CN104833922A - Battery charging discharging current limited value calculating method and device - Google Patents

Abstract

The invention discloses a battery charging discharging current limited value calculating method and a battery charging discharging current limited value calculating device. The battery charging discharging current limited value calculating method comprises the following steps: acquiring a current charge state and current test temperature of a battery unit of a battery pack; calculating current AC impedance and current compensation voltage according to the current charge state, the current test temperature, the predetermined AC impedance relation table, and the predetermined compensation voltage relation table; acquiring an estimation battery voltage calculating formula according to the current charge state, the current AC impedance, and the current compensation voltage; determining a plurality of charging current values and a plurality of discharge current values, and calculating the corresponding estimation battery voltage values respectively according to the estimation battery voltage calculating formula; and calculating battery charging discharging current limited values according to a plurality of charging current values, a plurality of discharging current values, and the corresponding estimation battery voltage values. The battery charging discharging current limited value calculating method is advantageous in that the battery charging discharging current limited values can be calculated in a real-time manner during the use of the battery, and the calculating precision of the battery charging discharging battery limited values can be improved.

Description

The computing method of battery charging and discharging current limit and device

Technical field

The present invention relates to cell art, particularly a kind of computing method of battery charging and discharging current limit and a kind of calculation element of battery charging and discharging current limit.

Background technology

In electric automobile during traveling process, entire car controller needs the power limit obtaining battery, so need calculate the charging and discharging currents limit value of battery.Correlation technique is for first testing power brick mostly, obtains a charging and discharging currents limit value and looks into value table, and be stored in electronic control unit, looks into the charging and discharging currents limit value that value table obtains battery afterwards by this charging and discharging currents limit value of inquiry.

But the shortcoming that correlation technique exists is that the data looked in value table are fixed, and the parameter of battery can constantly change in battery use procedure, the data obtained by looking into value table will there will be deviation, thus the precision of the charging and discharging currents limit value of battery is lower.

Summary of the invention

The present invention is intended to solve one of technical matters in correlation technique at least to a certain extent.For this reason, one object of the present invention is the computing method proposing a kind of battery charging and discharging current limit, can improve the computational accuracy of battery charging and discharging current limit.

Another object of the present invention is the calculation element proposing a kind of battery charging and discharging current limit.

The computing method of the battery charging and discharging current limit of embodiment proposition according to an aspect of the present invention, comprise the following steps: obtain the current state-of-charge of element cell in power brick and current probe temperature; Current AC impedance and current bucking voltage is calculated according to described current state-of-charge and described current probe temperature and default AC impedance relation table and predesigned compensation voltage relationship table; Estimating battery voltage computing formula is obtained according to described current state-of-charge, described current AC impedance and described current bucking voltage; Determine multiple charging current value and multiple discharge current value, and calculate described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to described estimating battery voltage computing formula; Battery charging and discharging current limit is calculated according to described multiple charging current value and multiple discharge current value and described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

According to the computing method of the battery charging and discharging current limit that the embodiment of the present invention proposes, battery charging and discharging current limit can be calculated in real time in battery use procedure, compared with looking into value method with the static state of correlation technique, the computing method of the embodiment of the present invention can improve the computational accuracy of battery charging and discharging current limit.Further, by battery management system, the battery charging and discharging current limit calculated in real time is supplied to entire car controller, the performance of whole-control system can be improved.

According to one embodiment of present invention, describedly obtain estimating battery voltage computing formula according to described current state-of-charge, described current AC impedance and described current bucking voltage and specifically comprise: calculate estimation voltage according to described current state-of-charge, described current AC impedance and described current bucking voltage, and calculate the voltage difference between test voltage and described estimation voltage; According to described voltage difference, described current state-of-charge, described current AC impedance and described current bucking voltage are revised; Revise to obtain final described estimating battery voltage computing formula to described estimation voltage further according to described current state-of-charge, described current AC impedance and described current bucking voltage after revising.

Wherein, according to the present invention's specific embodiment, described estimating battery voltage computing formula is:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor described estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after described correction, U _{off_est}for the current bucking voltage after described correction, U _{ocv_est}for the open-circuit voltage after correction, described U _{ocv_est}calculated by the current state-of-charge after described correction and obtain.

According to one embodiment of present invention, when testing battery charging current limit, describedly specifically to comprise according to described multiple charging current value and estimating battery magnitude of voltage counting cell charging current limit corresponding to described multiple charging current value: the estimating battery magnitude of voltage that predetermined maximum voltage value is corresponding with described multiple charging current value successively compares; If the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than described predetermined maximum voltage value, then using the 1st charging current value as described battery charge limit value; If the estimating battery magnitude of voltage that a jth charging current value is corresponding is greater than described predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than described predetermined maximum voltage value, then battery charge limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is described battery charge limit value, and Ich (j) is a described jth charging current value, Ich (j+1) for described jth+1 charging current value, f be gain, U _maxfor described predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a described jth charging current value, j be more than or equal to 2 positive integer.

