Battery equivalent circuit model parameter identification method and device, equipment and vehicle

Abstract

The invention provides a battery equivalent circuit model parameter identification method, device and equipment and a vehicle. The method comprises the steps that equivalent circuit model parameters corresponding to multi-section charging and discharging data of a battery in the vehicle are acquired; fitting equivalent circuit model parameters corresponding to each section of charging and discharging data to obtain a corresponding relation between different charge states and the equivalent circuit model parameters, and generating a first curve corresponding to open-circuit voltage in the charge states and the equivalent circuit model parameters; generating a second curve with the charge state corresponding to the open-circuit voltage by translating or scaling the first curve; and identifying equivalent circuit model parameters of the battery in different charge states according to the second curve. According to the method, the second curve with the charge state corresponding to the open-circuit voltage is obtained after the first curve is corrected, and then the equivalent circuit model parameters of the battery in different charge states are identified according to the second curve, so that the identification precision of the equivalent circuit model parameters can be improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a method, device, equipment and vehicle for identifying battery equivalent circuit model parameters. Background Art

[0002] At present, the research on batteries generally establishes an equivalent circuit model of the battery. The equivalent circuit model of the battery converts the complex electrochemical reaction inside the battery into an equivalent circuit composed of electrical components such as resistors, capacitors, and power supplies to reflect the battery characteristics. For establishing an equivalent circuit model of the battery, it is crucial to obtain the values ​​of the equivalent circuit model parameters.

[0003] The related technology is based on the battery HPPC (Hybrid Pulse Power Characteristic) test, which substitutes the measured charging and discharging data into the equivalent circuit model for fitting to identify the values ​​of the equivalent circuit model parameters. However, the identification accuracy of the equivalent circuit model parameters identified by the battery HPPC test is low. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, the first purpose of the present invention is to propose a method for identifying parameters of a battery equivalent circuit model. First, a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model is generated, and the first curve is corrected to obtain a second curve corresponding to the state of charge and the open circuit voltage. Then, the equivalent circuit model parameters of the battery at different states of charge are identified according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0006] The second object of the present invention is to provide a device for identifying battery equivalent circuit model parameters.

[0007] The third objective of the present invention is to provide a battery management device.

[0008] A fourth object of the present invention is to provide a vehicle.

[0009] A fifth object of the present invention is to provide a computer-readable storage medium.

[0010] A sixth object of the present invention is to provide a computer program product.

[0011] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a method for identifying battery equivalent circuit model parameters, including: obtaining equivalent circuit model parameters corresponding to multiple segments of charging and discharging data of a battery in a vehicle; fitting the equivalent circuit model parameters corresponding to each segment of the charging and discharging data to obtain the correspondence between different states of charge and the equivalent circuit model parameters, and generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters; generating a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve; and identifying the equivalent circuit model parameters of the battery at different states of charge according to the second curve.

[0012] According to the method for identifying the battery equivalent circuit model parameters of an embodiment of the present invention, the equivalent circuit model parameters corresponding to multiple sections of charge and discharge data of the battery in the vehicle are first obtained, and then the equivalent circuit model parameters corresponding to each section of charge and discharge data are fitted to obtain the corresponding relationship between different states of charge and the equivalent circuit model parameters, and a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters is generated, and then a second curve corresponding to the state of charge and the open circuit voltage is generated by translating and scaling the first curve, and finally the equivalent circuit model parameters of the battery at different states of charge are identified according to the second curve. Thus, the method first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0013] In addition, the method for identifying battery equivalent circuit model parameters proposed in the first aspect of the present invention may also have the following additional technical features:

[0014] According to one embodiment of the present invention, the step of obtaining equivalent circuit model parameters corresponding to multiple segments of charge and discharge data of a battery in a vehicle includes:

[0015] Acquiring charging and discharging data of the battery;

[0016] Segmenting the charge-discharge data according to the set ampere-hours to obtain multiple segments of the charge-discharge data;

[0017] Substitute each section of the charge and discharge data into the equivalent circuit model of the battery to obtain equivalent circuit model parameters corresponding to the multiple sections of the charge and discharge data.

[0018] According to an embodiment of the present invention, the fitting of the equivalent circuit model parameters corresponding to each segment of the charge and discharge data includes:

[0019] The equivalent circuit model parameters corresponding to the charge and discharge data of each segment are fitted using the least squares method.

