Wiring sequence identification circuit, sampling circuit, battery management system and battery device

Abstract

The application provides a wiring sequence identification circuit, a sampling circuit, a battery management system and a battery device. Each wiring detection end in the wiring sequence identification circuit is used for being connected with any first sampling line; a positive electrode wiring end is connected with a positive electrode of a battery pack; a negative electrode wiring end is connected with a negative electrode of the battery pack; a reference wiring end is connected with any sampling access end through a pair of series connection voltage division modules; a switch module is used for controlling the on-off between each wiring detection end and the corresponding sampling access end; an input end of a control module is connected with a series connection point in each pair of voltage division modules, used for acquiring the corresponding voltage, so as to determine the actual corresponding connection relationship. When the first sampling line is connected with the wiring detection end in disorder, the actual corresponding connection relationship is determined according to the voltage of the wiring detection end, so that the battery parameters can be correctly sampled even in the case of disordered wiring, repeated wiring is avoided, and the battery installation efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and in particular to a wiring sequence identification circuit, a sampling circuit, a battery management system, and a battery device. Background Technology

[0002] Electric two-wheelers are typically powered by battery packs, such as lead-acid battery packs or lithium-ion battery packs containing multiple battery cells.

[0003] Lithium-ion battery packs have each battery cell pre-connected and secured according to the designed connection structure at the factory, eliminating the need for manual connection and installation when installing them in an electric two-wheeler. Lead-acid battery packs, however, differ from lithium-ion packs. During installation, operators must connect each battery cell to the lead-acid BMS (Battery Management System). This requires distinguishing the sampling lines of different battery cells and connecting them to the power consumption module's connection points in a specified order. Incorrect connections will cause the lead-acid battery management system to malfunction or even be damaged, typically necessitating rewiring.

[0004] The process of installing lead-acid battery packs described above is usually difficult to complete efficiently and accurately. This connection method increases the workload of installers and results in low installation efficiency. Summary of the Invention

[0005] This invention provides a wiring sequence identification circuit, a sampling circuit, a battery management system, and a battery device, enabling the battery cells and BMS to obtain the actual corresponding connection relationship even when they are connected out of order. This allows for the correct sampling of battery pack parameters without rewiring, thus improving battery installation efficiency.

[0006] In a first aspect, the present invention provides a wiring sequence identification circuit, wherein the battery pack includes a first sampling line located between two adjacent battery cells, and the number of the first sampling lines is N-1; N is the number of battery cells, and N is an integer greater than or equal to 3; the identification circuit includes:

[0007] The system comprises N-1 connection detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal, and multiple voltage divider modules; each of the connection detection terminals is used to connect to any one of the first sampling lines; the positive terminal is used to connect to the positive terminal of the battery pack, and the negative terminal is used to connect to the negative terminal of the battery pack; a pair of voltage divider modules connected in series are respectively connected between the reference terminal and any of the sampling access terminals; the reference terminal is either the negative terminal or the positive terminal;

[0008] A switch module is disposed between the N-1 wiring detection terminals and the N-1 sampling access terminals. The switch module is used to control the connection and disconnection between each wiring detection terminal and the corresponding sampling access terminal.

[0009] The control module, connected to the switch module, is used to output on / off signals to the switch module. The input terminal of the control module is connected to the series connection point in each pair of voltage divider modules. It is used to obtain the voltage of each of the wiring detection terminals when each wiring detection terminal is connected to the corresponding sampling access terminal, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the obtained voltage of each wiring detection terminal.

[0010] In one embodiment, the control module includes a voltage acquisition unit and an identification unit. The voltage acquisition unit is connected between the identification unit and the series connection point in each pair of voltage divider modules, and is used to detect the voltage at each of the series connection points and output the detected voltage at each of the series connection points to the identification unit. The identification unit is used to determine the voltage of each wiring detection terminal based on the voltage at each of the series connection points, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the voltage at each of the wiring detection terminals.

[0011] Among them, a pair of voltage divider modules adjacent to any sampling access terminal belongs to the first group; the sampling resistance ratio of any pair of voltage divider modules in the first group is within a first range; the first range indicates that when any of the first sampling lines is connected to the corresponding wiring detection terminal, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy and range requirements of the voltage acquisition unit.

