Energy storage system and data storage method

Abstract

The invention discloses an energy storage system and a data storage method, and relates to the technical field of energy storage. The energy storage system comprises a battery pack, a data collector, a memory and a controller. The data collector is connected with a plurality of batteries in the battery pack through a bus, the data collector is used for collecting operation data of the battery pack, the operation data comprises data streams of M dimensions, and M is a positive integer. The memory includes a volatile memory device and a non-volatile memory device, the volatile memory device including a cache and M first-in first-out buffers. The controller is electrically connected with the data acquisition unit and the memory, and is used for acquiring data streams of M dimensions, writing the data streams of M dimensions into the M first-in first-out buffers frame by frame, reading target data streams stored in the first-in first-out buffers to the cache when the data streams stored in the first-in first-out buffers meet storage conditions, and storing the target data streams in the memory. And writing the target data set stored in the cache into the nonvolatile memory device.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage system and a data storage method. Background Art

[0002] Energy storage systems usually include a battery pack formed by connecting multiple batteries. When a battery in the battery pack fails, whether the fault warning, fault location and fault diagnosis can be carried out in time is crucial to the safety and reliability of the energy storage system. Current storage systems usually locate and diagnose faults based on snapshot information at the time of the fault, but since the snapshot information contains less data, the accuracy of fault location and fault diagnosis is low. Summary of the invention

[0003] In view of this, the embodiments of the present application provide an energy storage system and a data storage method, aiming to solve the problem of how to improve the accuracy of fault location and fault diagnosis.

[0004] The first aspect of the embodiment of the present application provides an energy storage system, which includes a battery pack, a data collector, a memory and a controller; the battery pack includes a plurality of batteries. The data collector is connected to the plurality of batteries via a bus, and the data collector is used to collect the operating data of the battery pack, and the operating data includes a data stream of M dimensions, where M is a positive integer. The memory includes a volatile memory device and a non-volatile memory device, and the volatile memory device includes a cache and M first-in-first-out buffers. The controller is electrically connected to the data collector and the memory, and the controller is used to obtain the data stream of M dimensions, write the data stream of M dimensions into the M first-in-first-out buffers frame by frame, and when the data stream stored in the first-in-first-out buffer meets the storage condition, read the target data stream stored in the first-in-first-out buffer into the cache, and write the target data set stored in the cache into the non-volatile memory device. Among them, the target data stream is the data stream of the time period when the fault occurs, and the target data set includes the target data stream stored in the M first-in-first-out buffers.

[0005] In this embodiment, the target data set includes data streams of the fault occurrence time period in various dimensions, which can reflect the state change process of the battery pack and each battery contained therein before and after the fault occurs, which is conducive to fault location and fault cause analysis, and can improve the accuracy of fault location and fault diagnosis, and improve the efficiency of fault location and fault clearing, thereby improving the safety and reliability of the energy storage system.

[0006] In one embodiment, the data stream stored in the FIFO buffer meets the storage condition including: the number of fault data frames stored in the FIFO buffer is greater than or equal to the storage threshold. The storage threshold is less than the depth of the FIFO buffer, and the depth of the FIFO buffer is related to the recording time and the data collection cycle. The recording time is the length of the fault occurrence time period, and the data collection cycle is the period of the data collector collecting a single-dimensional data stream.

[0007] In this embodiment, by establishing a correlation between the depth of the first-in-first-out buffer and the recording time and the data acquisition cycle, the depth of the first-in-first-out buffer can be flexibly adjusted according to the recording time and the data acquisition cycle to adjust the storage capacity of the first-in-first-out buffer, thereby improving the storage flexibility of the first-in-first-out buffer. Since the first-in-first-out buffer occupies the storage resources of the volatile memory device, the flexible and adjustable first-in-first-out buffer can improve the storage space utilization of the volatile memory device and reduce the waste of storage resources.

[0008] In another embodiment, the depth of the FIFO buffer is positively correlated with the recording duration and negatively correlated with the data acquisition period.