[0020] According to an embodiment of the present invention, the fitting of the equivalent circuit model parameters corresponding to each segment of the charge and discharge data further includes:

[0021] Obtain estimated values ​​of the open circuit voltage under different states of charge by using the corresponding relationship between the different states of charge obtained after fitting and the open circuit voltage in the equivalent circuit model parameters;

[0022] Obtaining actual values ​​of the open circuit voltage under different states of charge;

[0023] calculating a loss function based on the squares of the differences between a plurality of estimated values ​​of the open circuit voltage and actual values ​​of the open circuit voltage;

[0024] The loss function is used to update the equivalent circuit model of the battery.

[0025] According to an embodiment of the present invention, before generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameter, the method further includes:

[0026] Obtaining the charge status of each segment uploaded by the vehicle;

[0027] The state of charge of each segment is used as the starting value of the state of charge of each segment in the first curve.

[0028] According to an embodiment of the present invention, the step of translating and scaling the first curve to generate a second curve corresponding to the state of charge and the open circuit voltage includes:

[0029] Obtaining a reference curve corresponding to the state of charge and the open circuit voltage of the battery when it leaves the factory;

[0030] The first curve is translated and scaled so as to make the first curve fit the reference curve, thereby obtaining the second curve.

[0031] To achieve the above-mentioned purpose, the second aspect of the present invention proposes a device for identifying battery equivalent circuit model parameters, including: an acquisition module, used to obtain equivalent circuit model parameters corresponding to multiple segments of charging and discharging data of a battery in a vehicle; a first generation module, used to fit the equivalent circuit model parameters corresponding to each segment of the charging and discharging data to obtain the correspondence between different states of charge and the equivalent circuit model parameters, and generate a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters; a second generation module, used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and moving the first curve; an identification module, used to identify the equivalent circuit model parameters of the battery at different states of charge according to the second curve.

[0032] According to the device for identifying battery equivalent circuit model parameters of an embodiment of the present invention, an acquisition module is used to acquire equivalent circuit model parameters corresponding to multiple sections of battery charge and discharge data in a vehicle, and a first generation module is used to fit the equivalent circuit model parameters corresponding to each section of charge and discharge data to obtain the corresponding relationship between different states of charge and equivalent circuit model parameters, and a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters is generated, and a second generation module is used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve, and an identification module is used to identify the equivalent circuit model parameters of the battery at different states of charge according to the second curve. Thus, the device obtains the second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0033] In addition, the device for identifying battery equivalent circuit model parameters proposed in the second aspect of the present invention may also have the following additional technical features:

[0034] According to one embodiment of the present invention, when the acquisition module is used to acquire equivalent circuit model parameters corresponding to multiple segments of charge and discharge data of a battery in a vehicle, it includes:

[0035] Acquiring charging and discharging data of the battery;

[0036] Segmenting the charge-discharge data according to the set ampere-hours to obtain multiple segments of the charge-discharge data;

[0037] Substitute each section of the charge and discharge data into the equivalent circuit model of the battery to obtain equivalent circuit model parameters corresponding to the multiple sections of the charge and discharge data.

[0038] According to an embodiment of the present invention, when the first generating module is used to fit the equivalent circuit model parameters corresponding to each segment of the charging and discharging data, it includes:

[0039] The equivalent circuit model parameters corresponding to the charge and discharge data of each segment are fitted using the least squares method.

[0040] According to an embodiment of the present invention, when the first generating module is used to fit the equivalent circuit model parameters corresponding to each segment of the charging and discharging data, it also includes:

[0041] Obtain estimated values ​​of the open circuit voltage under different states of charge by using the corresponding relationship between the different states of charge obtained after fitting and the open circuit voltage in the equivalent circuit model parameters;

[0042] Obtaining actual values ​​of the open circuit voltage under different states of charge;

[0043] calculating a loss function based on the squares of the differences between a plurality of estimated values ​​of the open circuit voltage and actual values ​​of the open circuit voltage;

[0044] The loss function is used to update the equivalent circuit model of the battery.

[0045] According to an embodiment of the present invention, before the first generating module is used to generate a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameter, it is also used to:

[0046] Obtaining the charge status of each segment uploaded by the vehicle;

[0047] The state of charge of each segment is used as the starting value of the state of charge of each segment in the first curve.

