Full-sensing single battery detection method

Abstract

The invention discloses a full-sensing single battery detection method, which relates to the field of battery state acquisition monitoring, and comprises the following steps: connecting voltage and temperature acquisition sensors to the positive and negative electrodes of each battery, connecting the voltage acquisition sensors to the two ends of the positive and negative electrodes of the battery, and connecting the temperature acquisition sensor to the main body of the battery; an output temperature acquisition sensor and an output voltage acquisition sensor are connected to a monitoring unit; a plurality of monitoring units are accessed to a BMS master controller through a topological structure framework; wherein the topological structure framework comprises power supply and CAN bus transmission, and is used for receiving data to adjust a link topological structure of a single battery so as to realize charge and discharge efficiency balance. According to the invention, the equalization efficiency of the battery system is greatly improved, the consistency of the battery system is guaranteed, and the use efficiency of the battery is improved.

Description

Technical Field

[0001] The invention relates to the field of battery status acquisition and monitoring, and in particular to a full-sensing single-cell battery detection method. Background Art

[0002] In the original battery system, each battery in the battery pack is connected to the BMS slave controller through the voltage acquisition line and the temperature acquisition line for centralized processing. A BMS slave controller can collect several to dozens of battery information at the same time. The disadvantages are:

[0003] 1. The collection harness transmits the battery voltage. The higher the voltage platform, the higher the voltage of the collection harness, and the higher the safety requirements for the harness;

[0004] 2. BMS collects the voltage and temperature of each battery in a time-division manner, and the frequency of information collection is slow. The information collected is inaccurate for pulse power applications.

[0005] 3. The system only estimates the SOX of the entire battery pack and cannot provide detailed information about the SOX status of each battery;

[0006] 4. Poor battery balancing effect;

[0007] 5. Not every battery string has independent temperature collection and monitoring, resulting in untimely and inaccurate temperature monitoring, posing a safety hazard.

[0008] In summary, the use of multi-channel centralized collection and processing mode cannot accurately and effectively collect and monitor single cells.

[0009] Therefore, there is an urgent need for a method to comprehensively characterize the voltage, temperature collection and internal state of a single battery cell. Summary of the invention

[0010] The present invention provides a full-sensing single-cell battery detection method, which solves the problems of the prior art.

[0011] In a first aspect, the present invention provides a fully sensing single cell battery detection method, comprising:

[0012] Connect the positive and negative electrodes of the battery to the voltage collection circuit, and connect the temperature sensor to the positive or negative electrode of the battery;

[0013] Integrate the voltage acquisition circuit and the temperature acquisition circuit into one monitoring unit to form a battery sensor;

[0014] The battery sensor contains a battery charging circuit, called active balancing, and a battery discharging circuit, called passive balancing;

[0015] Multiple battery sensors are connected to the BMS master through a topological structure;

[0016] The topology includes a power supply and an RS485 / CAN bus, which are used for the working power supply and receiving / sending data of the battery sensor, and realize active or passive balancing of a single battery;

[0017] The battery sensor software contains a variety of algorithms. Combined with the charge and discharge current data sent by the BMS master control, the SOX status of the single battery can be obtained through calculation to fully characterize the internal status of the battery.

[0018] The battery sensor is used in conjunction with the BMS main control, and key system parameters such as battery internal resistance, main line impedance, and wiring harness impedance can be obtained through software algorithms.

[0019] Furthermore, the power supply adopts a 12V power supply, which is used as the working power supply of the battery sensor and for active or passive balancing of the battery.

[0020] Furthermore, the battery sensor is designed with an RS485 / CAN communication bus connected to the BMS main control for transmitting data between the battery sensor and the BMS main control.

[0021] Furthermore, the data collected by the battery sensor is combined with the battery pack charge / discharge current data to obtain the battery SOX state after calculation, which is used to characterize the internal state of the battery, and the data is exchanged with the BMS master control through the RS485 / CAN bus.

