CN114814604A - Battery soc estimation method and device - Google Patents
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- 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
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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
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- 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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Abstract
The invention provides a method and a device for estimating a battery soc, wherein the method comprises the following steps: collecting charge and discharge currents in a preset sampling period, and acquiring the current battery capacity corresponding to the charge and discharge currents; calculating current integral capacity corresponding to the charge and discharge current; determining corresponding current battery capacity weight and current integral capacity weight according to whether the charging and discharging current meets the corresponding preset current range; and calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current, and greatly improving the estimation accuracy of the actual residual capacity of the battery by a weight distribution method.
Description
Technical Field
The invention relates to the technical field of power battery residual capacity calculation, in particular to a battery soc estimation method and device.
Background
The development of the new energy automobile industry cannot avoid the use of the power battery, and in order to better use the power battery, a battery Management system bms (battery Management system) is required to monitor the state of the battery, protect the battery, and control charging and discharging, so that the battery is in an optimal state. In which state monitoring of the current remaining capacity soc (state of charge) of the battery is particularly important.
Battery SOC, i.e., state of charge, is used to reflect the remaining capacity of the battery, which is numerically defined as the ratio of the remaining capacity to the battery capacity, expressed as a percentage. The value range is 0-1, which indicates that the battery is completely discharged when the SOC is 0 and indicates that the battery is completely charged when the SOC is 1. The SOC of the battery cannot be directly measured, and the SOC can only be estimated through parameters such as terminal voltage, charge and discharge current, internal resistance and the like of the battery, and the parameters are influenced by various uncertain factors such as battery aging, environmental temperature change, automobile driving state and the like, so that accurate SOC estimation becomes an urgent problem to be solved in the development of electric automobiles.
Disclosure of Invention
Therefore, the invention provides a method and a device for estimating a battery SOC, which aim to solve the technical problem of inaccurate SOC estimation in the prior art.
According to a first aspect, an embodiment of the present invention provides a battery soc estimation method, including the following steps:
collecting charge and discharge currents in a preset sampling period, and acquiring the current battery capacity corresponding to the charge and discharge currents;
calculating current integral capacity corresponding to the charge and discharge current;
determining corresponding current battery capacity weight and current integral capacity weight according to whether the charging and discharging current meets the corresponding preset current range;
and calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current.
Optionally, the determining a weight of a current battery capacity and a weight of a current integral capacity according to whether the charge-discharge current satisfies a corresponding preset current range includes:
under the condition that the current capacity meets the first preset current range, determining that the weight of the corresponding current battery capacity is 0 and the weight of the current integral capacity is 1;
if the charging and discharging current collected for m continuous times meets a second preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the m continuous times is (m-1) × d, the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the m continuous times is 1- (m-1) × d, wherein d is a constant;
if the charging and discharging current collected for n continuous times meets a third preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the n continuous times is n x k, the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the n continuous times is 1-n x k, wherein k is a constant, and k is larger than d;
the current in the second preset current range is smaller than the current in the first preset current range, and the current in the third preset current range is smaller than the current in the second preset current range.
Optionally, calculating an actual remaining capacity corresponding to the charge and discharge current according to the current battery capacity corresponding to the charge and discharge current, the current battery capacity weight, the current integral capacity, and the current integral capacity weight includes:
calculating actual residual capacity corresponding to the charge and discharge current acquired each time according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charge and discharge current acquired each time by adopting a preset mathematical model;
the preset mathematical model is as follows:
SOC(i)＝SOC(OCV i )×W+SOC(SOC i )×(1-W)
wherein i is the charge and discharge current of the battery to be tested, SOC (i) is the actual residual capacity corresponding to the charge and discharge current i, and SOC (OCV) i ) The current battery capacity, SOC (SOC), corresponding to the charging and discharging current i i ) And W is the current integral capacity corresponding to the charge and discharge current i, W is the weight of the current battery capacity corresponding to the charge and discharge current i, and 1-W is the weight of the current integral capacity corresponding to the charge and discharge current i.
Optionally, under the condition that the m-time continuous collected charging and discharging currents satisfy the second preset current range, when the weight of the current battery capacity corresponding to the p-th collected charging and discharging current reaches the weight threshold of the preset battery capacity, the weights of the current battery capacities corresponding to the [ (p +1), m ] th collected charging and discharging currents are the weight threshold of the preset battery capacity.
