Method for effectively reducing multi-channel acquisition data transmission communication load rate

Abstract

The invention discloses a method for effectively reducing the transmission and communication load rate of multichannel acquisition data. Comprising the steps that a data monitoring module processes data collected in the same period and packages the data into a data packet; transmitting the data packet to a management system through a network; the management system decodes the received data packet and performs back calculation processing to obtain original acquisition data; wherein the data packaging comprises the following steps of: obtaining an extreme value of each type of collected data in the same period; respectively calculating a difference value between each piece of data in the same kind of data and the extreme value; the extreme values and the difference values are packaged into a plurality of data packets, the first M bytes of at least one data packet in each type of data are used for filling the extreme values, the other bytes are used for filling the difference values, and M is smaller than or equal to the number of bytes of the data packets. According to the method and the device, the number of bytes required in the transmission process is reduced in a mode of transmitting the'extreme value 'and the'difference value' of the same type of acquired data, so that the load rate during communication is reduced, the network pressure is relieved, and the communication stability is improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method for effectively reducing the communication load rate of multi-channel acquisition data transmission. Background Art

[0002] The electrochemical energy storage system is mainly composed of battery packs, energy storage converters (PCS), battery management systems (BMS), energy management systems (EMS) and other electrical equipment. In each battery pack, the battery management system (BMS) analyzes the battery status based on the battery cell temperature, voltage and other information fed back from the control module (BMU), improves the consistency between battery packs (PACK), improves efficiency and increases the safety of the energy storage system.

[0003] Currently, the data between BMU and BMS is mainly battery cell data, including battery cell voltage and temperature data. Each energy storage cabinet contains multiple PACKs, and each PACK contains multiple battery cells. A BMU is used in each PACK for data collection and transmission. The BMU collects data for multi-channel data collection, and the collected data types are basically the same. BMU data transmission is mainly achieved through CAN communication. The defect of this method is that the data transmitted in each frame of CAN communication is limited, and the data transmitted by BMU is mostly the voltage and temperature data of the battery cells in the PACK. The data is relatively large, which leads to excessive load rate during CAN communication. When the load rate during CAN communication is too large, the following effects will occur:

[0004] (1) Decreased communication stability: When the load rate is too high, communication stability will decrease, resulting in data loss, delay or repeated transmission, affecting the reliability of the overall operation;

[0005] (2) Network congestion: Excessive load will increase the data flow on the bus, causing network congestion. This may cause data transmission speed to slow down or even make data unable to be transmitted.

[0006] (3) Hardware damage: Excessive load may exceed the processing capacity of the CAN controller, causing the controller to overheat or be damaged. This may cause permanent damage to the hardware of the bus system.

[0007] (4) Reduced communication efficiency: When the load is too large, communication on the bus may become inefficient. This may affect applications with high real-time requirements, such as the vehicle's autonomous driving system.

[0008] (5) Priority conflict: In CAN communication, the priority of a message is determined by an identifier. When the load is too large, multiple messages may have the same priority, resulting in a priority conflict. This may make communication on the bus more complex and unpredictable. Summary of the invention

[0009] In view of this, the present application provides a method for effectively reducing the communication load rate of multi-channel acquisition data transmission, comprising the following steps:

[0010] S1. The data monitoring module processes the same type of collected data obtained from multiple channels in the same cycle and packages them into data packets;

[0011] S2. Transmit the data packet to the management system through the network;

[0012] S3. The management system performs reverse calculation on the received data packets to obtain the original collected data;

[0013] Wherein, S1 comprises the following steps:

[0014] S11. Obtain the extreme value of each type of collected data in the same period, which is the maximum value or the minimum value;

[0015] S12. Calculate the difference between each data of the same type and the extreme value;

[0016] S13. Pack the extreme values ​​and differences in the same type of data into several data packets, and the first M bytes of at least one data packet in each type of data are used to fill the extreme values, and the remaining bytes are used to fill the differences, where M≤the number of bytes in the data packet.