[0022] Furthermore, the BMS master controller calculates the SOX state of the entire battery pack based on the voltage, current, temperature, time and SOX state of the battery corresponding to the battery sensor received.

[0023] Furthermore, the topology structure forms a battery pack by connecting all batteries in parallel and series in multiple stages, and a battery sensor is installed on each battery. Each battery sensor uploads the SOX status of the corresponding battery to the BMS master control through the RS485 / CAN bus. The BMS master control obtains the SOX status of all batteries through the battery number corresponding to the data, estimates the SOX status of the entire battery pack, and then sends the SOX status of the battery pack to all battery sensors through the RS485 / CAN bus. Each battery sensor actively or passively balances the battery according to the SOX status of the corresponding battery.

[0024] Furthermore, in the battery pack formed by the topological structure, the battery sensor can detect the internal resistance of each battery in the battery pack, the connection resistance between each battery, and the connection resistance of each wiring harness;

[0025] Furthermore, in the topology battery pack, when the SOX state of the battery is high, the corresponding battery sensor enters a passive balancing state, and when the SOX state of the battery is low, the corresponding battery sensor enters an active balancing state.

[0026] Furthermore, the working process of active / passive balancing includes the following steps:

[0027] a1. The BMS master analyzes the SOX status data of all batteries and combines the battery pack charge / discharge current data to obtain the battery pack's SOX status and real-time balancing efficiency;

[0028] a2. The BMS master sends the SOX status of the battery pack to all battery sensors via RS485 / CAN bus;

[0029] a3. Each battery sensor compares the SOX status of the corresponding battery with the SOX status of the battery pack and calculates the standard deviation. When the standard deviation is less than the preset threshold, it is unbalanced; when the standard deviation is low, active balancing is turned on; when the standard deviation is high, passive balancing is turned on;

[0030] a4. The battery sensor monitors the SOX status of the corresponding battery in real time and uploads the SOX status to the BMS master control;

[0031] a5. Repeat steps a1, a2, a3, and a4 to ensure that the SOX state of each battery in the entire battery pack gradually tends to be consistent and is less than a preset threshold.

[0032] Furthermore, the BMS master monitors all batteries of the battery pack in the topology structure at a time interval of 20 ms.

[0033] The present invention provides a fully sensing single-cell battery detection method, which can maximize the speed of monitoring battery voltage and temperature. The temperature monitoring covers each battery, ensuring that the SOX state of each battery can be quickly and real-timely grasped during battery use, greatly improving the safety and reliability of the battery pack.

[0034] In the present invention, the BMS no longer manages the passive balancing and active balancing of the battery; in the same battery pack, the battery sensor performs different balancing according to the SOX status of the corresponding battery, the battery with a high SOX status starts passive balancing, and the battery with a low SOX status starts active balancing. Most importantly, balancing can be performed during the charging and discharging process of the battery, which greatly improves the balancing efficiency of the battery pack, ensures the consistency of each battery in the battery pack, and improves the use efficiency of the battery;

[0035] In the present invention, each battery sensor has an independent 485 / CAN communication output, which can provide services for voltage and temperature monitoring of all single-cell batteries, and can be widely used in application environments such as batteries, capacitors, and electrolytic cells.

[0036] The voltage and temperature sampling speed of the battery sensor can reach 2ms, and the sampling speed of the entire battery pack can reach 20ms or lower. It can be used in a pulse power system to accurately monitor the voltage, temperature changes and power changes of a single battery in the pulse power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0038] Figure 1 A schematic diagram of a topological structure of a full-sensing single-cell battery detection method provided by an exemplary embodiment of the present invention.

[0039] Figure 2 A schematic diagram of another topological structure of an application of a full-sensing single-cell battery detection method provided by an exemplary embodiment of the present invention.