Optionally, under the condition that the charge and discharge current collected n times in succession satisfies the third preset current range, when the weight of the current battery capacity corresponding to the charge and discharge current collected q times reaches 1, the weights of the current battery capacities corresponding to the charge and discharge currents collected [ (q +1) th and n ] th times are all 1.
Optionally, the first preset current range is 1/3C to 1C; the second preset current range is 1/20C to 1/3C; the third predetermined current range is 0 to 1/20C.
Optionally, the charging and discharging current includes a current value and a current direction.
According to a second aspect, an embodiment of the present invention provides a battery soc estimation apparatus, including:
the acquisition module is used for acquiring the charge and discharge current in a preset sampling period and acquiring the current battery capacity corresponding to the charge and discharge current;
the integration module is used for calculating current integration capacity corresponding to the charge and discharge current;
the judging module is used for determining the corresponding current battery capacity weight and current integral capacity weight according to whether the charging and discharging current meets the corresponding preset current range;
and the calculation module is used for calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current.
According to a third aspect, an embodiment of the present invention provides a computer device, including: the battery soc estimation method comprises a memory and a processor, wherein the memory and the processor are in communication connection with each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the battery soc estimation method.
According to a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium storing computer instructions for causing the computer to execute the above-mentioned battery soc estimation method.
The technical scheme of the invention has the following advantages:
according to the embodiment of the invention, firstly, charging and discharging currents are collected according to a preset sampling period, the charging and discharging currents corresponding to each collecting moment are obtained, the corresponding current battery capacity is obtained, and the corresponding current integral capacity is calculated; secondly, according to the preset current range met by the collected charging and discharging current, determining the weight of the corresponding current battery capacity and the weight of the current integral capacity, and finally calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight. The actual residual capacity estimation method aims at the problem that the estimation of the residual capacity of the battery in the prior art is inaccurate, the preset range of the current is judged according to the acquired current, the current battery capacity weight and the current integral capacity weight are respectively determined, and the accuracy of the estimation of the actual residual capacity of the battery is greatly improved through a weight distribution method.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flowchart of a specific example of a battery soc estimation method in embodiment 1 of the present invention;
fig. 2 is a curve diagram of a specific example between the open-circuit voltage of the battery to be tested and the current ideal battery capacity during the charging process in embodiment 1 of the present invention;
fig. 3 is a curve diagram of a specific example between the open-circuit voltage of the battery to be tested and the current ideal battery capacity during the discharging process in embodiment 1 of the present invention;
fig. 4 is a schematic block diagram of a specific example of a battery soc estimation device in embodiment 2 of the present invention;
fig. 5 is a schematic structural diagram of a specific example of a computer device in embodiment 3 of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases by those skilled in the art.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict between them.
Example 1
This embodiment provides a method for estimating a battery soc, which may first acquire a charge/discharge current and a voltage signal of a battery to be measured by hardware devices such as circuit detection, then perform calculation, determination and data output according to the acquired data by devices such as a server, and finally program the estimation method into a battery charge/discharge device or other devices for detecting the battery soc, so as to estimate the battery soc during the charge/discharge of the battery to be measured, as shown in fig. 1, including the following steps:
step S101, collecting the charging and discharging current in a preset sampling period, and acquiring the current battery capacity corresponding to the charging and discharging current.
The battery to be tested in the embodiment can be a lithium battery, a lead-acid battery or a nickel-cadmium battery and the like used by a new energy automobile. During the charging and discharging process of the battery, the constant charging and discharging current of the battery can be obtained according to the rated capacity, the charging and discharging multiplying power, the charging and discharging time and the like of the battery. In the process of charging and discharging the battery, the battery is usually charged and discharged rapidly by using a constant current, then the charging current is gradually reduced, and finally trickle charging and discharging are adopted.
However, in the actual charging and discharging process of the battery, the current fluctuates to different degrees, and for a smaller charging and discharging current, the current fluctuation increases the error of charging and discharging current collection, so that the estimated actual remaining capacity of the battery is inaccurate.