[0017] Preferably, the method of filling the difference in S13 is:

[0018] The highest bit of a byte is used to indicate the integrity of the difference data expressed by the byte. When a byte can express a complete difference data, the highest bit of the byte is set to 0, and the other data bits are used to fill the number system of the difference data. When a byte needs to express a complete difference data together with the next one or more bytes, the difference data needs to be filled into multiple bytes in sequence after encoding. The highest bit of the first byte is set to 1, and the next one or more bytes do not need the highest bit to indicate data integrity. The number system of the difference data needs to be filled into multiple bytes in sequence. Multiple bytes expressing a complete difference data need to be in the same data frame or different data frames in the same data packet.

[0019] Preferably, the back calculation method in S3 is:

[0020] The management system receives the first M bytes of specific data in the data packet, and stores them as extreme values ​​after reverse calculation;

[0021] The management system receives the remaining byte data in the data packet. When the highest bit of a byte is 0, the current byte is reversed and stored as a complete difference. When the highest bit of a byte is 1, the current byte and the next one or more bytes without the highest bit 0 or 1 are reversed and stored as a complete difference.

[0022] Preferably, in S2, before transmitting the data packet to the management system through the network, it is necessary to determine the integrity of the data packet. The method for determining the integrity of the data packet is as follows: if there is a byte with the highest bit being 1 in the data packet except for the specific first M bytes and there is no other byte after the byte, it indicates that the data packet contains incomplete data, and the data packet is determined to be incomplete; otherwise, the data packet is determined to be complete;

[0023] If the data packet is complete, it is transmitted to the management system; if the data packet is incomplete, the bytes that do not express the complete data need to be filtered out, combined with other bytes until a complete data packet can be expressed, and then packaged into the next data packet. When the next data packet is complete, it is transmitted to the management system.

[0024] Preferably, in S13, M is determined as follows: for each type of extreme value data, a suitable number of bytes M is preset according to conventional data in the application field, and specific continuous M bytes are preset for filling the extreme value.

[0025] Preferably, each byte includes 8 data bits, the first bit is the most significant bit, indicating the integrity of the difference data expressed by the byte, and the Di To represent the difference between the i-th data in a certain type of data and the extreme value of this type of data, Y Di Take the integer;

[0026] When 0≤Y Di ≤(2 8*1 -1) i.e. 0≤Y Di When <127, the difference is filled in the last seven bits of a byte as a binary number, and the first bit is set to 0;

[0027] When 2 8*1 ≤Y Di ≤(2 8*2 -1) i.e. 128≤Y Di When <32767, the difference is filled in the last seven bits of the first byte and the full eight bits of the second byte in binary form. The two bytes together express a complete difference data, and the first bit of the first byte is set to 1;

[0028] And so on.

[0029] Preferably, in S3, the management system performs reverse calculation on the received data packet to obtain the original collected data in the following process:

[0030] S31. The management system receives a specific first M bytes of data in a data packet and stores them as extreme values ​​after reverse calculation;

[0031] S32. The management system receives the remaining bytes in the data packet and determines the integrity of the data expressed by the byte based on the highest bit of each byte. If the data is complete, the difference Y is directly obtained. Di ; If incomplete, calculate the difference Y Di , and its calculation formula is:

[0032] Y Di =X Hi *256+X Li Calculate the complete data, X Di is the decimal value converted from the high byte of the ith cell difference data, X Di+1 Y is the decimal value converted from the low-order byte of the ith cell difference data. Di is the difference of the ith battery cell;

[0033] S33. Combining the extreme value obtained in S31 and the difference obtained in S32, back-calculation is performed to obtain the original collected data;

[0034] When the extreme value is the maximum value, the inverse calculation formula is:

[0035] Z i =MaxY extremum -Y Di , MaxY extremum is the maximum value, Z i is the i-th collected data, Y Di is the difference corresponding to the i-th data;

[0036] When the extreme value is the minimum value, the inverse calculation formula is:

[0037] Z i ′=MinY extremum +Y Di , MinY extremum is the minimum value, Z i ′ is the i-th collected data, Y Di is the difference corresponding to the i-th data.