According to another embodiment of the invention, when test battery discharge current limit value, describedly calculate battery discharge current limit value according to described multiple discharge current value and estimating battery magnitude of voltage corresponding to described multiple discharge current value and specifically comprise: the estimating battery magnitude of voltage that preset minimum voltage value is corresponding with described multiple discharge current value successively compares; If the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than described preset minimum voltage value, then using the 1st discharge current value as described battery discharge current limit value; If the estimating battery magnitude of voltage that a jth discharge current value is corresponding is less than described preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than described preset minimum voltage value, then battery discharge current limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{IDch}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is described battery discharge current limit value, and IDch (j) is a described jth discharge current value, IDch (j+1) for described jth+1 discharge current value, f be gain, U _minfor described preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a described jth discharge current value, j be more than or equal to 2 positive integer.

The calculation element of the battery charging and discharging current limit of embodiment proposition, comprising: acquisition module, for obtaining the current state-of-charge of element cell in power brick and current probe temperature according to a further aspect of the invention; Estimation block, for calculating 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, and obtain estimating battery voltage computing formula according to described current state-of-charge, described current AC impedance and described current bucking voltage; Current limit computing module, for determining multiple charging current value and multiple discharge current value, and calculate described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to described estimating battery voltage computing formula, and calculate battery charging and discharging current limit according to described multiple charging current value and multiple discharge current value and described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

According to the calculation element of the battery charging and discharging current limit that the embodiment of the present invention proposes, battery charging and discharging current limit can be calculated in real time in battery use procedure, compared with looking into value method with the static state of correlation technique, the computing method of the embodiment of the present invention can improve the computational accuracy of battery charging and discharging current limit.Further, by battery management system, the battery charging and discharging current limit calculated in real time is supplied to entire car controller, the performance of whole-control system can be improved.

According to one embodiment of present invention, described estimation block specifically for: according to described current state-of-charge, described current AC impedance and described current bucking voltage calculate estimation voltage, and the voltage difference calculated between test voltage and described estimation voltage, and according to described voltage difference to described current state-of-charge, described current AC impedance and described current bucking voltage are revised, and according to the described current state-of-charge after correction, described current AC impedance and described current bucking voltage are revised to obtain final described estimating battery voltage computing formula to described estimation voltage further.

Wherein, according to a specific embodiment of the present invention, it is characterized in that, described estimating battery voltage computing formula is:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor described estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after described correction, U _{off_est}for the current bucking voltage after described correction, U _{ocv_est}for the open-circuit voltage after correction, described U _{ocv_est}calculated by the current state-of-charge after described correction and obtain.

According to one embodiment of present invention, when testing battery charging current limit, described current limit computing module specifically for: the estimating battery magnitude of voltage that predetermined maximum voltage value is corresponding with described multiple charging current value successively compares, if the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than described predetermined maximum voltage value, then using the 1st charging current value as described battery charge limit value, if and estimating battery magnitude of voltage corresponding to a jth charging current value is greater than described predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than described predetermined maximum voltage value, then battery charge limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is described battery charge limit value, and Ich (j) is a described jth charging current value, Ich (j+1) for described jth+1 charging current value, f be gain, U _maxfor described predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a described jth charging current value, j be more than or equal to 2 positive integer.

According to another embodiment of the invention, when test battery discharge current limit value, described current limit computing module specifically for: the estimating battery magnitude of voltage that preset minimum voltage value is corresponding with described multiple discharge current value successively compares, if the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than described preset minimum voltage value, then using the 1st discharge current value as described battery discharge current limit value, if and estimating battery magnitude of voltage corresponding to a jth discharge current value is less than described preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than described preset minimum voltage value, then battery discharge current limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{IDch}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is described battery discharge current limit value, and IDch (j) is a described jth discharge current value, IDch (j+1) for described jth+1 discharge current value, f be gain, U _minfor described preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a described jth discharge current value, j be more than or equal to 2 positive integer.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the computing method of battery charging and discharging current limit according to the embodiment of the present invention;

Fig. 2 is the process flow diagram obtaining estimating battery voltage computing formula in the computing method of battery charging and discharging current limit according to an embodiment of the invention;

Fig. 3 is the process flow diagram of the computing method of battery charging and discharging current limit according to the present invention's specific embodiment; And

Fig. 4 is the block diagram of the calculation element of battery charging and discharging current limit according to the embodiment of the present 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.Be exemplary below by the embodiment be described with reference to the drawings, be intended to for explaining the present invention, and can not limitation of the present invention be interpreted as.

Below with reference to the accompanying drawings computing method and the device of the battery charging and discharging current limit of the embodiment of the present invention are described.

Fig. 1 is the process flow diagram of the computing method of battery charging and discharging current limit according to the embodiment of the present invention.As shown in Figure 1, the computing method of battery charging and discharging current limit comprise the following steps:

S1: obtain the current state-of-charge of element cell in power brick and current probe temperature.

Wherein, it should be noted that, in power brick, element cell can refer to minimum series unit battery in power brick.

Also need to be described, the current state-of-charge of current time t+1 can be calculated according to the measuring current of previous moment t and probe temperature.Specifically, 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 battery current time t+1, current state-of-charge can be designated as SOC ₁.

S2: calculate 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 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: obtain estimating battery voltage computing formula according to current state-of-charge, current AC impedance and current bucking voltage.

According to one embodiment of present invention, as shown in Figure 2, specifically comprise according to current state-of-charge, current AC impedance and current bucking voltage acquisition estimating battery voltage computing formula and step S3:

S31: calculate estimation voltage according to current state-of-charge, current AC impedance and current bucking voltage, and calculate the voltage difference between test voltage and estimation voltage.