[0048] According to an embodiment of the present invention, when the second generating module is used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve, the second generating module includes:

[0049] Obtaining a reference curve corresponding to the state of charge and the open circuit voltage of the battery when it leaves the factory;

[0050] The first curve is translated and scaled so as to make the first curve fit the reference curve, thereby obtaining the second curve.

[0051] To achieve the above object, a third aspect of the present invention provides a battery management device, including:

[0052] Processor and memory;

[0053] The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method for identifying the battery equivalent circuit model parameters of the embodiment of the first aspect.

[0054] The battery management device of the embodiment of the present invention, by utilizing the above-mentioned method for identifying the battery equivalent circuit model parameters, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge based on the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0055] In order to achieve the above-mentioned purpose, a fourth aspect of the present invention provides a vehicle, comprising: a battery management device as described in the first aspect of the present invention.

[0056] The vehicle of the embodiment of the present invention, by utilizing the above-mentioned battery management device, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge based on the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0057] To achieve the above objectives, the fifth aspect of the present invention proposes a computer-readable storage medium. When the instructions in the computer-readable storage medium are executed by a processor, the processor can execute the method for identifying the battery equivalent circuit model parameters of the first aspect of the present invention.

[0058] The computer-readable storage medium of an embodiment of the present invention, by executing the above-mentioned method for identifying parameters of a battery equivalent circuit model, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and corrects the first curve to obtain a second curve corresponding to the state of charge and the open circuit voltage, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0059] To achieve the above objectives, a sixth aspect of the present invention provides a computer program product. When an instruction processor in the computer program product executes, the method for identifying battery equivalent circuit model parameters of the first aspect of the present invention is executed.

[0060] The computer program product of the embodiment of the present invention executes the above-mentioned method for identifying the battery equivalent circuit model parameters, firstly generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0061] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0063] Figure 1 is a schematic diagram of a battery equivalent circuit model according to an embodiment of the present invention;

[0064] Figure 2 is a flow chart of a method for identifying parameters of a battery equivalent circuit model according to an embodiment of the present invention;

[0065] Figure 3 is a graph of SOC-Uocv_start and SOC-OCV according to one embodiment of the present invention;

[0066] Figure 4 is a graph of SOC-Uocv_start and SOC-OCV according to another embodiment of the present invention;

[0067] Figure 5 is a flow chart of a method for identifying battery equivalent circuit model parameters according to an embodiment of the present invention;

[0068] Figure 6 4 is a block diagram of a device for identifying parameters of a battery equivalent circuit model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0069] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein reference numerals set or similar throughout represent set or similar elements or elements having set or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0070] The following describes a method for identifying battery equivalent circuit model parameters, an apparatus for identifying battery equivalent circuit model parameters, a battery management device, a vehicle, and a computer-readable storage medium according to an embodiment of the present invention with reference to the accompanying drawings.

[0071] Before introducing the method for identifying parameters of a battery equivalent circuit model according to an embodiment of the present invention, the battery equivalent circuit model is first introduced.

[0072] like Figure 1As shown, the battery equivalent circuit model of the embodiment of the present invention includes: battery internal polarization capacitor Ci (i=1, 2, ..., n), battery internal polarization resistor Ri (i=1, 2, ..., n), battery ohmic internal resistance R0 and battery open circuit voltage Uocv. Among them, the battery internal polarization capacitor Ci is connected in parallel with the battery polarization internal resistance Ri, and then forms a series circuit with the battery ohmic internal resistance R0 and the battery open circuit voltage Uocv in sequence. The voltage across the series circuit is the output voltage Uoutput, and the calculation formula of the output voltage Uoutput is as follows:

[0073]

[0074] in,

[0075] I(t) is the current value measured at time t.

[0076] Figure 2 4 is a flow chart of a method for identifying battery equivalent circuit model parameters according to an embodiment of the present invention.

[0077] like Figure 2 As shown, the method for identifying battery equivalent circuit model parameters according to an embodiment of the present invention comprises the following steps:

[0078] S201, obtaining equivalent circuit model parameters corresponding to multiple stages of charge and discharge data of a battery in a vehicle.

[0079] Among them, the equivalent circuit model parameters include: open circuit voltage Uocv, ohmic internal resistance R0, battery internal polarization resistance Ri and battery internal polarization capacitance Ci.

