A lithium battery data acquisition system and method

Abstract

The present invention provides a lithium battery data acquisition system and method in the field of lithium battery technology, the system includes: a host computer; a communication board, including an Ethernet communication module, a first MCU and eight first RS485 communication modules; one end of the first MCU is connected to the Ethernet communication module, and the other end is connected to each first RS485 communication module; the Ethernet communication module is connected to the host computer; eight data acquisition boards, including a second RS485 communication module, a second MCU, an isolation chipset and a data acquisition chip with 16 channels; one end of each of the second RS485 communication modules is connected to a first RS485 communication module, and the other end is connected to the second MCU; one end of the isolation chipset is connected to the second MCU, and the other end is connected to the data acquisition chip. The advantage of the present invention is that the efficiency of lithium battery data acquisition is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a lithium battery data acquisition system and method. Background Art

[0002] Lithium batteries are a type of battery that uses lithium metal or lithium alloy as positive / negative electrode materials and non-aqueous electrolyte solutions. As people pay more attention to environmental issues, they are gradually using electric energy to replace traditional energy sources. For example, electric vehicles are gradually replacing traditional fuel vehicles.

[0003] When lithium batteries leave the factory or are in use, the battery capacity of lithium batteries needs to be monitored, and the battery capacity is closely related to the two parameters of voltage and temperature. Therefore, in order to accurately calculate the battery capacity, it is necessary to collect the voltage and temperature of the lithium battery.

[0004] Lithium batteries are composed of several single cells, but traditional lithium battery charging and discharging equipment only supports the collection of 1 voltage and 1 temperature, which cannot meet the needs of collecting data from multiple single cells at the same time; for example, a 48V lithium battery has 13 strings of single cells (battery cells), which requires the collection of 13 voltages and 13 temperatures, so third-party equipment is needed to assist the lithium battery charging and discharging equipment in collecting the voltage and temperature of the lithium battery, but the number of channels collected by existing third-party equipment on the market is generally around 24, which cannot meet the actual collection needs, and due to the use of CAN bus or RS485 communication, the time interval between the voltage data and temperature data cached by the third-party equipment is long and cannot reach 10ms, resulting in the inability to calculate the battery capacity in real time.

[0005] Therefore, how to provide a lithium battery data acquisition system and method to improve the efficiency of lithium battery data acquisition has become an urgent problem to be solved. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a lithium battery data acquisition system and method to improve the efficiency of lithium battery data acquisition.

[0007] In a first aspect, the present invention provides a lithium battery data acquisition system, comprising:

[0008] A host computer;

[0009] A communication board, comprising an Ethernet communication module, a first MCU and eight first RS485 communication modules; one end of the first MCU is connected to the Ethernet communication module, and the other end is connected to each first RS485 communication module; the Ethernet communication module is connected to the host computer;

[0010] Eight data acquisition boards respectively include a second RS485 communication module, a second MCU, an isolation chipset and a data acquisition chip with 16 channels; one end of each of the second RS485 communication modules is connected to a first RS485 communication module, and the other end is connected to the second MCU; one end of the isolation chipset is connected to the second MCU, and the other end is connected to the data acquisition chip.

[0011] Furthermore, the model of the Ethernet communication module is LAN8720A.

[0012] Furthermore, the isolation chipset includes 16 isolation chips, one end of each isolation chip is connected to the second MCU, and the other end is connected to one of the channels of the data acquisition chip.

[0013] Furthermore, the isolation chip is an SPI bus isolation chip.

[0014] Furthermore, the data acquisition chip is a voltage acquisition chip or a temperature acquisition chip.

[0015] Furthermore, the model of the voltage acquisition chip is ADS8689.

[0016] Furthermore, the model of the temperature acquisition chip is ADS1118.

[0017] In a second aspect, the present invention provides a lithium battery data collection method, comprising the following steps:

[0018] Step S10, the communication board sets 8 UDP links and 8 UDP ports, each of the UDP links is respectively bound to a first RS485 communication module and a UDP port;

[0019] Step S20, the data acquisition board sets a data acquisition cycle and a data cache quantity, automatically acquires lithium battery data every data acquisition cycle, and caches the lithium battery data based on the data cache quantity;

[0020] Step S30: The communication board receives the data acquisition instruction sent by the host computer, obtains the lithium battery data from the corresponding data acquisition board based on the data acquisition instruction and the UDP link, and sends it to the host computer to complete the collection of the lithium battery data.