[0012] In one embodiment, the identification unit stores the sampling resistance ratio of each pair of voltage divider modules; when determining the voltage of each wiring detection terminal based on the voltage at each of the series connection points, the identification unit is specifically used for:

[0013] The voltage at the connection detection terminal corresponding to each series connection point is determined based on the voltage at each of the series connection points and the sampling resistance ratio of the corresponding pair of voltage divider modules.

[0014] In one embodiment, the first range is determined by a first resistance ratio and a second resistance ratio; the first resistance ratio is the difference between a first preset value and the value 1; the first preset value is the ratio of the total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to the range of the voltage acquisition unit; the target terminal is the end opposite to the reference terminal.

[0015] The second resistance ratio is the difference between the second preset value and the value 1; the second preset value is the ratio of the minimum value that the battery cell corresponding to the reference terminal can take to the accuracy of the voltage acquisition unit.

[0016] In one embodiment, the sampling resistance ratio of each pair of voltage divider modules in the first group is equal to the first resistance ratio.

[0017] In one embodiment, when the identification unit determines the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines based on the voltage of each of the wiring detection terminals, it is specifically used for:

[0018] The voltages of each of the wiring detection terminals are sorted by magnitude to obtain a sorting result, and the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines is determined based on the sorting result.

[0019] In one embodiment, the switching module includes: N-1 first switches;

[0020] One end of each of the first switches is connected to one of the wiring detection terminals, and the other end of each of the first switches is connected to one of the sampling access terminals.

[0021] In a second aspect, the present invention provides a sampling circuit, including the identification circuit described in any one of the first aspects, and a voltage sampling module; a pair of voltage divider modules connected in series between the negative terminal and the positive terminal; the control module is further configured to acquire the voltage between the positive and negative terminals of the battery pack when the connection between the positive terminal and the negative terminal is made;

[0022] The voltage sampling module is connected to the control module. The voltage sampling module is used to receive the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals sent by the control module, and to obtain the current voltage value of each battery cell based on the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals.

[0023] In one embodiment, the switch module includes: a second switch;

[0024] The second switch is connected between the positive terminal and the negative terminal.

[0025] In one embodiment, the voltage divider module connected in series between the positive terminal and the negative terminal belongs to the second group, and the sampling resistance ratio of the voltage divider module in the second group is within a second range; the second range indicates that the voltage at the series connection point of the voltage divider module in the second group meets the accuracy and range requirements of the voltage acquisition unit.

[0026] In one embodiment, the second range is determined by a third resistance ratio and a fourth resistance ratio; the third resistance ratio is the difference between a third preset value and a value of 1; the third preset value is the ratio of the total voltage of the N battery cells in the battery pack to the range of the voltage acquisition unit.

[0027] The fourth resistance ratio is the difference between the fourth preset value and the value 1; the fourth preset value is the ratio of the total voltage of the N battery cells in the battery pack to the accuracy of the voltage acquisition unit.

[0028] In one embodiment, when the voltage sampling module obtains the current voltage value of each battery cell based on the voltage of each of the wiring detection terminals and the voltage between the positive and negative electrodes, it is specifically used for:

[0029] Subtract two adjacent voltages from the sorting results to obtain N-2 subtraction results; the sorting results are the results of taking the absolute value of the voltage of each of the wiring detection terminals and then sorting them by size.

[0030] The current voltage values ​​of N-1 battery cells in the battery pack, excluding the battery cell corresponding to the target terminal, are determined based on the minimum value of the sorting results and N-2 subtraction results; the target terminal is the end opposite to the reference terminal.

[0031] The difference between the absolute value of the voltage between the positive and negative terminals and the maximum value of the sorting result is determined as the current voltage value of the battery cell corresponding to the target terminal.

[0032] In one embodiment, the voltage sampling module is further configured to:

[0033] The battery cell to be discharged is determined based on the current voltage value of each battery cell;

[0034] The battery cell to be discharged is the battery cell with the highest voltage among the N battery cells.

[0035] In one embodiment, the system further includes a circuit module connected to the control module and the voltage sampling module. The circuit module is configured to receive the actual corresponding connection relationship sent by the control module and the battery cell to be discharged sent by the voltage sampling module, so as to discharge the battery cell according to the actual corresponding connection relationship to balance the voltage of each battery cell.