Specifically, can calculate estimation voltage according to current state-of-charge, current measuring current, current AC impedance and current bucking voltage, formula is as follows:

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

Wherein, U _{est_1}for current 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.

It should be noted that, calculate current open circuit voltage by default open-circuit voltage relation table.Particularly, default open-circuit voltage relation table can be obtained by carrying out 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).Thus, 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}.

S32: current state-of-charge, current AC impedance and current bucking voltage are revised according to voltage difference.

Wherein, test voltage can be labeled as U _test, then the voltage difference delta U between test voltage and estimation voltage can be: Δ U=U _test-U _{est_1}.

Suppose that the difference utilizing ampere-hour integral method to calculate between the state-of-charge of battery and the state-of-charge of reality is Δ SOC, utilize the difference between AC impedance and actual AC impedance presetting the calculating of AC impedance relation table to be Δ R, the difference between the bucking voltage utilizing predesigned compensation voltage relationship table to calculate and actual bucking voltage is Δ U _off, then have following formula to set up:

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

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 (00.01] 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, can according to following formulae discovery Δ SOC, Δ R and Δ U _off:

${(\mathrm{\ΔSOC},\mathrm{\ΔR},{\mathrm{\ΔU}}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU}$

Wherein, above formula ${(\mathrm{\ΔSOC},\mathrm{\ΔR},{\mathrm{\ΔU}}_{\mathrm{off}})}^T=\frac{1}{(A^T\×A)}{A}^T\×\mathrm{\ΔU}$ Can by formula $(\frac{\∂U}{\∂\mathrm{SOC}},\frac{\∂U}{\∂R},\frac{\∂U}{{\∂U}_{\mathrm{off}}})\×{(\mathrm{\ΔSOC},\mathrm{\ΔR},{\mathrm{\ΔU}}_{\mathrm{off}})}^T=\mathrm{\ΔU}$ Derive.

As mentioned above, Δ SOC, Δ R and Δ U can be obtained _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:

$\left\{\begin{array}{c}{\mathrm{SOC}}_{\mathrm{est}}={\mathrm{SOC}}_1+\mathrm{\ΔSOC}\\ R_{\mathrm{est}}=R_1+\mathrm{\ΔR}\\ U_{\mathrm{off}\_\mathrm{est}}=U_{\mathrm{off}\_1}+{\mathrm{\ΔU}}_{\mathrm{off}}\end{array}\right.$

S33: revise to obtain final estimating battery voltage computing formula to estimation voltage further according to current state-of-charge, current AC impedance and current bucking voltage after revising.

Wherein, final estimating battery voltage computing formula can be:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after correction, U _{off_est}for the current bucking voltage after correction, U _{ocv_est}for the open-circuit voltage after correction.

Wherein, U _{ocv_est}by the current state-of-charge SOC after correction _estcalculate and obtain, namely say, can according to the current state-of-charge SOC after correction _estwith current probe temperature T ₁and relation table U _ocv=f (SOC, T), utilizes the open-circuit voltage U after interpolation calculation correction _{ocv_est}.

S4: determine multiple charging current value and multiple discharge current value, and calculate multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to estimating battery voltage computing formula.

Specifically, predeterminable multiple charging current value, and calculate estimating battery magnitude of voltage corresponding to multiple charging current value.

Suppose that the pairs of maximum charging current values of battery unit is Ich, then predeterminable multiple charging current value is Ich* [1,0.875,0.75,0.625,0.5,0.375,0.25,0.125,0], multiple charging current value can be denoted as [Ich (1), Ich (2), Ich (3) ..., Ich (9)], and respectively battery is charged with multiple charging current value, the duration of charging can be Preset Time such as 10s.

After battery charging 10s, calculate the state-of-charge of battery be [SOC (1), SOC (2), SOC (3) ..., SOC (9)], utilize these SOC value, by default open-circuit voltage relation table U _ocv=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T) corresponding open-circuit voltage and bucking voltage is obtained, then estimating battery voltage is utilized to calculate estimating battery magnitude of voltage corresponding to the multiple charging current value of formulae discovery, charging current value [Ich (1), Ich (2), Ich (3), Ich (9)] corresponding estimating battery magnitude of voltage can be denoted as [U [Ich (1)], U [Ich (2)], U [Ich (3)] ..., U [Ich (9)]].

Further, predeterminable multiple discharge current value, and calculate estimating battery magnitude of voltage corresponding to multiple discharge current value.

Suppose the maximum discharge current value IDch of battery, then predeterminable multiple discharge current value is IDch* [1,0.875,0.75,0.625,0.5,0.375,0.25,0.125,0], [IDch (1), IDch (2) is denoted as, IDch (3) ..., IDch (9)], and respectively battery is discharged with multiple discharge current value, can be Preset Time such as 10s discharge time.

After battery discharge 10s, calculate the state-of-charge of battery be [SOC (10), SOC (11), SOC (12) ..., SOC (18)], utilize these SOC value, by default open-circuit voltage relation table U _ocv=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T) obtains corresponding open-circuit voltage and bucking voltage, then utilizes estimating battery voltage to calculate estimating battery magnitude of voltage corresponding to the multiple discharge current value of formulae discovery.Discharge current [IDch (1), IDch (2), IDch (3), IDch (9)] corresponding magnitude of voltage is denoted as [U [IDch (1)], U [IDch (2)], U [IDch (3)],, U [IDch (9)]].

