CN107907834B - Current drift correction method, system and device of battery management system - Google Patents
Current drift correction method, system and device of battery management system Download PDFInfo
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- G01R19/32—Compensating for temperature change
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/374—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] with means for correcting the measurement for temperature or ageing
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- G—PHYSICS
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3842—Arrangements for monitoring battery or accumulator variables, e.g. SoC combining voltage and current measurements
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Abstract
The invention discloses a current drift correction method, a current drift correction system and a current drift correction device of a battery management system, wherein the method comprises the following steps: correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction; establishing a battery model, and calculating a voltage residual error between the established battery model and the actual measured voltage of the battery; calculating the drift current of the current sensor according to the calculated voltage residual; and adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain a current true value of the battery management system. The system comprises a temperature drift correction module, a voltage residual error calculation module, a drift current calculation module and a current true value acquisition module. The apparatus includes a memory and a processor. The current real value obtained by adding the current subjected to temperature drift correction and the drift current realizes closed-loop correction of the current sensor, has small measurement error, good robustness and good compatibility, and can be widely applied to the field of battery balancing.
Description
Technical Field
The invention relates to the field of battery equalization, in particular to a current drift correction method, a current drift correction system and a current drift correction device for a battery management system.
Background
In consideration of cost, the current sensor actually used by the battery management system often has a certain drift value and is not high in precision. When the accumulation-type state is measured (for example, when the remaining battery capacity is estimated by using a current integration method), the battery management system is easy to generate a divergence phenomenon caused by the drift of the current sensor. For this reason, it is necessary to correct the current sensor drift to reduce the measurement error.
The existing drift correction technology mainly adopts an open-loop method to correct the drift of the current sensor, or corrects the drift of the current sensor at zero current, and the method has poor robustness and poor compatibility to different use environments, temperatures or sensor models.
Disclosure of Invention
To solve the above technical problems, a first object of the present invention is to: the method for correcting the current drift of the battery management system is small in measurement error, good in robustness and good in compatibility.
The second object of the present invention is to: the current drift correction system of the battery management system is small in measurement error, good in robustness and good in compatibility.
The third object of the present invention is to: provided is a current drift correction device for a battery management system, which has a small measurement error, good robustness, and good compatibility.
The first technical scheme adopted by the invention is as follows:
a current drift correction method of a battery management system comprises the following steps:
correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
establishing a battery model, and calculating a voltage residual error between the established battery model and the actual measured voltage of the battery;
calculating the drift current of the current sensor according to the calculated voltage residual;
and adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain a current true value of the battery management system.
Further, the step of performing temperature drift correction on the measurement result of the current sensor to obtain a current after temperature drift correction specifically includes:
obtaining measurement results of the current sensor measuring different currents at different temperatures in an off-line manner;
carrying out numerical value fitting on the measurement result obtained offline and the true value of the current sensor to obtain a fitting relation f () between the measurement result MI obtained offline and the true value RI of the current sensor, wherein the expression of the fitting relation f () is as follows: RI ═ f (MI, T), where T is temperature;
and calculating the current after the temperature drift correction according to the obtained fitting relation f ().
Further, the step of establishing a battery model and calculating a voltage residual error between the established battery model and an actually measured voltage of the battery specifically includes:
obtaining a battery model of a battery to be used offline;
and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery according to the battery model obtained offline.
Further, the step of obtaining the battery model of the battery to be used offline specifically includes:
obtaining an OCV-SOC dispersion point table of a battery to be used at different temperatures in an off-line manner, and obtaining a battery model of the battery to be used by using a function fitting method according to the OCV-SOC dispersion point table obtained in the off-line manner, wherein the OCV is the open-circuit voltage of the battery to be used, and the SOC is the residual capacity of the battery to be used;
the method for acquiring the direct current internal resistance of the battery to be used comprises any one of an off-line method and an on-line method, and the expression of the direct current internal resistance DCR of the battery to be used is as follows: the DCR is delta V/delta I, wherein delta V is a voltage difference value before and after sudden change of the voltage V of the battery to be used, and delta I is a current difference value before and after sudden change of the current I of the battery to be used;
calculating the terminal voltage of the standby battery according to the battery model of the standby battery and the direct current internal resistance DCR, wherein the terminal voltage Vt of the standby battery is calculated by the formula: vt ═ OCV + I × DCR.