[0036] In one embodiment, the sampling circuit further includes a power supply module connected to the control module and also connected to the voltage sampling module. The power supply module is used to supply power to the control module and the voltage sampling module.

[0037] In one embodiment, the voltage divider module includes a resistor; or, the voltage divider module includes at least two resistors; the at least two resistors are connected in series, parallel, or mixed connection.

[0038] Thirdly, the present invention provides a battery management system, including a wiring sequence identification circuit as described in any of the first aspects, and / or a sampling circuit as described in any of the second aspects.

[0039] Fourthly, the present invention provides a battery device comprising a battery management system as described in the third aspect and a plurality of battery cells, wherein the battery management system and the plurality of battery cells are electrically connected.

[0040] In one embodiment, the battery cell is a lead-acid battery; and / or, the number of battery cells is 3 to 7.

[0041] This invention provides a wiring sequence identification circuit, a sampling circuit, a battery management system, and a battery device. The battery pack includes a first sampling line located between two adjacent battery cells, with the number of first sampling lines being N-1, where N is the number of battery cells. The wiring sequence identification circuit includes: N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal, and multiple voltage divider modules. Each wiring detection terminal is connected to any one of the first sampling lines. The positive terminal is connected to the positive terminal of the battery pack, and the negative terminal is connected to the negative terminal. A pair of voltage divider modules connected in series are respectively connected between a reference terminal and any one of the sampling access terminals. The reference terminal is either the negative terminal or the positive terminal. A switching module is disposed between the N-1 wiring detection terminals and the N-1 sampling access terminals, and the switching module is used to control each wiring detection terminal and its corresponding sampling access terminal. The control module, connected to the switch module, outputs an on / off signal to the switch module. The input terminal of the control module is connected to the series connection point in each pair of voltage divider modules. It is used to acquire the voltage of each wiring detection terminal when each wiring detection terminal is connected to the corresponding sampling access terminal. Based on the acquired voltage of each wiring detection terminal, the actual corresponding connection relationship between each wiring detection terminal and each first sampling line is determined. When the first sampling line is connected to the wiring detection terminal, the voltage of each wiring detection terminal relative to the same reference point has a certain magnitude relationship. Therefore, by acquiring the voltage of each wiring detection terminal relative to the reference wiring terminal, the actual corresponding connection relationship is determined based on the magnitude relationship of the acquired voltage of each wiring detection terminal. This enables the acquisition of the actual corresponding connection relationship when wiring is out of order, and allows for correct sampling of battery parameters even when wiring is out of order, avoiding repeated wiring and improving battery installation efficiency. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0043] Figure 1 This is a schematic diagram of a wiring sequence identification circuit provided in an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of a sampling circuit according to an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of another sampling circuit provided in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of an overall structure for load balancing of battery cells according to an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of an equalization circuit provided in an embodiment of the present invention.

[0048] The accompanying drawings have illustrated specific embodiments of the invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0049] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention.

[0050] When a battery pack consists of multiple battery cells connected in series, each battery cell can supply power to the outside. For example, when the battery pack is used in an electric two-wheeler, it can provide power to the vehicle. Taking lead-acid batteries as an example, during installation and use, operators need to connect each battery cell to the lead-acid battery management system. During installation, because it is difficult to quickly and accurately distinguish the first sampling lines between different battery cells, low connection efficiency or incorrect connections may occur. Therefore, this application sets up a switch module and a voltage divider module, and designs the connection relationships to enable the correct acquisition of battery parameter values ​​even in the event of disordered connections. This is achieved by collecting voltage data from each wiring detection terminal and determining the actual corresponding connection relationship between each first sampling line and each wiring detection terminal based on the voltage data. Once the actual wiring sequence is known, the battery parameter values ​​can be correctly acquired even without rewiring.