Therefore, in the embodiment of the present invention, the charging and discharging current of the battery to be tested is first collected by using a preset sampling period, where the preset sampling period may be 100ms, 200ms, and the like. Taking the sampling period of sampling once every 100ms as an example, that is, the sampling may be performed once in 0ms, once in 100ms, once in … … 1min, and so on at the initial time. Each acquisition moment corresponds to the charge and discharge current acquired by the acquisition device. Further, while the charging and discharging current is collected, the Open Circuit Voltage (OCV) of the battery corresponding to each sampling period can be obtained. The open-circuit voltage of the battery is the potential difference between the positive electrode and the negative electrode when the battery is in a static state. Determining the current ideal battery capacity according to the obtained current open-circuit voltage and an SOC _ OCV curve, where the SOC _ OCV curve is a curve relationship between the battery open-circuit voltage and the battery capacity of the battery at different multiplying powers obtained when the battery is subjected to the capacity test, as shown in fig. 2 and fig. 3, fig. 2 is a curve relationship between the battery open-circuit voltage and the current ideal battery capacity of the battery to be tested in the charging process, and fig. 3 is a curve relationship between the battery open-circuit voltage and the current ideal battery capacity of the battery to be tested in the discharging process, where the current battery capacity in this embodiment may be the current ideal battery capacity. That is, each collection time corresponds to not only the collected charge and discharge current, but also the current battery capacity.
And step S102, calculating the current integral capacity corresponding to the charge and discharge current.
The calculation method for calculating the current integration capacity according to the charging and discharging current of the battery may adopt an ampere-hour integration algorithm, which is essentially to estimate the remaining capacity of the battery by accumulating the charged or discharged electric quantity, that is, by integrating the time and the current, when the battery is charged or discharged, and to estimate the remaining capacity of the battery by using the ampere-hour integration algorithm, that is, the current integration capacity in this embodiment. In this embodiment, since the charge and discharge current is collected according to the preset sampling period, the current integration capacity corresponding to each sampling period can be estimated by using an ampere-hour integration algorithm.
And step S103, determining the corresponding current battery capacity weight and current integral capacity weight according to whether the charge and discharge current meets the corresponding preset current range.
As described above, in the charging and discharging processes of the battery to be tested, not only the current battery capacity corresponding to each acquisition time can be obtained, but also the current integral capacity corresponding to each sampling period can be estimated by using an ampere-hour integration algorithm.
For the current battery capacity, since the current battery capacity is directly related to the battery Open Circuit Voltage (OCV), and the battery open circuit voltage is easily polarized when the charging and discharging current is large, and the electrode deviates from the balance electrode potential, the battery open circuit voltage obtained when the charging and discharging current is large is not accurate, and the corresponding current battery capacity cannot represent the actual residual capacity of the battery.
For the current integral capacity, because the calculation mode of the current integral capacity is directly related to the current, the current fluctuates to different degrees in the actual charging and discharging process of the battery. When the charging and discharging current is a large current, the fluctuation of the current does not generate a large error on the charging and discharging current collected in each sampling period, but when the charging and discharging current is a small current, the small fluctuation of the current can also influence the collected charging and discharging current result. Under the condition that the collected charging and discharging current has a large error, the current integral capacity estimated by the ampere-hour integral algorithm also has a large error, so the current integral capacity cannot represent the actual residual capacity of the battery.
Therefore, in the present embodiment, the corresponding current battery capacity weight and current integral capacity weight are determined according to the corresponding preset current range satisfied by the charging and discharging current, and specifically, the method for determining the current battery capacity weight and the current integral capacity weight will be described below.
Because the determination of the current battery capacity and the current integral capacity is related to the current, the current has a fluctuation phenomenon and the polarization phenomenon of the battery can be generated by large current, so that the residual capacity of the battery represented by the current battery capacity and the current integral capacity is not accurate enough. And under the condition that the charging and discharging current is a small current, the current battery capacity corresponding to the battery open-circuit voltage value is more accurate, and under the condition that the charging and discharging current is a large current, the current integral capacity is more accurate.
And step S104, calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current.
As described above, each collection time corresponds to not only the collected charge and discharge current, but also the current battery capacity, and the current integral capacity corresponding to each sampling period estimated by the ampere-hour integration algorithm. Because the current battery capacity and the current integral capacity are both related to the current, the current battery capacity weight and the current integral capacity weight are determined according to the collected charging and discharging current, and the actual residual capacity corresponding to the charging and discharging current collected each time is calculated by using a preset mathematical model.
