Voltage consistency evaluation method and device for cascade utilization energy storage system

Abstract

The present application relates to the technical field of power battery evaluation, and in particular to a voltage consistency evaluation method and device for a cascade utilization energy storage system, wherein the method comprises: obtaining module voltage data and module current data of a power battery module, and screening the module voltage data and module current data to obtain steady-state voltage data of the power battery module; calculating the standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence using linear interpolation and filtering methods to obtain a standard deviation following sequence; mapping the standard deviation following sequence to a preset percentage interval to obtain the final consistency evaluation result of the power battery module. Thus, the standard deviation of the working voltage of the battery module is used as a consistency evaluation indicator, eliminating the influence of abnormal data points and noise, while intuitively reflecting the consistency of the battery system, and ultimately realizing the evaluation of massive operating data of a large-scale battery energy storage system.

Description

Technical Field

[0001] The present application relates to the technical field of power battery evaluation, and in particular to a method and device for evaluating voltage consistency of a cascade utilization energy storage system. Background Art

[0002] Battery Energy Storage System (BESS) has become an important part of the energy internet due to its advantages such as fast response speed and high energy density. In recent years, as a large number of electric vehicle power batteries have reached retirement age, large-scale retired power battery cascade utilization energy storage systems have received widespread attention. However, retired power batteries have defects such as poor consistency and weak safety, and their cascade utilization faces huge challenges.

[0003] Among the related technologies, the Dynamic Reconfigurable Battery Network (DRBN) is a key technology for realizing the cascade utilization of retired power batteries. Its working current level balancing capability and rapid fault removal capability can effectively improve the consistency and safety of the battery system. However, most of the research on DRBN remains in the theoretical analysis stage, and the operating performance of DRBN under actual working conditions is still unclear. In order to solve these problems, experimental verifications have been carried out for various performances of DRBN. For example, a hierarchical balancing method for DRBN, and the balancing effect of the system is verified through hardware-in-the-loop experiments; a method for preventing short circuits during the reconstruction process of DRBN, and the safety of the reconstruction process is verified through prototypes and experimental platforms; an operation optimization architecture of DRBN, and the higher energy efficiency of DRBN is verified on the experimental platform; an actual engineering case based on the DRBN energy storage system verifies the intrinsic safety mechanism of the system; a cycle data based on the actual DRBN energy storage system verifies the ability of the system's integrated electric and thermal management.

[0004] However, research in related technologies is mainly verified at the DRBN level. The experimental platform only includes the DC side, not the entire DRBN energy storage system. The amount of data involved is relatively small, only including operating data within one day. The analysis object only involves one DRBN, which is unable to cope with the evaluation of massive operating data of large-scale battery energy storage systems, and needs to be solved urgently. Summary of the invention

[0005] The present application provides a voltage consistency evaluation method and device for a cascade utilization energy storage system to solve the problems that the research in the related technology is mainly verified at the DRBN level, the experimental platform only includes the DC side, not the entire DRBN energy storage system, and the amount of data involved is small, only including the operation data within one day, the analysis object only involves one DRBN, and there is a lack of evaluation methods for massive operation data of large-scale battery energy storage systems.

[0006] The first aspect of the present application provides a voltage consistency assessment method for a cascade energy storage system, comprising the following steps: acquiring module voltage data and module current data of a power battery module, and screening the module voltage data and the module current data to obtain steady-state voltage data of the power battery module; calculating a standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence using a linear interpolation and filtering method to obtain a standard deviation following sequence; mapping the standard deviation following sequence to a preset percentile interval to obtain a final consistency assessment result of the power battery module.

[0007] Optionally, in one embodiment of the present application, the module voltage data and the module current data of the power battery module are acquired, and the module voltage data and the module current data are screened to obtain steady-state voltage data, including: determining a data screening condition based on a median voltage and a maximum current in the module voltage data and the module current data; and screening out the steady-state voltage data of the power battery module from the module voltage data and the module current data based on the data screening condition.