S5: calculate battery charging and discharging current limit according to multiple charging current value and multiple discharge current value and multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

According to one embodiment of present invention, when testing battery charging current limit, specifically comprise according to multiple charging current value and estimating battery magnitude of voltage counting cell charging current limit corresponding to multiple charging current value: estimating battery magnitude of voltage corresponding with multiple charging current value successively for predetermined maximum voltage value is compared; If the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than predetermined maximum voltage value, then using the 1st charging current value as battery charge limit value; If the estimating battery magnitude of voltage that a jth charging current value is corresponding is greater than predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than predetermined maximum voltage value, then according to following formulae discovery battery charge limit value:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is battery charge limit value, and Ich (j) is a jth charging current value, and Ich (j+1) is jth+1 charging current value, and f is gain, U _maxfor predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a jth charging current value, j be more than or equal to 2 positive integer.

That is, the object presetting multiple charging current value is utilize these current values to calculate corresponding estimating battery magnitude of voltage, multiple estimating battery magnitude of voltage and battery maximum voltage value is compared and can obtain battery charge limit value.

Specifically, the predetermined maximum voltage value of battery unit can be denoted as U _max, utilize the maximum voltage value U of battery unit _maxas initial voltage value, counting cell charging current limit, wherein, battery charge limit value can be denoted as Ichlim.

Will [Ich (1), Ich (2), Ich (3) ..., Ich (9)] and corresponding estimating battery magnitude of voltage and predetermined maximum voltage value U _maxcompare.

If U [Ich (1)] <U _max, then battery charge limit value is Ichlim=Ich (1), calculates and stops.

Otherwise, i.e. U [Ich (1)]>=U _max, by U [Ich (j)] (j=2,3 ..., 9) successively with maximum voltage value U _maxrelatively.

If U [Ich (j)] > is U _maxand U [Ich (j+1)] < U _max, then according to following formulae discovery gain f:

$f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}.$

Further according to following formulae discovery battery charge limit value Ichlim:

Ichlim＝Ich(j)*f+Ich(j+1)*(1-f)。

According to another embodiment of the invention, when test battery discharge current limit value, calculate battery discharge current limit value according to multiple discharge current value and estimating battery magnitude of voltage corresponding to multiple discharge current value and specifically comprise: estimating battery magnitude of voltage corresponding with multiple discharge current value successively for preset minimum voltage value is compared; If the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than preset minimum voltage value, then using the 1st discharge current value as battery discharge current limit value; If the estimating battery magnitude of voltage that a jth discharge current value is corresponding is less than preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than preset minimum voltage value, then according to following formulae discovery battery discharge current limit value:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{IDch}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is battery discharge current limit value, and IDch (j) is a jth discharge current value, and IDch (j+1) is jth+1 discharge current value, and f is gain, U _minfor preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a jth discharge current value, j be more than or equal to 2 positive integer.

That is, the object presetting multiple discharge current value is utilize these current values to calculate corresponding estimating battery magnitude of voltage, multiple estimating battery magnitude of voltage and battery minimum amount of voltage that is compared and can obtain battery discharge current limit value.

Specifically, the preset minimum voltage value of battery unit can be denoted as U _min, utilize the minimum amount of voltage that U of battery unit _minas initial voltage value, calculate battery discharge current limit value, wherein, battery discharge current limit value can be denoted as IDchlim.

Will [IDch (1), IDch (2), IDch (3) ..., IDch (9)] and corresponding estimating battery magnitude of voltage and preset minimum voltage value U _mincompare.

If U [IDch (1)] >U _min, then battery discharge current limit value is taken as IDchlim=IDch (1), calculates and stops.

Otherwise, i.e. U [IDch (1)]≤U _min, by U [IDch (j)] (j=2,3 ..., 9) successively with minimum amount of voltage that U _mincompare.

If U [IDch (j)] < is U _minand U [IDch (j+1)] > U _min, then according to following formulae discovery gain f:

$f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}.$

Further according to following formulae discovery battery charge limit value Ichlim:

IDchlim＝IDch(j)*f+IDch(j+1)*(1-f)。

In sum, as shown in Figure 3, the computing method of embodiment of the present invention battery charging and discharging current limit specifically comprise the following steps:

S101: test battery unit, to obtain default open-circuit voltage relation table, to preset AC impedance relation table and predesigned compensation voltage relationship table.

S102: calculate current state-of-charge, current AC impedance and current bucking voltage.

S103: revise current state-of-charge, current AC impedance and current bucking voltage, to obtain estimating battery voltage computing formula.

S104: with multiple charge/discharge current value to battery charging/discharging Preset Time, calculates corresponding estimating battery magnitude of voltage.

S105: calculate battery charging/discharging current limit.

To sum up, according to the computing method of the battery charging and discharging current limit that the embodiment of the present invention proposes, battery charging and discharging current limit can be calculated in real time in battery use procedure, compared with looking into value method with the static state of correlation technique, the computing method of the embodiment of the present invention can improve the computational accuracy of battery charging and discharging current limit.Further, by battery management system, the battery charging and discharging current limit calculated in real time is supplied to entire car controller, the performance of whole-control system can be improved.

In order to realize above-described embodiment, the present invention also proposes a kind of calculation element of battery charging and discharging current limit.