[0009] In another embodiment, the depth of the first-in-first-out buffer is the ratio of the recording duration to the data acquisition period.

[0010] In another embodiment, the storage capacity of the FIFO buffer is the product of the depth of the FIFO buffer and the width of the FIFO buffer, wherein the width of the FIFO buffer is the length of a single data frame stored in the FIFO buffer, and the length of each data frame stored in the FIFO buffer is equal.

[0011] In another embodiment, before writing the data streams of M dimensions into the M first-in-first-out buffers frame by frame, the controller adds a detection flag to each data frame in the data streams of M dimensions. The detection flag includes a fault flag and a normal flag, the fault flag is used to identify the data frame as a faulty data frame, and the normal flag is used to identify the data frame as a normal data frame.

[0012] In another embodiment, the detection flag includes a first fault flag and a second fault flag, the first fault flag is used to identify the data frame as a fault data frame under a first fault condition, and the second fault flag is used to identify the data frame as a fault data frame under a second fault condition.

[0013] In another embodiment, the controller adds a detection mark to each data frame in the data stream of M dimensions, including: when the w-th frame data is within the first value range, the w-th frame data is determined to be a faulty data frame under the first fault condition, and the detection mark added to the w-th frame data is the first fault mark. When the w-th frame data is within the second value range, the w-th frame data is determined to be a faulty data frame under the second fault condition, and the detection mark added to the w-th frame data is the second fault mark. When the w-th frame data is neither within the first value range nor within the second value range, the w-th frame data is determined to be a normal data frame, and the detection mark added to the w-th frame data is a normal mark. Wherein, w is a positive integer.

[0014] In another embodiment, the controller adds a detection mark to each data frame in the data stream of M dimensions, including: when the w-th frame data is greater than the first threshold, the w-th frame data is determined to be a faulty data frame under the first fault condition, and the detection mark added to the w-th frame data is the first fault mark. When the w-th frame data is less than or equal to the first threshold and greater than the second threshold, the w-th frame data is determined to be a faulty data frame under the second fault condition, and the detection mark added to the w-th frame data is the second fault mark. When the w-th frame data is less than or equal to the second threshold, the w-th frame data is determined to be a normal data frame, and the detection mark added to the w-th frame data is a normal mark.

[0015] In another embodiment, when the data stream stored in the FIFO buffer does not meet the storage condition, the controller deletes the data frames overflowing from the FIFO buffer.

[0016] A second aspect of an embodiment of the present application provides a data storage method, which is applied to an energy storage system, wherein the storage system includes a battery pack, a volatile memory device and a non-volatile memory device, wherein the volatile memory device includes a cache and M first-in-first-out buffers, where M is a positive integer. The method includes: obtaining operating data of the battery pack, wherein the operating data includes data streams of M dimensions. The data streams of M dimensions are written frame by frame into the M first-in-first-out buffers. When the data stream stored in the first-in-first-out buffer meets the storage condition, the target data stream stored in the first-in-first-out buffer is read into the cache, and the target data set stored in the cache is written into the non-volatile memory device. Among them, the target data stream is the data stream of the time period when the fault occurs, and the target data set includes the target data streams stored in the M first-in-first-out buffers.

[0017] It can be understood that the beneficial effects of the data storage method provided in the second aspect of the embodiment of the present application are substantially the same as the beneficial effects of the energy storage system provided in the first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The schematic diagram of the structure of the energy storage system provided as an example.

[0019] Figure 2 is a schematic diagram of the FIFO storage state provided by an example.

[0020] Figure 3 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0021] Figure 4 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0022] Figure 5 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0023] Figure 6 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0024] Figure 7 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0025] Figure 8 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0026] Fig. 9 FIG. 4 is a schematic diagram of a FIFO storage state provided by another example.