[0008] Optionally, in one embodiment of the present application, the evaluation formula of the final consistency evaluation result is:

[0009] cs i =max(60,100-θ·SD f,i )

[0010] Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i Indicates the standard deviation tracking value at the i-th moment, SD f The standard deviation tracking sequence is the standard deviation tracking value at all times.

[0011] Optionally, in one embodiment of the present application, the calculation formula of the standard deviation following sequence is:

[0012]

[0013] Among them, i represents the data point at the i-th moment, SDf,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD i Represents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

[0014] A second aspect of the present application provides a voltage consistency evaluation device for a cascade energy storage system, comprising: a screening module for acquiring module voltage data and module current data of a power battery module, and screening the module voltage data and the module current data to obtain steady-state voltage data of the power battery module; a calculation module for calculating a standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence using a linear interpolation and filtering method to obtain a standard deviation following sequence; an evaluation module for mapping the standard deviation following sequence to a preset percentile interval to obtain a final consistency evaluation result of the power battery module.

[0015] Optionally, in one embodiment of the present application, the screening module includes: a determination unit, used to determine a data screening condition based on the median voltage and the maximum current in the module voltage data and the module current data; and a screening unit, used to screen out the steady-state voltage data of the power battery module from the module voltage data and the module current data based on the data screening condition.

[0016] Optionally, in one embodiment of the present application, the evaluation formula of the final consistency evaluation result is:

[0017] cs i =max(60,100-θ·SD f,i )

[0018] Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i Indicates the standard deviation tracking value at the i-th moment, SD f The standard deviation tracking sequence is the standard deviation tracking value at all times.

[0019] Optionally, in one embodiment of the present application, the calculation formula of the standard deviation following sequence is:

[0020]

[0021] Among them, i represents the data point at the i-th moment, SD f,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD iRepresents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

[0022] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the voltage consistency assessment method for a cascade utilization energy storage system as described in the above embodiment.

[0023] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for evaluating voltage consistency of a cascaded energy storage system.

[0024] A fifth aspect of the present application provides a computer program product, which, when executed, is used to implement the above-mentioned voltage consistency assessment method for a cascade utilization energy storage system.

[0025] The embodiment of the present application can pre-process the current data and voltage data of the power battery module, screen out the steady-state voltage data in the plateau period, and calculate and process the standard deviation sequence of the steady-state voltage data, map the calculated standard deviation tracking sequence to the percentile interval, and finally obtain the consistency evaluation result of the power battery module. Thus, it is realized that the standard deviation sequence of the steady-state voltage data of the power battery is processed by linear interpolation and filtering methods, the influence of abnormal data points and noise is eliminated, the validity and reliability of the data are ensured, and the evaluation result obtained by mapping the standard deviation tracking sequence to the percentile interval can intuitively reflect the consistency of the battery system, and finally realize the evaluation of the massive operation data of the large-scale battery energy storage system. Thus, it solves the problems that the research in the related technology is mainly verified at the DRBN level, the experimental platform only includes the DC side, not the entire DRBN energy storage system, and the amount of data involved is small, only including the operation data within one day, the analysis object only involves one DRBN, and there is a lack of evaluation methods for the massive operation data of large-scale battery energy storage systems.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1A flowchart of a voltage consistency evaluation method for a cascade utilization energy storage system provided according to an embodiment of the present application;

[0029] Figure 2 A schematic diagram of a consistency scoring result of a battery system according to an embodiment of the present application;

[0030] Figure 3 A schematic diagram of consistency scoring results of another battery system according to an embodiment of the present application;

[0031] Figure 4 It is a structural schematic diagram of a voltage consistency assessment device for a cascade utilization energy storage system according to an embodiment of the present application;

[0032] Figure 5 Schematic diagram of the structure of an electronic device according to an embodiment of the present application. Description of the drawings:

[0034] 10-voltage consistency assessment device for cascade utilization energy storage system; 100-screening module, 200-calculation module and 300-assessment module; 501-memory, 502-processor and 503-communication interface. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same 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 application, and should not be construed as limiting the present application.

