Battery management system and time synchronization method thereof

Abstract

The present application relates to a battery management system and a time synchronization method thereof, for correcting a synchronization time of each of a plurality of battery monitoring devices connected in series in the battery management system. The method includes receiving time information, and obtaining a time offset value, a correction value, a delay value of each battery monitoring device, etc. from the time information to correct the synchronization time.

Description

Technical Field

[0001] This application relates to a battery management system (BMS) and its time synchronization method, and particularly to a method for correcting the synchronization time of each battery monitoring device in a wireless daisy-chain network topology battery management system. Background Technology

[0002] In previous technologies, to improve the efficiency of battery energy storage systems, battery packs in industrial and automotive battery energy storage systems were mostly arranged in series. The DC voltage of the battery pack increases with the number of batteries connected in series. However, battery energy storage systems must monitor and collect information such as the voltage and temperature of each battery in the system through a battery management system (BMS) to monitor and maintain the operation and safety of the battery storage. To monitor the parameters of each battery, current battery management systems can have multiple monitoring devices, with each battery equipped with one monitoring device. In the case of these monitoring devices forming a wireless daisy-chain topology, if the timing of the monitoring devices is not synchronized or differs, it cannot be ensured that the entire battery management system measures the voltage values ​​of each battery at the same time, affecting the accuracy of its battery management monitoring. Therefore, there is a need for a technology that can correct the synchronization time of the monitoring devices in a battery management system forming a wireless daisy-chain topology to improve battery management performance. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this application is to provide a battery management system (BMS) and its time synchronization method, which utilizes radio frequency couplers or optical transceivers in a wireless daisy-chain network topology to achieve time synchronization of various monitoring devices in the battery management system.

[0004] The objective of this application and the technical problem it solves are achieved through the following technical solution. From one perspective, this application proposes a time synchronization method for a battery management system. The battery management system includes multiple battery monitoring devices connected in series, and the multiple battery monitoring devices are wirelessly connected in series to form a wireless daisychain network topology. The time synchronization method for the battery management system includes receiving time information from the current level device among the multiple battery monitoring devices. The time synchronization method also includes the current level device performing time synchronization based on the time information. The above steps are repeated to sequentially synchronize the time of each of the multiple battery monitoring devices until the time synchronization of the last level among the multiple battery monitoring devices is completed.

[0005] In another aspect of this application, a battery management system is provided. The battery management system includes N battery monitoring devices wirelessly connected in series, forming a wireless daisy-chain network topology. N is a positive integer. Synchronization time correction among the N battery monitoring devices can be achieved by receiving time information from the nth device. The time information is sent by the (n-1)th device, which is one level above the nth device. Synchronization time correction among the N battery monitoring devices can also be achieved by the nth device obtaining a time offset value based on the time information and using the time offset value to correct the synchronization time in the nth device. Synchronization time correction among the N battery monitoring devices can also be achieved by the nth device forwarding the time information to the (n+1)th device, which is one level below the nth device. Synchronization time correction among the N battery monitoring devices can also be achieved by repeating the above steps sequentially among the N battery monitoring devices until the Nth battery monitoring device, the last level of the N battery monitoring devices, completes the correction. n is an integer from 2 to N.

[0006] In another aspect of this application, a method is provided for correcting the synchronization time between a master control device and N slave devices coupled in series in a battery management system. The master control device and the N slave devices form a wireless daisy-chain network topology. N is a positive integer. The method includes the master control device sending master time information to a first slave device among the N slave devices. The master time information includes the master control device's transmission time corresponding to the time when the master control device sends the master time information. The method also includes the first slave device receiving the master time information and obtaining a first reception time based on the time when the master time information is received. The method also includes the first slave device sending the first time information to a second slave device among the N slave devices. The first time information includes a first transmission time, a first reception time, a first correction time, and the master control device's transmission time corresponding to the time when the first slave device sends the first time information. The first correction time is 0. The method also includes the second slave device receiving the first time information and obtaining a second reception time based on the time when the first time information is received. The method also includes the second slave device sending second time information to a third slave device among the N slave devices. The second time information includes a second transmission time, a second reception time, a second correction time, and a master control device transmission time corresponding to the time point when the second slave device sends the second time information. The second correction time is the first processing time plus the first correction time. The first processing time is the first transmission time of the first slave device minus the first reception time. The method also includes a third slave device receiving the second time information and obtaining a third reception time based on the time point when the second time information is received. The method also includes a third slave device sending the third time information to a fourth slave device among the N slave devices. The third time information includes a third transmission time, a third reception time, a third correction time, and the master control device transmission time corresponding to the time point when the third slave device sends the third time information. The third correction time is the second processing time plus the second correction time, where the second processing time is the second transmission time of the second slave device minus the second reception time. The method also includes repeating the above steps until the Nth slave device of the last level among the N slave devices receives the (N-1)th time information sent by the (N-1)th slave device among the N slave devices, and obtaining the Nth reception time based on the time point when the (N-1)th time information is received. Each of the N devices has a delay value. When each of the N devices receives the corresponding time information, each of the N devices obtains a time offset value and uses the corresponding time offset value to correct the synchronization time of each of the N devices, so as to synchronize the time of the N devices. The time offset value used to correct the time synchronization of the nth device among the N devices is the information reception time of the (n)th device minus the correction value. The correction value is the sum of the transmission time of the main control device, the nth correction time, and the total delay value. The total delay value is n multiplied by the delay value.