[0027] Fig.10 A flowchart of a data storage method provided by an example. DETAILED DESCRIPTION

[0028] It should be noted that in the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more than two. The terms "first", "second", etc. in the specification, claims and drawings of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. The method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0029] Figure 1 The schematic diagram of the structure of the energy storage system provided as an example.

[0030] like Figure 1 As shown, the energy storage system 10 includes a battery pack 100 , an energy storage converter 200 , a data collector 300 , a memory 400 and a controller 500 .

[0031] The battery pack 100 includes N batteries Bat1-Bat N , N is a positive integer, and N>1. N batteries Bat1-Bat NThe batteries are connected in parallel to form a parallel battery pack. The battery includes a battery management system (BMS), which is used to monitor the battery status parameters. The battery status parameters include output voltage, output current, temperature, state of charge (SOC) and state of health (SOH).

[0032] In other embodiments, N batteries Bat1-Bat N They can be connected in series, or in a mixture of series and parallel.

[0033] Energy storage converter 200 and N batteries Bat1-Bat N The bus is connected via a bus. For example, the bus includes a controller area network (CAN) bus, and the CAN bus uses a CANH line and a CANL line for differential signal transmission.

[0034] The energy storage converter 200 is used to realize energy exchange between the energy storage system 10 and the power grid or other power systems. The energy storage converter 200 may include a bidirectional DC-AC converter, a bidirectional DC-DC converter, a unidirectional DC-AC converter, and a unidirectional DC-DC converter.

[0035] In other embodiments, the energy storage system 10 may not be provided with the energy storage converter 200 .

[0036] Data logger 300 and N batteries Bat1-Bat N The data collector 300 is used to collect the operating data of the battery pack 100, and the operating data includes a data stream of M dimensions, where M is a positive integer. Dimension refers to the data type. The data stream of M dimensions may include total voltage, total current, insulation resistance value, digital input (DI) signal, digital output (DO) signal and the state parameters of each battery and its corresponding logical address.

[0037] The data collector 300 includes M collection chips IC1-IC M The acquisition chip is used to collect a single-dimensional data stream. The number of acquisition chips is equal to the number of dimensions of the running data. The acquisition chip collects data streams according to the data acquisition cycle, and the data acquisition cycles of each acquisition chip are independent of each other. For example, the i-th acquisition chip IC i The data stream used to collect the voltage of a single cell has a data collection period of 100 milliseconds (ms). The voltage of a single cell refers to the output voltage of each cell. jThe data stream used to collect the current of a single battery has a data collection cycle of 10ms. The current of a single battery refers to the output current of each battery. k The data stream used to collect the temperature of a single battery has a data collection period of 500ms. The temperature of a single battery refers to the temperature of each battery. i, j, and k are all positive integers.

[0038] The memory 400 includes a volatile memory device 410 and a nonvolatile memory device 420. The volatile memory device 410 includes a cache and M first in first out buffers (FIFO).

[0039] The FIFO is used to store a single-dimensional data stream from the controller 500. The number of FIFOs is equal to the number of dimensions of the running data. The data stream includes multiple data frames, and the data frame includes a timestamp and a detection flag. The timestamp is the moment when the data frame is collected. The detection flag includes a fault flag and a normal flag, and the fault flag is used to identify the data frame as a fault data frame, and the normal flag is used to identify the data frame as a normal data frame. The detection flag may include multiple different fault flags, and the multiple different fault flags are used to identify the data frame as a fault data frame under different fault conditions. For example, when the detection flag is the normal flag "0x00", it indicates that the data frame is a normal data frame. When the detection flag is the first fault flag "0x01", it indicates that the data frame is a fault data frame under the first fault condition. When the detection flag is the second fault flag "0x02", it indicates that the data frame is a fault data frame under the second fault condition.