[0051] This invention provides a wiring sequence identification circuit, wherein the battery pack includes a first sampling line located between two adjacent battery cells, and the number of the first sampling lines is N-1; N is the number of battery cells, and N is an integer greater than or equal to 3; the wiring sequence identification circuit includes:

[0052] The system comprises N-1 connection detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal, and multiple voltage divider modules; each of the connection detection terminals is used to connect to any one of the first sampling lines; the positive terminal is used to connect to the positive terminal of the battery pack, and the negative terminal is used to connect to the negative terminal of the battery pack; a pair of voltage divider modules connected in series are respectively connected between the reference terminal and any of the sampling access terminals; the reference terminal is either the negative terminal or the positive terminal;

[0053] A switch module is disposed between the N-1 wiring detection terminals and the N-1 sampling access terminals. The switch module is used to control the connection and disconnection between each wiring detection terminal and the corresponding sampling access terminal.

[0054] The control module, connected to the switch module, is used to output on / off signals to the switch module. The input terminal of the control module is connected to the series connection point in each pair of voltage divider modules. It is used to obtain the voltage of each of the wiring detection terminals when each wiring detection terminal is connected to the corresponding sampling access terminal, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the obtained voltage of each wiring detection terminal.

[0055] Figure 1 This is a schematic diagram of a wiring sequence identification circuit provided in an embodiment of the present invention, as shown below. Figure 1 As shown, BAT1 to BAT N For N battery cells connected in series, B+ is the sampling line connected to the positive terminal of the battery pack, B- is the sampling line connected to the negative terminal of the battery pack, B+ is connected to the positive terminal in the wiring sequence identification circuit, and B- is connected to the negative terminal in the wiring sequence identification circuit.

[0056] B1 to B N-1 The first sampling line is defined as P1, where N is the number of battery cells. The first sampling line is located at the series connection point between two adjacent battery cells. N-1 There are N-1 wiring detection terminals. When installing the battery unit, it is necessary to manually connect each first sampling line and each wiring detection terminal. The wiring sequence identification circuit can obtain the actual corresponding connection relationship between each first sampling line and each wiring detection terminal.

[0057] Optionally, a reference terminal can be set, which can be either the negative or positive terminal of the battery pack. After determining the reference terminal, a voltage divider module can be set between the reference terminal and the sampling access terminal, such as... Figure 1 As shown, the sampling access terminals are points A, B, C, and D, and the reference connection terminal is the negative terminal.

[0058] Since each wiring detection terminal is connected to each first sampling line, the voltage at each terminal may be the voltage of a single battery cell, or the sum of the voltages of two, three, or even N-1 battery cells. For lead-acid batteries, the voltage of a single cell may be 10V to 14V. When N equals 5, the voltage at the wiring detection terminal can reach approximately 50V. However, when measuring voltage, the voltage measuring equipment typically cannot directly measure the voltage at the wiring detection terminal due to its limited range. Therefore, for the wiring sequence identification circuit, a pair of voltage divider modules is set between the sampling input terminal and the reference wiring terminal. The control module is connected to the series connection point of each pair of voltage divider modules to obtain the voltage at the series connection point, and then the voltage at the wiring detection terminal is obtained.

[0059] In acquiring the voltage at the wiring detection terminal, to obtain the voltage at a series connection point at a specific moment, a switch can be used to control the connection between the wiring detection terminal and the sampling access terminal, such as... Figure 1 As shown, for P1 to P N-1 Each of these N-1 wiring detection terminals can be equipped with a switch, such as switch K1, switch K2, etc. When the voltage of the wiring detection terminal P1 needs to be obtained, switch K1 can be closed. The voltage collected at this time is the voltage at the series connection point between R1 and R2. Based on this voltage, the voltage at point P1 can be obtained. Similarly, when the voltage of point P2 needs to be obtained, switch K2 is closed. The voltage collected at this time is the voltage at the series connection point between R3 and R4. Based on this voltage, the voltage at point P can be obtained. By closing each switch in sequence as described above, the voltage at each P point, that is, the voltage of each wiring detection terminal, can be obtained.

[0060] Optionally, when controlling the switch module to close or open, the control module can output an on / off signal to the switch module, thereby controlling the closure or opening of the switch module. For example, when there are N-1 switches in the switch module, one switch is controlled to close sequentially while the others are open. For example, K1 closes while the others are open, or K2 closes while the others are open, and so on.