[0021] Furthermore, the step S20 is specifically as follows:

[0022] When the lithium battery data is voltage data, the method includes the following steps:

[0023] Step S211, the second MCU of the data acquisition board sets a data acquisition cycle and a data buffer quantity;

[0024] Step S212, the second MCU reads the device ID of the voltage acquisition chip every data acquisition cycle, and determines whether it is consistent with the pre-stored device ID. If so, it means that the SPI communication is normal, and the voltage acquisition chip is used to automatically collect voltage data and perform analog-to-digital conversion, and the voltage data is cached in the memory of the second MCU based on the data cache quantity; if not, it means that the SPI communication is abnormal, and the process ends;

[0025] When the lithium battery data is temperature data, the method includes the following steps:

[0026] Step S221, the second MCU of the data acquisition board sets a data acquisition cycle, a data buffer quantity, a register configuration value and a thermocouple table in which temperature and voltage correspond one to one;

[0027] Step S222, the second MCU sends the register configuration value to the temperature acquisition chip every data acquisition cycle. After receiving the register configuration value, the temperature acquisition chip returns the cold node temperature value and the register configuration value to the second MCU. The second MCU converts the cold node temperature value into a cold node voltage value using the thermocouple table. The second MCU determines whether the received register configuration value is consistent with the set value. If so, it indicates that the SPI communication is normal, and the process goes to step S223; if not, it indicates that the SPI communication is abnormal, and the process ends.

[0028] Step S223, the second MCU sends the register configuration value to the temperature acquisition chip. After receiving the register configuration value, the temperature acquisition chip returns the hot node voltage value and the register configuration value to the second MCU. The second MCU determines whether the received register configuration value is consistent with the set one. If so, it means that the SPI communication is normal, and the process goes to step S224; if not, it means that the SPI communication is abnormal, and the process ends.

[0029] Step S224: The second MCU adds the hot node voltage value to the cold node voltage value to obtain an actual voltage value, and converts the actual voltage value into temperature data based on the thermocouple table.

[0030] Furthermore, the step S30 specifically includes:

[0031] Step S31, the communication board receives the data acquisition instruction sent by the host computer through the Ethernet interrupt, parses the target UDP port from the data acquisition instruction, and determines whether the target UDP port belongs to one of the set 8 UDP ports. If so, proceed to step S32; if not, end the process;

[0032] Step S32: the communication board uses Uart interruption to send the data acquisition instruction to the corresponding data acquisition board based on the target UDP port and the UDP link, and the data acquisition board uses Uart interruption to cache the received data acquisition instruction into a pre-created circular queue;

[0033] Step S33, the data acquisition board obtains the data acquisition instruction from the circular queue, and encapsulates the cached lithium battery data into a data packet based on the data acquisition instruction, and sends the data packet to the communication board through DMA;

[0034] Step S34, the communication board receives the data packet through DMA, and when the Uart interrupt of the communication board triggers an idle interrupt, the data packet is sent to the host computer through the Ethernet communication module to complete the collection of lithium battery data.

[0035] The advantages of the present invention are:

[0036] 1. By setting 8 first RS485 communication modules in the communication board and connecting them with 8 data acquisition boards, and each of the data acquisition boards is provided with a data acquisition chip with 16 channels, the data acquisition system has 128 lithium battery data acquisition channels, and can simultaneously collect the voltage or temperature of 128 single cells; and the communication board uses the Ethernet communication module to communicate with the host computer, and the time interval can be shortened to 10ms, that is, the time span of battery capacity calculation is shortened to 10ms, which ultimately greatly improves the efficiency of lithium battery data acquisition.

[0037] 2. By setting the model of the voltage acquisition chip to ADS8689 and the model of the temperature acquisition chip to ADS1118; ADS8689 is a successive approximation 16-bit analog-to-digital converter with built-in input isolation and stronger anti-interference ability; ADS1118 is a precision, low-power 16-bit analog-to-digital converter with an integrated programmable gain amplifier, voltage reference and high-precision temperature sensor. The data conversion rate can reach up to 860 samples per second. The internal high-precision temperature sensor can be used for cold node compensation of T-type thermocouples, thereby greatly improving the accuracy of lithium battery data acquisition. The voltage accuracy can reach ±0.02% FS, and the temperature accuracy can reach ±1°C (-45°C to 260°C). BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0039] Figure 1 The present invention is a circuit principle block diagram of a lithium battery data acquisition system.

[0040] Figure 2It is a circuit principle block diagram of the voltage acquisition board of the present invention.

[0041] Figure 3 It is a circuit principle block diagram of the current collection board of the present invention.

[0042] Figure 4 It is a structural schematic diagram of a lithium battery data acquisition system of the present invention.