[0040] Figure 3 A flowchart of the working process of active / passive balancing of a full-sensing single-cell battery detection method provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0041] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0042] Battery status SOX is one of the important bases for BMS system operation and decision-making, including SOC / SOH / SOP / SOE, etc. It is also the technical difficulty and core algorithm of BMS software. Existing technology cannot directly obtain the specific data of single battery SOX. Whether it is SOC, SOH, SOP or SOE, they are all internal states of the battery that cannot be directly measured. However, the battery sensor can collect data such as voltage, current, temperature and time through the chip, and use this to calculate the SOX of the corresponding battery, where X is C, H, P and E. Among them, the hardware topology architecture of BMS is divided into two types: centralized and distributed. The centralized type is to concentrate all electrical components on a PCB board. The advantages of this hardware architecture are simple circuit design and low cost. The disadvantages are that the wiring harness for single-cell sampling is relatively long, the sampling voltage drop is different, the sampling wiring harness design is complex, and the number of sampling channels is limited, which is suitable for smaller battery packs; the distributed hardware architecture includes the main control and battery sensors. The advantage of this hardware architecture is that the sampling wiring harness distance is uniform, and the disadvantage is that the cost is high, but with the advancement of chip technology, the cost will drop significantly.

[0043] The specific application scenario of the present invention is the field of battery status acquisition and monitoring.

[0044] The present invention provides a full-sensing single-cell battery detection method, which aims to solve the above technical problems in the prior art.

[0045] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0046] Example: Active / passive balancing process, such as Figure 1 Schematic diagram of possible topological structures of or 2 and Figure 3 The working process flow chart of active / passive balancing shown in the figure includes the following hardware settings:

[0047] Connect the positive and negative electrodes of the battery to the voltage collection circuit, and connect the temperature sensor to the positive or negative electrode of the battery;

[0048] Integrate the voltage acquisition circuit and the temperature acquisition circuit into one monitoring unit to form a battery sensor;

[0049] Multiple battery sensors via Figure 1 or Figure 2 The topology structure is connected to the BMS master control;

[0050] Among them, the topology structure includes a power supply and a CAN bus. The CAN bus is used to transmit data such as the SOX status between the BMS main control and the battery sensor. The power supply is used to provide working power for the battery sensor and active / passive balancing of the battery. The battery sensor collects the voltage and temperature of the battery, receives the charge and discharge current data transmitted by the BMS main control, and calculates the SOX status of the battery. The BMS main control transmits the charge and discharge current data of the battery pack to the battery sensor, receives the SOX status data of each battery uploaded by all battery sensors, calculates the SOX status of the entire battery pack, and then transmits it to all battery sensors. The battery sensor compares the SOX status of the corresponding battery with the SOX status of the battery pack, calculates the standard deviation, and determines whether to enter the balanced state according to the pre-set standard deviation threshold.

[0051] The working process of active / passive balancing includes the following steps and Figure 3 As shown:

[0052] a1. The BMS master analyzes the SOX status data of all batteries and combines the battery pack charge / discharge current data to obtain the battery pack's SOX status and real-time balancing efficiency;

[0053] a2. The BMS master sends the SOX status of the battery pack to all battery sensors via RS485 / CAN bus;

[0054] a3. Each battery sensor compares the SOX status of the corresponding battery with the SOX status of the battery pack and calculates the standard deviation. When the standard deviation is less than the preset threshold, it is unbalanced; when the standard deviation is low, active balancing is turned on; when the standard deviation is high, passive balancing is turned on;

[0055] a4. The battery sensor monitors the SOX status of the corresponding battery in real time and uploads the SOX status to the BMS master control;

[0056] a5. Repeat steps a1, a2, a3, and a4 to ensure that the SOX state of each battery in the entire battery pack gradually tends to be consistent and is less than a preset threshold.

[0057] In the embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0058] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0059] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0060] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0061] Those skilled in the art will appreciate that the embodiments of the present invention may be provided as methods or systems. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects.

[0062] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0063] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

[0064] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only, and the true scope and spirit of the present invention is indicated by the claims above.