[0061] After the first sampling line is connected to the wiring detection terminal, when the voltage of each wiring detection terminal is acquired, the voltage of that wiring detection terminal is the same as the voltage of the connected first sampling line. When the reference wiring terminal is determined, the voltage of each first sampling line follows a certain pattern. Therefore, the actual corresponding connection relationship between each wiring detection terminal and the first sampling line can be determined based on the voltage of each wiring detection terminal.

[0062] For example, when the reference terminal is the negative terminal, then from B1 to B N-1 The voltage increases sequentially. Since each point B is connected to each wiring detection terminal, the actual corresponding connection relationship between each wiring detection terminal and each first sampling line can be determined after obtaining the voltage of each wiring detection terminal.

[0063] This invention provides a wiring sequence identification circuit. The battery pack includes a first sampling line located between two adjacent battery cells, and the number of the first sampling lines is N-1, where N is the number of battery cells. The wiring sequence identification circuit includes: N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal, and multiple voltage divider modules. Each wiring detection terminal is used to connect to any one of the first sampling lines. The positive terminal is used to connect to the positive terminal of the battery pack, and the negative terminal is used to connect to the negative terminal of the battery pack. A pair of voltage divider modules connected in series are respectively connected between a reference terminal and any one of the sampling access terminals. The reference terminal is either the negative terminal or the positive terminal. A switch module is disposed between the N-1 wiring detection terminals and the N-1 sampling access terminals, and the switch module is used to control each wiring detection... The control module, connected to the switch module, outputs an on / off signal to the switch module. The input terminal of the control module is connected to the series connection point in each pair of voltage divider modules. It is used to obtain the voltage of each wiring detection terminal when each wiring detection terminal is connected to the corresponding sampling access terminal, and to determine the actual corresponding connection relationship between each wiring detection terminal and each first sampling line based on the obtained voltage of each wiring detection terminal. When the first sampling line is connected to the wiring detection terminal, the voltage of each wiring detection terminal has a certain magnitude relationship. The actual corresponding connection relationship is determined based on the magnitude relationship of the obtained voltage of each wiring detection terminal, so that the actual corresponding connection relationship can be obtained when the wiring is out of order. This enables correct sampling of battery parameters even when the wiring is out of order, avoids repeated wiring, and improves battery installation efficiency.

[0064] In one embodiment, the control module includes a voltage acquisition unit and an identification unit. The voltage acquisition unit is connected between the identification unit and the series connection point in each pair of voltage divider modules, and is used to detect the voltage at each of the series connection points and output the detected voltage at each of the series connection points to the identification unit. The identification unit is used to determine the voltage of each wiring detection terminal based on the voltage at each of the series connection points, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the voltage at each of the wiring detection terminals.

[0065] Among them, a pair of voltage divider modules adjacent to any sampling access terminal belongs to the first group; the sampling resistance ratio of any pair of voltage divider modules in the first group is within a first range; the first range indicates that when any of the first sampling lines is connected to the corresponding wiring detection terminal, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy and range requirements of the voltage acquisition unit.

[0066] The control module's function is to acquire the voltage at each wiring detection terminal and identify the wiring sequence. Therefore, the control module can consist of a voltage acquisition unit and an identification unit. The voltage acquisition unit can be implemented using an analog-to-digital converter chip.

[0067] To achieve the goal of acquiring the voltage of each connection detection terminal using the same voltage acquisition unit, the sampling resistance ratio of each pair of voltage divider modules in the first group needs to be set. Since the connection detection terminals and the first sampling lines are connected in random order, each connection detection terminal may be connected to B1, or may be connected to B... N-1 Therefore, when collecting the total voltage of N-1 battery cells close to the reference terminal, the sampling resistance ratio needs to meet the range requirements of the voltage acquisition unit; at the same time, when collecting the voltage of the battery cell corresponding to the reference terminal, the sampling resistance ratio needs to meet the accuracy requirements of the voltage acquisition unit.

[0068] By setting the sampling resistance ratio of each voltage divider module as described above, the voltage of each wiring detection terminal can be accurately obtained using a single voltage acquisition unit.

[0069] In one embodiment, the identification unit stores the sampling resistance ratio of each pair of voltage divider modules; when determining the voltage of each wiring detection terminal based on the voltage at each of the series connection points, the identification unit is specifically used for:

[0070] The voltage at the connection detection terminal corresponding to each series connection point is determined based on the voltage at each of the series connection points and the sampling resistance ratio of the corresponding pair of voltage divider modules.