Further, the step of calculating a voltage residual error between the established battery model and the actually measured voltage of the battery according to the battery model obtained offline includes:
determining the SOC of the battery to be used, the determination method of the SOC of the battery to be used including manual setting, any one of reading from the last recorded data and OCV-SOC calibration;
measuring the actual terminal voltage Ut of the battery to be used;
calculating terminal voltage Vt of a standby battery model according to the SOC of the standby battery;
calculating a voltage residual error between the established battery model and the actual measured voltage of the battery according to the actual terminal voltage Ut of the battery to be used and the terminal voltage Vt of the battery model to be used, wherein the calculation formula of the voltage residual error between the battery model and the actual measured voltage of the battery is as follows: err ═ Ut-Vt.
Further, the step of calculating the drift current of the current sensor according to the calculated voltage residual specifically includes:
calculating the drift current of the current sensor according to the calculated voltage residual, wherein the drift current calculation formula of the current sensor is as follows: iflo (k +1) ═ a × Iflo (k) + g (Err), where Err is the calculated voltage residual, a is a constant of 0-1, Iflo (k +1) and Iflo (k) are the current drift current and the last drift current of the current sensor, respectively, and g (Err) is the current drift change value determined by the voltage residual Err.
Further, the calculation method of the current drift change value g (err) includes any one of a linear method and a proportional-integral method, and the linear method corresponds to the expression g (err) as follows: g (Err) ═ K Err, where K is a constant greater than 0; the expression of g (err) corresponding to the proportional-integral method is as follows: g (Err) ═ K1 × Err + K2 × jerr; where K1 and K2 are both constants greater than 0, and ^ is the integral sign.
Further, the method also comprises the following steps:
and taking the current true value of the battery management system as current input, and estimating the residual capacity of the battery by adopting a current integration method.
The second technical scheme adopted by the invention is as follows:
a current drift correction system for a battery management system, comprising:
the temperature drift correction module is used for correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
the voltage residual error calculation module is used for establishing a battery model and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery;
the drift current calculation module is used for calculating the drift current of the current sensor according to the calculated voltage residual error;
and the current true value acquisition module is used for adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain the current true value of the battery management system.
The third technical scheme adopted by the invention is as follows:
a current drift correction device for a battery management system, comprising:
a memory for storing a program;
a processor for loading the program to execute the current drift correction method of the battery management system according to the first technical solution.
The method has the beneficial effects that: firstly, performing preliminary temperature drift correction on a measurement result of a current sensor by adopting a conventional temperature drift correction method; secondly, establishing an accurate battery model, and obtaining a voltage residual error through comparison between the battery model and the actual measured voltage of the battery; further calculating the drift of the current sensor by using the voltage residual error; finally, the current after temperature drift correction is added with drift current to obtain the true current value of the battery management system, the technical scheme of the invention is additionally provided with a method for further drift correction according to voltage residual on the basis of the existing temperature drift correction method, the voltage residual between the voltage output by the model and the actually measured voltage is taken as one of the causes of current sensor drift, the current true value obtained by adding the current after temperature drift correction and the drift current realizes the closed-loop correction of the current sensor, the error of the current measurement result is smaller, the current sensor can meet the requirements of different use environments, temperatures or sensor models, the robustness is good, the realization complexity is low, no additional hardware is needed, the cost is low, and the result can be directly combined with most of the existing battery management system schemes, and has good compatibility.
