CN117321834A - Method and device for calibrating contact resistance of battery connector and power utilization device - Google Patents
Method and device for calibrating contact resistance of battery connector and power utilization device Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
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Abstract
The embodiment of the application provides a calibration method of contact resistance of a battery connector, which is used for acquiring battery assembly currents at a plurality of moments in a preset time period and battery assembly voltages crossing the connector; when a first preset condition is met, correcting the initial value of the contact resistance to obtain a corrected value of the initial value of the contact resistance, wherein the first preset condition comprises that the voltage difference value of the battery assembly and the current difference value of the battery assembly at any two moments are larger than a preset threshold value; calibrating the contact resistance based on the corrected value of the initial value of the contact resistance. The method realizes the monitoring of the change of the contact resistance value so as to timely correct the initial value of the contact resistance, and takes the corrected contact resistance value as the calibration value of the contact resistance value, thereby avoiding inaccurate calibration of the whole resistance value of the connecting piece caused by the change of the contact resistance value.
Description
The present disclosure relates to the field of battery technologies, and in particular, to a method and an apparatus for calibrating resistance of a battery connector, and an electric device.
Batteries include a variety of forms, such as: cell, module and battery package. Batteries of different forms are used in different technical fields. Generally, a battery pack includes a plurality of battery modules, each of which includes a plurality of unit cells. The battery modules, the battery cores and the battery packs are often connected through connecting pieces.
The whole resistance value of the connecting piece is easy to drift due to the fact that torque loosens and oxidizes in the using process of the connecting piece. The conventional calibration method of the integral resistance only considers the influence of the environment on the inherent resistance, but in reality, the integral resistance of the connecting piece not only comprises the inherent resistance, but also comprises a non-negligible contact resistance.
Therefore, the overall resistance value cannot be accurately calibrated by considering only the variation in the intrinsic resistance value. Therefore, a method for calibrating the contact resistance value is needed so as to realize more accurate calibration of the whole resistance value.
Disclosure of Invention
The embodiment of the application provides a method and a device for calibrating contact resistance of a battery connector and an electric device.
In a first aspect, a method for calibrating contact resistance of a battery connector is provided, the method comprising: acquiring battery currents at a plurality of moments within a predetermined time period and battery voltages across the connection; when a first preset condition is met, correcting the initial value of the contact resistance to obtain a corrected value of the initial value of the contact resistance, wherein the first preset condition comprises that the difference value of the battery voltage and the difference value of the battery current at any two adjacent moments are larger than a preset threshold value; and taking the corrected value of the initial value of the contact resistance as the calibrated value of the contact resistance value.
The method has the advantages that the change of the contact resistance at the position of the connecting piece is determined by collecting the battery current and the battery voltage at the position of the connecting piece, so that the initial value of the contact resistance is corrected, the contact resistance is recalibrated based on the corrected contact resistance, the change of the contact resistance can be timely detected according to the change of the circuit parameter at the position of the connecting piece, and the contact resistance is calibrated, so that the follow-up more accurate calibration of the whole resistance of the connecting piece based on the contact resistance is realized.
In one possible implementation, when the first preset condition is satisfied multiple times within the predetermined period of time, the initial contact resistance value is corrected multiple times, so as to obtain corrected values of multiple initial contact resistance values.
In one possible implementation, a calculation is performed based on the correction values of the initial values of the contact resistances, so as to obtain a calculated value of the correction value of the initial value of the contact resistance; and taking the calculated value of the correction value of the initial value of the contact resistance as the calibration value of the contact resistance of the connecting piece.
According to the scheme, the plurality of correction values are calculated, and the contact resistance value of the connecting piece is calibrated based on the calculated value, so that negative influence of fluctuation of the contact resistance value caused by instability of a battery system on the accuracy of a calibration result of the contact resistance value can be effectively avoided, and the calibration accuracy of the contact resistance value is improved.