[0071] For each pair of voltage divider modules, a sampling resistance ratio needs to be set. For example, each pair of voltage divider modules includes a first voltage divider module and a second voltage divider module. The sampling resistance ratio can be the resistance ratio between the second voltage divider module and the first voltage divider module. The first voltage divider module is the voltage divider module adjacent to the reference terminal.

[0072] Based on the wiring sequence, the circuit identification uses the voltage conversion formula V1 = V * R1 / (R1 + R2), where V1 is the voltage at the series connection point, V is the voltage at the wiring detection terminal, R1 is the first voltage divider module, and R2 is the second voltage divider module. Therefore, according to this formula, R2 / R1 = V / V1 - 1. Thus, after setting the sampling resistance ratio, the identification unit can store each sampling resistance ratio. When the voltage at the corresponding series connection point is obtained, the voltage at the corresponding wiring detection terminal can be calculated based on the above formula. That is, the sampling resistance ratio is the resistance ratio between the second voltage divider module and the first voltage divider module.

[0073] For example, when calculating the voltage at point P1, the control module can first control K1 to close and then control K2 to K... N-1 When disconnected, the voltage V1 acquired by the voltage acquisition unit is the voltage at the series connection point between R1 and R2. Based on this voltage and the sampling resistance ratio, the voltage at point P1 can be determined, i.e., V = V1 + V 1* R2 / R1.

[0074] When calculating the voltage at point P2, the control module can first close K2 and control K1, K3, and K2. N-1 When disconnected, the voltage V1 acquired by the voltage acquisition unit is the voltage at the series connection point between R3 and R4. Based on this voltage and the sampling resistance ratio, the voltage at point P2 can be determined, i.e., V = V1 + V 1* R4 / R3.

[0075] Optionally, the sampling resistance ratio of each pair of voltage divider modules can be different, and the identification unit only needs to store each sampling resistance ratio.

[0076] In addition, the sampling resistance ratio can also be the resistance ratio between the first voltage divider module and the second voltage divider module.

[0077] By storing the sampling resistance ratio through the identification unit, the voltage at the wiring detection terminal can be determined based on the voltage at each series connection point after obtaining the voltage at that series connection point. This eliminates the need to set the sampling resistance ratio of each voltage divider module to be the same, reducing the resistance setting requirements for each pair of voltage divider modules.

[0078] In one embodiment, the first range is determined by a first resistance ratio and a second resistance ratio; the first resistance ratio is the difference between a first preset value and the value 1; the first preset value is the ratio of the total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to the range of the voltage acquisition unit; the target terminal is the end opposite to the reference terminal.

[0079] The second resistance ratio is the difference between the second preset value and the value 1; the second preset value is the ratio of the minimum value that the battery cell corresponding to the reference terminal can take to the accuracy of the voltage acquisition unit.

[0080] Since the first sampling lines and the various connection detection terminals can be connected in random order, each connection detection terminal may be connected to B. N-1 The two first sampling lines, B1 and B2, are connected. For each sampling resistance ratio, there is the same first range, which includes the first resistance ratio and the second resistance ratio.

[0081] When measuring the total voltage of N-1 battery cells excluding the cell corresponding to the target terminal, if the reference terminal is the negative terminal and the target terminal is the positive terminal, then BAT N For the battery cell corresponding to the positive terminal, then when measuring except BAT N When the voltage of the N-1 battery cells other than the target terminal is the sum of the voltages of the N-1 battery cells, that is, when the voltage measured by the voltage acquisition unit is the maximum measurement voltage, the sampling resistance ratio needs to meet the measurement range requirements of the voltage acquisition unit. That is, the first resistance ratio is the difference between the first preset value and the value 1. The first preset value is the ratio of the total voltage of the N-1 battery cells other than the battery cell corresponding to the target terminal to the range of the voltage acquisition unit. At this time, the total voltage is the sum of the voltages of the N-1 battery cells in the fully charged state.

[0082] For example, when the voltage of N-1 battery cells is in the range of 10V to 14V, where the voltage is 10V in the depleted state and 14V in the fully charged state, then the total voltage of N-1 battery cells is 14*(N-1).