[0043] Figure 5 It is a schematic diagram of the use status of a lithium battery data acquisition system of the present invention.

[0044] Figure 6 It is a circuit diagram of the voltage acquisition chip of the present invention.

[0045] Figure 7 It is a circuit diagram of the temperature acquisition chip of the present invention.

[0046] Figure 8 The present invention is a flow chart of a lithium battery data acquisition method.

[0047] Marking Description:

[0048] 100-A lithium battery data acquisition system, 1-host computer, 2-communication board, 3-data acquisition board, 4-monocell, 21-Ethernet communication module, 22-first MCU, 23-first RS485 communication module, 31-second RS485 communication module, 32-MCU, 33-isolation chipset, 34-data acquisition chip. DETAILED DESCRIPTION

[0049] The technical solution in the embodiment of the present application has the following general idea: by setting 8 data acquisition boards 3, each of which has 16 channels, the number of lithium battery data acquisition channels reaches 128, and the communication board 2 uses the Ethernet communication module 21 to communicate with the host computer 1, shortening the time interval to 10ms, so as to improve the efficiency of lithium battery data acquisition.

[0050] Please refer to Figures 1 to 8 As shown, a preferred embodiment of a lithium battery data acquisition system 100 of the present invention includes:

[0051] A host computer 1, used to control the operation of the data acquisition system 100;

[0052] A communication board 2, comprising an Ethernet communication module 21, a first MCU 22 and eight first RS485 communication modules 23; one end of the first MCU 22 is connected to the Ethernet communication module 21, and the other end is connected to each first RS485 communication module 23; the Ethernet communication module 21 is connected to the host computer 1; the communication board 2 is used for communication between the host computer 1 and the data acquisition board 3;

[0053] Eight data acquisition boards 3 respectively include a second RS485 communication module 31, a second MCU32, an isolation chipset 33 and a data acquisition chip 34 with 16 channels; one end of each of the second RS485 communication modules 31 is connected to a first RS485 communication module 23, and the other end is connected to the second MCU32; one end of the isolation chipset 33 is connected to the second MCU32, and the other end is connected to the data acquisition chip 34; the data acquisition board 3 is used to collect voltage data or temperature data of the single battery 4.

[0054] The model of the Ethernet communication module 21 is LAN8720A, which is a low-power 10 / 100M Ethernet physical layer chip, and is connected to the first MCU 22 via an RMII interface (not shown), so that the first MCU 22 can communicate with the host computer 1 through Ethernet.

[0055] The isolation chipset group 33 includes 16 isolation chips (not shown), one end of each isolation chip is connected to the second MCU 32 , and the other end is connected to one channel of the data acquisition chip 34 .

[0056] The isolation chip is a SPI bus isolation chip.

[0057] The data acquisition chip 34 is a voltage acquisition chip or a temperature acquisition chip; the temperature acquisition chip 34 uses a T-type thermocouple (not shown) to perform temperature acquisition.

[0058] The voltage acquisition chip 34 is of model ADS8689, which is a successive approximation 16-bit analog-to-digital converter with built-in input isolation and stronger anti-interference performance.

[0059] The model of the temperature acquisition chip 34 is ADS1118, which is a precise, low-power 16-bit analog-to-digital converter. It integrates a programmable gain amplifier, a voltage reference and a high-precision temperature sensor. The data conversion rate can reach up to 860 samples per second. The internal high-precision temperature sensor can be used for cold node compensation of T-type thermocouples.

[0060] A preferred embodiment of a lithium battery data collection method of the present invention comprises the following steps:

[0061] Step S10, the communication board sets 8 UDP links and 8 UDP ports, each of the UDP links is respectively bound to a first RS485 communication module and a UDP port; for example, the UDP ports corresponding to the 8 first RS485 communication modules are respectively set to 3001, 3002, 3003 ..., 3008;

[0062] Step S20, the data acquisition board sets a data acquisition cycle and a data cache quantity, automatically acquires lithium battery data every data acquisition cycle, and caches the lithium battery data based on the data cache quantity;

[0063] Step S30: The communication board receives the data acquisition instruction sent by the host computer, obtains the lithium battery data from the corresponding data acquisition board based on the data acquisition instruction and the UDP link, and sends it to the host computer to complete the collection of the lithium battery data.