In one possible implementation, when the second preset condition is satisfied, stopping correcting the initial value of the contact resistance; the second preset condition comprises that the correction times reach a preset value or the duration of a preset time period reaches the preset value or the battery is powered down.
In one possible implementation, an initial measurement of the overall resistance of the connection and an inherent resistance of the connection are obtained; and calculating the difference between the initial measured value of the overall resistance of the connecting piece and the inherent resistance value, and taking the difference as the initial value of the contact resistance of the connecting piece.
In one possible implementation, the battery voltage difference and the battery current difference across the connection at adjacent times are calculated; calculating the ratio of the battery voltage difference across the connection to the battery current difference; and calculating the difference between the ratio of the battery voltage difference value and the battery current difference value of the connecting piece and the inherent resistance value, and taking the difference as a correction value of the initial value of the contact resistance.
In one possible implementation manner, the temperature value of the connecting piece at the current moment is obtained, and the correction value of the initial value of the contact resistance at the standard temperature is obtained by performing standard value conversion on the correction value of the initial value of the contact resistance based on the temperature value.
Since the contact resistance is different at different temperatures, a series of points need to be recorded to characterize the correlation of contact resistance and temperature, but this can lead to several problems: firstly, the data storage capacity is increased and more resources are occupied, so the data storage capacity is converted into a standard value, and the impedance is predicted by using the relation between the standard value and the temperature, so that the data storage capacity can be reduced; secondly, the directly recorded original value has larger fluctuation and cannot be directly used for correcting the processing needing system error elimination, the contact resistance standard value converted to the same temperature point is subjected to error correction, the sample size (the sample size at the standard temperature is increased), and the correction accuracy is improved; finally, the measured temperature point cannot cover all temperature intervals, so that the contact impedance is converted into a standard temperature, and then the relation between the temperature and the impedance is predicted, so that a relatively smooth temperature-contact impedance prediction curve can be obtained, and the contact impedance at a temperature which is not experienced when the correction is performed can be predicted.
In one possible implementation, the overall resistance value of the connection is calibrated based on the calibrated value of the contact resistance value and the intrinsic resistance value.
In a second aspect, there is provided a calibration device for a contact resistance of a battery connector, comprising: the acquisition module is used for acquiring battery currents at a plurality of moments in a preset time period and battery voltages across the connecting piece; the correction module corrects the initial contact resistance value to obtain a correction value of the initial contact resistance value when a first preset condition is met, wherein the first preset condition comprises that the difference value of the battery voltage and the difference value of the battery current at any two adjacent moments are larger than a preset threshold value; and the calibration module is used for taking the corrected value of the initial value of the contact resistance as the calibration value of the contact resistance value.
The method comprises the steps of acquiring battery current and battery voltage crossing the position of the connecting piece, determining that the contact resistance crossing the position of the connecting piece changes, correcting the initial value of the contact resistance, recalibrating the contact resistance based on the corrected contact resistance, detecting the change of the contact resistance according to the change of circuit parameters of the position of the connecting piece, calibrating the contact resistance, and accordingly achieving the follow-up more accurate calibration of the whole resistance value of the connecting piece based on the contact resistance.
In a third aspect, there is provided a calibration device for a contact resistance of a battery connector, comprising: a memory storing a computer program; and the processor is used for executing the computer program, and the calibration method is executed when the computer program runs.
In a fourth aspect, a computer storage medium is provided, the storage medium storing a computer program, the computer program executing the calibration method described above when running.
In a fifth aspect, a battery management system is provided, including a calibration device for a contact resistance of the battery connector.
In a sixth aspect, an electrical device is provided, including the above battery management system.
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and that other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic view of a conventional battery connection structure.
Fig. 2 is a flowchart of a method for calibrating contact resistance of a battery connector according to an embodiment of the present application.
Fig. 3 is a flowchart of a method for calibrating contact resistance of a battery connector according to an embodiment of the present application.
Fig. 4 is a schematic block diagram of a calibration device for the contact resistance of a battery connector according to an embodiment of the present application.