The system of the invention has the beneficial effects that: firstly, performing primary temperature drift correction on a measurement result of a current sensor by adopting a conventional temperature drift correction method in a temperature drift correction module; secondly, establishing an accurate battery model in a voltage residual error calculation module, and obtaining a voltage residual error through comparison between the battery model and the actual measured voltage of the battery; further calculating the drift of the current sensor by using the voltage residual error in a drift current calculation module; finally, the current after temperature drift correction is added with drift current in a current true value acquisition module to obtain the current true value of the battery management system, the technical scheme of the invention is additionally provided with a method for further drift correction according to voltage residual on the basis of the existing temperature drift correction method, the voltage residual between the voltage output by the model and the voltage actually measured is taken as one of the causes of current sensor drift, the current true value obtained by adding the current after temperature drift correction and the drift current realizes the closed-loop correction of the current sensor, the error of the current measurement result is smaller, the current sensor can adapt to the requirements of different use environments, temperatures or sensor models, the robustness is good, the realization complexity is low, no additional hardware is needed, the cost is low, and the result can be directly combined with most of the existing battery management system schemes, has good compatibility.
The device of the invention has the advantages that: firstly, a program stored in a loading memory of a processor carries out preliminary temperature drift correction on a measurement result of a current sensor by adopting a conventional temperature drift correction method; secondly, establishing an accurate battery model, and obtaining a voltage residual error through comparison between the battery model and the actual measured voltage of the battery; further calculating the drift of the current sensor by using the voltage residual error; finally, the current after temperature drift correction is added with drift current to obtain the true current value of the battery management system, the technical scheme of the invention is additionally provided with a method for further drift correction according to voltage residual on the basis of the existing temperature drift correction method, the voltage residual between the voltage output by the model and the actually measured voltage is taken as one of the causes of current sensor drift, the current true value obtained by adding the current after temperature drift correction and the drift current realizes the closed-loop correction of the current sensor, the error of the current measurement result is smaller, the current sensor can meet the requirements of different use environments, temperatures or sensor models, the robustness is good, the realization complexity is low, no additional hardware is needed, the cost is low, and the result can be directly combined with most of the existing battery management system schemes, and has good compatibility.
Drawings
FIG. 1 is a flowchart illustrating steps of a method for correcting current drift in a battery management system according to the present invention;
FIG. 2 is a flow chart of an embodiment of the current drift correction method of the present invention;
FIG. 3 is a diagram of the relationship between DC resistance and SOC according to embodiment 1 of the present invention;
FIG. 4 is a graph comparing the calculated drift current value with the actual drift current value in example 1 of the present invention;
FIG. 5 is a comparison chart of SOC estimation results obtained by different current correction methods in example 1 of the present invention.
Detailed Description
Referring to fig. 1, a current drift correction method of a battery management system includes the steps of:
correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
establishing a battery model, and calculating a voltage residual error between the established battery model and the actual measured voltage of the battery;
calculating the drift current of the current sensor according to the calculated voltage residual;
and adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain a current true value of the battery management system.
In the traditional open-loop current drift correction method, the relation that the current drift is a determined numerical value at a certain temperature is preset, and feedback correction is not performed by combining residual errors, so that the accuracy is low and the robustness is poor. The method can improve the accuracy of current detection in average by a closed loop correction method of temperature drift correction and residual error feedback correction, not only can improve the estimation accuracy when the method is combined with a current integration method to estimate the residual electric quantity of the battery, but also can generate self-adaptive correction on the aging of the battery, has low implementation complexity, does not need additional hardware and low cost, can be directly combined with most of the existing battery management system schemes, and has good compatibility.
Further, as a preferred embodiment, the step of performing temperature drift correction on the measurement result of the current sensor to obtain a current after temperature drift correction specifically includes:
obtaining measurement results of the current sensor measuring different currents at different temperatures in an off-line manner;
carrying out numerical value fitting on the measurement result obtained offline and the true value of the current sensor to obtain a fitting relation f () between the measurement result MI obtained offline and the true value RI of the current sensor, wherein the expression of the fitting relation f () is as follows: RI ═ f (MI, T), where T is temperature;
and calculating the current after the temperature drift correction according to the obtained fitting relation f ().