[0036] The following describes the voltage consistency evaluation method and device of the cascade utilization energy storage system of the embodiment of the present application with reference to the accompanying drawings. In response to the problems mentioned in the above background technology, the present application provides a voltage consistency evaluation method for the cascade utilization energy storage system, in which the current data and voltage data of the power battery module can be preprocessed, the steady-state voltage data in the plateau period can be screened out, and the standard deviation sequence of the steady-state voltage data can be calculated and processed, and the calculated standard deviation tracking sequence is mapped to the percentile interval, and finally the consistency evaluation result of the power battery module is obtained. In this way, the standard deviation sequence of the steady-state voltage data of the power battery is processed by linear interpolation and filtering methods, the influence of abnormal data points and noise is eliminated, the validity and reliability of the data are ensured, and the evaluation result obtained by mapping the standard deviation tracking sequence to the percentile interval can intuitively reflect the consistency of the battery system, and finally the evaluation of massive operating data of large-scale battery energy storage systems is realized. This solves the problems that the research in related technologies is mainly verified at the DRBN level, the experimental platform only includes the DC side, not the entire DRBN energy storage system, and the amount of data involved is small, only including operating data within one day, the analysis object only involves one DRBN, and there is a lack of evaluation methods for massive operating data of large-scale battery energy storage systems.

[0037] Specifically, Figure 1 A flowchart of a voltage consistency assessment method for a cascade utilization energy storage system provided in an embodiment of the present application.

[0038] like Figure 1 As shown, the voltage consistency evaluation method of the cascade utilization energy storage system includes the following steps:

[0039] In step S101 , module voltage data and module current data of the power battery module are acquired, and the module voltage data and module current data are screened to obtain steady-state voltage data of the power battery module.

[0040] It is understandable that as the power batteries of a large number of electric vehicles have reached their retirement age, large-scale retired power battery recycling energy storage systems have received a lot of attention. However, retired batteries often have defects such as poor consistency and weak safety, which is a major challenge for their recycling. Therefore, the embodiment of the present application can use the standard deviation of the working voltage of the power battery module as a consistency evaluation indicator to achieve consistency evaluation of the voltage of the retired battery recycling energy storage system.

[0041] In some embodiments, when evaluating the voltage consistency of a retired battery recycling energy storage system, the module voltage data and module current data of the power battery module can be used as basic data for preliminary data preparation, but are not limited to. However, due to the complexity of the working conditions of the recycled energy storage system, not all data at each moment are suitable as valid data for consistency evaluation. Therefore, the embodiments of the present application can screen the module voltage data and module current data to obtain the steady-state voltage data of the power battery module for use as valid data.

[0042] The embodiment of the present application can filter out steady-state voltage data from the module voltage data and module current data of the power battery module as preparation data for subsequent calculations. On the premise of ensuring the validity and stability of the data, it can eliminate the influence of some invalid data on the module voltage consistency evaluation, thereby ensuring the accuracy of the evaluation results.

[0043] Optionally, in one embodiment of the present application, module voltage data and module current data of a power battery module are obtained, and the module voltage data and module current data are screened to obtain steady-state voltage data, including: determining data screening conditions based on the median voltage and maximum current in the module voltage data and the module current data; and screening out the steady-state voltage data of the power battery module from the module voltage data and the module current data based on the data screening conditions.

[0044] Based on the relevant descriptions of other embodiments, it can be understood that when using the standard deviation of the working voltage of the power battery module as a consistency evaluation indicator, it is necessary to first obtain the module voltage data and module current data of the power battery module, and filter out the steady-state voltage data. The screening process is further explained below.

[0045] First, the embodiments of the present application can limit the voltage range. Because the working conditions of the energy storage system are complex, not all data at every moment are suitable as the basis for consistency evaluation. Among them, according to the OCV-SOC (Open Circuit Voltage-State of Charge) curve characteristics of the lithium iron phosphate battery, the charge and discharge curve of the battery module is divided into a plateau period and a non-plateau period. The module voltage change rate in the plateau period is very small, while the voltage change rate in the non-plateau period is large, so the voltage consistency of energy storage units with different SOC levels is not comparable.