[0038] Preferably, when the method is used in a battery management system of an electrochemical energy storage system, the data monitoring module is a BMU, the management system is a BMS, and the collected data is battery cell data, including voltage data and temperature data; the electrochemical energy storage system includes a number of battery packs, each battery pack includes a number of battery cells, and the voltage data and temperature data of the battery cells are processed and packaged into a number of data packets, respectively, and the extreme values ​​are the maximum or minimum battery cell data in each battery pack.

[0039] Preferably, the network in S2 is a CAN network, each data in S13 includes at most 8 bytes, and the extreme value data is the maximum or minimum value of the voltage data and the temperature data, which are integers and filled in the first 2 bytes of one of the respective data packets.

[0040] Compared with the prior art, the beneficial effects of this application are:

[0041] Since the "difference" of the same type of collected data is much smaller than the original collected data, fewer bytes are required for transmission. This application reduces the number of bytes required during transmission by transmitting the "extreme value" and "difference" of the same type of collected data, thereby reducing the load rate during communication, alleviating network pressure, and improving communication stability; and then reversely calculating the received "extreme value" and "difference" to obtain the original collected data, and finally realizing the overall transmission of the collected data. In addition, the transmission of "extreme values" can also help quickly determine whether there are abnormal conditions, such as overcharging, over-discharging, fire and other faults of the battery cell.

[0042] Furthermore, in order to solve the situation where the difference data is greater than 128 and requires 2 or more bytes to be transmitted, the present application uses the highest bit of each byte to indicate whether the current byte is complete data. If it is complete, it can be transmitted directly. If it is incomplete, it needs to be transmitted together with the next one or more bytes to ensure the integrity of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the data transmission process in an embodiment of the present application;

[0044] Figure 2 This is a schematic diagram of data transmission;

[0045] In the figure: x represents a specific data bit. DETAILED DESCRIPTION

[0046] The present invention provides a method for effectively reducing the communication load rate of multi-channel acquisition data transmission, comprising the following steps:

[0047] S1. The data monitoring module processes the same type of collected data obtained from multiple channels in the same cycle and packages them into data packets;

[0048] S2. Transmit the data packet to the management system through the network;

[0049] S3. The management system performs reverse calculation on the received data packets to obtain the original collected data;

[0050] Wherein, S1 comprises the following steps:

[0051] S11. Obtain the extreme value of each type of collected data in the same period, which is the maximum value or the minimum value;

[0052] S12. Calculate the difference between each data in the same category and the extreme value of the data in the same category;

[0053] S13. Pack the extreme values ​​and differences in the same type of data into several data packets, the first M bytes of at least one data packet in each type of data are used to fill the extreme values, and the remaining bytes of the data packet and the bytes of other data packets are used to fill the differences, where M≤the number of bytes in the data packet.

[0054] In the present application, by obtaining extreme value data of the same type of data as the starting data, and using difference data from the starting data to represent the remaining data, it is possible to transmit the difference data using only 1 byte, thereby reducing the 2 bytes that need to be sent in the prior art to 1 byte, i.e. reducing the original load by 1 times, thereby reducing the communication load rate.

[0055] Specifically, for example, in an electrochemical energy storage system, the cut-off voltage of a lithium iron phosphate cell when fully charged is 3600mV, and the cut-off voltage when discharged is 2800mV. When a fire occurs, the cell voltage will quickly drop below 2000mV; the overcharge judgment voltage is generally set to 3800mV; the over-discharge judgment voltage is generally set to 2600mV. The data of the remaining cells in the same battery pack are transmitted in the form of the difference between the extreme value and the starting point data. This is because in most scenarios, in the same battery pack, the fluctuations between the data of each cell are very small, and only in a few cases, such as when a cell fails, there will be large fluctuations between the cells. Therefore, in most cases, only one byte is used to ensure the rationality of transmitting the cell data difference. At the same time, when a cell fails, the extreme value is most sensitive. Therefore, in this application, the extreme value is used as the transmission reference for judging whether the system has overcharging, over-discharging, fire and other faults, which is convenient for timely detection of faulty cells. Using the difference as the transmission reference for data can also effectively reduce the number of bytes required to transmit data, thereby reducing the communication load rate.

