CN104360285B - A kind of battery capacity modification method based on improved ampere-hour integration method - Google Patents

Abstract

The invention discloses a kind of battery capacity modification method based on improved ampere-hour integration method, step is as follows：Set of cells on-board running；Calculate SOC using ampere-hour integration method；Judge whether battery electric quantity is too low；Judge minimum cell voltage V_minWhether it is less than cubage correction pattern threshold voltage V_mdy；Enter cubage correction pattern；Carry out cubage correction, be then log out cubage correction pattern；Battery charges, and calculates SOC；Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h；Charging terminates, and preserves battery capacity Q of this charging process accumulation, and instead front battery capacity Q_n, change current battery capacity value is Q simultaneously, changes SOC value.The latter stage that the present invention is charged in battery, the charge value of the SOC value to battery and storage is corrected, each charging complete is enable to obtain accurate SOC initial value, battery discharge latter stage can select to enter battery capacity calibration pattern simultaneously, to calibrate the capacity of present battery, thus eliminating the calculation error that cell degradation brings.

Description

A kind of battery capacity modification method based on improved ampere-hour integration method

Technical field

The present invention relates to a kind of battery capacity modification method based on improved ampere-hour integration method.

Background technology

Battery dump energy is to represent that battery is currently available for using also known as battery charge state (State of Charge, SOC) One of how many parameter of electricity that electric equipment uses, SOC can for the energy management strategies of electric automobile whole provide important according to According to.Accurately estimating remaining capacity of battery can make SOC maintain in rational scope when battery uses, prevent overcharge or Person crosses battery of being rivals in a contest and causes to damage, and for rationally utilizing battery, extends battery, reduces battery use cost and provides weight Will foundation.Accurately estimation SOC value is one of vital task of battery management system.

Both at home and abroad numerous studies are done to battery SOC estimation at present.Due to battery management system in actual product application Hard-wired restriction, conventional method is the method that open-circuit voltage and ampere-hour integration combine, in addition with Kalman filtering Method and neural network.

Kalman filtering, neutral net：Operand is big, and limited by hardware, algorithm itself is immature, does not obtain actual in a large number answering With.

Open circuit voltage method：The method needs battery to be stood for a long time and needs the ocv curve of battery to have relatively Big slope, but, ferric phosphate lithium cell has flatter charging and discharging curve, is not suitable for ferric phosphate lithium cell in this way Soc estimation.

Ampere-hour integration method：The method is integration between electric current is set time to calculate the energy of input and output battery, Determine the value of soc by the ratio with rated capacity.The shortcoming of the method is that the determination of initial soc value must accurately otherwise can There is very big error, prolongation over time, have larger cumulative error, and occur after battery is using the long period Aging, the computational accuracy of ampere-hour integration method also can decline.

Chinese invention patent (the patent No.：201410074003, patent name：SOC in charging process for the lithium ion battery On-line checking and modification method), this patent passes through SOC-V curve and voltage difference under the different discharge-rate of test, obtains 3rd-SOC relation, is modified to SOC by cell voltage when calculating soc.But the impropriety of this method：

(1) discharge curve of lithium battery, particularly ferric phosphate lithium cell, the linearity is very poor, and battery capacity arrives 90% Voltage difference between 20% only has 200mV, so voltage sample precision is had higher requirements, and easily causes calculation error；

(2) the battery performance discordance of each producer is larger, and same battery performance after a long time use also can There is large change, so result in the substantial amounts of test job of needs during the battery adapting to different manufacturers, and can not solve The problem that after cell degradation, soc computational accuracy reduces.

Chinese invention patent (the patent No.：201110165914X, patent name：Remaining battery capacity and health status are pre- Survey method) although being also to correct the impact to power quantity predicting for the cell degradation, but there is defect at two in this patent：

(1) method of calculating aged battery capacity isThe method is passed through current battery level V1 and is determined public affairs SOC value in formula, current voltage V1 is not the voltage after standing, and inapplicable sending out with open-circuit voltage determines SOC, so this Plant computational methods precision and can receive impact；

(2) used in patent, open circuit voltage method and ampere-hour integration is sent out the method combining to be applied to voltage linear degree preferable Lead-acid battery, but inapplicable and lithium battery.

Chinese invention patent (the patent No.：2013107193759, patent name：A kind of self-correcting based on Kalman filtering Battery SOC evaluation method), this patent can solve ampere-hour integration method and can produce asking of cumulative error after long-play Topic, but the impact that cell degradation causes volume change that SOC is calculated can not be solved.