[0083] The first resistance ratio is the minimum value of the sampling resistance ratio. According to the formula R2 / R1 = V / V1 - 1, let V / V1 be the voltage division ratio. When the maximum voltage at the connection detection terminal is 48V, if the voltage division ratio is 3:1, then V1 is 16V; if the voltage division ratio is 20:1, then V1 is 2.4V. Therefore, the smaller the voltage division ratio, the larger V1 will be, which may exceed the range of the voltage acquisition unit, thus burning out the voltage acquisition unit. Therefore, the sampling resistance ratio must be greater than the first resistance ratio.

[0084] When measuring the voltage of a battery cell corresponding to a reference terminal, if the reference terminal is the negative terminal, then BAT1 is the battery cell corresponding to the negative terminal. When measuring the voltage of battery cell BAT1, which is the voltage measured by the voltage acquisition unit at this time, the sampling resistance ratio needs to meet the measurement accuracy requirements of the voltage acquisition unit. Specifically, the second resistance ratio is the difference between a second preset value and the value 1. The second preset value is the ratio of the minimum possible value of the battery cell corresponding to the reference terminal to the accuracy of the voltage acquisition unit. The minimum possible value of the battery cell corresponding to the reference terminal refers to the minimum value among the possible values ​​of that battery cell. For example, the voltage of the battery cell is 10V to 14V, where the voltage is 10V in a depleted state and 14V in a fully charged state. The minimum possible value of the battery cell is 10V.

[0085] The second resistance ratio is the maximum value of the sampling resistance ratio. When the minimum possible value of the battery cell is 12V, V1 is 4V when the voltage division ratio is 3:1; and 0.6V when the voltage division ratio is 20:1. Therefore, the larger the voltage division ratio, the smaller V1 is. The actual accuracy of the voltage acquisition unit after passing through the voltage divider circuit may be less than the accuracy requirement for the sampling circuit to acquire the battery cell voltage in the engineering design, thus making accurate measurement impossible. Therefore, the sampling resistance ratio must be less than the second resistance ratio.

[0086] By limiting the first resistance ratio and the second resistance ratio, the voltage acquisition unit can accurately measure the voltage at each series connection point, thereby accurately acquiring the voltage at each wiring detection terminal and avoiding problems such as inaccurate voltage measurement or exceeding the measurement range when measuring the voltage at the series connection point.

[0087] In one embodiment, the sampling resistance ratio of each pair of voltage divider modules in the first group is equal to the first resistance ratio.

[0088] The higher the sampling resistance ratio, the lower the measurement accuracy. For example, when the maximum voltage at the connection detection terminal is 48V, V1 is 16V when the voltage division ratio is 3:1; and 2.4V when the voltage division ratio is 20:1. It is evident that the higher the voltage division ratio, i.e., the higher the sampling resistance ratio, the lower the accuracy of voltage measurement. The first resistance ratio is the minimum sampling resistance ratio. To improve the measurement accuracy of the voltage acquisition unit, the sampling resistance ratio of each pair of voltage divider modules in the first group can be determined as the first resistance ratio.

[0089] By setting the sampling resistance ratio of each pair of voltage divider modules in the first group to the first resistance ratio, the measurement accuracy when measuring voltage can be improved.

[0090] In an embodiment, the identification unit is specifically configured to, when determining the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the voltage of each of the wiring detection terminals:

[0091] Sort the voltages of the respective wiring detection terminals by magnitude to obtain a sorting result, and determine the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the sorting result.

[0092] After acquiring the voltage of each wiring detection terminal, the identification unit may sort the voltages of the respective wiring detection terminals by magnitude, and the actual corresponding connection relationship can be obtained according to the sorting result.

[0093] For example, when the reference wiring terminal is the negative wiring terminal, the voltages from B1 to B N-1 are all positive values, and the voltages from B1 to B N-1 increase sequentially. Since each first sampling line (each B point) is connected to each wiring detection terminal (each P point), the voltage of each wiring detection terminal is equal to the voltage of each first sampling line. Since the voltages of the first sampling lines follow a certain magnitude rule, the actual corresponding connection relationship can be determined by sorting the voltages of the respective wiring detection terminals.