[0080] In this step, the charge and discharge data of the battery such as current I, output voltage Uoutput and battery state of charge SOC are collected, and the collected data are segmented according to the set ampere-hours, wherein the set ampere-hours can be segmented according to 1% of the total ampere-hours of the battery, and the ohmic internal resistance R0 of the battery, the internal polarization resistance Ri of the battery and the internal polarization capacitance Ci of the battery in the equivalent circuit model of each segment of data are considered to be unchanged. In order to improve the accuracy of the fitting, considering the change of the open circuit voltage Uocv of the battery, it is considered that the open circuit voltage Uocv (t) changes linearly with △Ah (ampere-hours) between the open circuit voltage Uocv_start of the starting state and the open circuit voltage Uocv_end of the end state. The current I, output voltage Uoutput and charge state SOC of each ampere period are obtained, and the current I and output voltage Uoutput are substituted into the equivalent circuit model to obtain the open circuit voltage Uocv of the battery in each ampere period, the ohmic internal resistance R0 of the battery, the internal polarization resistance Ri of the battery and the internal polarization capacitance Ci of the battery.

[0081] Among them, only the initial state of charge SOC is the vehicle uploaded value, and the subsequent SOC is reduced by 1 (because the data is segmented by 1% of the total ampere-hours). An example is as follows:

[0082] Table 1

[0083] SOC ΔAh Uocv_start Uocv_end R0 R τ 90(Vehicle upload value) 1 4.000 3.990 0.0006 0.00006 10 89 2 3.990 3.980 0.0005 0.00005 10 … … … … … … … 30 61 3.000 2.990 0.0004 0.00004 10

[0084] S202, fitting the equivalent circuit model parameters corresponding to each section of charge and discharge data to obtain the corresponding relationship between different charge states and the equivalent circuit model parameters, and generating a first curve corresponding to the charge state and the open circuit voltage in the equivalent circuit model parameters.

[0085] In this step, the open circuit voltage Uocv of the battery, the ohmic internal resistance R0 of the battery, the internal polarization resistance Ri of the battery, and the internal polarization capacitance Ci of the battery are fitted respectively to obtain the corresponding relationships between different charge states and the open circuit voltage Uocv of the battery, the ohmic internal resistance R0 of the battery, the internal polarization resistance Ri of the battery, and the internal polarization capacitance Ci of the battery, and generate a curve corresponding to the open circuit voltage in the charge state and the equivalent circuit model parameters as the first curve.

[0086] S203 , generating a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve.

[0087] Because the SOC uploaded by the vehicle has errors, after obtaining the above Table 1, the first curve SOC-Uocv_start of the state of charge and the open circuit voltage in the starting state in Table 1 and the reference curve SOC-OCV corresponding to the state of charge and the open circuit voltage of the battery at the factory are fitted, as shown in Figure 3 As shown. SOC-Uocv_start is translated and scaled to fit the SOC-OCV curve, as shown Figure 4 As shown, the curve obtained by translating and scaling SOC-Uocv_start and fitting it to the SOC-OCV curve is used as the second curve.

[0088] S204: Identify equivalent circuit model parameters of the battery at different states of charge according to the second curve.

[0089] In this step, the distance of SOC-Uocv_start translation is the error of SOC, and the scaling size is the SOH (State Of Health) value, so the SOH, the current SOC-OCV curve and the equivalent circuit model parameters under each SOC can be obtained at the same time.

[0090] If the Uocv under different ΔAh is known, the starting soc and soh are known, according to Δsoc = ΔAh / (total battery capacity * SOH), the soc-ocv curve should coincide with the soc-ocv curve when the battery leaves the factory, which is the basic ocv characteristic of the battery. The Uocv under different ΔAh has been obtained above, and the starting soc and soh are calculated to minimize the difference between the two curves. Because there is an error in the starting soc, it needs to be translated horizontally, and the amount of translation is the size of the error. The change in SOH determines that under the same ΔAh, the Δsoc is different, and visually the soc-ocv curve will be enlarged or reduced horizontally.

[0091] Therefore, the method for identifying the parameters of the battery equivalent circuit model of the embodiment of the present invention uses a changing Uocv to fit each segment of data, thereby improving the fitting accuracy and avoiding errors caused by directly using the uploaded SOC. By fitting the SOC-OCV based on ΔAh and the SOC-OCV curve when the battery leaves the factory, the current SOC-OCV curve can be obtained and the SOH of the battery can be estimated synchronously. The present invention dynamically identifies and models the battery parameters to adapt to the changes in model parameters caused by battery aging during user use, and helps improve the accuracy of SOH estimation throughout the life cycle.