Fig. 4 is the block diagram of the calculation element of battery charging and discharging current limit according to the embodiment of the present invention.As shown in Figure 4, the calculation element of battery charging and discharging current limit comprises: acquisition module 1, estimation block 2 and current limit computing module 3.

Wherein, acquisition module 1 is for obtaining the current state-of-charge of element cell in power brick and current probe temperature.It should be noted that, in power brick, element cell can refer to minimum series unit battery in power brick.Also need to be described, acquisition module 1 can calculate the current state-of-charge of current time t+1 according to the measuring current of previous moment t and probe temperature.Specifically, 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 battery current time t+1, current state-of-charge can be designated as SOC ₁.

As shown in Figure 4, estimation block 2 is connected with acquisition module 1, for calculating 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, and obtain estimating battery voltage computing formula according to current state-of-charge, current AC impedance and current bucking voltage.

Wherein, default AC impedance relation table and predesigned compensation voltage relationship table can be obtained by carrying out 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, estimation block 2 can 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.

As shown in Figure 4, current limit computing module 3 is connected with estimation block 2, for determining multiple charging current value and multiple discharge current value, and calculate multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to estimating battery voltage computing formula, and calculate battery charging and discharging current limit according to multiple charging current value and multiple discharge current value and multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

Specifically, the predeterminable multiple charging current value of current limit computing module 3, and calculate estimating battery magnitude of voltage corresponding to multiple charging current value.

Suppose that the pairs of maximum charging current values of battery unit is Ich, then predeterminable multiple charging current value is Ich* [1,0.875,0.75,0.625,0.5,0.375,0.25,0.125,0], multiple charging current value can be denoted as [Ich (1), Ich (2), Ich (3) ..., Ich (9)], and respectively battery is charged with multiple charging current value, the duration of charging can be Preset Time such as 10s.

After battery charging 10s, the state-of-charge that acquisition module 1 can calculate battery is [SOC (1), SOC (2), SOC (3) ..., SOC (9)], estimation block 2 utilizes these SOC value, by default open-circuit voltage relation table U _ocv=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T) corresponding open-circuit voltage and bucking voltage is obtained, then current limit computing module 3 utilizes estimating battery voltage to calculate estimating battery magnitude of voltage corresponding to the multiple charging current value of formulae discovery, charging current value [Ich (1), Ich (2), Ich (3), Ich (9)] corresponding estimating battery magnitude of voltage can be denoted as [U [Ich (1)], U [Ich (2)], U [Ich (3)] ..., U [Ich (9)]].

Further, the predeterminable multiple discharge current value of current limit computing module 3, and calculate estimating battery magnitude of voltage corresponding to multiple discharge current value.

Suppose the maximum discharge current value IDch of battery, then predeterminable multiple discharge current value is IDch* [1,0.875,0.75,0.625,0.5,0.375,0.25,0.125,0], [IDch (1), IDch (2) is denoted as, IDch (3) ..., IDch (9)], and respectively battery is discharged with multiple discharge current value, can be Preset Time such as 10s discharge time.

After battery discharge 10s, the state-of-charge that acquisition module 1 calculates battery is [SOC (10), SOC (11), SOC (12) ..., SOC (18)], estimation block 2 utilizes these SOC value, by default open-circuit voltage relation table U _ocv=f (SOC, T) and predesigned compensation voltage relationship table U _off=f (SOC, T) obtains corresponding open-circuit voltage and bucking voltage, and then current limit computing module 3 utilizes estimating battery voltage to calculate estimating battery magnitude of voltage corresponding to the multiple discharge current value of formulae discovery.Discharge current [IDch (1), IDch (2), IDch (3), IDch (9)] corresponding magnitude of voltage is denoted as [U [IDch (1)], U [IDch (2)], U [IDch (3)],, U [IDch (9)]].

Wherein it should be noted that, default open-circuit voltage relation table can be obtained by carrying out 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).Thus, 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}.

Thus, the calculation element of the battery charging and discharging current limit that the embodiment of the present invention proposes, battery charging and discharging current limit can be calculated in real time in battery use procedure, compared with looking into value method with the static state of correlation technique, the computing method of the embodiment of the present invention can improve the computational accuracy of battery charging and discharging current limit.Further, by battery management system, the battery charging and discharging current limit calculated in real time is supplied to entire car controller, the performance of whole-control system can be improved.

According to one embodiment of present invention, estimation block 2 specifically for: according to current state-of-charge, current AC impedance and current bucking voltage calculate estimation voltage, and the voltage difference calculated between test voltage and estimation voltage, and revise current state-of-charge, current AC impedance and current bucking voltage according to voltage difference, and revise to obtain final estimating battery voltage computing formula to estimation voltage further according to current state-of-charge, current AC impedance and the current bucking voltage after revising.Wherein, according to a specific embodiment of the present invention, estimating battery voltage computing formula can be:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after correction, U _{off_est}for the current bucking voltage after correction, U _{ocv_est}for the open-circuit voltage after correction, U _{ocv_est}acquisition is calculated by the current state-of-charge after revising.

Specifically, estimation block 2 can calculate estimation voltage according to current state-of-charge, current measuring current, current AC impedance and current bucking voltage, and formula is as follows:

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

Wherein, U _{est_1}for current 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, current open circuit voltage U _{ocv_1}calculate by default open-circuit voltage relation table.