Content of the invention

The purpose of the present invention is exactly to solve the above problems, providing a kind of battery based on improved ampere-hour integration method to hold Amount correction method, it has the shortcomings that the latter stage being charged for ampere-hour integration method, the present invention, the SOC to battery in battery The charge value of value and storage is corrected so that each charging complete can obtain accurate SOC initial value, battery discharge end simultaneously Phase can select to enter battery capacity calibration pattern, to calibrate the capacity of present battery, thus eliminating the meter that cell degradation brings The advantage calculating error.

To achieve these goals, the present invention adopts the following technical scheme that：

A kind of battery capacity modification method based on improved ampere-hour integration method, comprises the steps：

Step (1)：Set of cells on-board running；

Step (2)：Obtain the monomer battery voltage V of set of cells in real time_i, highest cell voltage V_max, minimum cell voltage V_min, charging and discharging currents I；Calculate SOC using ampere-hour integration method；

Step (3)：Judge whether battery electric quantity is too low, if being put into step (4)；It is returned to step (2) if not；

Step (4)：Judge minimum cell voltage V_minWhether it is less than cubage correction pattern threshold voltage V_mdy, if just entering Enter step (5)；It is put into step (6) if not；

Step (5)：Enter cubage correction pattern；Carry out cubage correction, be then log out cubage correction pattern；Enter step (7)；

Step (6)：Battery charges, and calculates SOC；Enter step (7)；

Step (7)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than be put into walk Suddenly (8)；Otherwise return to step (6)；

Step (8)：Charging terminates, and preserves battery capacity Q of this charging process accumulation, and instead front battery capacity Q_n, change current battery capacity value is Q simultaneously, changes SOC value.

The step of described step (5) includes：

Step (5-1)：Enter cubage correction pattern；Empty battery capacity and calculate variable；

Step (5-2)：Battery charges, and carries out the integral and calculating of SOC；

Step (5-3)：Judge whether to meet cubage correction condition, if being put into step (5-4)；It is put into if not Step (5-6)；

Step (5-4)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into Step (5-5)；Otherwise return to step (5-2)；

Step (5-5)：Battery charges and terminates, and changes SOC value, changes battery capacity Q_n；Enter step (1)；

Step (5-6)：Exit cubage correction pattern, enter step (7).

Described cubage correction pattern refers to the state manually entering or automatically capturing, in this state Carry out step (5) operation, discharge condition or V occur_max>V_hWhen, automatically exit from this pattern.

The formula of the integral and calculating carrying out SOC in described step (5-2) is：

Wherein, the meaning of parameters of SOC is present battery SOC value, SOC₀Meaning of parameters be initial SOC value, the parameter of t contains Justice is the time, accumulation battery capacity temporary variable Q.

Beneficial effects of the present invention：

1. the latter stage that the present invention is charged in battery, the charge value of the SOC value of battery and storage is corrected so that Every time charging complete can obtain accurate SOC initial value, simultaneously battery discharge latter stage can select to enter battery capacity calibration mould Formula, to calibrate the capacity of present battery, thus the advantage eliminating the calculation error that cell degradation brings.

2 present invention are used for solving electric bus, under changing power mode application, ferric phosphate lithium cell group SOC computational accuracy Raising；

3 are easily achieved, and make full use of and change the operation characteristic of power mode electric bus and carry out the calibration of ampere-hour integration method and repair Just, to improve the precision of SOC estimation；

4 each battery charging and discharging circulations carry out initial SOC value demarcation, eliminate the cumulative error in a circulation, will not produce The cumulative error of growth time；

5 from the health status of motion tracking battery and can revise the capacity of present battery, public by revising ampere-hour integration method Denominator in formula, eliminates the calculation error that cell degradation brings.

6. the inventive method can also avoid the generation of cumulative error, and is easier to Project Realization.

7. to be calculated in units of charge and discharge cycles and calibration battery energy value and soc value, it is to avoid produce long-time Error accumulation

8. automatic battery calculation of capacity, and soc computing formula is modified, the calculating that elimination cell degradation brings is by mistake Difference.

Brief description

Fig. 1 is method of the present invention flow chart.

Specific embodiment

The invention will be further described with embodiment below in conjunction with the accompanying drawings.