[0007] To provide a better understanding of the above and other aspects of this disclosure, specific embodiments are described below in conjunction with the accompanying drawings: Attached Figure Description

[0008] Figure 1 A schematic diagram of a battery system 1000 and its battery management system 200 according to various embodiments of this application is shown.

[0009] Figure 2A This diagram illustrates the use of a downlink data link to transmit time information to a battery monitoring device according to various embodiments of this application.

[0010] Figure 2B A schematic diagram illustrating a battery monitoring device according to various embodiments of this application receiving and transmitting messages with time information.

[0011] Figure 3A A schematic diagram illustrating example time information formats according to various embodiments of this application is provided.

[0012] Figure 3B A schematic diagram illustrating another example time information format according to various embodiments of this application is shown.

[0013] Figure 3C A schematic diagram illustrating yet another example time information format according to various embodiments of this application is shown.

[0014] Figure 4 A flowchart illustrating an example procedure for performing synchronization time correction on a battery monitoring device according to various embodiments of this application is shown. Detailed Implementation

[0015] The foregoing descriptions and other technical contents, features, and effects of this application will be clearly presented in the following detailed description of preferred embodiments with reference to the accompanying drawings. The following descriptions of the embodiments are with reference to the accompanying drawings and are used to illustrate specific embodiments in which this application can be implemented. The foregoing descriptions and other technical contents, features, and effects of this application will be clearly presented in the following detailed description of preferred embodiments with reference to the accompanying drawings.

[0016] The accompanying drawings and descriptions are intended to be illustrative in nature, not restrictive. In the drawings, structurally similar units are denoted by the same reference numerals. Furthermore, for ease of understanding and description, the dimensions and thicknesses of each component shown in the drawings are arbitrary, but this application is not limited thereto.

[0017] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features and effects of a battery management system (BMS) and its time synchronization method proposed in this application.

[0018] Please refer to Figure 1 The diagram illustrates a battery system 1000 and its battery management system 200 according to various embodiments of this application. The battery system 1000 includes several battery cells 900j and a battery management system 200. These battery cells 900j are connected in series. During operation of the battery system 1000, these battery cells 900j need to be monitored to confirm whether battery parameters such as temperature and voltage are normal. Therefore, a battery monitoring device (battery monitoring device 200S1 (first level) to battery monitoring device 200S) needs to be provided for each battery cell 900j. N (The last level) One of the corresponding ones), for monitoring.

[0019] like Figure 1 As shown, the battery management system 200 includes a master control device 200M and battery monitoring devices 200S1 to 200S2. N and multiple communication couplers 300j. Multiple battery monitoring devices (battery monitoring device 200S1 to battery monitoring device 200S) N (This can be referred to as a slave device relative to the master control device 200M). Each communication coupler 300j can be an optical communication coupler or an radio frequency coupler, and is installed between the master control device 200M and the battery monitoring device 200S1 (first stage), and between the battery monitoring device 200S1 (first stage) and the battery monitoring device 200S... N Between (the last level). Main control unit 200M, battery monitoring unit 200S1 to battery monitoring unit 200S N Both devices communicate wirelessly via whispers through a communication coupler 300j to the battery monitoring device 200S. N Data, messages, or information (downlink data link) are transmitted sequentially from the battery monitoring device 200S. N The confirmation messages (uplink data links) are sent back sequentially, enabling the main control device 200M, battery monitoring device 200S1 to battery monitoring device 200S2 to transmit confirmation messages in sequence. N Form a wireless daisy-chain network topology (N is a positive integer).