In this embodiment, first, charge and discharge currents are collected according to a preset sampling period, so as to obtain a charge and discharge current corresponding to each collection time, obtain a corresponding current battery capacity, and calculate a corresponding current integral capacity; secondly, according to the preset current range met by the collected charging and discharging current, determining the weight of the corresponding current battery capacity and the weight of the current integral capacity, and finally calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight. The actual residual capacity estimation method aims at the problem that the estimation of the residual capacity of the battery in the prior art is inaccurate, the preset range of the current is judged according to the acquired current, the current battery capacity weight and the current integral capacity weight are respectively determined, and the accuracy of the estimation of the actual residual capacity of the battery is greatly improved through a weight distribution method.
As an optional implementation manner, in an embodiment of the present invention, the determining, according to whether the charge and discharge current satisfies a corresponding preset current range, a weight of a current capacity and a weight of a current integration capacity includes:
and under the condition that the first preset current range is met, determining that the weight of the corresponding current battery capacity is 0, and the weight of the current integral capacity is 1.
During the charging process of the battery, the battery is usually charged rapidly by large current, then the battery is charged continuously, namely the charging current is gradually reduced to ensure that the battery is in a full charge critical state, and finally trickle charging is adopted, namely the battery is charged by weak pulse current until the battery is fully charged. Similarly, in the discharging process of the battery, the battery is usually discharged quickly by using a large current, then the battery is discharged continuously, namely the charging current is gradually reduced, so that the battery is ensured to enter a critical state of discharging, and finally the battery is discharged by using a small current until the battery is really discharged.
In this embodiment, the first preset current range may be set to 1/3C to 1C (including 1C), that is, the preset large current range, as described above, in the case that the charging and discharging current of the battery is a large current, the battery is prone to generate polarization phenomenon, and the electrode deviates from the balanced electrode potential, resulting in inaccurate obtained battery open-circuit voltage, and thus inaccurate current battery capacity. And for the current fluctuation under the condition that the charging and discharging current is large current, the charging and discharging current collected in each sampling period cannot generate large errors. Therefore, under a large current condition, in this embodiment, that is, the current in the first preset current range of 1/3C to 1C, the current battery capacity may be weighted to 0 and the current integrated capacity may be weighted to 1, that is, the remaining battery capacity of the charge-discharge current under the first preset current range may fully adopt the current integrated capacity.
If the charging and discharging current collected for m continuous times meets a second preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the m continuous times is (m-1) × d, the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the m continuous times is 1- (m-1) × d, wherein d is a constant;
in the present embodiment, the second preset current range may be set to 1/20C to 1/3C (including 1/3C). Further, when the continuously collected charging and discharging currents are all within a second preset current range, the current battery capacity weight is increased by d, wherein d can be 1% by setting to collect once per cycle. Because a percentage of confidence above 1% will only affect the current battery capacity weight when the current approaches zero from less than 1/3C to a few seconds later.
Specifically, taking d as 1% as an example, for example, the current collected at the time of T1 is 1/2C, the current collected at the time of T2 is 1/11C, the current collected at the time of T3 is 1/9C, the current collected at the time of T4 is 1/9C, and the current collected at the time of T5 is 1/21C, at this time, the charge and discharge currents collected 3 times (at the time of T2, at the time of T3, and at the time of T4) satisfy the second preset current range, the weight of the current battery capacity corresponding to the charge and discharge current collected at the time of T2 is (m-1) d and 0, the weight of the current battery capacity corresponding to the charge and discharge current collected at the time of T3 is (m-1) d, that is 1%, and the weight of the current battery capacity corresponding to the charge and discharge current collected at the time of T4 is (m-1) d, i.e. 2 x 1%, to 2%.
Accordingly, the weight of the current integral capacity corresponding to the charge and discharge current collected at the time T2 is 1- (m-1) × d and is 1, the weight of the current integral capacity corresponding to the charge and discharge current collected at the time T3 is (m-1) × d, that is, 1-1 × 1% and is 99%, and the weight of the current integral capacity corresponding to the charge and discharge current collected at the time T4 is 1- (m-1) × d and is 98%.