[0056] Further, in a possible implementation manner of the embodiment of the present invention, the method of filling the difference in S13 is:

[0057] The highest bit of a byte indicates the integrity of the difference data expressed by the byte. When a byte can express a complete difference data, the highest bit of the byte is set to 0, and the other data bits are used to fill the number system of the difference data; when a byte needs to express a complete difference data together with the next one or more bytes, the highest bit of the byte is set to 1, and the next one or more bytes do not need the highest bit to indicate data integrity (such as the attached Figure 2As shown, if the highest bit of the current byte is 1, then the highest bit of the next one or more bytes is the data bit). The number system of the difference data needs to be filled into the byte data bit in sequence, and multiple bytes expressing a complete difference data need to be in the same data packet.

[0058] In this embodiment, by using the highest bit of a byte as the basis for judging the integrity of data, it is possible to quickly judge whether the data expressed by the byte is complete data. Each byte still has the remaining bits to express data, which can ensure that small difference data can be completely transmitted using one byte. When the difference data is large and requires two or more bytes to be transmitted, the judgment of the highest bit can effectively avoid the situation where the same difference is transmitted by different bytes and stored in different data packets, resulting in errors in reverse calculation.

[0059] In S13, the extreme value can be filled in each data packet, or only in one of the data packets (such as the first one), and the remaining data packets are only filled with the difference value. The latter can minimize the number of bytes required for transmitting data.

[0060] Further, in a possible implementation of the embodiment of the present invention, the back calculation method in S3 is:

[0061] The management system receives the first M bytes of specific data in the data packet, and stores them as extreme values ​​after reverse calculation;

[0062] The management system receives the remaining byte data in the data packet. When the highest bit of a byte is 0, the current byte is reversed and stored as a complete difference. When the highest bit of a byte is 1, the current byte and the next one or more bytes without the highest bit 0 or 1 are reversed and stored as a complete difference.

[0063] Furthermore, each data packet corresponds to a frame of data. In order to ensure the integrity and accuracy of each frame of data transmission, in S2, before the data packet is transmitted to the management system through the network, the integrity of each data packet needs to be judged. The specific judgment method is: if there is a byte with the highest bit of 1 in the data packet except for the specific first M bytes and there are no other bytes after the byte, it indicates that the data packet contains incomplete data, and the data packet is judged to be incomplete. Otherwise, the data packet is judged to be complete; if the data packet is complete, it is transmitted to the management system; if the data packet is incomplete, it is necessary to filter out the bytes that do not express the complete data, combine them with other bytes until a complete data can be expressed, and then pack them into the next data packet, and when the next data packet is complete, it is transmitted to the management system.

[0064] In a possible implementation of the embodiment of the present invention, each byte includes 8 data bits, the first bit is the most significant bit, indicating the integrity of the difference data expressed by the byte, and the Y DiTo represent the difference between the i-th data in a certain type of data and the extreme value of this type of data, Y Di Take the integer;

[0065] When 0≤Y Di ≤(2 8*1 -1) i.e. 0≤Y Di When <127, the difference is filled in the last seven bits of a byte as a binary number, and the first bit is set to 0;

[0066] When 2 8*1 ≤Y Di ≤(2 8*2 -1) i.e. 128≤Y Di When <32767, the difference is filled in the last seven bits of the first byte and the full eight bits of the second byte in binary form. The two bytes together express a complete difference data, and the first bit of the first byte is set to 1;

[0067] And so on.

[0068] For example, when the difference is 100, a byte of 8-bit binary is represented as 01100100, and the first bit 0 indicates that the byte is a complete data; when the difference is 300, two bytes of 16-bit binary are represented as: 10000001 00101100, and the first bit 1 of the first byte indicates that the byte is not a complete data and needs to be expressed together with the second byte to form a complete data. In most cases, the difference data is generally less than 32767, and 1-2 bytes are sufficient to express the conventional difference. Common voltage and temperature parameters of battery cells are within this range, so judging the integrity of battery cell data by the highest bit of a byte can meet the requirements.