Fig. 5 is a schematic block diagram of a calibration device for the contact resistance of a battery connector according to an embodiment of the present application.
Fig. 6 is a schematic block diagram of a battery management system according to an embodiment of the present application.
Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the present application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.
In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like indicate an orientation or positional relationship merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.
The directional terms appearing in the following description are all directions shown in the drawings and do not limit the specific structure of the present application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the present application can be understood as appropriate by one of ordinary skill in the art.
In the field of batteries, batteries include various forms, such as: a battery cell, a module, or a battery pack. Different forms of batteries are used in different fields. For example: single cell batteries are commonly used in small household appliances, electric toys, and common types include 1V, 5V, and 7V batteries. Modules or battery packs are commonly used in large electric machines, for example: an electric vehicle. From the application scene, the module or the battery pack can be applied to power devices such as automobiles, ships and the like as a power source. From the connection relation, the battery pack comprises a plurality of battery modules, and each battery module comprises a plurality of single battery cells. The battery modules, the battery cores and the battery packs are often connected through connecting pieces, so that the electric connection among the battery cores, the battery modules or the battery packs is realized.
The connector in the embodiment of the application is a device for connecting batteries together, and functions to transmit current and connect electrical equipment in a circuit. For example: the device made of metal materials such as copper bars and aluminum bars can be fixedly connected with the anode and the cathode of the battery, so that the electric connection between the batteries is realized.
Fig. 1 is a schematic view showing a conventional battery connection structure. The battery BT1 and the battery BT2 are electrically connected through a connector in the middle. The connector has an inherent resistance R 1 The battery BT1 and the battery BT2 also have contact resistance values R at points B and C B R is as follows C (not shown). The conventional method for calibrating the overall resistance of the battery connector only considers the inherent resistance value R1 of the connector, namely the inherent resistance value R1 is equivalent to the overall resistance value. The traditional method ignores the contact resistance value generated by the connection position of the connecting piece and the battery, so that the calibration of the whole resistance value is inaccurate. The contact resistance value is easily ignored because the contact resistance value of the connection member is relatively small in proportion to the overall resistance value of the connection member with respect to the intrinsic resistance value, and the contact resistance value is generally not directly measured. However, although the specific gravity of the contact resistance value to the overall resistance value is relatively small, there is a possibility that the specific gravity of the contact resistance value to the overall resistance value becomes large with a change in temperature or by fluctuation of the battery system, which tends to have a non-negligible effect on the accuracy of calibrating the overall resistance value. Therefore, a method is needed that can determine the change in contact resistance value in time, so that it can be corrected and recalibrated.
Fig. 2 shows a flowchart of a method for calibrating contact resistance of a battery connector according to an embodiment of the present application. As shown in the figure, the method for calibrating the contact resistance of the battery connector comprises the following steps:
step S210: acquiring battery currents at a plurality of moments within a predetermined time period and battery voltages across the connection;
step S220: when a first preset condition is met, correcting the initial value of the contact resistance to obtain a corrected value of the initial value of the contact resistance, wherein the first preset condition comprises that the difference value of the battery voltage and the difference value of the battery current at any two adjacent moments are larger than a preset threshold value;
step S230: and taking the corrected value of the initial value of the contact resistance as the calibrated value of the contact resistance value.
It is understood that the voltage of the battery across the connection is the difference between the voltage of the positive or negative electrode of the battery and the voltage of the end of the connection remote from the battery. Taking the battery BT1 in fig. 1 as an example, the voltage of the battery BT1 across the connection member is the difference between the voltage at point a (positive electrode of the battery BT 1) and the voltage at point C (end of the adjacent connection member away from the battery). Taking the battery BT2 in fig. 1 as an example, the voltage of the battery BT2 across the connection is the difference between the voltage of the negative electrode and the voltage at point B (the end of the adjacent connection that is far from the battery).