[0092] Figure 5 is a flow chart of a method for identifying battery equivalent circuit model parameters according to an embodiment of the present invention.

[0093] like Figure 5 As shown, the method for identifying battery equivalent circuit model parameters according to an embodiment of the present invention comprises the following steps:

[0094] S501, obtaining battery charge and discharge data.

[0095] During vehicle driving, the battery management device obtains battery charge and discharge data such as current I and output voltage Uoutput in real time, and uploads the acquired battery charge and discharge data to the cloud.

[0096] S502, segmenting the charge and discharge data according to the set ampere-hours to obtain multiple segments of charge and discharge data.

[0097] The set ampere-hour value may be set according to actual needs, for example, it may be 1% of the total ampere-hour value of the battery.

[0098] In this step, the acquired charge and discharge data such as the current I and the output voltage Uoutput are segmented according to the set ampere-hours to obtain multiple segments of charge and discharge data.

[0099] S503, respectively substituting each section of charge and discharge data into the equivalent circuit model of the battery to obtain equivalent circuit model parameters corresponding to the multiple sections of charge and discharge data.

[0100] In this step, the current I and the output voltage Uoutput are substituted into the equivalent circuit model to obtain the open circuit voltage Uocv of the battery in each ampere period, the ohmic internal resistance R0 of the battery, the internal polarization resistance Ri of the battery, and the internal polarization capacitance Ci of the battery.

[0101] S504, fitting the equivalent circuit model parameters corresponding to each section of charge and discharge data by the least square method to obtain the corresponding relationship between different charge states and the equivalent circuit model parameters, and generating a first curve corresponding to the charge state and the open circuit voltage in the equivalent circuit model parameters.

[0102] In this step, the principle of the least square method is to find the optimal solution so that the sum of the squares of the difference between the estimated output voltage and the actual output voltage is minimized, that is, the loss function of the least square method is the root mean square of the voltage error. As a feasible way to find the optimal parameters, a commonly used optimization method such as gradient descent is adopted.

[0103] After obtaining the correspondence between different states of charge and the open circuit voltage in the equivalent circuit model parameters by fitting using the least squares method, the obtained correspondence between different states of charge and the open circuit voltage in the equivalent circuit model parameters is used to obtain estimated values ​​of the open circuit voltage at different states of charge, and at the same time, the actual values ​​of the open circuit voltage at different states of charge are obtained. For example, the actual value of the open circuit voltage can be obtained using a voltage sensor, and then the loss function is calculated based on the square of the difference between the estimated values ​​of multiple open circuit voltages and the actual values ​​of the open circuit voltage, and finally the equivalent circuit model of the battery is updated using the loss function.

[0104] Before generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters, first obtain each section of the state of charge uploaded by the vehicle, and use each section of the state of charge as the starting value of each section of the state of charge in the first curve.

[0105] S505, obtaining a reference curve corresponding to the state of charge and open circuit voltage of the battery when it leaves the factory.

[0106] S506: The first curve is made to fit with the reference curve by translating and scaling the first curve to obtain a second curve.

[0107] S507, identifying equivalent circuit model parameters of the battery at different states of charge according to the second curve.

[0108] It should be noted that the execution process of step S305 to step S307 refers to the above-mentioned step S203 and step S204, and the details are not repeated here.

[0109] In summary, according to the method for identifying the battery equivalent circuit model parameters of an embodiment of the present invention, the equivalent circuit model parameters corresponding to multiple sections of charge and discharge data of the battery in the vehicle are first obtained, and then the equivalent circuit model parameters corresponding to each section of charge and discharge data are fitted to obtain the corresponding relationship between different states of charge and the equivalent circuit model parameters, and a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters is generated, and then a second curve corresponding to the state of charge and the open circuit voltage is generated by translating and scaling the first curve, and finally the equivalent circuit model parameters of the battery at different states of charge are identified according to the second curve. Therefore, the method first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0110] Figure 6 4 is a block diagram of a device for identifying parameters of a battery equivalent circuit model according to an embodiment of the present invention.

[0111] like Figure 6 As shown, the battery equivalent circuit model parameter identification device 600 according to the embodiment of the present invention includes: an acquisition module 610 , a first generation module 620 , a second generation module 630 and an identification module 640 .