[0020] In one embodiment, due to multiple battery monitoring devices (battery monitoring device 200S1 to battery monitoring device 200S) NEach of the battery monitoring devices (battery monitoring device 200S1 to battery monitoring device 200S) in the battery management system 200 has a standard time. N The time synchronization of the battery monitoring devices is to ensure that the battery management system 200 can measure the voltage value or other relevant battery parameters of each battery 900j at the same time. The technology for correcting the synchronization time of each battery monitoring device provided in this disclosure can transmit time information that can be used for synchronization or time correction through downlink data links between battery monitoring devices. The synchronization time (or circuit time) of each battery monitoring device can be corrected by the front-end of each battery monitoring device to the front-end (e.g., the (n-1)th battery monitoring device to the nth battery monitoring device, where n is an integer between 2 and N), or by the main control device 200M to each battery monitoring device.

[0021] Figure 2A The illustration depicts the use of a downlink data link for battery monitoring devices (battery monitoring device 200S1 to battery monitoring device 200S) according to various embodiments of this application. N This diagram illustrates the transmission of time information 401. In an established wireless daisy-chain network topology, on the downlink data link, message 400 (which may contain only time information 401, meaning message 400 is time information 401 itself, or it may contain both data 402 and time information 401, meaning time information 401 is embedded within the general transmitted data) can be sequentially transmitted from the main control device 200M to the first-stage battery monitoring device 200S1, then forwarded from the first-stage battery monitoring device 200S1 to the second-stage battery monitoring device 200S2, and so on, until the last-stage (or tail slave) battery monitoring device 200S2. N Then, via the uplink data link, it is sequentially transmitted from the last stage battery monitoring device 200S. N Send a confirmation message 500 times to the previous stage's battery monitoring device 200 seconds. (N-1) By analogy with the main control device 200M, all battery monitoring devices (or slave devices) in the battery management system can receive time information 401, and the time information 401 can be used to correct the synchronization time (CurrentSysTime) of each battery monitoring device.

[0022] Figure 2B A schematic diagram illustrating the receiving and transmitting of a message 400 having time information 401 by a battery monitoring device 200S1 to battery monitoring device 200S2 according to various embodiments of this application is shown. In the case where the message 400 includes data 402 and time information 401, the following applies to battery monitoring devices 200S1 to 200S2: NAny of the battery monitoring devices (e.g., battery monitoring device 200Sn) can automatically capture the current time point inside the message 400 when it receives the k-th bit of the time information 401 in the message 400 through the built-in hardware timestamp function, and store this time in the register as the reception time T2sn of the received time information 401.

[0023] In one embodiment, when sending a message 400 containing time information 401, when the message reaches the k-th bit containing time information 401, the current time point within it can be automatically captured using the hardware timestamp function, and this time can be used as the transmission time T1sn and appended to the message 400, for example, before the cyclic redundancy check (CRC) (e.g. Figure 2B (as shown), and also stored in the cache.

[0024] It is understandable that when time information 401 is received, it will include the transmission time of the corresponding time point in time from the previous-level battery monitoring device (or slave device) that sent time information 401 (for example, battery monitoring device 200S(n+1) receives the transmission time T1sn from time information 401 sent by battery monitoring device 200Sn). The battery monitoring device receiving this transmission time can use it as the previous-level transmission time and store it in its buffer. It should be noted that the time information 401 sent by the main control device 200 can be regarded as the main time information, and the transmission time corresponding to the time point in time when the main control device sends the main time information can be regarded as the main control device transmission time T1M.

[0025] Figure 3A Schematic diagrams illustrating example time information formats according to various embodiments of this application are shown. For example... Figure 3A As shown, when the battery monitoring device 200Sn receives the time information 401, whether it is embedded in other messages or only contains the time information 401, as discussed above, the battery monitoring device 200Sn can obtain the transmission time T1S(n-1) of the preceding battery monitoring device 200S(n-1) and its own reception time T2sn corresponding to the time point when it received the time information 401 from the time information 401. That is to say, in this example, the time correction message information 401 only contains the transmission time of the preceding battery monitoring device, so the transmitted time information can be represented as TX_TimeSyncInfoSn = {T1Sn}, and the received time information can be represented as RX_TimeSyncInfoSn = TX_TimeSyncInfoS(n-1) = {T1S(n-1)}.