[0069] In step S13, M is determined in the following manner: each type of extreme value data is preset with a suitable number of bytes according to the conventional data in the application field to achieve filling of specific data in a specific byte position, that is, when the conventional data of each type of extreme value data requires M bytes to be filled, specific continuous M bytes are preset to fill the extreme value. When filling, the extreme value is also filled in the preset M bytes of data bits with a binary number. When the extreme value is between the range of 0-127, M=1; when the extreme value is between the range of 128-32767, M=2, and so on.

[0070] For example, in an electrochemical energy storage system, when transmitting the voltage data of a battery cell, since the common voltage data is between 2000mV and 3600mV, it can be fully expressed by 2 bytes, so it is necessary to preset the first 2 bytes of at least one data packet to store the extreme value. Assuming that the maximum value of the voltage data is 3000mV, the 16-bit binary number of the first 2 bytes is:

[0071] 00001011 10111000.

[0072] Further, in a possible implementation of the embodiment of the present invention, in S3, the management system performs a back-calculation process on the received data packet to obtain the original collected data as follows:

[0073] S31. The management system receives a specific first M bytes of data in a data packet and stores them as extreme values ​​after reverse calculation;

[0074] S32. The management system receives the remaining byte data in the data packet and determines the integrity of the data expressed by the byte based on the highest bit. If it is complete, the difference Y is directly obtained. Di ; If incomplete, calculate the difference Y Di , and its calculation formula is:

[0075] Y Di =X Hi *256+X Li , X Hi is the decimal value converted from the high byte of the ith cell difference data, X Li Y is the decimal value converted from the low-order byte of the ith cell difference data. Di is the difference of the ith battery cell;

[0076] S33. Combining the extreme value obtained in S31 and the difference obtained in S32, back-calculation is performed to obtain the original collected data;

[0077] When the extreme value is the maximum value, the inverse calculation formula is:

[0078] Z i =MaxY extremum -Y Di , MaxY extremum is the maximum value, Z i is the i-th collected data, Y Di is the difference corresponding to the i-th data;

[0079] When the extreme value is the minimum value, the inverse calculation formula is:

[0080] Z i ′=MinY extremum +Y Di , MinY extremum is the minimum value, Z i ′ is the i-th collected data, Y Di is the difference corresponding to the i-th data.

[0081] When inversely calculating the extreme value, M=1, that is, the extreme value is expressed in one byte, and the extreme value is obtained by calculating the decimal value corresponding to the byte; when M=2, the extreme value is expressed in two bytes, and its calculation method is the same as when the difference is expressed in two bytes, which is the decimal value converted from the high-order byte × 2 8 The sum of the high-order byte converted to a decimal value.

[0082] For example, when the first M bytes are represented as 00001011 10111000, the extreme value obtained by reverse calculation is:

[0083] (0×2 7 +0×2 6 +0×2 5 +0×2 4 +1×2 3 +0×2 2 +1×2 1 +1×2 0 )×2 8 +

[0084] 1×2 7 +0×2 6 +1×2 5 +1×2 4 +1×2 3 +0×2 2 +0×2 1 +0×2 0 =2048+512+256+128+32+16+8=3000.

[0085] When inversely calculating the difference data, when a byte is represented as 01100100, the first bit is 0, which means that the byte represents a complete difference. The difference obtained by decoding and inversely calculating the 2nd to 8th bits is:

[0086] Y Di =1×2 6 +1×2 5 +0×2 4 +0×2 3 +1×2 2 +0×2 1 +0×2 0 =64+32+0+0+4+0+0=100;

[0087] When two consecutive bytes are expressed as 10000001 00101100, the first bit of the first byte is 1, which means that the byte needs to express a complete data together with the second byte. The method for calculating the difference is as follows:

[0088] The high byte is 0000001, X Hi =0×2 6+0×2 5 +0×2 4 +0×2 3 +0×2 2 +0×2 1 +1*2 0 =1;

[0089] The low byte is 00101100, X Li =0×2 7 +0×2 6 +1×2 5 +0×2 4 +1×2 3 +1×2 2 +0×2 1 +0×2 0 =44;

[0090] Difference Y Di =X Hi ×256+X Li =1×256+44=300.