[0046] Since the voltage change rate in the non-plateau period is large, the inconsistency of the battery module is more obvious. In order to evaluate the module consistency in the plateau period, the embodiment of the present application can filter out the data in the plateau period. The method used can be but is not limited to: taking the median of the voltage of N battery modules in a battery system as the index for data screening, taking the module voltage when the state of charge (State of Charge) of the battery module is equal to 20% as the lower limit value, taking the module voltage when the SOC is equal to 80% as the upper limit value, and only the module voltage between the upper and lower limits is selected and used as the data for consistency analysis.

[0047] In addition, the embodiments of the present application can also limit the current range. Among them, only when the current of the battery module is equal to 0 and the working voltage measured after standing for one hour can it truly reflect the state of the battery module. However, there are few data points in the energy storage system operation data where the current is strictly 0. Since the working voltage is approximately equal to the open circuit voltage when the module current is very small, the embodiments of the present application can relax the current restriction condition to a certain current range.

[0048] Since the module voltage of the actual energy storage system will change with the current during operation, and different currents will also bring different degrees of polarization to the battery, increasing the uncertainty of the voltage, making the voltage consistency under different currents incomparable. Therefore, the embodiment of the present application can set an upper limit value for the module current, and only when the current does not exceed the upper limit value, the module operating voltage measured can be used for consistency analysis. Specifically, the maximum value of the module current in the battery system can be used as an indicator for data screening, and the module voltage data with a maximum module current of no more than 20A and a maximum module current of no more than 20A in the previous hour can be taken as the data for consistency analysis.

[0049] The embodiment of the present application can determine data screening conditions for module voltage data and module current data, and screen out steady-state voltage data of the power battery module from the module voltage data and module current data, comprehensively consider various influencing factors, screen out data suitable for voltage consistency analysis, improve the pertinence and applicability of the data, and eliminate the influence of non-plateau period and current effect on module voltage consistency evaluation.

[0050] Step S102, calculating the standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence using a linear interpolation and filtering method to obtain a standard deviation tracking sequence.

[0051] Optionally, in one embodiment of the present application, the calculation formula of the standard deviation following sequence can be expressed as:

[0052]

[0053] Among them, i represents the data point at the i-th moment, SDf,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD i Represents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

[0054] In the actual execution process, after obtaining the steady-state voltage data of the power battery module, the embodiment of the present application can perform further calculations based on the steady-state voltage data to obtain the standard deviation sequence of the steady-state voltage data.

[0055] Specifically, the standard deviation sequence calculation step can be expressed as follows: Those skilled in the art can understand that the standard deviation (SD) is an indicator to measure the degree of dispersion of a group of samples. In the embodiment of the present application, x v,k is the operating voltage of the kth battery module, N is the number of battery modules, μ v is the average value of the working voltage of all battery modules, then the calculation formula of SD can be expressed as:

[0056]

[0057] Among them, SD is the standard deviation sequence of steady-state voltage data, x v,k is the operating voltage of the kth battery module, N is the number of battery modules, μ v It is the average value of the operating voltage of all battery modules.

[0058] Due to the voltage plateau characteristics of lithium iron phosphate batteries, the voltage change rate varies greatly at different SOC levels, resulting in large differences in the standard deviation calculated for the same cluster of batteries at different SOC levels. Therefore, the embodiment of the present application preprocesses the used data, that is, the plateau data is screened by setting the upper and lower limits of the voltage.

[0059] After calculating the standard deviation sequence of the steady-state voltage data, the embodiment of the present application can also process the standard deviation sequence by linear interpolation and filtering methods to eliminate the influence of abnormal data points and noise, which can be specifically expressed as follows:

[0060] Interpolation: Since the data has been screened, there are some zero-value intervals in the calculated standard deviation sequence. Therefore, the embodiment of the present application can use linear interpolation to supplement the missing data points, that is, identify the continuous zero-value intervals in the standard deviation sequence calculated in the previous step, use the standard deviation mean of the 60 frames before the starting position of the zero-value interval as the starting value, and use the standard deviation mean of the 60 frames after the ending position of the zero-value interval as the ending value to perform linear interpolation on the continuous zero-value intervals.