Particularly, test voltage can be labeled as U _test, then the voltage difference delta U between test voltage and estimation voltage can be: Δ U=U _test-U _{est_1}.

Suppose that the difference utilizing ampere-hour integral method to calculate between the state-of-charge of battery and the state-of-charge of reality is Δ SOC, utilize the difference between AC impedance and actual AC impedance presetting the calculating of AC impedance relation table to be Δ R, the difference between the bucking voltage utilizing predesigned compensation voltage relationship table to calculate and actual bucking voltage is Δ U _off, then have following formula to set up:

$(\frac{\&PartialD;U}{\&PartialD;\mathrm{SOC}},\frac{\&PartialD;U}{\&PartialD;R},\frac{\&PartialD;U}{{\&PartialD;U}_{\mathrm{off}}})\&times;{(\mathrm{\&Delta;SOC},\mathrm{\&Delta;R},{\mathrm{\&Delta;U}}_{\mathrm{off}})}^T=\mathrm{\&Delta;U}$

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 (00.01] 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, can according to following formulae discovery Δ SOC, Δ R and Δ U _off:

${(\mathrm{\&Delta;SOC},\mathrm{\&Delta;R},{\mathrm{\&Delta;U}}_{\mathrm{off}})}^T=\frac{1}{(A^T\&times;A)}{A}^T\&times;\mathrm{\&Delta;U}$

Wherein, above formula ${(\mathrm{\&Delta;SOC},\mathrm{\&Delta;R},{\mathrm{\&Delta;U}}_{\mathrm{off}})}^T=\frac{1}{(A^T\&times;A)}{A}^T\&times;\mathrm{\&Delta;U}$ Can by formula $(\frac{\&PartialD;U}{\&PartialD;\mathrm{SOC}},\frac{\&PartialD;U}{\&PartialD;R},\frac{\&PartialD;U}{{\&PartialD;U}_{\mathrm{off}}})\&times;{(\mathrm{\&Delta;SOC},\mathrm{\&Delta;R},{\mathrm{\&Delta;U}}_{\mathrm{off}})}^T=\mathrm{\&Delta;U}$ Derive.

As mentioned above, Δ SOC, Δ R and Δ U can be obtained _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:

$\left\{\begin{array}{c}{\mathrm{SOC}}_{\mathrm{est}}={\mathrm{SOC}}_1+\mathrm{\&Delta;SOC}\\ R_{\mathrm{est}}=R_1+\mathrm{\&Delta;R}\\ U_{\mathrm{off}\_\mathrm{est}}=U_{\mathrm{off}\_1}+{\mathrm{\&Delta;U}}_{\mathrm{off}}\end{array}\right.$

Thus, final estimating battery voltage computing formula can be U _est=U _{ocv_est}+ IR _est ⁺u _{off_est}.

Wherein, U _{ocv_est}by the current state-of-charge SOC after correction _estcalculate and obtain, namely say, can according to the current state-of-charge SOC after correction _estwith current probe temperature T ₁and relation table U _ocv=f (SOC, T), utilizes the open-circuit voltage U after interpolation calculation correction _{ocv_est}.

According to one embodiment of present invention, when testing battery charging current limit, current limit computing module 3 specifically for: estimating battery magnitude of voltage corresponding with multiple charging current value successively for predetermined maximum voltage value is compared, if the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than predetermined maximum voltage value, then using the 1st charging current value as battery charge limit value, if and estimating battery magnitude of voltage corresponding to a jth charging current value is greater than predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than predetermined maximum voltage value, then according to following formulae discovery battery charge limit value:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is battery charge limit value, and Ich (j) is a jth charging current value, and Ich (j+1) is jth+1 charging current value, and f is gain, U _maxfor predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a jth charging current value, j be more than or equal to 2 positive integer.

That is, the object presetting multiple charging current value is utilize these current values to calculate corresponding estimating battery magnitude of voltage, multiple estimating battery magnitude of voltage and battery maximum voltage value is compared and can obtain battery charge limit value.

Specifically, the predetermined maximum voltage value of battery unit can be denoted as U _max, current limit computing module 3 can utilize the maximum voltage value U of battery unit _maxas initial voltage value, counting cell charging current limit, wherein, battery charge limit value can be denoted as Ichlim.

Will [Ich (1), Ich (2), Ich (3) ..., Ich (9)] and corresponding estimating battery magnitude of voltage and predetermined maximum voltage value U _maxcompare.

If U [Ich (1)] <U _max, then battery charge limit value is Ichlim=Ich (1), calculates and stops.

Otherwise, i.e. U [Ich (1)]>=U _max, by U [Ich (j)] (j=2,3 ..., 9) successively with maximum voltage value U _maxrelatively.

If U [Ich (j)] > is U _maxand U [Ich (j+1)] < U _max, then according to following formulae discovery gain f:

$f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}.$

Further according to following formulae discovery battery charge limit value Ichlim:

Ichlim＝Ich(j)*f+Ich(j+1)*(1-f)。

According to another embodiment of the invention, when test battery discharge current limit value, current limit computing module 3 specifically for: estimating battery magnitude of voltage corresponding with multiple discharge current value successively for preset minimum voltage value is compared, if the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than preset minimum voltage value, then using the 1st discharge current value as battery discharge current limit value, if and estimating battery magnitude of voltage corresponding to a jth discharge current value is less than preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than preset minimum voltage value, then according to following formulae discovery battery discharge current limit value:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is battery discharge current limit value, and IDch (j) is a jth discharge current value, and IDch (j+1) is jth+1 discharge current value, and f is gain, U _minfor preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a jth discharge current value, j be more than or equal to 2 positive integer.