[0026] In some embodiments, for each battery monitoring device (battery monitoring device 200S1 to battery monitoring device 200S) N Each battery monitoring device (or slave device) needs to correct its synchronization time (CurrentSysTimeSn) using an offset value (TimeOffsetSn) to obtain the corrected synchronization time (CurrentSysTimeSn' = TimeOffsetSn + CurrentSysTimeSn). When the preceding stage of each battery monitoring device corrects the synchronization time of its current stage (e.g., the (n-1)th battery monitoring device to the nth battery monitoring device, where n is an integer between 2 and N), the offset value (TimeOffsetSn) is the receiving time (T2Sn) minus the transmitting time (T1S(n-1)) and the delay value (Delay), and can therefore be expressed as TimeOffsetSn = T2Sn – (T1S(n-1) + Delay). The delay value (Delay) is a fixed constant that can be calculated and measured, and can be used to correct the synchronization time of each battery monitoring device, as described above.

[0027] Figure 3B A schematic diagram illustrating another example time information format according to various embodiments of this application is shown. When the main control device 200M corrects the synchronization time (or circuit time) of each battery monitoring device, that is, when all battery monitoring devices are synchronized with the main control device 200M, the aforementioned main control device transmission time T1 needs to be taken into account. M Therefore, the offset value (TimeOffsetSn) is the receiving time (T2Sn) minus the main control device's transmission time T1. M The sum of the delay value (Delay xn) and the correction time (TimeCorrectionSn) can be expressed as TimeOffsetSn = T2 Sn –(T1 M + Delay x n + TimeCorrectionSn). This takes into account the different information required, such as T1. M And TimeCorrectionSn, therefore in this example, the time information needs to carry more different data, so the sent time information can be represented as TX_TimeSyncInfoSn = {T1 M , TimeCorrectionSn = ( TimeCorrectionS(n-1) +ProcessTimeS(n-1)), T2 Sn T1 Sn}, where ProcessTimeS(n-1) = (T1S(n-1) – T2 S(n-1) The received correction information can be represented as RX_TimeSyncInfoSn = TX_TimeSyncInfoS(n-1). From the above, it can be seen that TimeCorrectionSn is the sum of the previous stage's processing time ProcessTimeS(n-1). The previous stage's processing time ProcessTimeS(n-1) can be determined by the previous stage's transmission time T1. S(n-1) Subtract the receiving time T2 of the preceding stage S(n-1) To obtain it. Because the reception time T2 of the current level will also be included when forwarding. Sn and the current transmission time T1 Sn When the downstream stage receives the time information, it can also calculate the processing time ProcessTimeSn and add it to the correction time TimeCorrectionSn to form TimeCorrectionS(n+1), which is then appended to TX_TimeSyncInfoS(n+1). The total delay value (Delay xn) is the sum of the delay values ​​of battery monitoring device 200Sn and its upstream stages (battery monitoring device 200S1 to battery monitoring device 200S). (n-1) The sum of the delay values ​​(Delay) is therefore represented as Delay multiplied by n.

[0028] Reference to Figure 3B Specifically, when the main control device 200M sends the main time information (TX_TimeSyncInfoM = {0, 0, 0, T1M}) to the first-level battery monitoring device 200S1, the battery monitoring device 200S1 receives the time information as RX_TimeSyncInfoS1 = TX_TimeSyncInfoM, and forwards the time information as TX_TimeSyncInfoS1 = {T1M, TimeCorrectionS1=0, T2M}. S1 T1 S1 Since the processing time of the main control device does not need to be considered, and the main device does not need to receive time information, the correction time TimeCorrectionS1 of the battery monitoring device 200S1 is 0. The receiving time T2 used for forwarding... S1 and sending time T1 S1 As mentioned above, the battery monitoring device 200S1 can automatically capture the time points corresponding to the received time information TX_TimeSyncInfoM and the sent time information TX_TimeSyncInfoS1 through its hardware timestamp function.

[0029] Next, the battery monitoring device 200S2 at the next level receives the time information RX_TimeSyncInfoS2 = TX_TimeSyncInfoS1, and forwards the time information TX_TimeSyncInfoS2 = {T1 M ,TimeCorrectionS2= TimeCorrectionS+ ProcessTimeS1, T2 S2 T1 S2 Since the correction time TimeCorrectionS1 of battery monitoring device 200S1 is 0, the correction time TimeCorrectionS2 required for battery monitoring device 200S2 to forward is 0 + ProcessTimeS1 = T1. S1 – T2 S1 Similarly, the reception time T2 used for forwarding S2 and sending time T1 S2 As mentioned above, the battery monitoring device 200S2 can automatically capture the time points corresponding to the received time information TX_TimeSyncInfoS1 and the sent time information TX_TimeSyncInfoS2 through its internal hardware timestamp function.

[0030] This process can be repeated until the final stage of the battery monitoring device 200S. N Received battery monitoring device 200S from the previous level (N-1) The sent time information TX_TimeSyncInfoS(N-1) is used to obtain the information needed for the offset value used to correct the synchronization time (TimeOffsetSN = T2). SN – (T1 M +Delay x N+TimeCorrectionSN).