The method comprises the steps of obtaining a measurement result with temperature drift of a current sensor, obtaining a real value of the measurement result with temperature drift of a part of the current sensor, obtaining a real value of the real value with temperature drift of the current sensor, obtaining a relation curve or a relation function of the measurement result with temperature drift of the part of the current sensor, and obtaining current after temperature drift correction according to the real-time temperature, the measurement result and the relation curve or the relation function.
Further, as a preferred embodiment, the step of establishing a battery model and calculating a voltage residual between the established battery model and an actually measured voltage of the battery specifically includes:
obtaining a battery model of a battery to be used offline;
and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery according to the battery model obtained offline.
Further as a preferred embodiment, the step of obtaining the battery model of the battery to be used offline specifically includes:
obtaining an OCV-SOC dispersion point table of a battery to be used at different temperatures in an off-line manner, and obtaining a battery model of the battery to be used by using a function fitting method according to the OCV-SOC dispersion point table obtained in the off-line manner, wherein the OCV is the open-circuit voltage of the battery to be used, and the SOC is the residual capacity of the battery to be used;
the method for acquiring the direct current internal resistance of the battery to be used comprises any one of an off-line method and an on-line method, and the expression of the direct current internal resistance DCR of the battery to be used is as follows: the DCR is delta V/delta I, wherein delta V is a voltage difference value before and after sudden change of the voltage V of the battery to be used, and delta I is a current difference value before and after sudden change of the current I of the battery to be used;
calculating the terminal voltage of the standby battery according to the battery model of the standby battery and the direct current internal resistance DCR, wherein the terminal voltage Vt of the standby battery is calculated by the formula: vt ═ OCV + I × DCR.
Further as a preferred embodiment, the step of calculating a voltage residual between the established battery model and the actually measured voltage of the battery according to the battery model obtained offline includes:
determining the SOC of the battery to be used, the determination method of the SOC of the battery to be used including manual setting, any one of reading from the last recorded data and OCV-SOC calibration;
measuring the actual terminal voltage Ut of the battery to be used;
calculating terminal voltage Vt of a standby battery model according to the SOC of the standby battery;
calculating a voltage residual error between the established battery model and the actual measured voltage of the battery according to the actual terminal voltage Ut of the battery to be used and the terminal voltage Vt of the battery model to be used, wherein the calculation formula of the voltage residual error between the battery model and the actual measured voltage of the battery is as follows: err ═ Ut-Vt.
Further, as a preferred embodiment, the step of calculating the drift current of the current sensor according to the calculated voltage residual specifically includes:
calculating the drift current of the current sensor according to the calculated voltage residual, wherein the drift current calculation formula of the current sensor is as follows: iflo (k +1) ═ a × Iflo (k) + g (Err), where Err is the calculated voltage residual, a is a constant of 0-1, Iflo (k +1) and Iflo (k) are the current drift current and the last drift current of the current sensor, respectively, and g (Err) is the current drift change value determined by the voltage residual Err.
In a further preferred embodiment, the method for calculating the current drift change value g (err) includes any one of a linear method and a proportional-integral method, and the linear method corresponds to the expression g (err) as follows: g (Err) ═ K Err, where K is a constant greater than 0; the expression of g (err) corresponding to the proportional-integral method is as follows: g (Err) ═ K1 × Err + K2 × jerr; where K1 and K2 are both constants greater than 0, and ^ is the integral sign.
Referring to fig. 1, further as a preferred embodiment, the method further includes the following steps:
and taking the current true value of the battery management system as current input, and estimating the residual capacity of the battery by adopting a current integration method.
The current true value of the battery management system obtained by calculation can generate self-adaptive correction on battery aging, can be seamlessly butted with other existing SOC estimation algorithms, and has good compatibility.