Further, in the present embodiment, the weight (m-1) × d of the current battery capacity does not exceed 30%, and if the weight (m-1) × d of the current battery capacity is 30%, it is maintained at 30%. So as to prevent the problem that the calculated actual residual capacity of the battery is inaccurate due to the fact that the weight of the current battery capacity is completely 'trusted' in the second preset current range.
And when the continuously acquired charging and discharging current is not in the second preset current range, setting the current battery capacity weight to be 0 and the current integral capacity weight to be 1 until the continuously acquired charging and discharging current is in the second preset current range.
If the charging and discharging current collected for n continuous times meets a third preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the n continuous times is n x k, the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the n continuous times is 1-n x k, wherein k is a constant, and k is larger than d;
in the present embodiment, the third preset current range may be set to 0 to 1/20C (including 1/20C). Further, when the continuously collected charging and discharging currents are all within a third preset current range, the current battery capacity weight is increased by k once per cycle, wherein k is larger than d, and k can be 2%. The calculation method of the weight of the current battery capacity and the weight of the current integral capacity in the third preset current range is the same as that of the second preset current range, and redundant description is omitted here. In the case of a small current, more current battery capacity can be "trusted" until the current battery capacity is completely "trusted", thereby calculating more accurate actual remaining capacity of the battery.
Further, when the continuously collected charging and discharging current is not within the third preset current range, the current battery capacity weight is set to k, that is, 2% in this embodiment, and when the continuously collected charging and discharging current is again within the third preset current range, the current battery capacity weight for the first time is still set to k, so that it is ensured that the actual remaining capacity calculated at each time is relatively stable.
The current in the second preset current range is smaller than the current in the first preset current range, and the current in the third preset current range is smaller than the current in the second preset current range.
In the embodiment, the influence of the current on the current battery capacity and the current integral capacity is fully considered, and the weight of the current battery capacity and the weight of the current integral capacity are determined under different current conditions, so that the actual residual capacity of the battery is more accurately calculated.
As an optional implementation manner, in an embodiment of the present invention, calculating an actual remaining capacity corresponding to the charge and discharge current according to a current battery capacity corresponding to the charge and discharge current, a current battery capacity weight, a current integrated capacity, and a current integrated capacity weight includes:
calculating actual residual capacity corresponding to the charge and discharge current acquired each time according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charge and discharge current acquired each time by adopting a preset mathematical model;
the preset mathematical model is as follows:
SOC(i)＝SOC(OCV i )×W+SOC(SOC i )×(1-W)
wherein i is the charge and discharge current of the battery to be tested, SOC (i) is the actual residual capacity corresponding to the charge and discharge current i, and SOC (OCV) i ) The current battery capacity, SOC (SOC), corresponding to the charging and discharging current i i ) And W is the current integral capacity corresponding to the charge and discharge current i, W is the weight of the current battery capacity corresponding to the charge and discharge current i, and 1-W is the weight of the current integral capacity corresponding to the charge and discharge current i.
In this embodiment, according to the charge and discharge current collected at each time, in combination with a preset current range, the weight of the current battery capacity and the weight of the current integral capacity at each time are determined, and the product of the current battery capacity and the current battery capacity weight and the product of the current integral capacity and the current integral capacity weight are added, so that a more accurate actual remaining capacity of the battery corresponding to each time is calculated.
As an optional implementation manner, in the embodiment of the present invention, under the condition that the charge and discharge currents collected m times consecutively satisfy the second preset current range, when the weight of the current battery capacity corresponding to the charge and discharge current collected p times reaches the weight threshold of the preset battery capacity, the weights of the current battery capacity corresponding to the charge and discharge currents collected [ (p +1), m ] th times are both the weight threshold of the preset battery capacity.
In this embodiment, the weight threshold of the preset battery capacity may be a maximum value of the weight of the current battery capacity within the second preset current range. Further, in this embodiment, the preset weight threshold of the battery capacity may be set to be 30%, and when the weight (m-1) × d of the current battery capacity reaches 30%, the weight of the current battery capacity at the p +1 th time is maintained to be 30%. So as to prevent the problem that the calculated actual remaining capacity of the battery is inaccurate due to the fact that the weight of the current battery capacity is completely 'trusted' in the second preset current range.