[0091] In the present application, when the method is used in a battery management system of an electrochemical energy storage system, the data monitoring module is a BMU, the management system is a BMS, and the collected data is battery cell data, including voltage data, temperature data, etc.; the electrochemical energy storage system includes a number of battery packs (i.e., PACKs), each battery pack includes a number of battery cells, and the voltage data and temperature data of the battery cells are processed and packaged into a number of data packets, and the extreme values ​​are the maximum or minimum battery cell data in each battery pack.

[0092] In a specific embodiment, the network in S2 is a CAN network, and each data packet in S13 has only 8 data bytes. The extreme value data is the maximum or minimum value of the voltage data and the temperature data. The integers are taken and filled in the first 2 bytes of one of the respective data packets, preferably the first one.

[0093] It should be noted that:

[0094] In the communication frame of the CAN network, the data bit is at most 64 bits, that is, 8 bytes, and the transmission of voltage or temperature data requires 2 bytes for transmission. If a storage cabinet has 5 PACKs, each PACK has 52 battery cells. When the BMU and BMS communicate through CAN, the baud rate is 250Kbps. After actual measurement, the load rate at this time is 43.13%, and the CAN communication load rate is generally recommended to be controlled within 30%. The actual load rate exceeds the control value. Compared with the prior art that each frame of CAN communication can only transmit 4 battery cell data, the method provided by the present application is adopted, taking a certain PACK as an example, the extreme value is the maximum voltage value or the minimum voltage value of the 52 battery cells in the PACK at a certain moment, and the difference is the difference between the voltage of the 52 battery cells and the maximum voltage value or the minimum voltage value (the battery cell corresponding to the extreme value also transmits the difference to facilitate the judgment of which battery cell the extreme value corresponds to). That is, at a certain moment, each PACK corresponds to 1 extreme value and 52 differences, and multiple data packets are required to transmit data. The extreme value is filled in the first data packet, and the remaining data packets are only filled with the difference, so that 1 byte can replace the traditional CAN communication that requires 2 bytes to transmit voltage or temperature data, so that the number of transmitted bytes is reduced by 1, and 8 battery cell data can be transmitted in each frame, which reduces the original load by 1 time, thereby improving the transmission efficiency, greatly reducing the network load rate during CAN communication, effectively controlling the CAN communication load rate within 30%, and improving the stability of CAN communication.

[0095] At the same time, the transmission difference only requires one bit in a byte as the basis for judging the integrity of the data, and each byte has 7 bits that can be used for data storage, which can ensure that in most cases, data transmission can use one byte to transmit complete data.

[0096] It should be noted that in the present application, the load rate during CAN communication is reduced by reducing the transmission bytes. This method is not limited to the field of energy storage, but is also applicable to the transmission of other collected data.

[0097] Example

[0098] This embodiment takes the data transmission of an electrochemical energy storage system as an example to illustrate a method for effectively reducing the communication load rate of multi-channel acquisition data transmission. Figure 1 As shown, in this embodiment, data collection, packaging and processing are all completed by the data monitoring module BMU; data transmission is completed in the form of CAN network communication; the management system adopts the battery management system BMS.

[0099] In this embodiment:

[0100] Step 1: The BMU processes the collected data of different types of cells in each battery pack in the same cycle and packages them into data packets. The specific process of processing and packaging is as follows:

[0101] 1. Obtain the extreme values ​​(i.e., maximum or minimum values) of various collected data of different cells in the battery pack in the same cycle; for example, in the same battery pack, obtain the maximum or minimum values ​​of the voltage or temperature data of each cell in the same cycle;

[0102] 2. Calculate the difference between the data corresponding to each cell in the same battery pack and the extreme value;

[0103] 3. Pack the extreme values ​​and differences of the same type of data into several data packets. Since each CAN data packet contains 8 bytes of data, use the first 2 bytes of the first data packet to fill in the extreme values ​​of the voltage data or temperature data, and the bytes of the remaining data packets are used to fill in the differences.