In step S220, when the first preset condition is satisfied, the initial value of the contact is corrected. As an example, the setting of the preset threshold may be determined according to actual battery usage. For example: the battery is often in a working condition with large output power variation, the threshold value can be set to be a relatively large value; the threshold value may also be set to a relatively small value if the battery is often in a condition where the change in output power is small; in addition, in order to adapt to the condition that the battery is frequently switched under various working conditions, the threshold value can be dynamically adjusted according to the working conditions of the battery, so that a reasonable number of samples can be obtained in a preset time period.
In some embodiments, when the second preset condition is met, stopping the correction of the initial value of the contact resistance; the second preset condition comprises that the correction times reach a preset value or the duration of a preset time period reaches the preset value or the battery is powered down.
It will be appreciated that the number of corrections within the preset time period is related to the preset threshold, the greater the preset threshold, the fewer the number of corrections; and vice versa.
The duration of the predetermined time period may be manually set or may be determined according to actual conditions. Specifically, taking a power battery as an example, the predetermined time period may be a total time period of a single driving.
For battery power down, a power battery is taken as an example, and the electric vehicle may stop or stop charging.
In some embodiments, an initial measurement of the overall resistance of the connection and an intrinsic resistance value of the connection are obtained; and calculating the difference between the initial measured value of the overall resistance of the connecting piece and the inherent resistance value, and taking the difference as the initial value of the contact resistance of the connecting piece. It will be appreciated that when the connector is not used to connect a battery, the overall resistance of the connector is equal to its inherent resistance. When the connecting piece is used for connecting a plurality of batteries so as to realize the electrical connection among the batteries, a contact resistance value is generated at the position where the connecting piece is contacted with the positive electrode and the negative electrode of the batteries, and the overall resistance value of the connecting piece is equal to the sum of the inherent resistance value and the contact resistance value.
The initial value of the overall resistance value of the connector is generally determined before the battery leaves the factory or before the battery is not formally put into use, and can be measured by a measuring tool (such as a universal meter). It will be appreciated that this initial measurement may be used to calculate the intrinsic resistance or contact resistance of the connection, and may also be used as a basis for calibrating the overall resistance during use of the battery. For the used battery, the calibration value of the contact resistance of the last preset time period is the initial value of the contact resistance of the next preset time period, and so on.
The intrinsic resistance of the connecting piece is generally determined by the material, the sectional area and the length of the connecting piece, and the intrinsic resistance can be obtained through actual measurement or calculation, so that the stability and the consistency are high. Therefore, an intrinsic resistance value under a specific temperature condition is generally adopted as an intrinsic resistance value of the corresponding connection member. For example, the intrinsic resistance of the connector at 20 degrees celsius is generally used as a standard value for calibrating the overall resistance of the connector.
In step S220, the manner of correcting the initial value of the contact resistance includes calculating the variation value of the overall resistance across the connecting member at the adjacent time, calculating the difference between the variation value and the intrinsic resistance value, and using the difference as the correction value of the initial value of the contact resistance at the current time.
Specifically, calculating a battery voltage difference and a battery current difference between adjacent moments across the connection; calculating the ratio of the battery voltage difference value and the battery current difference value of the cross-connecting piece to obtain the change value of the overall resistance of the cross-connecting piece at adjacent moments; and then calculating the difference value of the ratio of the battery voltage difference value and the battery current difference value of the cross-connecting piece and the inherent resistance value to obtain the corrected value of the initial value of the contact resistance at the current moment.
In some embodiments, the change in temperature causes a change in contact resistance value as the metal thermal conductivity is temperature dependent. Therefore, in order to further improve the accuracy of calculating the correction value of the contact resistance value, the correction value of the initial value of the contact resistance at the present time may be converted into the correction value of the initial value of the contact resistance at the standard temperature. Specifically, the temperature value of the connecting piece at the current moment can be obtained (for example, a temperature sensor can be arranged on the connecting piece or the temperature of a thermistor on the connecting piece can be directly collected), and the correction value of the initial value of the contact resistance is converted into the standard value based on the temperature value, so that the correction value of the initial value of the contact resistance at the standard temperature is obtained.