[0040] Cache is used to store target data sets from M FIFOs. The target data set includes target data streams stored in M ​​FIFOs. The target data stream is the data stream of the fault occurrence time period, which includes the data stream of the first time period before the fault occurs and the data stream of the second time period after the fault occurs. The fault occurrence time is the time when the first fault data frame is collected, that is, the timestamp of the first fault data frame. For example, when the fault occurs at 12:00 and the fault occurrence time period is 10 seconds (s), the target data stream includes the data stream of 11:56-12:00 and the data stream of 12:01-12:05.

[0041] The volatile memory device 410 may include, but is not limited to, random access memory (Random Access Memory, RAM), static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDR SDRAM), etc.

[0042] The non-volatile memory device 420 is used to store the target data set from the Cache. The target data set includes data streams of the fault occurrence time period in various dimensions, which can reflect the state change process of the battery pack 100 and each battery contained therein before and after the fault occurs, which is conducive to fault location and fault cause analysis, and can improve the efficiency of fault location and fault clearing, thereby improving the safety and reliability of the energy storage system 10.

[0043] In this embodiment, the non-volatile memory device 420 stores H data records L1-L H , H is a positive integer. Each data record contains the data stream of each dimension of a corresponding fault occurrence time period. For example, data record L i Contains data streams of each dimension of the i-th fault occurrence time period, i is an integer, and 1≤i≤H. Each data record contains summary information and detailed data. The summary information includes a set of fault occurrence times, a set of detection flags, and a summary information check value. The set of fault occurrence times includes the fault occurrence times of the data streams of each dimension of the fault occurrence time period, the set of detection flags includes the detection flags of the data streams of each dimension of the fault occurrence time period, and the summary information check value is used to verify the integrity and accuracy of the summary information. The detailed data includes the data streams of each dimension of the fault occurrence time period and the detailed data check value. The detailed data check value is used to verify the integrity and accuracy of the detailed data. Exemplarily, the summary information check value and the detailed data check value can be calculated by a cyclic redundancy check (CRC) or a message digest algorithm 5 (MD5).

[0044] The non-volatile memory device 420 may include, but is not limited to, Flash Memory, Read-Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Magnetoresistive RAM (MRAM), Resistive RAM (RRAM), Phase Change Memory (PCM), etc.

[0045] The controller 500 is electrically connected to the data collector 300 and the memory 400. The controller 500 includes a fault detection module 510 and a fault recording module 520. The fault detection module 510 is used to obtain M-dimensional data streams from the data collector 300 and add a detection mark to each data frame in the M-dimensional data streams.

[0046] In one embodiment, adding a detection mark to each data frame in the data stream of M dimensions includes: when the w-th frame data is within a first value range, determining that the w-th frame data is a faulty data frame under a first fault condition, and the detection mark added to the w-th frame data is a first fault mark. When the w-th frame data is within a second value range, determining that the w-th frame data is a faulty data frame under a second fault condition, and the detection mark added to the w-th frame data is a second fault mark. When the w-th frame data is neither within the first value range nor within the second value range, determining that the w-th frame data is a normal data frame, and the detection mark added to the w-th frame data is a normal mark.

[0047] In another embodiment, adding a detection mark to each data frame in the data stream of M dimensions includes: when the w-th frame data is greater than the first threshold, determining that the w-th frame data is a faulty data frame under the first fault condition, and the detection mark added to the w-th frame data is a first fault mark. When the w-th frame data is less than or equal to the first threshold and greater than the second threshold, determining that the w-th frame data is a faulty data frame under the second fault condition, and the detection mark added to the w-th frame data is a second fault mark. When the w-th frame data is less than or equal to the second threshold, determining that the w-th frame data is a normal data frame, and the detection mark added to the w-th frame data is a normal mark.

[0048] Wherein, w is a positive integer, and the first value range and the second value range, the first threshold and the second threshold can be set as needed.

[0049] The fault recording module 520 is used to obtain the data stream from the fault detection module 510, write the data stream into the FIFO frame by frame, and when the data stream stored in the FIFO meets the storage conditions, read the target data stream stored in the FIFO into the Cache, and write the target data set stored in the Cache into the non-volatile storage device 420.