[0104] Step 2: BMU transmits data via CAN;

[0105] Before data transmission, the integrity of the data packet is judged. If it is complete, the reception is completed; if it is incomplete, it waits for the next frame of data from the BMU. In the BMU, the bytes that do not express complete data are filtered out and combined with other bytes until a complete data can be expressed. Then, it is packaged into the next data packet and transmitted to the BMS when the next data packet is complete.

[0106] The integrity of the data packet is determined by identifying whether the highest bit of the byte in the data packet is 0 (except for the first 2 bytes of the first data packet). If the highest bit of the byte in the data packet is 0, it means that the data is complete; if not, it means that the data is incomplete.

[0107] Step 3: BMS receives the complete data packet, and obtains the original collected data by decoding and reverse calculating the received data packet.

[0108] After receiving the data, BMS decodes the data. The extreme value decoding process is as follows:

[0109] Decode the first M bytes in the first data packet, and store them as extreme values ​​after reverse calculation;

[0110] The difference decoding process is:

[0111] Decode the bytes of the first data packet except the first M bytes and all bytes of other data packets, and make the following judgments:

[0112] A: If it is 0, the remaining 7 bits of the current byte directly obtain the battery cell difference data;

[0113] B: If it is 1, the remaining 7 bits of the current byte and the next byte together are the cell difference data.

[0114] The process of judging the integrity of decoded data is as follows:

[0115] Use the number 1 and the highest bit of each byte for comparison:

[0116] If the bitwise AND of the highest bit of the current self-node and 1 is 0, it is case A;

[0117] If the bitwise AND of the highest bit of the current byte and 1 is 1, it is case B;

[0118] For case A, directly obtain the difference Y Di ;

[0119] For case B, the difference Y needs to be calculated Di , and its calculation formula is:

[0120] Y Di =X Hi *256+X Li , X Hi is the decimal value converted from the high byte of the ith cell difference data, X Li Y is the decimal value converted from the low-order byte of the ith cell difference data. Di is the difference of the ith battery cell;

[0121] The original collected data is obtained by combining the acquired extreme values ​​and differences and back-calculating;

[0122] When the extreme value is the maximum value, the inverse calculation formula is:

[0123] Z i =MaxY extremum -Y Di , MaxY extremum is the maximum value, Z i is the i-th collected data, Y Di is the difference corresponding to the i-th data;

[0124] When the extreme value is the minimum value, the inverse calculation formula is:

[0125] Z i ′=MinY extremum +Y Di , MinY extremum is the minimum value, Z i ′ is the i-th collected data, Y Di is the difference corresponding to the i-th data.

[0126] The BMS uses the maximum or minimum value and the difference in the data obtained, and decodes and reversely calculates the voltage data or temperature data of all cells in the same battery pack in the same cycle.

Claims

1. A method for effectively reducing the communication load rate of multi-channel acquisition data transmission, characterized in that: The following steps are involved: S1. The data monitoring module processes the same type of collected data obtained from multiple channels in the same cycle and packages them into data packets; S2. Transmit the data packet to the management system through the network; S3. The management system performs reverse calculation on the received data packets to obtain the original collected data; Wherein, S1 comprises the following steps: S11. Obtain the extreme value of each type of collected data in the same period, which is the maximum value or the minimum value; S12. Calculate the difference between each data of the same type and the extreme value respectively; S13. Pack the extreme values ​​and differences in the same type of data into several data packets, and the first M bytes of at least one data packet in each type of data are used to fill the extreme values, and the remaining bytes are used to fill the differences, where M≤the number of bytes in the data packet.

2. A method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to claim 1, characterized in that: The method of filling the difference in S13 is: The highest bit of a byte indicates the integrity of the difference data expressed by the byte. When a byte can express a complete difference data, the highest bit of the byte is set to 0, and the other data bits are used to fill the number system of the difference data. When a byte needs to express a complete difference data together with the next one or more bytes, the highest bit of the byte is set to 1, and the next one or more bytes do not need the highest bit to indicate data integrity. The number system of the difference data needs to be filled into multiple bytes in sequence, and multiple bytes expressing a complete difference data need to be in the same data packet.