It is understood that temperature affects the intrinsic resistance in addition to the contact resistance. Therefore, the intrinsic resistance value at the standard temperature can be compensated according to the current temperature, and the correction value of the initial value of the contact resistance at the current temperature is calculated based on the compensated intrinsic resistance value, so that the calculation accuracy is further improved.
It can be understood that the initial value of the contact resistance value is corrected based on the temperature value or the intrinsic resistance value at the standard temperature is compensated according to the current temperature, and the corresponding relation between the two resistances and the temperature can be found through experimental or simulation means. For example, the contact resistance and the intrinsic resistance of the connector at different temperatures can be measured, and the relationship between temperature and both resistances can be fitted by linear regression.
In step S230, the correction value of the initial value of the contact resistance is set as the calibration value of the contact resistance value. As an example, the original calibration value is updated, and the correction value of the contact resistance value is assigned to the original calibration value.
In some embodiments, calibration is based on a calibrated value of the contact resistance value and an overall resistance value of the intrinsic resistance connector. For example, the sum of the calibration value of the contact resistance value and the intrinsic resistance value is taken as the calibration value of the overall resistance value. It is understood that the intrinsic resistance may be an intrinsic resistance at a standard temperature or an intrinsic resistance compensated based on the current temperature.
In this embodiment, the batteries are electrically connected by a connecting member. Therefore, when current passes through, a certain partial voltage is generated on the battery voltage across the connecting member due to the overall resistance value of the connecting member, and the battery voltage across the connecting member fluctuates due to the variation of the overall resistance value of the connecting member during the use of the battery. Therefore, the monitoring of the integral resistance value change of the connecting piece can be realized by collecting the battery current at a plurality of moments in a certain time and the battery voltage across the connecting piece and calculating the battery current difference value at adjacent moments and the battery voltage difference value across the connecting piece. Because the contact resistance value occupies a certain proportion in the integral resistance value of the connecting piece, when the integral resistance value changes, the initial value of the contact resistance across the connecting piece can be determined to change, so that the monitoring of the change of the contact resistance value is realized, the initial value of the contact resistance is corrected in time, the corrected contact resistance value is used as the calibration value of the contact resistance value, and the follow-up inaccurate calibration of the integral resistance value of the connecting piece caused by the change of the contact resistance value is avoided.
Fig. 3 shows a flowchart of a method for calibrating contact resistance of a battery connector according to an embodiment of the present application. Steps S310 to S320 in the method are identical to steps S210 to S220 in the embodiment shown in fig. 2, so that the description of steps S310 to S320 is omitted. As shown in fig. 3, the method for calibrating the contact resistance of the battery connector further comprises the following steps:
and step S330, when the first preset condition is met for a plurality of times within the preset time period, the initial contact resistance values are corrected for a plurality of times, and corrected values of the initial contact resistance values are obtained.
Step S340, calculating based on the correction values of the initial values of the contact resistances to obtain the calculated value of the correction value of the initial value of the contact resistance; and taking the calculated value of the correction value of the initial value of the contact resistance as the calibration value of the contact resistance of the connecting piece.
In step S330, the initial values of the contact resistances are not calibrated immediately after each correction of the initial values of the contact resistances, but the correction values of all the initial values of the contact resistances within a predetermined period of time are recorded. As an example, correction values of the recorded initial values of the contact resistance are buffered for subsequent calculation based on these correction values.
In step S340, the acquired plurality of contact resistance initial values are calculated, including calculating an average value, a median, or a standard deviation of all the contact resistance initial values recorded in a predetermined period of time.
As an example, the step of taking the calculated value of the correction value of the initial value of the contact resistance as the calibration value of the contact resistance of the connection member is to take the average value, the median value or the standard deviation of all the initial values of the contact resistance in a predetermined period of time as the calibration value of the contact resistance.