Corresponding to the method of fig. 1, the present invention provides a current drift correction system for a battery management system, comprising:
the temperature drift correction module is used for correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
the voltage residual error calculation module is used for establishing a battery model and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery;
the drift current calculation module is used for calculating the drift current of the current sensor according to the calculated voltage residual error;
and the current true value acquisition module is used for adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain the current true value of the battery management system.
Corresponding to the method of fig. 1, a current drift correction device of a battery management system comprises:
a memory for storing a program;
a processor for loading the program to execute the current drift correction method of a battery management system as shown in fig. 1.
The invention will be further explained and explained with reference to the drawings and the embodiments. The step numbers in the following embodiments are provided only for convenience of illustration, the order between the steps is not limited at all, and the execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.
Example 1
Referring to fig. 2, the process of estimating the remaining capacity of the lithium iron phosphate battery by using the current drift correction method of the present invention specifically includes the following steps:
A. obtaining the drift current of the current sensor at different temperatures in an off-line manner;
B. obtaining a battery model of a battery to be used offline;
C. identifying drift current on line;
D. and estimating the SOC of the battery based on a current integration method.
The step A can be specifically subdivided into the following steps:
a1, obtaining a measurement result MI when the current sensor measures different currents at different temperatures T;
a2, performing numerical fitting on the result MI of the step a1 and the true value RI to obtain a fitting relationship f () of the two, wherein the fitting relationship f () can be expressed as: RI ═ f (MI, T);
and A3, calculating the measured current I of the battery management system by using the fitting relation f () and the real-time measurement result.
Preferably, the fitting relationship of the present embodiment is: RI ═ MI.
The step B specifically comprises the following steps:
and B1, obtaining an OCV-SOC dispersion point table of the battery at different temperatures in an off-line manner, and fitting by using a high-order function to obtain a corresponding battery model. Where OCV refers to an open circuit voltage of the battery and SOC refers to a remaining capacity of the battery.
Preferably, the battery model fitted in this example is:
Vmo＝E0+Iinput·r-k0/SOC-k1·SOC+k2·ln(SOC)+k3ln (1-SOC) where VmoFor the model output voltage, IinputInputting current for a model, and r is the internal resistance of the battery; e0、k0、k1And k2All are model coefficients, which can be preset or given.
B2, acquiring the direct current internal resistance of the battery;
the method for acquiring the direct current internal resistance includes, but is not limited to, an off-line method and an on-line method. The direct internal resistance DCR is defined as the ratio of the difference of the voltage V to the difference of the current I when the current I abruptly changes:
DCR＝ΔV/ΔI
b3, calculating the terminal voltage of the battery to be used;
the terminal voltage Vt of the battery can be expressed as the result of the voltage drop of the OCV and the dc impedance under the current I (positive current when charging, negative current when discharging):
Vt＝OCV+I*DCR
preferably, in this embodiment, the dc internal resistance of the battery is dynamically obtained online in real time and is fit-corrected by low-pass filtering, as shown in fig. 3.
The step C specifically comprises the following steps:
c1, specifying the initial SOC of the battery;
methods of initial SOC specification include, but are not limited to: manual setting, OCV-SOC calibration, reading from the last recorded data, etc.; preferably, the method of SOC specification in the present embodiment is an initial OCV-SOC calibration.
And C2, circulating according to the initial SOC to finally obtain the drift current Iflo.
The step C2 sequentially executes the following steps C21 to C25 while performing a loop (conditions for ending the loop, such as the number of loops, etc., may be preset):
c21, measuring the terminal voltage Ut and the current I of the battery;
c22, correcting the current I according to the temperature drift method;
c23, calculating the terminal voltage Vt of the battery according to the battery model;
c24, calculating voltage residuals of model and actual measurement: err ═ Ut-Vt;
c25, calculating the drift current, iffo, according to method g from the residual Err:
iflo (k +1) ═ a × Iflo (k) + g (err), where a is a constant between 0 and 1, and Iflo (k +1) and Iflo (k) are the drift current of the current sensor at the (k +1) th (i.e. current) cycle and the k (i.e. last) cycle, respectively.