[0050] In this embodiment, the data stream stored in the FIFO satisfies the storage condition including: the number of fault data frames stored in the FIFO is greater than or equal to the storage threshold. The storage threshold is less than the depth of the FIFO. Exemplarily, when the depth of the FIFO is x, x is a positive integer, the storage threshold can be x / 2, x / 3 or x / 4.

[0051] The depth of FIFO refers to the maximum number of data frames stored in FIFO. The depth of FIFO is related to the recording time and the data acquisition cycle. The recording time refers to the length of the time period when the fault occurs, which can be set as needed. By establishing a correlation between the depth of FIFO and the recording time and the data acquisition cycle, the depth of FIFO can be flexibly adjusted according to the recording time and the data acquisition cycle to adjust the storage capacity of FIFO, thereby improving the flexibility of FIFO storage. Since FIFO occupies the storage resources of the volatile memory device 410, the flexible and adjustable FIFO can improve the storage space utilization of the volatile memory device 410 and reduce the waste of storage resources.

[0052] The storage capacity of a FIFO is the product of the depth of the FIFO and the width of the FIFO. The width of a FIFO refers to the length of a single data frame stored in the FIFO. The length of each data frame stored in the FIFO is equal. The length of the data frame is related to the data transmission protocol. For example, in the CAN protocol, the length of the data frame is 0-8 bytes.

[0053] In one embodiment, the depth of the FIFO is positively correlated with the recording duration and negatively correlated with the data acquisition cycle. Exemplarily, the depth of the FIFO is the ratio of the recording duration to the data acquisition cycle. For example, when the recording duration is 10s and the data acquisition cycle is 500ms, the depth of the FIFO is 10s / 500ms=20, indicating that the FIFO can store up to 20 data frames. When the length of the data frame is 2 bytes and the width of the FIFO is 2 bytes, the storage capacity of the FIFO is 20*2byte=40byte.

[0054] The controller 500 may include, but is not limited to, a microcontroller unit (MCU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic controller (PLC), a microprocessor unit (MPU), an application-specific integrated circuit (ASIC), a system on a chip (SoC), etc.

[0055] It can be understood that the fault detection module 510 and the fault recording module 520 can be implemented by software, hardware or a combination of software and hardware.

[0056] The above is a detailed description of the structure of the energy storage system. In the above embodiment, the fault recording function of the energy storage system relies on the FIFO storage mechanism. Figures 2 to 9 Describe the storage mechanism of FIFO in detail.

[0057] like Figure 2 As shown, the depth of the FIFO is 20, and before the controller 500 writes the data stream to the FIFO, the FIFO is empty. Since the storage space of the volatile memory device 410 will be cleared after power failure, after the volatile memory device 410 is powered on, the controller 500 can configure the number of FIFOs according to the data type of the operating data of the battery pack 100, configure the depth of each FIFO according to the recording time and data acquisition cycle, and configure the width of each FIFO according to the length of the data frame. Each FIFO can store data streams in parallel or in series.

[0058] like Figure 3 As shown, after determining whether the first data frame D0 is a faulty data frame, the controller 500 writes the first data frame D0 into the FIFO. The controller 500 writes a data stream into the FIFO according to the data acquisition cycle. The data stream includes data frames D0-D z , z is a positive integer, data frame D0-D z Each data frame includes a timestamp and a detection flag.

[0059] like Figure 4As shown, after writing the first data frame D0 to the FIFO, the controller 500 determines whether the data frame D1 is a faulty data frame after a data collection cycle, and writes the data frame D1 to the FIFO. Similarly, the controller 500 writes five data frames D0-D4 to the FIFO.

[0060] like Figure 5 As shown, when the controller 500 writes 20 data frames D0-D to the FIFO 19 , FIFO is full, FIFO is full means that the number of data frames stored in FIFO reaches the maximum number.