That is, the object presetting multiple discharge current value is utilize these current values to calculate corresponding estimating battery magnitude of voltage, multiple estimating battery magnitude of voltage and battery minimum amount of voltage that is compared and can obtain battery discharge current limit value.

Specifically, the preset minimum voltage value of battery unit is denoted as U _min, current limit computing module 3 can utilize the minimum amount of voltage that U of battery unit _minas initial voltage value, calculate battery discharge current limit value, wherein, battery discharge current limit value can be denoted as IDchlim.

Will [IDch (1), IDch (2), IDch (3) ..., IDch (9)] and corresponding estimating battery magnitude of voltage and preset minimum voltage value U _mincompare.

If U [IDch (1)] >U _min, then battery discharge current limit value is taken as IDchlim=IDch (1), calculates and stops.

Otherwise, i.e. U [IDch (1)]≤U _min, by U [IDch (j)] (j=2,3 ..., 9) successively with minimum amount of voltage that U _mincompare.

If U [IDch (j)] < is U _minand U [IDch (j+1)] > U _min, then according to following formulae discovery gain f:

$f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}.$

Further according to following formulae discovery battery charge limit value Ichlim:

IDchlim＝IDch(j)*f+IDch(j+1)*(1-f)。

To sum up, according to the calculation element of the battery charging and discharging current limit that the embodiment of the present invention proposes, battery charging and discharging current limit can be calculated in real time in battery use procedure, compared with looking into value method with the static state of correlation technique, the computing method of the embodiment of the present invention can improve the computational accuracy of battery charging and discharging current limit.Further, by battery management system, the battery charging and discharging current limit calculated in real time is supplied to entire car controller, the performance of whole-control system can be improved.

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, to the schematic representation of above-mentioned term not must for be identical embodiment or example.And the specific features of description, structure, material or feature can combine in one or more embodiment in office or example in an appropriate manner.In addition, when not conflicting, the feature of the different embodiment described in this instructions or example and different embodiment or example can carry out combining and combining by those skilled in the art.

In addition, term " first ", " second " only for describing object, and can not be interpreted as instruction or hint relative importance or imply the quantity indicating indicated technical characteristic.Thus, be limited with " first ", the feature of " second " can express or impliedly comprise at least one this feature.In describing the invention, the implication of " multiple " is at least two, such as two, three etc., unless otherwise expressly limited specifically.

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.Although illustrate and describe embodiments of the invention above, be understandable that, above-described embodiment is exemplary, can not be interpreted as limitation of the present invention, and those of ordinary skill in the art can change above-described embodiment within the scope of the invention, revises, replace and modification.

Claims (10)

1. computing method for battery charging and discharging current limit, is characterized in that, comprise the following steps:

Obtain the current state-of-charge of element cell in power brick and current probe temperature;

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

Estimating battery voltage computing formula is obtained according to described current state-of-charge, described current AC impedance and described current bucking voltage;

Determine multiple charging current value and multiple discharge current value, and calculate described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to described estimating battery voltage computing formula; And

Battery charging and discharging current limit is calculated according to described multiple charging current value and multiple discharge current value and described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

2. the computing method of battery charging and discharging current limit as claimed in claim 1, is characterized in that, describedly obtain estimating battery voltage computing formula according to described current state-of-charge, described current AC impedance and described current bucking voltage and specifically comprise:

Calculate estimation voltage according to described current state-of-charge, described current AC impedance and described current bucking voltage, and calculate the voltage difference between test voltage and described estimation voltage;

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

Revise to obtain final described estimating battery voltage computing formula to described estimation voltage further according to described current state-of-charge, described current AC impedance and described current bucking voltage after revising.

3. the computing method of battery charging and discharging current limit as claimed in claim 2, it is characterized in that, described estimating battery voltage computing formula is:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor described estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after described correction, U _{off_est}for the current bucking voltage after described correction, U _{ocv_est}for the open-circuit voltage after correction, described U _{ocv_est}calculated by the current state-of-charge after described correction and obtain.

4. the computing method of battery charging and discharging current limit as claimed in claim 1, it is characterized in that, when testing battery charging current limit, describedly specifically to comprise according to described multiple charging current value and estimating battery magnitude of voltage counting cell charging current limit corresponding to described multiple charging current value:

The estimating battery magnitude of voltage that predetermined maximum voltage value is corresponding with described multiple charging current value successively compares;

If the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than described predetermined maximum voltage value, then using the 1st charging current value as described battery charge limit value;

If the estimating battery magnitude of voltage that a jth charging current value is corresponding is greater than described predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than described predetermined maximum voltage value, then battery charge limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is described battery charge limit value, and Ich (j) is a described jth charging current value, Ich (j+1) for described jth+1 charging current value, f be gain, U _maxfor described predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a described jth charging current value, j be more than or equal to 2 positive integer.