[0031] Figure 3C A schematic diagram illustrating yet another example time information format according to various embodiments of this application is shown. Figure 3C In the example, when the main control device 200M corrects the synchronization time (or circuit time) of each battery monitoring device, that is, when all battery monitoring devices are synchronized with the main control device 200M, the aforementioned main control device transmission time T1 must also be taken into account. MThe correction time (TimeCorrectionSn) and the preceding processing time (ProcessTimeS(n-1)) are considered. With the hardware support of each battery monitoring device, the preceding processing time (ProcessTimeS(n-1)) can be directly obtained by subtracting the receiving time (T2S(n-1)) of the previously received time information (RX_TimeSyncInfoS(n-1)) from the sending time (TX_TimeSyncInfoS(n-1)) of the preceding battery monitoring device when it sends the time information (TX_TimeSyncInfoS(n-1)). This gives the processing time (ProcessTimeS(n-1)) as: ProcessTimeS(n-1) = T1S(n-1) - T2S(n-1). Similarly, the processing time can also be expressed as ProcessTimeS(n) = T1S(n) - T2S(n). Given the processing time ProcessTimeS(n) beforehand, before sending the time information, the previously accumulated processing time, i.e., the correction time TimeCorrectionS(n-1), can be further added to the current level's processing time ProcessTimeS(n) to obtain the current level's correction time TimeCorrectionSn. Therefore, the time information TX_TimeSyncInfoSn sent by each level of battery monitoring device can only contain the time T1 sent by the main control device. M The correction time, TimeCorrectionSn, is used, but the transmission time T2Sn and reception time T1 do not need to be included. Sn Therefore, the time information sent is represented as TX_TimeSyncInfoSn = {T1 M ,TimeCorrectionSn}, as discussed above, where TimeCorrectionSn = (TimeCorrectionS(n-1) + ProcessTimeS(n-1)), and ProcessTimeS(n-1) = (T1 S(n-1) – T2 S(n-1) This information is calculated by the hardware of the preceding device before it transmits the time information, and the correction time TimeCorrectionSn is directly appended to the transmitted time information TX_TimeSyncInfoSn. Similarly, the received correction information can be represented as RX_TimeSyncInfoSn = TX_TimeSyncInfoS(n-1). Similar to... Figure 3BFor example, since TimeCorrectionSn is the sum of the previous stage's processing time ProcessTimeS(n-1), and the previous stage's processing time ProcessTimeS(n-1) can be obtained by subtracting the previous stage's receiving time T2 from the previous stage's receiving time T1S(n-1). S(n-1) To obtain it. Because the forwarding is accompanied by the reception time T2 associated with the current level. Sn and the current transmission time T1 Sn The TimeCorrectionSn, when the subsequent stage receives the time information, can also calculate its own processing time ProcessTimeS(n+1) (based on its own receiving time T2). S(n+1) and sending time T1 (Sn+1) This is accumulated to the correction time TimeCorrectionSn, forming TimeCorrectionS(n+1), which is then appended to TX_TimeSyncInfoS(n+1). Similarly, the total delay value (Delay xn) is calculated for battery monitoring device 200Sn and its upstream stages (battery monitoring devices 200S1 to 200S...). (n-1) The delay value (Delay) is accumulated and therefore represented as Delay multiplied by n. Similarly, the above steps can be repeated until the last stage of the battery monitoring device 200S. N Received battery monitoring device 200S from the previous level (N-1) The sent time information TX_TimeSyncInfoS(N-1) is used to obtain the information needed for the offset value used to correct the synchronization time (TimeOffsetSN = T2). SN – (T1 M +Delay x N+TimeCorrectionSN).

[0032] Because TimeCorrectionSn accumulates continuously at each level, when a retransmission occurs between two slave devices due to message loss, T1Sn-1 will be delayed due to the retransmission, but T2... Sn-1 The time will not change due to retransmission, therefore, the calculation TimeCorrectionSn = TimeCorrectionSn-1 + T1 is correct. Sn-1 – T2 Sn-1 At that time, T1 Sn-1 – T2 Sn-1 It will increase and be included in TimeCorrection, which can increase the accuracy of synchronization time correction.

[0033] Therefore, by means of the above example, when each stage of the battery monitoring device receives time information, the offset value used to correct the synchronization time can be obtained by means of the master device transmission time, correction time (calculated by the previous stage), reception time (previous stage) and transmission time (previous stage) contained in the time information, or by means of the master device transmission time contained in the time information and the correction time (calculated by the previous stage) relating to the processing time (calculated before the previous stage).

