize and as independently production marketing or use time, also can be stored in a computer read/write memory medium.

The above-mentioned storage medium mentioned can be ROM (read-only memory), disk or CD etc.

In the description of this instructions, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means to describe in conjunction with this embodiment or example are contained at least one embodiment of the present invention or example.In this manual, identical embodiment or example are not necessarily referred to the schematic representation of above-mentioned term.And the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiment or example.

Although illustrate and describe embodiments of the invention, for the ordinary skill in the art, be appreciated that and can carry out multiple change, amendment, replacement and modification to these embodiments without departing from the principles and spirit of the present invention, scope of the present invention is by claims and equivalency thereof.

Claims (10)

1. computing method for power brick state-of-charge, is characterized in that, comprise the following steps:

Obtain the current state-of-charge of battery unit in power brick and current probe temperature;

Current AC impedance and current bucking voltage is obtained according to described current state-of-charge and described current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table;

The estimation voltage of described battery unit is calculated according to described current state-of-charge, described current AC impedance and described current bucking voltage;

Calculate the voltage difference between the estimation voltage of described battery unit and test voltage;

Obtain the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, and obtain the modified value of described current state-of-charge, described current AC impedance and described current bucking voltage according to described correction formula;

According to described modified value, described current state-of-charge, described current AC impedance and described current bucking voltage are revised; And

The state-of-charge of described power brick is obtained according to the described current state-of-charge after described battery unit correction.

2. the computing method of power brick state-of-charge as claimed in claim 1, is characterized in that, obtain the current state-of-charge of battery unit in power brick and current probe temperature, specifically comprise:

Obtain electric current and the probe temperature in a upper moment, and calculate described current state-of-charge according to default open-circuit voltage relation table and ampere-hour method; And

Detect described current probe temperature.

3. the computing method of power brick state-of-charge as claimed in claim 2, it is characterized in that, the described estimation voltage calculating described battery unit according to described current state-of-charge, described current AC impedance and described current bucking voltage, specifically comprises:

According to described current state-of-charge, current probe temperature and described default open-circuit voltage relation table, by interpolation calculation current open circuit voltage; And

Calculate the estimation voltage of described battery unit according to described current open circuit voltage, described current AC impedance and described current bucking voltage, wherein, described estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

4. the computing method of power brick state-of-charge as claimed in claim 1, it is characterized in that, obtain the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, wherein, described correction formula is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},{\mathrm{\ΔU}}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU},$ Wherein, $A=[\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{{\∂U}_{\mathrm{off}}}],$

Wherein, be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential, Δ SOC be calculate described current state-of-charge and actual state-of-charge between difference, Δ R be calculate described current AC impedance and practical impedance between difference, Δ U _offfor calculate bucking voltage and actual bucking voltage between difference, Δ U be calculate described voltage difference.

5. the computing method of power brick state-of-charge as claimed in claim 1, is characterized in that, also comprise:

The health status of described battery unit is calculated according to the impedance of the described current AC impedance after described battery unit correction and described current bucking voltage and described battery unit end of life and bucking voltage; And

The health status of described power brick is calculated according to the Data distribution8 of the health status of described battery unit.

6. a computing mode for power brick state-of-charge, is characterized in that, comprising:

Acquisition module, for obtaining the current state-of-charge of battery unit in power brick and current probe temperature, and obtain current AC impedance and current bucking voltage according to described current state-of-charge and described current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table;

Correcting module, described correcting module is according to described current state-of-charge, described current AC impedance and described current bucking voltage calculate the estimation voltage of described battery unit, and the voltage difference calculated between the estimation voltage of described battery unit and test voltage, and obtain described current state-of-charge according to described voltage difference, the correction formula that described current AC impedance and described current bucking voltage meet, and obtain described current state-of-charge according to described correction formula, the modified value of described current AC impedance and described current bucking voltage, according to described modified value to described current state-of-charge, described current AC impedance and described current bucking voltage are revised,

State-of-charge computing module, for obtaining the state-of-charge of described power brick according to the described current state-of-charge after described battery unit correction.

7. the calculation element of power brick state-of-charge as claimed in claim 6, it is characterized in that, described acquisition module is also for obtaining electric current and the probe temperature in a upper moment, calculate described current state-of-charge according to default open-circuit voltage relation table and ampere-hour method, and detect described current probe temperature.

8. the calculation element of power brick state-of-charge as claimed in claim 7, it is characterized in that, described correcting module is also for according to described current state-of-charge, current probe temperature and described default open-circuit voltage relation table, by interpolation calculation current open circuit voltage, and the estimation voltage of described battery unit is calculated according to described current open circuit voltage, described current AC impedance and described current bucking voltage, wherein, described estimation voltage meets following formula:

U _{est_1}＝U _{ocv_1}+I ₁R ₁+U _{off_1}

Wherein, U _{est_1}for estimation voltage, I ₁for current measuring current, R ₁for current AC impedance, U _{off_1}for current bucking voltage, U _{ocv_1}for current open circuit voltage.

9. the calculation element of power brick state-of-charge as claimed in claim 6, it is characterized in that, described correcting module obtains the satisfied correction formula of described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, and wherein, described correction formula is specially:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},{\mathrm{\ΔU}}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU},$ Wherein, $A=[\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{{\∂U}_{\mathrm{off}}}],$

Wherein, be the voltage of battery unit to the partial differential of state-of-charge SOC, the partial differential of voltage to AC impedance R of battery unit, that the voltage of battery unit is to bucking voltage U _offpartial differential, Δ SOC be calculate described current state-of-charge and actual state-of-charge between difference, Δ R be calculate described current AC impedance and practical impedance between difference, Δ U _offfor calculate bucking voltage and actual bucking voltage between difference, Δ U be calculate described voltage difference.

10. the calculation element of the state-of-charge of power brick as claimed in claim 6, it is characterized in that, described calculation element also comprises:

Health status computing module, for calculating the health status of described battery unit according to the impedance of the described current AC impedance after described battery unit correction and described current bucking voltage and described battery unit end of life and bucking voltage, and calculate the health status of described power brick according to the Data distribution8 of the health status of described battery unit.