[0061] like Figure 6 As shown, when the controller 500 continues to write data frame D to the FIFO 20 , data frame D0 overflows, and the data frames stored in FIFO include data frames D1-D 20 When the overflowed data frame D0 is a normal data frame, the data frame D0 is deleted. Similarly, when the controller 500 continues to write data frame D0 to the FIFO, 23 , data frame D3 overflows, and the data frames stored in FIFO include data frames D4-D 23 When the overflowed data frame D3 is a normal data frame, the data frame D3 is deleted.

[0062] like Figure 7 As shown, when the controller 500 determines the data frame D 24 Write data frame D to FIFO for fault data frame 24 Since data frame D0-D 23 are all normal data frames, so data frame D 24 is the first fault data frame. The timestamp of the first fault data frame is the time when the fault occurs.

[0063] like Figure 8 As shown, the controller 500 writes the first fault data frame D to the FIFO. 24 After that, a data collection cycle is taken to determine the data frame D 25 Is it a fault data frame? Write data frame D to FIFO 25 Similarly, the controller 500 writes 5 fault data frames D to the FIFO. 24 -D 28 .

[0064] like Fig. 9 As shown in FIG. 1 , when the number of faulty data frames stored in the FIFO is greater than or equal to half of its depth, the controller 500 reads all data frames stored in the FIFO into the Cache. The total data frames stored in the FIFO include 20 data frames D 14 -D 33 , where 10 data frames D14 -D 23 is a normal data frame, 10 data frames D 24 -D 33 It is the fault data frame.

[0065] The storage mechanism of FIFO is specifically described above. In the above embodiment, when the number of fault data frames stored in FIFO is greater than or equal to half of its depth, all data frames stored in FIFO are data of the time period when the fault occurs, and the data of the time period when the fault occurs is read into Cache. Cache stores data of various dimensions of the time period when the fault occurs from all FIFOs, writes data of various dimensions of the time period when the fault occurs into non-volatile storage device 420, and stores data of various dimensions of the time period when the fault occurs through non-volatile storage device 420. The data of various dimensions of the time period when the fault occurs can reflect the state change process of the battery pack 100 and each battery contained therein before and after the fault occurs, which is conducive to fault location and fault cause analysis, can improve the accuracy of fault location and fault diagnosis, and improve the efficiency of fault location and fault clearing, thereby improving the safety and reliability of the energy storage system 10.

[0066] Based on the above FIFO storage mechanism, the data storage method is specifically described below by taking the data stream of the temperature of a single cell of a battery pack as an example.

[0067] Fig.10 A flowchart of a data storage method provided by an example.

[0068] Data storage methods are applied to energy storage systems, e.g. Figure 1 The energy storage system shown. Fig.10 As shown, the data storage method includes the following steps:

[0069] S101, acquiring a data stream of the temperature of a single cell of a battery pack according to a data collection cycle.

[0070] The data stream of the single cell temperature includes data frames D0-D z , z is a positive integer.

[0071] S102, when acquiring data frame D i , determine the data frame D i Whether it is a fault data frame.

[0072] If yes, execute step S103; if no, execute step S104.

[0073] Wherein, i is an integer, and 0≤i≤z.

[0074] S103, give data frame D i Added failure flag.

[0075] S104, give data frame D i Add normal flag.

[0076] After executing step S103 or S104, execute step S105.

[0077] In this embodiment, the data frame includes a timestamp and a detection flag. The timestamp is the time when the data frame is collected. The detection flag includes a fault flag and a normal flag, the fault flag is used to identify the data frame as a fault data frame, and the normal flag is used to identify the data frame as a normal data frame. The detection flag may include multiple different fault flags, and the multiple different fault flags are used to identify the data frame as a fault data frame under different fault conditions.