[0034] Please refer to Figure 4 The diagram illustrates a flowchart of an example procedure for performing synchronization time correction on a battery monitoring device according to multiple embodiments of this application. In step S410, time information is received by the current-level device (e.g., battery monitoring device 200Sn) among the multiple battery monitoring devices. The time information may be received by a previous-level device located one level above the current-level device (e.g., battery monitoring device 200S(n-1)) or a main control device (e.g., a front ...). Figure 1 The main control device (200M) transmits the time information. The time information includes the transmission time corresponding to the point in time the time information was transmitted (e.g., T1s(n-1)). In step S420, the current stage device obtains the reception time (e.g., T2sn) based on the point in time the time information was received, and uses the transmission time in the time information as the previous stage transmission time (T1s(n-1) is different from T1sn). In step S430, the current stage device obtains a time offset value (e.g., TimeOffsetSn), and corrects the synchronization time (e.g., CurrentSysTimeSn) in the current stage device using the time offset value (e.g., CurrentSysTimeSn' = TimeOffsetSn + CurrentSysTimeSn). The time offset value is the reception time minus the correction value (e.g., TimeOffsetSn = T2Sn - CVSn). The correction value relates to the previous stage transmission time and the delay value. In step S440, when the primary device forwards time information to the secondary device located at the next level (e.g., battery monitoring device 200S(n+1)), the time information includes the transmission time (T1sn) corresponding to the time point when the primary device forwards the time information.

[0035] In one embodiment, as described above, the technology provided in this disclosure, in the battery management system of a wireless cascade network topology, allows the main control device to periodically or irregularly send messages containing time information or send time information. The time information can be used to enable each battery monitoring device in the wireless cascade network topology to correct its synchronization time, ensuring that each battery monitoring device measures various parameters of the battery at the same time, such as measuring the voltage value of each battery, thereby improving the stability and accuracy of the battery management system (BMS).

[0036] The above disclosure provides different features for implementing some embodiments or examples of this disclosure. Specific examples of components and configurations described above (e.g., mentioned values ​​or names) are used to simplify / illustrate some embodiments of this disclosure. Of course, these components and configurations are merely examples and are not intended to be limiting. Furthermore, reference numerals and / or letters may be repeated in various instances of some embodiments of this disclosure. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. The phrase "in one embodiment" is used repeatedly. This phrase does not usually refer to the same embodiment; however, it may refer to the same embodiment. The words "comprising," "having," and "including" are synonyms unless the context otherwise indicates otherwise.

[0037] The above description is merely a specific embodiment of this application, intended to facilitate understanding of the content of this application by those skilled in the art, and is not intended to limit this application in any way. Although this application has been disclosed above with specific embodiments, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A time synchronization method for a battery management system, the battery management system comprising a plurality of battery monitoring devices connected in series, and the battery monitoring devices forming a wireless daisy-chain network topology via wireless daisy-chaining, characterized in that, The time synchronization method of the battery management system includes: A time information is received by one of the current devices in the battery monitoring device; The current-level device performs time synchronization based on the time information; and Repeat the above steps to synchronize the time of each other in the battery monitoring device until the time synchronization of the last stage in the battery monitoring device is completed.

2. The time synchronization method for a battery management system as described in claim 1, characterized in that, The time information includes a transmission time corresponding to the time point when the time information was transmitted, and each of the battery monitoring devices has a delay value. The time synchronization of the current-level device based on the time information includes: The current stage device obtains a receiving time based on the time point when the time information is received, and uses the sending time in the time information as a previous stage sending time. The current-level device forwards the time information to the next-level device, and the time information includes a transmission time corresponding to the time point when the current-level device forwards the time information; The current-level device subtracts the previous-level transmission time and the delay value from the reception time to obtain a time offset value, and uses the time offset value to correct the synchronization time in the current-level device; and The above steps are repeated sequentially for each of the battery monitoring devices until the synchronization time of the last stage in the battery monitoring device is calibrated.