3. A method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to claim 2, characterized in that: The back calculation method in S3 is: The management system receives the first M bytes of data in the data packet, and stores them as extreme values ​​after reverse calculation; The management system receives the remaining bytes of the data packet. When the highest bit of a byte is 0, the current byte is reversed and stored as a complete difference. When the highest bit of a byte is 1, the current byte and the next one or more bytes without the highest bit 0 or 1 are reversed and stored as a complete difference.

4. The method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to any one of claim 2 or 3, characterized in that: In S2, before transmitting the data packet to the management system through the network, it is necessary to determine the integrity of the data packet. The method for determining the integrity of the data packet is as follows: if there is a byte with the highest bit as 1 in the data packet except for the specific first M bytes and there are no other bytes after the byte, it indicates that the data packet contains incomplete data, and the data packet is determined to be incomplete; otherwise, the data packet is determined to be complete; If the data packet is complete, it is transmitted to the management system; if the data packet is incomplete, the bytes that do not express the complete data need to be filtered out, combined with other bytes until a complete data packet can be expressed, and then packaged into the next data packet. When the next data packet is complete, it is transmitted to the management system.

5. The method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to any one of claims 1, 2 or 3, characterized in that: In S13, M is determined as follows: for each type of extreme value data, a suitable number of bytes M is preset according to conventional data in the application field, and specific continuous M bytes are preset to fill the extreme value.

6. The method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to any one of claims 2 or 3, characterized in that: Each byte consists of 8 data bits, the first bit is the highest bit, indicating the integrity of the difference data expressed by the byte. Di To represent the difference between the i-th data in a certain type of data and the extreme value of this type of data, Y Di Take the integer; When 0≤Y Di ≤(2 8*1 -1) i.e. 0≤Y Di When <127, the difference is filled in the last seven bits of a byte as a binary number, and the first bit is set to 0; When 2 8*1 ≤Y Di ≤(2 8*2 -1) i.e. 128≤Y Di When <32767, the difference is filled in the last seven bits of the first byte and the full eight bits of the second byte in binary form. The two bytes together express a complete difference data, and the first bit of the first byte is set to 1; And so on.

7. The method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to claim 1, characterized in that: In S3, the management system performs reverse calculation on the received data packets to obtain the original collected data in the following process: S31. The management system receives a specific first M bytes of data in a data packet and stores them as extreme values ​​after reverse calculation; S32. The management system receives the remaining bytes in the data packet and determines the integrity of the data expressed by the byte based on the highest bit of each byte. If the data is complete, the difference Y is directly obtained. Di ; If incomplete, calculate the difference Y Di , and its calculation formula is: Y Di =X Hi *256+X Li , X Hi is the decimal value converted from the high byte of the ith cell difference data, X Li Y is the decimal value converted from the low-order byte of the ith cell difference data. Di is the difference of the ith battery cell; S33. Combining the extreme value obtained in S31 and the difference obtained in S32, back-calculation is performed to obtain the original collected data; When the extreme value is the maximum value, the inverse calculation formula is: Z i =MaxY extremum -Y Di , MaxY extremum is the maximum value, Z i is the i-th collected data, Y Di is the difference corresponding to the i-th data; When the extreme value is the minimum value, the inverse calculation formula is: Z i ′=MinY extremum +Y Di , MinY extremum is the minimum value, Z i ′ is the i-th collected data, Y Di is the difference corresponding to the i-th data.

8. The method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to claim 1, characterized in that: When the method is used in a battery management system of an electrochemical energy storage system, the data monitoring module is a BMU, the management system is a BMS, and the collected data is battery cell data, including voltage data and temperature data; the electrochemical energy storage system includes a plurality of battery packs, each battery pack includes a plurality of battery cells, and the voltage data and temperature data of the battery cells are processed and packaged into a plurality of data packets, respectively, and the extreme values ​​are the maximum or minimum battery cell data in each battery pack.

9. A method for effectively reducing the communication load rate of multi-channel acquisition data transmission according to claim 8, characterized in that: The network in S2 is a CAN network. Each data in S13 includes at most 8 bytes. The extreme value data is the maximum or minimum value of the voltage data and the temperature data. The integer is taken and filled in the first 2 bytes of one of the respective data packets.

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