As an optional implementation manner, in the embodiment of the present invention, under the condition that the charge and discharge current collected n times in succession satisfies the third preset current range, when the weight of the current battery capacity corresponding to the charge and discharge current collected q times reaches 1, the weights of the current battery capacities corresponding to the charge and discharge currents collected [ (q +1), n ] th times are all 1.
That is, when the weight n × k of the current battery capacity reaches 1, the weight of the current battery capacity at the q +1 th time is kept to 1, that is, the current battery capacity is completely "trusted".
As an alternative implementation, in the embodiments of the present invention,
the first preset current range is 1/3C to 1C;
the second preset current range is 1/20C to 1/3C;
the third predetermined current range is 0 to 1/20C. Wherein C is a charge unit coulomb.
As an optional implementation manner, in an embodiment of the present invention, the charging and discharging current includes a current value and a current direction. The soc estimation method in the present embodiment is applicable not only to the case of charging the battery but also to the case of discharging the battery. The soc estimation method in the embodiment can effectively improve the accuracy of the estimation of the actual residual capacity of the battery.
Example 2
This embodiment provides a battery soc estimation apparatus, which can be used to perform the battery soc estimation method in embodiment 1, and which can be disposed inside a server or other devices, and the modules cooperate with each other to realize the estimation of the battery soc, as shown in fig. 4, and the apparatus includes:
an obtaining module 201, configured to collect charge and discharge currents in a preset sampling period, and obtain a current battery capacity corresponding to the charge and discharge currents;
an integration module 202, configured to calculate a current integration capacity corresponding to the charge and discharge current;
the judging module 203 is configured to determine a corresponding current battery capacity weight and a corresponding current integral capacity weight according to whether the charge-discharge current meets a corresponding preset current range;
the calculating module 204 is configured to calculate an actual remaining capacity corresponding to the charging and discharging current according to a current battery capacity, a current battery capacity weight, a current integral capacity, and a current integral capacity weight corresponding to the charging and discharging current.
In this embodiment, first, charge and discharge currents are collected according to a preset sampling period, so as to obtain a charge and discharge current corresponding to each collection time, obtain a corresponding current battery capacity, and calculate a corresponding current integral capacity; secondly, according to the preset current range met by the collected charging and discharging current, determining the weight of the corresponding current battery capacity and the weight of the current integral capacity, and finally calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight. The actual residual capacity estimation method aims at the problem that the estimation of the residual capacity of the battery in the prior art is inaccurate, the preset range of the current is judged according to the acquired current, the current battery capacity weight and the current integral capacity weight are respectively determined, and the accuracy of the estimation of the actual residual capacity of the battery is greatly improved through a weight distribution method.
For the detailed description of the above device part, reference may be made to the above method embodiments, which are not described herein again.
Example 3
The present embodiment provides a computer device, as shown in fig. 5, the computer device includes a processor 301 and a memory 302, where the processor 301 and the memory 302 may be connected by a bus or by other means, and fig. 5 takes the connection by a bus as an example.
The memory 302 is a non-transitory computer readable storage medium, and can be used to store non-transitory software programs, non-transitory computer executable programs, and modules, such as the battery soc estimation method in the embodiment of the present invention. Corresponding program instructions/modules. The processor 301 executes various functional applications and data processing of the processor by running non-transitory software programs, instructions and modules stored in the memory 302, so as to implement the battery soc estimation method in the above method embodiment.
The memory 302 may further include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created by the processor 301, and the like. Further, the memory 302 may include a high speed random access memory, and may also include a non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, memory 302 may optionally include memory located remotely from processor 301, which may be connected to processor 301 through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The memory 302 stores one or more modules that, when executed by the processor 301, perform the battery soc estimation method in the embodiment shown in fig. 1.
The details of the computer device can be understood by referring to the corresponding related descriptions and effects in the embodiment shown in fig. 1, and are not described herein again.
An embodiment of the present invention further provides a computer-readable storage medium, where computer-executable instructions are stored, and the computer-executable instructions may execute the battery soc estimation method in any of the above embodiments. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD), a Solid State Drive (SSD), or the like; the storage medium may also comprise a combination of memories of the kind described above.
It should be understood that the above-described embodiments are merely examples for clarity of description and are not intended to limit the scope of the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This list is neither intended to be exhaustive nor exhaustive. And obvious variations or modifications therefrom are within the scope of the invention.