Taking a power battery as an example, the output power requested by an electric automobile during driving changes in real time, the current output by the battery also varies, and the current direction also changes in consideration of the working conditions such as braking, road jolting, back flushing caused by downhill, charging and the like, so that the current is greatly fluctuated within a shorter duration. In addition, when current is passed through the connector, a partial voltage may be generated at the connector location in the circuit due to the overall resistance of the connector, causing the battery voltage across the connector to fluctuate. Therefore, in consideration of the accuracy of correction of the contact resistance value, the accuracy of subsequent calibration of the whole resistance and the robustness of voltage acquisition of a battery across the connecting piece are improved, the average value or the median of all the contact resistance initial values in the preset time can be calculated, and the average value or the median of the contact resistance initial values is used for calibrating the contact resistance initial values, so that the negative influence of current or voltage fluctuation caused by instability of the battery system on the correction of the contact resistance initial values can be effectively avoided.
In addition, in addition to current and voltage fluctuations caused by different working conditions of the battery, in the case of abnormal or malfunctioning of the battery, larger fluctuations in current and voltage usually occur. For this case, it is possible to judge whether or not the fluctuation of the current, voltage is within the normal range by calculating the standard deviation of all the initial values of the contact resistance. For example, if the standard deviation of the initial values of the plurality of contact resistances in the predetermined period is excessively large, it is considered that the battery may be abnormal. If the standard deviation is within the acceptable range, the battery is considered to be in a normal state.
It will be appreciated that the above described calculation modes may be combined. As an example, the standard deviation may be preferentially calculated so as to determine whether the battery is in a normal state, and when the battery is in an abnormal state, the battery management system may send a message of battery abnormality or failure to the vehicle controller, and after receiving the message, the vehicle controller may send out alarm information such as stopping the vehicle and stopping charging to close the battery system, so that the battery is powered down to check the abnormal or failed battery later. When the battery is in a normal state, the average value or the median of the initial values of the plurality of contact resistances in the predetermined period of time can be continuously calculated so as to calibrate the initial value of the contact resistance in the predetermined period of time.
In this embodiment, by calculating the plurality of correction values and calibrating the contact resistance value of the connecting member based on the calculated values, negative effects of fluctuation of the contact resistance value caused by instability of the battery system on the accuracy of the calibration result of the contact resistance value can be effectively avoided, thereby improving the calibration accuracy of the contact resistance value.
Fig. 4 shows a schematic block diagram of a calibration device for the contact resistance of a battery connector according to an embodiment of the present application.
As shown in fig. 4, the calibration device 400 includes an acquisition module 410, a correction module 420, and a calibration module 430.
An acquisition module 410 for acquiring battery current and battery voltage across the connection at a plurality of times over a predetermined period of time.
And the correction module 420 corrects the initial value of the contact resistance to obtain a correction value of the initial value of the contact resistance when a first preset condition is met, wherein the first preset condition comprises that the difference value of the battery voltage and the difference value of the battery current at any two moments are larger than a preset threshold value.
And the calibration module 430 is used for calibrating the contact resistance based on the corrected value of the initial value of the contact resistance.
Taking the application scenario of the power battery as an example, the calibration device may be a control board (or a main board) in the battery management system, the acquisition module may be a CSC, CSU or CMC module of the main board, which is used for acquiring the voltage, current or temperature of the battery, and converting the acquired analog signal into a digital signal to be sent to a processor (i.e. the correction module 420) in the main board. The processor sends the processing results to the memory module (i.e., calibration module 430).
It will be appreciated that CSC, CSU or CMC may be integrated into a single module that can collect current, voltage and resistance simultaneously or as separate modules for a single function. The present application is not limited in this regard.