[0064] The step S20 is specifically as follows:

[0065] When the lithium battery data is voltage data, the method includes the following steps:

[0066] Step S211, the second MCU of the data acquisition board sets a data acquisition cycle and a data buffer quantity;

[0067] Step S212, the second MCU reads the device ID of the voltage acquisition chip every data acquisition cycle, and determines whether it is consistent with the pre-stored device ID. If so, it means that the SPI communication is normal, and the voltage acquisition chip is used to automatically collect voltage data and perform analog-to-digital conversion, and the voltage data is cached in the memory of the second MCU based on the data cache quantity; if not, it means that the SPI communication is abnormal, and the process ends;

[0068] For example, if the device ID is set to 0x0B, you can determine whether the SPI communication is normal by simply checking whether the device ID of the voltage acquisition chip is 0x0B.

[0069] When the lithium battery data is temperature data, the method includes the following steps:

[0070] Step S221, the second MCU of the data acquisition board sets a data acquisition cycle, a data buffer quantity, a register configuration value and a thermocouple table with one-to-one correspondence between temperature and voltage; the data acquisition cycle is preferably 10ms; the data buffer quantity is preferably 30;

[0071] Step S222, the second MCU sends the register configuration value to the temperature acquisition chip every data acquisition cycle. After receiving the register configuration value, the temperature acquisition chip returns the cold node temperature value and the register configuration value to the second MCU. The second MCU converts the cold node temperature value into a cold node voltage value using the thermocouple table. The second MCU determines whether the received register configuration value is consistent with the set value. If so, it indicates that the SPI communication is normal, and the process goes to step S223; if not, it indicates that the SPI communication is abnormal, and the process ends.

[0072] Step S223, the second MCU sends the register configuration value to the temperature acquisition chip. After receiving the register configuration value, the temperature acquisition chip returns the hot node voltage value and the register configuration value to the second MCU. The second MCU determines whether the received register configuration value is consistent with the set one. If so, it means that the SPI communication is normal, and the process goes to step S224; if not, it means that the SPI communication is abnormal, and the process ends.

[0073] Step S224: The second MCU adds the hot node voltage value to the cold node voltage value to obtain an actual voltage value, and converts the actual voltage value into temperature data based on the thermocouple table.

[0074] The cold node temperature value is the temperature of the temperature acquisition chip itself, and the hot node temperature value is the potential difference between the hot node and the cold node of the T-type thermocouple. The actual temperature of the single cell can be calculated through the cold node voltage value and the hot node voltage value.

[0075] The step S30 specifically includes:

[0076] Step S31, the communication board receives the data acquisition instruction sent by the host computer through the Ethernet interrupt, parses the target UDP port from the data acquisition instruction, and determines whether the target UDP port belongs to one of the set 8 UDP ports. If so, proceed to step S32; if not, end the process;

[0077] Step S32: Based on the target UDP port and the UDP link, the communication board uses a Uart (Universal Asynchronous Receiver / Transmitter) interrupt to send the data acquisition instruction to the corresponding data acquisition board, and the data acquisition board uses the Uart interrupt to cache the received data acquisition instruction into a pre-created circular queue;

[0078] Step S33, the data acquisition board obtains the data acquisition instruction from the circular queue, and encapsulates the cached lithium battery data into a data packet based on the data acquisition instruction, and sends the data packet to the communication board through DMA (Direct Memory Access); sending through DMA is faster and does not occupy MCU resources;

[0079] Step S34, the communication board receives the data packet through DMA, and when the Uart interrupt of the communication board triggers an idle interrupt, the data packet is sent to the host computer through the Ethernet communication module to complete the collection of lithium battery data.

[0080] In summary, the advantages of the present invention are:

[0081] 1. By setting 8 first RS485 communication modules in the communication board and connecting them with 8 data acquisition boards, and each of the data acquisition boards is provided with a data acquisition chip with 16 channels, the data acquisition system has 128 lithium battery data acquisition channels, and can simultaneously collect the voltage or temperature of 128 single cells; and the communication board uses the Ethernet communication module to communicate with the host computer, and the time interval can be shortened to 10ms, that is, the time span of battery capacity calculation is shortened to 10ms, which ultimately greatly improves the efficiency of lithium battery data acquisition.

[0082] 2. By setting the model of the voltage acquisition chip to ADS8689 and the model of the temperature acquisition chip to ADS1118; ADS8689 is a successive approximation 16-bit analog-to-digital converter with built-in input isolation and stronger anti-interference ability; ADS1118 is a precision, low-power 16-bit analog-to-digital converter with an integrated programmable gain amplifier, voltage reference and high-precision temperature sensor. The data conversion rate can reach up to 860 samples per second. The internal high-precision temperature sensor can be used for cold node compensation of T-type thermocouples, thereby greatly improving the accuracy of lithium battery data acquisition. The voltage accuracy can reach ±0.02% FS, and the temperature accuracy can reach ±1°C (-45°C to 260°C).