The method g includes but is not limited to the following methods:
a) the linear method comprises the following steps: g (Err) ═ K Err; wherein K is a constant greater than 0;
b) proportional-integral method: g (Err) ═ K1 × Err + K2 × jerr; where K1 and K2 are both constants greater than 0.
In the step D, the current used for integration is the cumulative sum of the current corrected for temperature drift and the drift current.
Preferably, the method g in the present embodiment employs a proportional-integral method, a specific current drift tracking result, and a corresponding SOC estimation result, as shown in fig. 4 and 5.
As can be seen from fig. 4 and 5, the drift correction method of the present invention can effectively suppress the current drift in the battery management system, and ensure that the battery current is measured accurately in an average sense, and the estimation error of the battery residual capacity (SOC) estimated by using the current is less than 3%.
Example 2
The present embodiment adopts a method similar to that of embodiment 1 to estimate the remaining capacity of the lithium iron phosphate battery, and the main differences from embodiment 1 are as follows 3 points:
1) the present embodiment fits the expression of the relationship f () in step a2 as follows:
RI＝(1.123+0.1662*MI-0.004063*MI*MI-0.1168/MI)*(1.928+0.1929*△T-0.002464*△T*△T-0.147/△T)
where △ T represents the difference between the current temperature sensor temperature and 0 degrees celsius, i.e., △ T ═ T-0.
2) The battery model expression fitted in step B1 in this embodiment is:
Uoc＝β0+β1SOC+β2SOC2+β3SOC3+β4SOC4+β5SOC5
wherein, UocIs the open circuit voltage of the battery, β0、β1、β2、β3、β4And β5All parameters are parameters of the battery model and can be preset or given.
3) In this embodiment, the manner of obtaining the dc internal resistance DCR of the battery is specified offline.
The specific SOC estimation results of the present embodiment are shown in table 1 below.
TABLE 1
As can be seen from table 1, the drift correction method of the present invention can effectively suppress the current drift in the battery management system, and ensure that the battery current is measured accurately in an average sense, and the estimation error of the battery residual capacity (SOC) estimated by using the current is less than 3%.
In summary, the invention discloses a method, a system and a device for correcting current drift of a battery management system, which are characterized in that a method for further drift correction according to voltage residual errors is added on the basis of the existing temperature drift correction method, the voltage residual error between the voltage output by a model and the actually measured voltage is taken as one of the causes of current sensor drift, the current real value obtained by adding the current after temperature drift correction and drift current realizes closed-loop correction of the current of a current sensor, the error of the current measurement result is smaller, the method, the system and the device can meet the requirements of different use environments, temperatures or sensor models, the complexity is low, extra hardware is not needed, the cost is low, the result can be directly combined with most of the existing battery management system schemes, and the method, the system and the device have good compatibility. The method can ensure that the battery current is accurately measured in an average sense, the estimation error of the residual charge (SOC) of the battery estimated by the current is less than 3 percent, and the method can be seamlessly butted with other existing SOC estimation algorithms, and has a wide market application scene.
While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A current drift correction method of a battery management system is characterized in that: the method comprises the following steps:
correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
establishing a battery model, and calculating a voltage residual error between the established battery model and the actual measured voltage of the battery;
calculating the drift current of the current sensor according to the calculated voltage residual;
and adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain a current true value of the battery management system.
2. The method of claim 1, wherein the method further comprises: the step of correcting the temperature drift of the measurement result of the current sensor to obtain the current corrected by the temperature drift specifically includes: obtaining measurement results of the current sensor measuring different currents at different temperatures in an off-line manner;
carrying out numerical fitting on the measurement result obtained offline and the true value of the current sensor to obtain a fitting relation f of the measurement result MI obtained offline and the true value RI of the current sensor, wherein the expression of the fitting relation f is as follows: RI ═ f (MI, T), where T is temperature;
and calculating the current after the temperature drift correction according to the obtained fitting relation f.