The calibration device of the embodiment collects battery currents at a plurality of moments in a certain time and battery voltages across the connecting piece, calculates battery current difference values at adjacent moments and battery voltage difference values across the connecting piece, and can monitor the integral resistance value change of the connecting piece. Because the contact resistance value occupies a certain proportion in the integral resistance value of the connecting piece, when the integral resistance value changes, the initial value of the contact resistance across the connecting piece can be determined to change, so that the monitoring of the change of the contact resistance value is realized, the initial value of the contact resistance is corrected in time, the corrected contact resistance value is used as the calibration value of the contact resistance value, and the follow-up inaccurate calibration of the integral resistance value of the connecting piece caused by the change of the contact resistance value is avoided.
In some embodiments, correction module 420 is further to: and when the first preset condition is met for a plurality of times within the preset time period, correcting the initial value of the contact resistance for a plurality of times to obtain corrected values of the initial values of the contact resistance.
Calculating based on the correction values of the initial values of the contact resistances to obtain calculated values of the correction values of the initial values of the contact resistances;
the calibration module 430 is also configured to: and taking the calculated value of the correction value of the initial value of the contact resistance as the calibration value of the contact resistance of the connecting piece.
According to the calibration device, the plurality of correction values are calculated, and the calculated value of the correction value of the initial value of the contact resistance is used as the calibration value of the contact resistance of the connecting piece, so that negative influence of fluctuation of the contact resistance caused by instability of a battery system on the accuracy of the calibration result of the contact resistance can be effectively avoided, and the calibration accuracy of the contact resistance is improved.
Fig. 5 shows a schematic block diagram of a calibration device for the contact resistance of a battery connector according to an embodiment of the present application. As shown in fig. 5, the calibration device 500 includes a processor 510, and optionally, the control circuit 500 further includes a memory 520, wherein the memory 520 is configured to store instructions, and the processor 510 is configured to read the instructions and execute the calibration method of the contact resistance of the battery connector according to the various embodiments of the present application described above based on the instructions.
Taking the power battery application scenario as an example, the calibration device may be a chip in a control board (or motherboard) of the battery management system, where the chip includes a processor (i.e., the processing module 510) and a memory module (i.e., the memory 520)
The embodiment of the application also provides a computer storage medium, wherein the storage medium stores a computer program, and the computer program executes the calibration method when running.
The embodiment of the application also provides a battery management system, which comprises the calibration device of the contact resistance of the battery connector.
Taking the application scenario of the power battery as an example, the battery management system may be a battery management system of the battery itself or a battery management system of an electric device (for example, an electric automobile).
The embodiment of the application also provides an electric device, which comprises the battery management system.
Taking the application scene of the power battery as an example, the electric device can be an electric automobile, an electric ship and the like.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.
In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes or substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (13)
- A method for calibrating contact resistance of battery connector is characterized in that,acquiring battery currents at a plurality of moments within a predetermined time period and battery voltages across the connection;when a first preset condition is met, correcting the initial value of the contact resistance to obtain a corrected value of the initial value of the contact resistance, wherein the first preset condition comprises that the difference value of the battery voltage and the difference value of the battery current at any two moments are larger than a preset threshold value;and taking the corrected value of the initial value of the contact resistance as the calibrated value of the contact resistance value.
- The calibration method according to claim 1, wherein the step of correcting the initial value of the contact resistance includes:and when the first preset condition is met for a plurality of times within the preset time period, correcting the initial value of the contact resistance for a plurality of times to obtain corrected values of the initial values of the contact resistance.
- The method according to claim 2, wherein the step of calibrating the contact resistance based on the correction value of the initial value of the contact resistance includes:calculating a correction value based on the initial values of the contact resistances to obtain a calculated value of the correction value of the initial value of the contact resistance;and taking the calculated value of the correction value of the initial value of the contact resistance as the calibration value of the contact resistance of the connecting piece.
- The calibration method according to claim 1, wherein correction of the initial value of the contact resistance is stopped when a second preset condition is satisfied; the second preset condition comprises that the correction times reach a preset value or the duration of the preset time period reaches a preset value or the battery is powered down.