5. the computing method of battery charging and discharging current limit as claimed in claim 1, it is characterized in that, when test battery discharge current limit value, describedly calculate battery discharge current limit value according to described multiple discharge current value and estimating battery magnitude of voltage corresponding to described multiple discharge current value and specifically comprise:

The estimating battery magnitude of voltage that preset minimum voltage value is corresponding with described multiple discharge current value successively compares;

If the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than described preset minimum voltage value, then using the 1st discharge current value as described battery discharge current limit value;

If the estimating battery magnitude of voltage that a jth discharge current value is corresponding is less than described preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than described preset minimum voltage value, then battery discharge current limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{IDch}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is described battery discharge current limit value, and IDch (j) is a described jth discharge current value, IDch (j+1) for described jth+1 discharge current value, f be gain, U _minfor described preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a described jth discharge current value, j be more than or equal to 2 positive integer.

6. a calculation element for battery charging and discharging current limit, is characterized in that, comprising:

Acquisition module, for obtaining the current state-of-charge of element cell in power brick and current probe temperature;

Estimation block, for calculating 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, and obtain estimating battery voltage computing formula according to described current state-of-charge, described current AC impedance and described current bucking voltage; And

Current limit computing module, for determining multiple charging current value and multiple discharge current value, and calculate described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value respectively according to described estimating battery voltage computing formula, and calculate battery charging and discharging current limit according to described multiple charging current value and multiple discharge current value and described multiple charging current value and estimating battery magnitude of voltage corresponding to multiple discharge current value.

7. the calculation element of battery charging and discharging current limit as claimed in claim 6, is characterized in that, described estimation block, specifically for:

Estimation voltage is calculated according to described current state-of-charge, described current AC impedance and described current bucking voltage, and the voltage difference calculated between test voltage and described estimation voltage, and revise described current state-of-charge, described current AC impedance and described current bucking voltage according to described voltage difference, and revise to obtain final described estimating battery voltage computing formula to described estimation voltage further according to described current state-of-charge, described current AC impedance and the described current bucking voltage after revising.

8. the calculation element of battery charging and discharging current limit as claimed in claim 7, it is characterized in that, described estimating battery voltage computing formula is:

U _est＝U _{ocv_est}+IR _est+U _{off_est}

Wherein, U _estfor described estimating battery voltage, I is current measuring current, R _estfor the current AC impedance after described correction, U _{off_est}for the current bucking voltage after described correction, U _{ocv_est}for the open-circuit voltage after correction, described U _{ocv_est}calculated by the current state-of-charge after described correction and obtain.

9. the calculation element of battery charging and discharging current limit as claimed in claim 6, is characterized in that, when testing battery charging current limit, and described current limit computing module, specifically for:

The estimating battery magnitude of voltage that predetermined maximum voltage value is corresponding with described multiple charging current value successively compares, if the estimating battery magnitude of voltage that the 1st charging current value is corresponding is less than described predetermined maximum voltage value, then using the 1st charging current value as described battery charge limit value, if and estimating battery magnitude of voltage corresponding to a jth charging current value is greater than described predetermined maximum voltage value and estimating battery magnitude of voltage corresponding to jth+1 charging current value is less than described predetermined maximum voltage value, then battery charge limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{Ichlim}=\mathrm{Ich}\left(j\right)*f+\mathrm{Ich}(j+1)*(1-f)\\ f=\frac{U_{\max }-U\left[\mathrm{Ich}(j+1)\right]}{U\left[\mathrm{Ich}\left(j\right)\right]-U\left[\mathrm{Ich}(j+1)\right]}\end{array}\right.$

Wherein, Ichlim is described battery charge limit value, and Ich (j) is a described jth charging current value, Ich (j+1) for described jth+1 charging current value, f be gain, U _maxfor described predetermined maximum voltage value, U [Ich (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 charging current value, U [Ich (j)] is estimating battery magnitude of voltage corresponding to a described jth charging current value, j be more than or equal to 2 positive integer.

10. the calculation element of battery charging and discharging current limit as claimed in claim 6, is characterized in that, when test battery discharge current limit value, and described current limit computing module, specifically for:

The estimating battery magnitude of voltage that preset minimum voltage value is corresponding with described multiple discharge current value successively compares, if the estimating battery magnitude of voltage that the 1st discharge current value is corresponding is greater than described preset minimum voltage value, then using the 1st discharge current value as described battery discharge current limit value, if and estimating battery magnitude of voltage corresponding to a jth discharge current value is less than described preset minimum voltage value and estimating battery magnitude of voltage corresponding to jth+1 discharge current value is greater than described preset minimum voltage value, then battery discharge current limit value according to following formulae discovery:

$\left\{\begin{array}{c}\mathrm{IDchlim}=\mathrm{IDch}\left(j\right)*f+\mathrm{IDch}(j+1)*(1-f)\\ f=\frac{U_{\min }-U\left[\mathrm{IDch}(j+1)\right]}{U\left[\mathrm{IDch}\left(j\right)\right]-U\left[\mathrm{IDch}(j+1)\right]}\end{array}\right.$

Wherein, IDchlim is described battery discharge current limit value, and IDch (j) is a described jth discharge current value, IDch (j+1) for described jth+1 discharge current value, f be gain, U _minfor described preset minimum voltage value, U [IDch (j+1)] is estimating battery magnitude of voltage corresponding to described jth+1 discharge current value, U [IDch (j)] is estimating battery magnitude of voltage corresponding to a described jth discharge current value, j be more than or equal to 2 positive integer.