[0065] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A fully sensing single cell battery detection method, characterized in that: include: Connect the positive and negative electrodes of the battery to the voltage collection circuit, and connect the temperature sensor to the positive or negative electrode of the battery; Integrate the voltage acquisition circuit and the temperature acquisition circuit into one monitoring unit to form a battery sensor; The battery sensor contains a battery charging circuit, called active balancing, and a battery discharging circuit, called passive balancing; Multiple battery sensors are connected to the BMS master through a topological structure; The topology includes power supply and RS485 / CAN bus transmission for receiving / sending data and realizing active or passive balancing of a single battery cell; The battery sensor's software algorithm combines the charge and discharge current data sent by the BMS master control to calculate the SOX state of the single battery, where X is C, H, P and E. SOX is used to fully characterize the internal state of the battery. The battery sensor is combined with the BMS main control to obtain the battery internal resistance, main line impedance, and wiring harness impedance parameters through software algorithms.

2. A fully sensing single cell battery detection method according to claim 1, characterized in that: The power supply adopts 12V power supply, which is used for the working power supply of the battery sensor and for active or passive balancing of the battery.

3. A fully sensing single cell battery detection method according to claim 1, characterized in that: The battery sensor is provided with a RS485 / CAN communication bus connected to the BMS master control.

4. A fully sensing single cell battery detection method according to claim 3, characterized in that: The data collected by the battery sensor is combined with the battery pack charge / discharge current data to calculate the battery SOX state, which is used to characterize the internal state of the battery and exchange data with the BMS master control through the RS485 / CAN bus.

5. A fully sensing single cell battery detection method according to claim 4, characterized in that: The BMS main control includes a main control chip, which calculates the SOX of the entire battery pack based on the voltage, current, temperature, time and SOX data of the battery corresponding to the battery sensor received.

6. A fully sensing single cell battery detection method according to claims 1, 4 and 5, characterized in that: The topology structure forms a battery pack by connecting all batteries in parallel and series in multiple stages. A battery sensor is installed on each battery. The battery sensor uploads the SOX status of each battery to the BMS main control. The main control chip obtains the SOX status of all batteries through the battery number corresponding to the data, estimates the SOX status of the entire battery pack, and then sends the SOX status of the battery pack to all battery sensors through the CAN bus. Each battery sensor actively or passively balances the battery according to the SOX status of the corresponding battery.

7. A fully sensing single cell battery detection method according to claims 1 and 6, characterized in that: The battery pack formed by the topological structure has a battery sensor capable of detecting the internal resistance of each battery in the battery pack, the connection resistance between each battery, and the connection resistance of each wiring harness.

8. A fully sensing single cell battery detection method according to claim 6, characterized in that: In the topological structure, when the SOX of the battery is high, the corresponding battery sensor enters a passive balancing state, and when the SOX of the battery is low, the corresponding battery sensor enters an active balancing state.

9. A fully sensing single cell battery detection method according to claim 6, characterized in that: The working process of active / passive balancing includes the following steps: a1. The BMS master analyzes the SOX status data of all batteries and combines the battery pack charge / discharge current data to obtain the battery pack's SOX status and real-time balancing efficiency; a2. The BMS master sends the SOX status of the battery pack to all battery sensors via the CAN bus; a3. Each battery sensor compares the SOX status of the corresponding battery with the SOX status of the battery pack and calculates the standard deviation. When the standard deviation is less than the preset threshold, it is unbalanced; when the standard deviation is low, active balancing is turned on; when the standard deviation is high, passive balancing is turned on; a4. The battery sensor monitors the SOX status of the corresponding battery in real time and uploads the SOX status to the BMS master control; a5. Repeat steps a1, a2, a3, and a4 to ensure that the SOX state of each battery in the entire battery pack is less than a preset threshold.

10. A fully sensing single cell battery detection method according to claim 8, characterized in that: The BMS master monitors all batteries in the battery pack in the topology at 20ms intervals.

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