3. The time synchronization method for a battery management system as described in claim 1, characterized in that, The first stage in the battery monitoring device is a main control device, and the time information sent by the main control device includes a main control device sending time. The time information received and forwarded by each of the battery monitoring devices includes the main control device's transmission time, a calibration time, a transmission time, and a reception time. The correction time is the sum of the preceding processing times of each of the battery monitoring devices; the transmission time corresponds to the time point at which the time information is transmitted; the reception time corresponds to the time point at which the time information transmitted by the preceding battery monitoring device is received; and each of the battery monitoring devices has a delay value. The time synchronization of the current-level device based on the time information includes: The current-level device uses the correction time, the transmission time, and the reception time in the time correction information as a previous-level correction time, a previous-level transmission time, and a previous-level reception time, respectively, and obtains the corresponding current-level reception time based on the time point in the received time information. The current-level device subtracts the transmission time of the main control device, a summed delay value, and the correction time from the reception time to obtain a time offset value, and uses the time offset value to correct the synchronization time in the current-level device, wherein the summed delay value is the sum of the delay values ​​of each of the battery monitoring devices and each of the preceding stages. The current stage device subtracts the previous stage receiving time from the previous stage sending time to obtain the previous stage processing time. The current-level device adds the previous-level processing time to the previous-level correction time to obtain a current-level correction time in the time correction information used for forwarding. The current-level device forwards the time information to the next-level device, wherein the time information includes the transmission time of the main control device, the current-level correction time, the transmission time of a current-level device corresponding to the time point at which the current-level device forwards the time information, and the current-level reception time; and The above steps are repeated sequentially for each of the battery monitoring devices until the synchronization time of the last stage in the battery monitoring device is calibrated.

4. The time synchronization method for a battery management system as described in claim 1, characterized in that, The first stage in the battery monitoring device is a main control device, and the time information sent by the main control device includes a main control device sending time. The time information received and forwarded by each of the battery monitoring devices includes the transmission time of the main control device and a correction time. The correction time is calculated by summing the processing times of each component in the battery monitoring device for all preceding components and itself. The processing time is the time taken for each component in the battery monitoring device to forward the time information minus the time taken for each component in the battery monitoring device to receive the time information sent by the preceding component. Each component in the battery monitoring device has a delay value. The time synchronization of the current-level device based on the time information includes: When the current-level device uses the correction time in the time correction information as a previous-level correction, it obtains the corresponding current-level receiving time based on the time point in the received time information. The current-level device subtracts the transmission time of the main control device, a summed delay value, and the correction time from the reception time to obtain a time offset value, and uses the time offset value to correct the synchronization time in the current-level device, wherein the summed delay value is the sum of the delay values ​​of each of the battery monitoring devices and each of the preceding stages. The current-level device forwards the time information to the next-level device, wherein the time information includes the transmission time of the main control device and a current-level correction time, wherein the current-level correction time is the sum of the previous-level correction time and the current-level processing time, and the current-level processing time is calculated by the current-level device by subtracting the current-level reception time from the current-level transmission time at the time the time information was forwarded; and The above steps are repeated sequentially for each of the battery monitoring devices until the synchronization time of the last stage in the battery monitoring device is calibrated.

5. A battery management system, characterized in that, The battery management system includes: A wireless daisy-chain network topology is formed by N battery monitoring devices connected in series wirelessly, where N is a positive integer. The synchronization time correction among the N battery monitoring devices is achieved by: The nth device among the N battery monitoring devices receives time information, wherein the time information is sent by a (n-1)th device located one level above the nth device; The nth device obtains a time offset value based on the time information, and uses the time offset value to correct the synchronization time in the nth device; The nth device forwards the time information to an (n+1)th device located at the next level below the nth device; and The above steps are repeated sequentially for each of the N battery monitoring devices until the Nth battery monitoring device, the last stage of the N battery monitoring devices, completes the calibration. Where n is an integer from 2 to N.

6. The battery management system as described in claim 5, characterized in that, The time information includes a transmission time corresponding to the time point when the (n-1)th device sends the time information, and each of the N battery monitoring devices has a delay value. The nth device obtains the time offset value based on the time information by including: The nth device obtains a receiving time based on the time point when it receives the time information, and uses the sending time in the time information as a previous sending time. The nth device subtracts the previous stage transmission time and the delay value from the reception time to obtain a time offset value, and uses the time offset value to correct the synchronization time in the nth device.

7. The battery management system as described in claim 5, characterized in that, The first level among the N battery monitoring devices is a main control device, and the time information sent by the main control device includes the main control device sending time. The time information received and forwarded by each of the N battery monitoring devices includes the transmission time of the main control device, a calibration time, a transmission time, and a reception time. The correction time is the sum of the preprocessing times of each of the N battery monitoring devices; the transmission time corresponds to the time point at which the time information is transmitted; the reception time corresponds to the time point at which the time information transmitted by the previous battery monitoring device is received; and each of the N battery monitoring devices has a delay value. The nth device performing time synchronization based on the time information includes: The nth device uses the correction time, the transmission time, and the reception time in the time correction information as a previous correction time, a previous transmission time, and a previous reception time, respectively, and obtains the corresponding current reception time based on the time point in the received time information. The nth device obtains a time offset value by subtracting the transmission time of the main control device, a summed delay value, and the correction time from the reception time, and uses the time offset value to correct the synchronization time in the current stage device, wherein the summed delay value is the sum of the delay values ​​of each of the battery monitoring devices and each of their predecessors.