Claims (10)
1. A battery soc estimation method, comprising the steps of:
collecting charge and discharge currents in a preset sampling period, and acquiring the current battery capacity corresponding to the charge and discharge currents;
calculating the current integral capacity corresponding to the charge and discharge current;
determining corresponding current battery capacity weight and current integral capacity weight according to whether the charging and discharging current meets the corresponding preset current range;
and calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current.
2. The battery soc estimation method according to claim 1, wherein the determining the weight of the current battery capacity and the weight of the current integration capacity according to whether the charging and discharging current satisfies the corresponding preset current range includes:
under the condition that the current capacity meets the first preset current range, determining that the weight of the corresponding current battery capacity is 0, and the weight of the current integral capacity is 1;
if the charging and discharging current collected for m continuous times meets a second preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the m continuous times is (m-1) × d, and the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the m continuous times is 1- (m-1) × d, wherein d is a constant;
if the charging and discharging current collected for n continuous times meets a third preset current range, the weight of the current battery capacity corresponding to the charging and discharging current collected for each time in the n continuous times is n x k, the weight of the current integral capacity corresponding to the charging and discharging current collected for each time in the n continuous times is 1-n x k, wherein k is a constant, and k is larger than d;
the current in the second preset current range is smaller than the current in the first preset current range, and the current in the third preset current range is smaller than the current in the second preset current range.
3. The battery soc estimation method according to claim 1, wherein calculating the actual remaining capacity corresponding to the charge and discharge current according to the current battery capacity, the current battery capacity weight, the current integrated capacity, and the current integrated capacity weight corresponding to the charge and discharge current comprises:
calculating the actual residual capacity corresponding to the charge and discharge current acquired each time according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charge and discharge current acquired each time by adopting a preset mathematical model;
the preset mathematical model is as follows:
SOC(i)＝SOC(OCV i )×W+SOC(SOC i )×(1-W)
wherein i is the charge and discharge current of the battery to be tested, SOC (i) is the actual residual capacity corresponding to the charge and discharge current i, and SOC (OCV) i ) The current battery capacity, SOC (SOC), corresponding to the charging and discharging current i i ) And W is the current integral capacity corresponding to the charge and discharge current i, W is the weight of the current battery capacity corresponding to the charge and discharge current i, and 1-W is the weight of the current integral capacity corresponding to the charge and discharge current i.
4. The battery soc estimation method according to claim 2, wherein under the condition that the m consecutive collected charging and discharging currents satisfy the second preset current range, when the weight of the current battery capacity corresponding to the p-th collected charging and discharging current reaches the weight threshold of the preset battery capacity, the weight of the current battery capacity corresponding to the [ (p +1), m ] th collected charging and discharging current is the weight threshold of the preset battery capacity.
5. The battery soc estimation method according to claim 2, wherein when the weight of the current battery capacity corresponding to the q-th collected charging and discharging current reaches 1 under the condition that the charging and discharging current collected n times in succession satisfies a third preset current range, the weight of the current battery capacity corresponding to the [ (q +1), n ] th collected charging and discharging current is 1.
6. The battery soc estimation method according to claim 2,
the first preset current range is 1/3C to 1C;
the second preset current range is 1/20C to 1/3C;
the third predetermined current range is 0 to 1/20C.
7. The battery soc estimation method according to any of the claims 1-6, wherein the charging and discharging current comprises a current value and a current direction.
8. A battery soc estimation device, comprising:
the acquisition module is used for acquiring the charge and discharge current in a preset sampling period and acquiring the current battery capacity corresponding to the charge and discharge current;
the integration module is used for calculating current integration capacity corresponding to the charge and discharge current;
the judging module is used for determining the corresponding current battery capacity weight and current integral capacity weight according to whether the charging and discharging current meets the corresponding preset current range;
and the calculation module is used for calculating the actual residual capacity corresponding to the charging and discharging current according to the current battery capacity, the current battery capacity weight, the current integral capacity and the current integral capacity weight corresponding to the charging and discharging current.
9. A computer device, comprising:
a memory and a processor, the memory and the processor being communicatively connected to each other, the memory having stored therein computer instructions, the processor executing the computer instructions to perform the battery soc estimation method of any of claims 1-6.
10. A computer-readable storage medium storing computer instructions for causing a computer to perform the battery soc estimation method of any one of claims 1 to 6.
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