[0061] Filtering: There is a lot of noise in the standard deviation sequence after linear interpolation. The standard deviation sequence calculated in the previous step is filtered using the average value filtering method. The calculation formula can be expressed as follows:

[0062]

[0063] Where i represents the i-th moment. avg,i Indicates the voltage standard deviation filtered value at the i-th moment. SD n It represents the voltage standard deviation at the nth moment. The numerator means the sum of all standard deviations from the i-αth moment to the i+αth moment. α is the parameter that controls the mean filter range.

[0064] There are some jump points in the filtered standard deviation sequence. This is because the sensor may be disturbed by some impact during the measurement process, and the working conditions of the energy storage system may fluctuate greatly. In order to prevent the voltage consistency score from jumping, according to the standard deviation sequence calculated in the previous step, set the following rate and calculate the standard deviation following sequence. The calculation formula can be expressed as follows:

[0065]

[0066] Among them, i represents the data point at the i-th moment, SD f,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD i Represents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

[0067] The embodiment of the present application can calculate the steady-state voltage data of the power battery module to obtain a standard deviation sequence, and use linear interpolation and filtering methods to calculate the standard deviation sequence to eliminate the influence of zero-value intervals and noise, and then set a following sequence to obtain a standard deviation following sequence, so as to prevent the voltage consistency score obtained later from jumping, thereby greatly improving the stability of the evaluation.

[0068] Step S103, mapping the standard deviation tracking sequence to a preset percentage interval to obtain a final consistency evaluation result of the power battery module.

[0069] Optionally, in one embodiment of the present application, the evaluation formula of the final consistency evaluation result can be expressed as:

[0070] cs i =max(60,100-θ·SD f,i )

[0071] Among them, cs iis the consistency evaluation score, θ is the multiplier coefficient of the standard deviation following the sequence to the consistency score conversion, SD f,i is the standard deviation following series.

[0072] Those skilled in the art can understand that the standard deviation is a quasi-indicator in statistics, which is not conducive to users judging consistency directly by the standard deviation. Therefore, in the embodiment of the present application, the standard deviation tracking sequence can be mapped to the percentile interval for score calculation, and the formula for calculating the consistency score can be expressed as follows:

[0073] cs i =max(60,100-θ·SD f,i )

[0074] Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i SD is the standard deviation tracking value at the i-th moment. f The standard deviation tracking sequence is the standard deviation tracking value at all times.

[0075] In order to prevent negative scores, the embodiment of the present application can set the lower limit of the consistency score to 60. This is because when the consistency score is less than or equal to 60, the consistency problem of the battery system is already quite serious and measures need to be taken to improve consistency.

[0076] like Figure 2 and Figure 3 The figure shows the consistency score results of two battery systems of an embodiment of the present application, which respectively show the consistency score, voltage curve and enlarged view of the local voltage curve during operation. The consistency score of the battery system shown in the left figure is significantly lower than that of the right figure. From the voltage curve, it can be seen that the voltage distribution of the battery system shown in the left figure is more dispersed and the consistency is relatively poor; the voltage distribution of the battery system shown in the right figure is more concentrated and the consistency is high.

[0077] By comparing the voltage curves with high voltage consistency scores and low voltage consistency scores, it can be concluded that the voltage consistency score can obviously reflect the actual consistency of the voltage, and the low voltage consistency score proves that the voltage consistency level within the cluster is low.