3. The method of claim 1, wherein the method further comprises: the step of establishing a battery model and calculating a voltage residual error between the established battery model and the actual measured voltage of the battery specifically comprises:
obtaining a battery model of a battery to be used offline;
and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery according to the battery model obtained offline.
4. The method of claim 3, wherein the step of correcting the current drift of the battery management system comprises: the step of obtaining the battery model of the battery to be used offline specifically comprises:
obtaining an OCV-SOC dispersion point table of a battery to be used at different temperatures in an off-line manner, and obtaining a battery model of the battery to be used by using a function fitting method according to the OCV-SOC dispersion point table obtained in the off-line manner, wherein the OCV is the open-circuit voltage of the battery to be used, and the SOC is the residual capacity of the battery to be used;
the method for acquiring the direct current internal resistance of the battery to be used comprises any one of an off-line method and an on-line method, and the expression of the direct current internal resistance DCR of the battery to be used is as follows: the DCR is delta V/delta I, wherein delta V is a voltage difference value before and after sudden change of the voltage V of the battery to be used, and delta I is a current difference value before and after sudden change of the current I of the battery to be used;
calculating the terminal voltage of the standby battery according to the battery model of the standby battery and the direct current internal resistance DCR, wherein the terminal voltage Vt of the standby battery is calculated by the formula: vt ═ OCV + I × DCR.
5. The method of claim 4, wherein the step of correcting the current drift of the battery management system comprises the steps of: the step of calculating a voltage residual error between the established battery model and the actual measured voltage of the battery according to the battery model obtained offline specifically includes:
determining the SOC of the battery to be used, the determination method of the SOC of the battery to be used including any one of manual setting and reading from the last recorded data;
measuring the actual terminal voltage Ut of the battery to be used;
calculating terminal voltage Vt of a standby battery model according to the SOC of the standby battery;
calculating a voltage residual error between the established battery model and the actual measured voltage of the battery according to the actual terminal voltage Ut of the battery to be used and the terminal voltage Vt of the battery model to be used, wherein the calculation formula of the voltage residual error between the battery model and the actual measured voltage of the battery is as follows: err ═ Ut-Vt.
6. The method of claim 1, wherein the method further comprises: the step of calculating the drift current of the current sensor according to the calculated voltage residual specifically comprises:
calculating the drift current of the current sensor according to the calculated voltage residual, wherein the drift current calculation formula of the current sensor is as follows: iflo (k +1) ═ a × Iflo (k) + g (Err), where Err is the calculated voltage residual, a is a constant of 0-1, Iflo (k +1) and Iflo (k) are the current drift current and the last drift current of the current sensor, respectively, and g (Err) is the current drift change value determined by the voltage residual Err.
7. The method of claim 6, wherein the step of correcting the current drift comprises the steps of: the calculation method of the current drift change value g (err) comprises any one of a linear method and a proportional-integral method, wherein the linear method corresponds to the expression g (err) as follows: g (Err) ═ K Err, where K is a constant greater than 0; the expression of g (err) corresponding to the proportional-integral method is as follows: g (Err) ═ K1 × Err + K2 × jerr; where K1 and K2 are both constants greater than 0, and ^ is the integral sign.
8. The method of claim 1, wherein the method further comprises: further comprising the steps of:
and taking the current true value of the battery management system as current input, and estimating the residual capacity of the battery by adopting a current integration method.
9. A current drift correction system for a battery management system, characterized by: the method comprises the following steps:
the temperature drift correction module is used for correcting the temperature drift of the measurement result of the current sensor to obtain the current after the temperature drift correction;
the voltage residual error calculation module is used for establishing a battery model and calculating the voltage residual error between the established battery model and the actual measured voltage of the battery;
the drift current calculation module is used for calculating the drift current of the current sensor according to the calculated voltage residual error;
and the current true value acquisition module is used for adding the current subjected to temperature drift correction and the drift current of the current sensor to obtain the current true value of the battery management system.