[0112] Among them, the acquisition module 610 is used to obtain the equivalent circuit model parameters corresponding to multiple sections of charging and discharging data of the battery in the vehicle. The first generation module 620 is used to fit the equivalent circuit model parameters corresponding to each section of charging and discharging data to obtain the correspondence between different states of charge and the equivalent circuit model parameters, and generate a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters. The second generation module 630 is used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve. The identification module 640 is used to identify the equivalent circuit model parameters of the battery at different states of charge according to the second curve.

[0113] According to one embodiment of the present invention, when the acquisition module 610 is used to acquire equivalent circuit model parameters corresponding to multiple segments of charging and discharging data of a battery in a vehicle, it includes:

[0114] Get battery charge and discharge data;

[0115] Segment the charge and discharge data according to the set ampere-hours to obtain multiple segments of charge and discharge data;

[0116] Substitute each section of charge and discharge data into the equivalent circuit model of the battery to obtain equivalent circuit model parameters corresponding to the multiple sections of charge and discharge data.

[0117] According to an embodiment of the present invention, when the first generation module 620 is used to fit the equivalent circuit model parameters corresponding to each segment of charging and discharging data, it includes:

[0118] The equivalent circuit model parameters corresponding to each section of charge and discharge data are fitted using the least squares method.

[0119] According to an embodiment of the present invention, when the first generation module 620 is used to fit the equivalent circuit model parameters corresponding to each segment of charging and discharging data, it also includes:

[0120] By using the corresponding relationship between different charge states obtained after fitting and the open circuit voltage in the equivalent circuit model parameters, the estimated value of the open circuit voltage under different charge states is obtained;

[0121] Get the actual value of open circuit voltage under different states of charge;

[0122] calculating a loss function based on the square of the difference between the estimated values ​​of the plurality of open circuit voltages and the actual values ​​of the open circuit voltages;

[0123] The loss function is used to update the equivalent circuit model of the battery.

[0124] According to an embodiment of the present invention, before the first generating module 620 is used to generate a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameter, it is also used to:

[0125] Get the state of charge of each segment uploaded by the vehicle;

[0126] Each state of charge is used as the starting value of each state of charge in the first curve.

[0127] According to one embodiment of the present invention, the second generating module 630 is used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve, including:

[0128] Obtain a reference curve corresponding to the state of charge and open circuit voltage of the battery when it leaves the factory;

[0129] The first curve is translated and scaled so as to fit the first curve with the reference curve, thereby obtaining the second curve.

[0130] It should be noted that for details not disclosed in the device for identifying battery equivalent circuit model parameters in an embodiment of the present invention, please refer to the details disclosed in the method for identifying battery equivalent circuit model parameters in an embodiment of the present invention, and the details will not be repeated here.

[0131] According to the device for identifying battery equivalent circuit model parameters of an embodiment of the present invention, an acquisition module is used to obtain equivalent circuit model parameters corresponding to multiple sections of battery charge and discharge data in a vehicle, and a first generation module is used to fit the equivalent circuit model parameters corresponding to each section of charge and discharge data to obtain the corresponding relationship between different states of charge and equivalent circuit model parameters, and a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters is generated, and a second generation module is used to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve, and an identification module is used to identify the equivalent circuit model parameters of the battery at different states of charge according to the second curve. Thus, the device obtains the second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0132] Based on the above embodiments, the present invention also proposes a battery management device.

[0133] The battery management device of an embodiment of the present invention includes: a processor and a memory; wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method for identifying the battery equivalent circuit model parameters of the first aspect embodiment.

[0134] The battery management device of the embodiment of the present invention, by utilizing the above-mentioned method for identifying the battery equivalent circuit model parameters, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge based on the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0135] Based on the above embodiments, the present invention also provides a vehicle.

[0136] A vehicle according to an embodiment of the present invention includes: the above-mentioned battery management device.

[0137] The vehicle of the embodiment of the present invention, by utilizing the above-mentioned battery management device, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge based on the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0138] Based on the above embodiments, the present invention also proposes a computer-readable storage medium.

[0139] In this embodiment, when the instructions in the computer-readable storage medium are executed by a processor, the processor is enabled to execute the above-mentioned method for identifying parameters of a battery equivalent circuit model.