[0078] According to the voltage consistency evaluation method of the cascade utilization energy storage system proposed in the embodiment of the present application, the current data and voltage data of the power battery module can be preprocessed, the steady-state voltage data in the plateau period can be screened out, and the standard deviation sequence of the steady-state voltage data can be calculated and processed, and the calculated standard deviation tracking sequence can be mapped to the percentage interval, and finally the consistency evaluation result of the power battery module can be obtained. Thus, the standard deviation sequence of the steady-state voltage data of the power battery is processed by linear interpolation and filtering methods, the influence of abnormal data points and noise is eliminated, the validity and reliability of the data are ensured, and the evaluation result obtained by mapping the standard deviation tracking sequence to the percentage interval can intuitively reflect the consistency of the battery system, and finally the evaluation of the massive operation data of the large-scale battery energy storage system is realized. Thus, the problems such as the research in the related technology is mainly verified at the DRBN level, the experimental platform only includes the DC side, not the entire DRBN energy storage system, and the amount of data involved is small, only including the operation data within one day, the analysis object only involves one DRBN, and there is a lack of large-scale battery energy storage system massive operation data evaluation method.

[0079] Next, a voltage consistency assessment device for a cascade utilization energy storage system proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

[0080] Figure 4 It is a structural schematic diagram of a voltage consistency assessment device for a cascade utilization energy storage system according to an embodiment of the present application.

[0081] like Figure 4 As shown, the voltage consistency assessment device 10 of the cascade utilization energy storage system includes: a screening module 100 , a calculation module 200 and an assessment module 300 .

[0082] The screening module 100 is used to obtain module voltage data and module current data of the power battery module, and screen the module voltage data and module current data to obtain steady-state voltage data of the power battery module.

[0083] The calculation module 200 is used to calculate the standard deviation sequence of the steady-state voltage data, and calculate the standard deviation sequence using a linear interpolation and filtering method to obtain a standard deviation tracking sequence.

[0084] The evaluation module 300 is used to map the standard deviation tracking sequence to a preset percentile interval to obtain a final consistency evaluation result of the power battery module.

[0085] Optionally, in one embodiment of the present application, the screening module 100 includes: a determination unit and a screening unit.

[0086] The determination unit is used to determine the data screening condition based on the voltage median and current maximum in the module voltage data and the module current data.

[0087] The screening unit is used to screen out the steady-state voltage data of the power battery module from the module voltage data and the module current data based on the data screening conditions.

[0088] Optionally, in one embodiment of the present application, the evaluation formula of the final consistency evaluation result can be expressed as:

[0089] cs i =max(60,100-θ·SD f,i )

[0090] Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i Indicates the standard deviation tracking value at the i-th moment, SD f The standard deviation tracking sequence is the standard deviation tracking value at all times.

[0091] Optionally, in one embodiment of the present application, the calculation formula of the standard deviation following sequence can be expressed as:

[0092]

[0093] Among them, i represents the data point at the i-th moment, SD f,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD i Represents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

[0094] It should be noted that the above explanation of the embodiment of the voltage consistency assessment method for the cascade utilization energy storage system is also applicable to the voltage consistency assessment device for the cascade utilization energy storage system of this embodiment, and will not be repeated here.

[0095] According to the voltage consistency evaluation device of the cascade utilization energy storage system proposed in the embodiment of the present application, the current data and voltage data of the power battery module can be preprocessed, the steady-state voltage data in the plateau period can be screened out, and the standard deviation sequence of the steady-state voltage data can be calculated and processed, and the calculated standard deviation tracking sequence can be mapped to the percentage interval, and finally the consistency evaluation result of the power battery module can be obtained. Thus, the standard deviation sequence of the steady-state voltage data of the power battery is processed by linear interpolation and filtering methods, the influence of abnormal data points and noise is eliminated, the validity and reliability of the data are ensured, and the evaluation result obtained by mapping the standard deviation tracking sequence to the percentage interval can intuitively reflect the consistency of the battery system, and finally the evaluation of the massive operation data of the large-scale battery energy storage system is realized. Thus, the problems that the research in the related technology is mainly verified at the DRBN level, the experimental platform only includes the DC side, not the entire DRBN energy storage system, and the amount of data involved is small, only including the operation data within one day, the analysis object only involves one DRBN, and there is a lack of large-scale battery energy storage system massive operation data evaluation method.

[0096] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0097] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0098] When the processor 502 executes the program, the voltage consistency assessment method of the cascade utilization energy storage system provided in the above embodiment is implemented.