As shown in figure 1, a kind of battery capacity modification method based on improved ampere-hour integration method, comprise the steps：

Step (1)：Set of cells on-board running；

Step (2)：Obtain the monomer battery voltage V of set of cells in real time_i, highest cell voltage V_max, minimum cell voltage V_min, charging and discharging currents I；Calculate SOC using ampere-hour integration method；

Step (3)：Judge whether battery electric quantity is too low, if being put into step (4)；It is returned to step (2) if not；

Step (4)：Judge minimum cell voltage V_minWhether it is less than cubage correction pattern threshold voltage V_mdy, if just entering Enter step (5)；It is put into step (6) if not；

Step (5)：Enter cubage correction pattern；Carry out cubage correction, be then log out cubage correction pattern；Enter step (7)；

Step (6)：Battery charges, and calculates SOC；Enter step (7)；

Step (7)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than be put into walk Suddenly (8)；Otherwise return to step (6)；

Step (8)：Charging terminates, and preserves battery capacity Q of this charging process accumulation, and instead front battery capacity Q_n, change current battery capacity value is Q simultaneously, changes SOC value.

The step of described step (5) includes：

Step (5-1)：Enter cubage correction pattern；Empty battery capacity and calculate variable；

Step (5-2)：Battery charges,Carry out the integral and calculating of SOC；The wherein parameter of SOC It is meant that present battery SOC value, SOC₀Meaning of parameters be initial SOC value, the meaning of parameters of t is the time, accumulation battery capacity Temporary variable Q；

Step (5-3)：Judge whether to meet cubage correction condition, if being put into step (5-4)；It is put into if not Step (5-6)；

Step (5-4)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into Step (5-5)；Otherwise return to step (5-2)；

Step (5-5)：Battery charges and terminates, and changes SOC value, changes battery capacity Q_n；Enter step (1)；

Step (5-6)：Exit cubage correction pattern, enter step (7).

Described cubage correction pattern refers to the state manually entering or automatically capturing, in this state Carry out step (5) operation, discharge condition or V occur_max>V_hWhen, automatically exit from this pattern.

Although the above-mentioned accompanying drawing that combines is described to the specific embodiment of the present invention, not model is protected to the present invention The restriction enclosed, one of ordinary skill in the art should be understood that on the basis of technical scheme, and those skilled in the art are not Need to pay the various modifications that creative work can make or deformation still within protection scope of the present invention.

Claims (4)

1. a kind of battery capacity modification method based on improved ampere-hour integration method, is characterized in that, comprise the steps：

Step (1)：Set of cells on-board running；

Step (2)：Obtain the monomer battery voltage V of set of cells in real time_i, highest cell voltage V_max, minimum cell voltage V_min, fill Discharge current I；Calculate SOC using ampere-hour integration method；

Step (3)：Judge whether battery electric quantity is too low, if being put into step (4)；It is returned to step (2) if not；

Step (4)：Judge minimum cell voltage V_minWhether it is less than cubage correction pattern threshold voltage V_mdy, if being put into walking Suddenly (5)；It is put into step (6) if not；

Step (5)：Enter cubage correction pattern；Carry out cubage correction, be then log out cubage correction pattern；Enter step (7)；

Step (6)：Battery charges, and calculates SOC；Enter step (7)；

Step (7)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into step (8)； Otherwise return to step (6)；

Step (8)：Charging terminates, and preserves battery capacity Q of this charging process accumulation, and instead front battery capacity Q_n, with The current battery capacity value of Shi Xiugai is Q, changes SOC value.

2. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 1, is characterized in that, institute The step stating step (5) includes：

Step (5-1)：Enter cubage correction pattern；Empty battery capacity and calculate variable；

Step (5-2)：Battery charges, and carries out the integral and calculating of SOC；

Step (5-3)：Judge whether to meet cubage correction condition, if being put into step (5-4)；It is put into step if not (5-6)；

Step (5-4)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into step (5-5)；Otherwise return to step (5-2)；

Step (5-5)：Battery charges and terminates, and changes SOC value, changes battery capacity Q_n；Enter step (1)；

Step (5-6)：Exit cubage correction pattern, enter step (7).

3. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 1, is characterized in that, institute State the state that cubage correction pattern refers to manually enter or automatically capture, carry out step in this state (5) operate, discharge condition or V occur_max>V_hWhen, automatically exit from this pattern.

4. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 2, is characterized in that, institute The formula stating the integral and calculating carrying out SOC in step (5-2) is：

$SOC={\mathrm{SOC}}_0+\frac{1}{Q}{\∫}_0^{t}Idt$

Wherein, the meaning of parameters of SOC is present battery SOC value, SOC₀Meaning of parameters be initial SOC value, the meaning of parameters of t is Time, Q is accumulation battery capacity temporary variable.