[0083] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A lithium battery data collection method, characterized in that: The method requires the use of a lithium battery data acquisition system as follows, including: A host computer; A communication board, comprising an Ethernet communication module, a first MCU and eight first RS485 communication modules; one end of the first MCU is connected to the Ethernet communication module, and the other end is connected to each first RS485 communication module; the Ethernet communication module is connected to the host computer; Eight data acquisition boards, each comprising a second RS485 communication module, a second MCU, an isolation chipset and a data acquisition chip with 16 channels; one end of each of the second RS485 communication modules is connected to a first RS485 communication module, and the other end is connected to the second MCU; one end of the isolation chipset is connected to the second MCU, and the other end is connected to the data acquisition chip; The model of the Ethernet communication module is LAN8720A; The isolation chipset includes 16 isolation chips, one end of each isolation chip is connected to the second MCU, and the other end is connected to one of the channels of the data acquisition chip; The isolation chip is an SPI bus isolation chip; The data acquisition chip is a voltage acquisition chip or a temperature acquisition chip; The model of the voltage acquisition chip is ADS8689; The model of the temperature acquisition chip is ADS1118; The method comprises the following steps: Step S10, the communication board sets 8 UDP links and 8 UDP ports, each of the UDP links is respectively bound to a first RS485 communication module and a UDP port; Step S20, the data acquisition board sets a data acquisition cycle and a data cache quantity, automatically acquires lithium battery data every data acquisition cycle, and caches the lithium battery data based on the data cache quantity; Step S30, the communication board receives the data acquisition instruction sent by the host computer, obtains the lithium battery data from the corresponding data acquisition board based on the data acquisition instruction and the UDP link, and sends it to the host computer to complete the collection of the lithium battery data; The step S20 is specifically as follows: When the lithium battery data is voltage data, the method includes the following steps: Step S211, the second MCU of the data acquisition board sets a data acquisition cycle and a data buffer quantity; Step S212, the second MCU reads the device ID of the voltage acquisition chip every data acquisition cycle, and determines whether it is consistent with the pre-stored device ID. If so, it means that the SPI communication is normal, and the voltage acquisition chip is used to automatically collect voltage data and perform analog-to-digital conversion, and the voltage data is cached in the memory of the second MCU based on the data cache quantity; if not, it means that the SPI communication is abnormal, and the process ends; When the lithium battery data is temperature data, the method includes the following steps: Step S221, the second MCU of the data acquisition board sets a data acquisition cycle, a data buffer quantity, a register configuration value and a thermocouple table in which temperature and voltage correspond one to one; Step S222, the second MCU sends the register configuration value to the temperature acquisition chip every data acquisition cycle. After receiving the register configuration value, the temperature acquisition chip returns the cold node temperature value and the register configuration value to the second MCU. The second MCU converts the cold node temperature value into a cold node voltage value using the thermocouple table. The second MCU determines whether the received register configuration value is consistent with the set value. If so, it indicates that the SPI communication is normal, and the process goes to step S223; if not, it indicates that the SPI communication is abnormal, and the process ends. Step S223, the second MCU sends the register configuration value to the temperature acquisition chip. After receiving the register configuration value, the temperature acquisition chip returns the hot node voltage value and the register configuration value to the second MCU. The second MCU determines whether the received register configuration value is consistent with the set one. If so, it means that the SPI communication is normal, and the process goes to step S224; if not, it means that the SPI communication is abnormal, and the process ends. Step S224: the second MCU adds the hot node voltage value to the cold node voltage value to obtain an actual voltage value, and converts the actual voltage value into temperature data based on the thermocouple table; The step S30 specifically includes: Step S31, the communication board receives the data acquisition instruction sent by the host computer through the Ethernet interrupt, parses the target UDP port from the data acquisition instruction, and determines whether the target UDP port belongs to one of the set 8 UDP ports. If so, proceed to step S32; if not, end the process; Step S32: the communication board uses Uart interruption to send the data acquisition instruction to the corresponding data acquisition board based on the target UDP port and the UDP link, and the data acquisition board uses Uart interruption to cache the received data acquisition instruction into a pre-created circular queue; Step S33, the data acquisition board obtains the data acquisition instruction from the circular queue, and encapsulates the cached lithium battery data into a data packet based on the data acquisition instruction, and sends the data packet to the communication board through DMA; Step S34, the communication board receives the data packet through DMA, and when the Uart interrupt of the communication board triggers an idle interrupt, the data packet is sent to the host computer through the Ethernet communication module to complete the collection of lithium battery data.

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