10. A current drift correction device for a battery management system, characterized by: the method comprises the following steps:
a memory for storing a program;
a processor for loading the program to perform a method of current drift correction for a battery management system as claimed in any one of claims 1 to 8.
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| CN108957349A (en) * | 2018-08-17 | 2018-12-07 | 北京航空航天大学 | A kind of lithium ion battery failure detection method and system |
| CN109061537B (en) * | 2018-08-23 | 2019-07-16 | 重庆大学 | Electric vehicle lithium ion battery sensor fault diagnosis method based on observer |
| US10948547B2 (en) * | 2018-11-23 | 2021-03-16 | Lg Chem, Ltd. | Battery monitoring system |
| CN110208707A (en) * | 2019-06-14 | 2019-09-06 | 湖北锂诺新能源科技有限公司 | A kind of lithium ion battery parameter evaluation method based on equivalent-circuit model |
| CN112651498B (en) * | 2020-09-22 | 2021-08-31 | 杭州杭越传感科技有限公司 | Method and device for improving temperature stability of self-learning current sensor |
| CN112415401B (en) * | 2020-10-26 | 2022-08-05 | 潍柴动力股份有限公司 | Battery monitoring method, device and equipment applied to vehicle |
| CN112834935A (en) * | 2020-12-31 | 2021-05-25 | 东软睿驰汽车技术（沈阳）有限公司 | Method and device for obtaining battery cell open-circuit voltage |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202204918U (en) * | 2011-07-26 | 2012-04-25 | 浙江吉利汽车研究院有限公司 | Temperature-compensation-based system on chip (SOC) accuracy improvement device |
| CN102735918A (en) * | 2012-06-30 | 2012-10-17 | 惠州市亿能电子有限公司 | Battery voltage acquisition method and system based on linear temperature compensation algorithm |
| CN103713271A (en) * | 2013-12-13 | 2014-04-09 | 惠州市亿能电子有限公司 | BMS current detection unit automatic calibration device and calibration method |
| JP2015200590A (en) * | 2014-04-09 | 2015-11-12 | 株式会社豊田自動織機 | Correction method of current sensor detecting current of electrification pertain to electric charge of secondary battery or discharge thereof |
| CN105652205A (en) * | 2014-11-20 | 2016-06-08 | 力智电子股份有限公司 | Electric quantity measuring device with temperature compensation and temperature compensation method thereof |
| CN106249186A (en) * | 2016-07-19 | 2016-12-21 | 北京长城华冠汽车科技股份有限公司 | The bearing calibration of a kind of battery management system diverter current acquisition data and device |
-
2017
- 2017-10-25 CN CN201711007506.5A patent/CN107907834B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202204918U (en) * | 2011-07-26 | 2012-04-25 | 浙江吉利汽车研究院有限公司 | Temperature-compensation-based system on chip (SOC) accuracy improvement device |
| CN102735918A (en) * | 2012-06-30 | 2012-10-17 | 惠州市亿能电子有限公司 | Battery voltage acquisition method and system based on linear temperature compensation algorithm |
| CN103713271A (en) * | 2013-12-13 | 2014-04-09 | 惠州市亿能电子有限公司 | BMS current detection unit automatic calibration device and calibration method |
| JP2015200590A (en) * | 2014-04-09 | 2015-11-12 | 株式会社豊田自動織機 | Correction method of current sensor detecting current of electrification pertain to electric charge of secondary battery or discharge thereof |
| CN105652205A (en) * | 2014-11-20 | 2016-06-08 | 力智电子股份有限公司 | Electric quantity measuring device with temperature compensation and temperature compensation method thereof |
| CN106249186A (en) * | 2016-07-19 | 2016-12-21 | 北京长城华冠汽车科技股份有限公司 | The bearing calibration of a kind of battery management system diverter current acquisition data and device |
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