- The calibration method according to claim 1, characterized in that the method further comprises:acquiring an initial measured value of the overall resistance of the connecting piece and an inherent resistance value of the connecting piece;and calculating a difference value between the initial measured value of the overall resistance of the connecting piece and the inherent resistance value, and taking the difference value as an initial value of the contact resistance of the connecting piece.
- The calibration method according to any one of claims 1 to 5, wherein the step of correcting the initial value of the contact resistance includes:calculating a battery pack voltage difference value and a battery pack current difference value of the cross-connecting piece at adjacent moments;calculating the ratio of the battery pack voltage difference value and the battery pack current difference value of the cross-connection piece;and calculating the difference value of the ratio of the voltage difference value of the battery assembly and the current difference value of the battery assembly and the inherent resistance value of the cross-connecting piece, and correcting the initial value of the contact resistance based on the difference value to obtain a corrected value of the initial value of the contact resistance.
- The calibration method of claim 6, the method further comprising:and acquiring a temperature value of the connecting piece at the current moment, and performing standard value conversion on the corrected value of the initial value of the contact resistance based on the temperature value to obtain the corrected value of the initial value of the contact resistance at the standard temperature.
- The calibration method according to claim 1, characterized in that the method further comprises:and calibrating the overall resistance value of the connecting piece based on the calibrated contact resistance value and the inherent resistance value.
- A device for calibrating contact resistance of a battery assembly connector, comprising:an acquisition module for acquiring battery pack currents at a plurality of times within a predetermined period of time and battery pack voltages across the connection;the correction module corrects the initial value of the contact resistance to obtain a correction value of the initial value of the contact resistance when a first preset condition is met, wherein the first preset condition comprises that the voltage difference value of the battery assembly and the current difference value of the battery assembly at any two moments are larger than a preset threshold value;and the calibration module is used for taking the corrected value of the initial value of the contact resistance as the calibration value of the contact resistance value.
- A device for calibrating contact resistance of a battery assembly connector, comprising:a memory storing a computer program;a processor for executing the computer program, which computer program, when run, performs the calibration method of any of the claims 1-8.
- A computer storage medium, characterized in that the storage medium stores a computer program which, when run, performs the calibration method of any one of claims 1-8.
- A battery management system comprising the calibration device for contact resistance of a battery assembly connector of claim 10.
- An electrical device comprising the battery management system of claim 12.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2022/076721 WO2023168542A1 (en) | 2022-03-09 | 2022-03-09 | Method and device for calibrating contact resistance of battery connecting piece, and electric device |
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| CN202280034919.5A Pending CN117321834A (en) | 2022-03-09 | 2022-03-09 | Method and device for calibrating contact resistance of battery connector and power utilization device |
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| WO (1) | WO2023168542A1 (en) |
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| CN117169753B (en) * | 2023-11-03 | 2024-03-08 | 合肥国轩高科动力能源有限公司 | Method and device for determining parameters of electric connection pieces of batteries connected in series and electronic equipment |
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| JP4816097B2 (en) * | 2006-01-20 | 2011-11-16 | 日産自動車株式会社 | Battery SOC calculation device |
| CN101363881B (en) * | 2007-08-08 | 2012-07-04 | 中芯国际集成电路制造(上海)有限公司 | Method for testing resistance |
| JP6541412B2 (en) * | 2015-05-01 | 2019-07-10 | カルソニックカンセイ株式会社 | Charging rate calculation method and charging rate calculation device |
| CN109085513B (en) * | 2018-10-12 | 2021-02-19 | 东软睿驰汽车技术（沈阳）有限公司 | Method and device for calculating internal resistance of battery |
| CN112909362B (en) * | 2018-10-16 | 2022-06-10 | 宁德时代新能源科技股份有限公司 | Cell voltage correction method, device, equipment and medium |
| CN113051852B (en) * | 2021-04-30 | 2022-05-13 | 蜂巢能源科技有限公司 | Method, device and equipment for acquiring contact resistance of battery cell structural member and storage medium |
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