8. The battery management system as described in claim 7, characterized in that, The forwarding of the time information from the nth device to the (n+1)th device includes: The nth device subtracts the previous stage receiving time from the previous stage transmission time to obtain the previous stage processing time; The nth device adds the previous stage processing time to the previous stage correction time to obtain a current stage correction time in the time correction information used for forwarding. The nth device forwards the time information to the (n+1)th device. The time information includes the sending time of the main control device, the current correction time, the current sending time corresponding to the time point when the current device forwards the time information, and the current receiving time.

9. The battery management system as described in claim 5, characterized in that, The first stage among the N battery monitoring devices is a main control device, and the time information sent by the main control device includes the main control device sending time. The time information received and forwarded by each of the N battery monitoring devices includes the transmission time of the main control device and a correction time. The correction time is calculated by summing the processing times of each of the N battery monitoring devices for all preceding stages and itself. Each processing time is the time taken for each battery monitoring device to forward the time information minus the time taken for each battery monitoring device to receive the time information sent by the preceding stage. Each of the N battery monitoring devices has a delay value. The nth device performing time synchronization based on the time information includes: The nth device uses the correction time in the time correction information as a previous correction time, and obtains the corresponding current receiving time based on the time point in the received time information. The nth device subtracts the main control device's transmission time, a summed delay value, and the correction time from the reception time to obtain a time offset value, and uses the time offset value to correct the synchronization time in the nth device, wherein the summed delay value is the sum of the delay values ​​of each of the battery monitoring devices and each of their predecessors.

10. The battery management system as described in claim 9, characterized in that, The forwarding of the time information from the nth device to the (n+1)th device includes: The nth device forwards the time information to the (n+1)th device. The time information includes the transmission time of the main control device and a current level correction time. The current level correction time is the sum of the previous level correction time and the current level processing time. The current level processing time is calculated by the nth device by subtracting the current level reception time from the current level transmission time at the time when the time information is forwarded.

11. A time synchronization method for a battery management system, used to correct the synchronization time between a master control device in the battery management system and N slave devices coupled in series to the master control device, wherein the master control device and the N slave devices form a wireless daisy-chain network topology, and N is a positive integer, characterized in that, The time synchronization method of the battery management system includes: The master control device sends a master time information to a first slave device among the N slave devices. The master time information includes a master control device sending time corresponding to the time point when the master control device sends the master time information. The first slave device receives the master time information and obtains a first receiving time based on the time point at which the master time information is received; The first slave device sends a first time information to a second slave device among the N slave devices. The first time information includes a first transmission time, a first reception time, a first correction time, and the transmission time of the main control device corresponding to the time point when the first slave device sends the first time information, wherein the first correction time is 0. The second slave device receives the first time information and obtains a second receiving time based on the time point at which the first time information is received; The second slave device sends a second time information to a third slave device among the N slave devices. The second time information includes a second transmission time, a second reception time, a second correction time, and the transmission time of the main control device corresponding to the time point when the second slave device sends the second time information. The second correction time is a first processing time plus the first correction time. The first processing time is the first transmission time of the first slave device minus the first reception time. The third slave device receives the second time information and obtains a third receiving time based on the time point at which the second time information is received; The third slave device sends a third time information to a fourth slave device among the N slave devices. The third time information includes a third transmission time, a third reception time, and a third correction time corresponding to the time point when the third slave device sends the third time information. The master control device transmits the time, wherein the third correction time is a second processing time plus the second correction time, wherein the second processing time is the second transmission time of the second slave device minus the second reception time; and The above steps are repeated until the Nth slave device, at the last stage among the N slave devices, receives the (N-1)th time information sent by the (N-1)th slave device among the N slave devices, and an Nth reception time is obtained based on the time point of receiving the (N-1)th time information, wherein each of the N devices has a delay value. When each of the N devices receives the corresponding time information, each of the N devices obtains a time offset value, and uses the corresponding time offset value to correct the synchronization time of the N devices, so as to synchronize the time of the N devices. The time offset value used for time synchronization correction of the nth device among the N devices is a (n)th information reception time minus a correction value. The correction value is the sum of the main control device's transmission time, an nth correction time, and a total delay value. The total delay value is n multiplied by the delay value.

Images