[0078] In one embodiment, determining frame by frame whether the data stream of the temperature of a single cell is a fault data frame comprises: when the data frame D i In the first value range, determine the data frame D i is a fault data frame under the first fault condition, and its detection flag is determined to be the first fault flag. i In the second value range, determine the data frame D i is a fault data frame under the second fault condition, and its detection flag is determined to be the second fault flag. i Neither in the first value range nor in the second value range, determine the data frame D i It is a normal data frame, and its detection flag is determined to be a normal flag.

[0079] In another embodiment, determining frame by frame whether the data stream of the temperature of the single cell is a fault data frame comprises: when the data frame D i is greater than the first threshold, determining the data frame D i is a fault data frame under the first fault condition, and its detection flag is determined to be the first fault flag. i is less than or equal to the first threshold and greater than the second threshold, determining the data frame D i is a fault data frame under the second fault condition, and its detection flag is determined to be the second fault flag. i is less than or equal to the second threshold, determining the data frame D i It is a normal data frame, and its detection flag is determined to be a normal flag.

[0080] S105, write data frame D to FIFO i .

[0081] The depth of the FIFO is x, where x is a positive integer.

[0082] S106: Determine data frame D i Whether it is the first fault data frame.

[0083] If yes, execute steps S107-S108; if no, execute step S109.

[0084] In this embodiment, by querying the data frame D i The detection flag is used to determine the data frame D i Is it a faulty data frame? i-1 Both are normal data frames and data frame D i is the fault data frame, determine the data frame D i This is the first fault data frame.

[0085] S107, continuously write data frame D to FIFO according to the data acquisition cycle i+1 -D z , when the number of faulty data frames stored in the FIFO is greater than or equal to the storage threshold, all data frames stored in the FIFO are read into the Cache.

[0086] In this embodiment, the storage threshold is less than the depth of the FIFO. When the number of fault data frames stored in the FIFO is greater than or equal to the storage threshold, all data frames stored in the FIFO are data of the fault time period, which can reflect the change process of the single cell temperature before and after the fault occurs.

[0087] S108. Write all data frames stored in the Cache into a non-volatile storage device.

[0088] S109, determine the data frame D stored in FIFO i Whether overflow occurs.

[0089] If yes, execute steps S110 - S111 ; if no, execute step S111 .

[0090] When FIFO is full and data frame D is written to FIFO x+i , the data frames stored in FIFO include data frames D i+1 -D x+i , the previously stored data frame D i overflow.

[0091] S110, delete data frame D i .

[0092] S111, continuously write data frame D to FIFO according to the data acquisition cycle i+1 -D z .

[0093] The data storage method is specifically described above. In the above embodiment, when the data stream of the temperature of the single cell of the battery pack is obtained, the data of the time period when the fault occurs is stored through the non-volatile storage device. The data of the time period when the fault occurs can reflect the change process of the temperature of the single cell before and after the fault occurs, which is conducive to fault location and fault cause analysis, and can improve the accuracy of fault location and fault diagnosis, and improve the efficiency of fault location and fault clearing, thereby improving the safety and reliability of the energy storage system.

[0094] It can be understood that when obtaining the data stream of any dimension of the battery pack, the data storage method of the above embodiment can be used to store the data of the time period when the fault occurs.

[0095] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. An energy storage system, characterized in that: It includes a battery pack, a data collector, a memory and a controller; the battery pack includes a plurality of batteries; The data collector is connected to the multiple batteries via a bus, and is used to collect operating data of the battery pack, wherein the operating data includes a data stream of M dimensions, where M is a positive integer; The memory includes a volatile memory device and a non-volatile memory device, and the volatile memory device includes a cache and M first-in-first-out buffers; The controller is electrically connected to the data collector and the memory, and is used to obtain the data streams of the M dimensions, write the data streams of the M dimensions into the M first-in-first-out buffers frame by frame, read the target data stream stored in the first-in-first-out buffer to the cache when the data streams stored in the first-in-first-out buffers meet the storage conditions, and write the target data set stored in the cache to the non-volatile memory device; wherein the target data stream is the data stream in the time period when the fault occurs, and the target data set includes the target data streams stored in the M first-in-first-out buffers.