[0099] Furthermore, the electronic device further comprises:

[0100] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0101] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0102] The memory 501 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0103] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0104] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0105] The processor 502 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0106] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the voltage consistency assessment method for a cascade utilization energy storage system as described above.

[0107] The embodiment of the present application also provides a computer program product, which can run computer instructions. When the computer instructions are executed by a processor, the voltage consistency assessment method of the cascade utilization energy storage system provided in the embodiment of the present application is implemented.

[0108] 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 application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N 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, without contradiction.

[0109] 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 technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0110] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application 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 technicians in the technical field to which the embodiments of the present application belong.

[0111] The logic and / or steps represented in the flowchart or otherwise described 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 of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), 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 by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0112] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: 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.

[0113] 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.

[0114] In addition, each functional unit in each embodiment of the present application 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.

[0115] 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 application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A voltage consistency evaluation method for a cascade utilization energy storage system, characterized in that: The following steps are involved: Acquiring module voltage data and module current data of the power battery module, and screening the module voltage data and the module current data to obtain steady-state voltage data of the power battery module; Calculating a standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence using a linear interpolation and filtering method to obtain a standard deviation following sequence; The standard deviation tracking sequence is mapped to a preset percentile interval to obtain a final consistency evaluation result of the power battery module.

2. The method according to claim 1, characterized in that The acquiring module voltage data and module current data of the power battery module, and screening the module voltage data and the module current data to obtain steady-state voltage data, includes: Determining data screening conditions based on the voltage median and the current maximum in the module voltage data and the module current data; The steady-state voltage data of the power battery module is screened out from the module voltage data and the module current data based on the data screening condition.

3. The method according to claim 1, characterized in that The evaluation formula of the final consistency evaluation result is: cs i =max(60,100-θ·SD f,i ) Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i Indicates the standard deviation tracking value at the i-th moment, SD f The standard deviation tracking sequence is the sum of the standard deviation tracking values ​​at all times.

4. The method according to claim 1, characterized in that: The calculation formula of the standard deviation following sequence is: Among them, i represents the data point at the i-th moment, SD f,i represents the standard deviation following value at the i-th moment, δ is the following rate, SD i Represents the standard deviation at the i-th moment, SD i-1 Represents the standard deviation at the i-1th moment, SD f.i-1 Represents the standard deviation tracking value at the i-1th moment.

5. A voltage consistency assessment device for a cascade utilization energy storage system, characterized in that: include: A screening module, used to obtain module voltage data and module current data of a power battery module, and screen the module voltage data and the module current data to obtain steady-state voltage data of the power battery module; A calculation module, used for calculating a standard deviation sequence of the steady-state voltage data, and calculating the standard deviation sequence by using a linear interpolation and filtering method to obtain a standard deviation following sequence; An evaluation module is used to map the standard deviation tracking sequence to a preset percentage interval to obtain a final consistency evaluation result of the power battery module.

6. The device according to claim 5, characterized in that The screening module comprises: A condition unit, used to determine a data screening condition based on a voltage median and a current maximum in the module voltage data and the module current data; A screening unit is configured to screen out the steady-state voltage data of the power battery module from the module voltage data and the module current data based on the data screening condition.

7. The device according to claim 5, characterized in that The evaluation formula of the final consistency evaluation result is: cs i =max(60,100-θ·SD f,i ) Among them, i represents the data point at the i-th moment, cs i represents the consistency score at the i-th moment, θ is the multiplier coefficient for the conversion of the standard deviation following the sequence to the consistency score, SD f,i Indicates the standard deviation tracking value at the i-th moment, SD f The standard deviation tracking sequence is the sum of the standard deviation tracking values ​​at all times.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the voltage consistency assessment method for a cascade utilization energy storage system as described in any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the voltage consistency assessment method for a cascade utilization energy storage system as described in any one of claims 1 to 4.

10. A computer program product, characterized in that When the computer program is executed, it is used to implement the voltage consistency assessment method for the cascade utilization energy storage system as described in any one of claims 1-4.

Images