[0140] The computer-readable storage medium of an embodiment of the present invention, by executing the above-mentioned method for identifying parameters of a battery equivalent circuit model, first generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and corrects the first curve to obtain a second curve corresponding to the state of charge and the open circuit voltage, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0141] Based on the above embodiments, the present invention also proposes a computer program product.

[0142] In this embodiment, when the instruction processor in the computer program product is executed, the above-mentioned method for identifying the battery equivalent circuit model parameters is executed.

[0143] The computer program product of the embodiment of the present invention executes the above-mentioned method for identifying the battery equivalent circuit model parameters, firstly generates a first curve corresponding to the state of charge and the open circuit in the equivalent circuit model, and obtains a second curve corresponding to the state of charge and the open circuit voltage after correcting the first curve, and then identifies the equivalent circuit model parameters of the battery at different states of charge according to the second curve, thereby improving the identification accuracy of the equivalent circuit model parameters.

[0144] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the set embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0145] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0146] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0147] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0148] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0149] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0150] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0151] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for identifying parameters of a battery equivalent circuit model, characterized in that: include: Obtain equivalent circuit model parameters corresponding to multiple-stage charging and discharging data of the battery in the vehicle; Fitting the equivalent circuit model parameters corresponding to each section of the charge and discharge data to obtain a corresponding relationship between different states of charge and the equivalent circuit model parameters, and generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters; Generating a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve; According to the second curve, the equivalent circuit model parameters of the battery at different states of charge are identified.

2. The method according to claim 1, characterized in that The obtaining of equivalent circuit model parameters corresponding to multiple segments of charge and discharge data of a battery in a vehicle includes: Acquiring charging and discharging data of the battery; Segmenting the charge-discharge data according to the set ampere-hours to obtain multiple segments of the charge-discharge data; Substitute each section of the charge and discharge data into the equivalent circuit model of the battery to obtain equivalent circuit model parameters corresponding to the multiple sections of the charge and discharge data.

3. The method according to claim 1, characterized in that The fitting of the equivalent circuit model parameters corresponding to each segment of the charge and discharge data includes: The equivalent circuit model parameters corresponding to the charge and discharge data of each segment are fitted using the least squares method.

4. The method according to claim 3, characterized in that The fitting of the equivalent circuit model parameters corresponding to each segment of the charge and discharge data also includes: Obtain estimated values ​​of the open circuit voltage under different states of charge by using the corresponding relationship between the different states of charge obtained after fitting and the open circuit voltage in the equivalent circuit model parameters; Obtaining actual values ​​of the open circuit voltage under different states of charge; calculating a loss function based on the squares of the differences between a plurality of estimated values ​​of the open circuit voltage and actual values ​​of the open circuit voltage; The loss function is used to update the equivalent circuit model of the battery.

5. The method according to claim 1, characterized in that Before generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameter, the method further includes: Obtaining the charge status of each segment uploaded by the vehicle; The state of charge of each segment is used as the starting value of the state of charge of each segment in the first curve.

6. The method according to claim 1, characterized in that The generating a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve comprises: Obtaining a reference curve corresponding to the state of charge and the open circuit voltage of the battery when it leaves the factory; The first curve is translated and scaled so as to make the first curve fit the reference curve, thereby obtaining the second curve.

7. A device for identifying parameters of a battery equivalent circuit model, characterized in that: include: An acquisition module, used to acquire equivalent circuit model parameters corresponding to multiple-stage charge and discharge data of a battery in a vehicle; A first generating module, used for fitting the equivalent circuit model parameters corresponding to each segment of the charge and discharge data to obtain a corresponding relationship between different states of charge and the equivalent circuit model parameters, and generating a first curve corresponding to the state of charge and the open circuit voltage in the equivalent circuit model parameters; A second generating module, configured to generate a second curve corresponding to the state of charge and the open circuit voltage by translating and scaling the first curve; An identification module is used to identify the equivalent circuit model parameters of the battery at different states of charge according to the second curve.

8. A battery management device, characterized in that: include: Processor and memory; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the method for identifying the battery equivalent circuit model parameters as described in any one of claims 1 to 6.

9. A vehicle, characterized in that: include: The battery management device as claimed in claim 8.

10. A computer-readable storage medium, when instructions in the computer-readable storage medium are executed by a processor, the processor is enabled to execute the method for identifying battery equivalent circuit model parameters as described in any one of claims 1 to 6.

Images