2. The energy storage system according to claim 1, characterized in that: The data stream stored in the FIFO buffer meets the storage condition including: the number of fault data frames stored in the FIFO buffer is greater than or equal to the storage threshold; Among them, the storage threshold is less than the depth of the first-in-first-out buffer, and the depth of the first-in-first-out buffer is related to the recording time and the data collection cycle. The recording time is the length of the fault occurrence time period, and the data collection cycle is the period for the data collector to collect a single-dimensional data stream.

3. The energy storage system according to claim 2, characterized in that: The depth of the first-in-first-out buffer is the ratio of the recording duration to the data collection period.

4. The energy storage system according to claim 2 or 3, characterized in that: The storage capacity of the FIFO buffer is the product of the depth and width of the FIFO buffer; The width of the FIFO buffer is the length of a single data frame stored in the FIFO buffer, and the length of each data frame stored in the FIFO buffer is equal.

5. The energy storage system according to any one of claims 1 to 4, characterized in that: Before writing the data streams of the M dimensions into the M first-in-first-out buffers frame by frame, the controller adds a detection flag to each data frame in the data streams of the M dimensions; The detection flag includes a fault flag and a normal flag, the fault flag is used to identify the data frame as a faulty data frame, and the normal flag is used to identify the data frame as a normal data frame.

6. The energy storage system according to claim 5, characterized in that: The detection flag includes a first fault flag and a second fault flag, wherein the first fault flag is used to identify that the data frame is a fault data frame under a first fault condition, and the second fault flag is used to identify that the data frame is a fault data frame under a second fault condition.

7. The energy storage system according to claim 6, characterized in that: The controller adding a detection mark to each data frame in the data stream of the M dimensions includes: When the w-th frame data is within the first value range, determining that the w-th frame data is a fault data frame under the first fault condition, and adding the detection flag added to the w-th frame data as the first fault flag; When the w-th frame data is within the second value range, determining that the w-th frame data is a fault data frame under the second fault condition, and adding the detection flag added to the w-th frame data as the second fault flag; When the w-th frame data is neither within the first value range nor within the second value range, the w-th frame data is determined to be a normal data frame, and the detection flag added to the w-th frame data is the normal flag; wherein w is a positive integer.

8. The energy storage system according to claim 6, characterized in that: The controller adding a detection mark to each data frame in the data stream of the M dimensions includes: When the w-th frame data is greater than the first threshold, determining that the w-th frame data is a fault data frame under the first fault condition, and adding the detection flag added to the w-th frame data as the first fault flag; When the w-th frame data is less than or equal to the first threshold value and greater than the second threshold value, it is determined that the w-th frame data is a fault data frame under the second fault condition, and the detection flag added to the w-th frame data is the second fault flag; When the w-th frame data is less than or equal to the second threshold, the w-th frame data is determined to be a normal data frame, and the detection flag added to the w-th frame data is the normal flag; wherein w is a positive integer.

9. The energy storage system according to any one of claims 1 to 8, characterized in that: When the data stream stored in the FIFO buffer does not meet the storage condition, the controller deletes data frames overflowing from the FIFO buffer.

10. A data storage method, applied to an energy storage system, characterized in that: The storage system includes a battery pack, a volatile memory device and a non-volatile memory device, wherein the volatile memory device includes a cache and M first-in-first-out buffers, where M is a positive integer; and the method includes: Acquire operating data of the battery pack, where the operating data includes data streams of M dimensions; Writing the data streams of the M dimensions into the M first-in-first-out buffers frame by frame; When the data stream stored in the first-in-first-out buffer meets the storage condition, the target data stream stored in the first-in-first-out buffer is read into the cache, and the target data set stored in the cache is written into the non-volatile memory device; wherein the target data stream is the data stream in the time period when the fault occurs, and the target data set includes the target data streams stored in the M first-in-first-out buffers.

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