[0094] For example, when the reference wiring terminal is the negative wiring terminal and N is 4, that is, when 4 battery cells are connected in series, U B4 is the voltage of B+ relative to B-, U B4 =U BAT1 +U BAT2 +U BAT3 +U BAT4 ; U B1 is the voltage of B1 relative to B-, U B1 =U BAT1 ; U B2 is the voltage of B2 relative to B-, U B2 =U BAT1 +U BAT2 ; U B3 is the voltage of B3 relative to B-, U B3 =U BAT1 +U BAT2 +U BAT3 . It can be seen that U B1 <U B2 <U B3 . After acquiring the voltage of each P point, for example, the voltage U1 at point P1 is 24V, the voltage U2 at point P2 is 36V, and the voltage U3 at point P3 is 12V, sorting U1, U2, and U3 from small to large gives U3<U1<U2. Since U B1 <U B2 <U B3, so it can be known that U3=U B1 , U1=U B2 , U2=U B3 , from this, the actual corresponding connection relationship can be obtained as: B1 is connected to P3, B2 is connected to P1, and B3 is connected to P2.

[0095] Exemplarily, when the reference terminal is the positive terminal, BAT N is the battery unit corresponding to the positive terminal of the battery pack, and BAT1 is the battery unit corresponding to the negative terminal of the battery pack. The voltages from B1 to B N-1 are all negative values, U B1 is the voltage of B1 relative to B+, U B2 is the voltage of B2 relative to B+, since the voltage of each B point is a negative value, the voltages from B1 to B N-1 increase sequentially. When N is equal to 4, the voltages from B1 to B3 increase sequentially. After obtaining the voltage of each P point, for example, the voltage U1 at point P1 is -24V, the voltage U2 at point P2 is -36V, and the voltage U3 at point P3 is -12V, sorting U1, U2, and U3 in ascending order gives U2<U1<U3. Since U B1 <U B2 <U B3 , so it can be known that U2=U B1 , U1=U B2 , U3=U B3 , from this, the actual corresponding connection relationship can be obtained as: B1 is connected to P2, B2 is connected to P1, and B3 is connected to P3.

[0096] In addition, when N is equal to other values, the process of determining the actual corresponding connection relationship is similar to the above process, and will not be repeated here.

[0097] By sorting the obtained voltages of each wiring detection terminal, the magnitude relationship of the voltages corresponding to each first sampling line is obtained according to the reference wiring terminal, so as to determine the actual corresponding connection relationship between each first sampling line and each wiring detection terminal.

[0098] In one embodiment, the switch module includes: N-1 first switches;

[0099] One end of each of the first switches is connected to one of the wiring detection terminals, and the other end of each of the first switches is connected to one of the sampling access terminals.

[0100] The switch module is used to control the connection between each wiring detection terminal and the corresponding sampling access terminal. Since there are N-1 wiring detection terminals, the switch module can contain N-1 first switches. One end of each first switch can be connected to a wiring detection terminal, and the other end of the first switch can be connected to a sampling access terminal.

[0101] By setting N-1 first switches, it is convenient to individually control the on / off state of each wiring detection terminal and corresponding sampling access terminal, which can improve the accuracy of the switch module control.

[0102] The present invention also provides a sampling circuit, including the identification circuit described in any of the above embodiments, and a voltage sampling module; a pair of voltage divider modules connected in series between the negative terminal and the positive terminal; the control module is further configured to acquire the voltage between the positive and negative terminals of the battery pack when the connection between the positive terminal and the negative terminal is made;

[0103] The voltage sampling module is connected to the control module. The voltage sampling module is used to receive the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals sent by the control module, and to obtain the voltage of each battery cell based on the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals.

[0104] For battery packs with multiple battery cells connected in series, the voltage of each battery cell may differ. When the voltage of one battery cell is higher, it is necessary to discharge that battery cell so that its voltage is comparable to that of the other battery cells, i.e., voltage balancing is required.

[0105] When performing voltage equalization on battery cells in a battery pack, it is necessary to first identify the battery cells to be discharged. This identification requires determining the voltage of each individual battery cell, thus necessitating the acquisition of the voltage of each cell within the battery pack.

[0106] Based on the above problems, a sampling circuit can be designed on the basis of the identification circuit in the above embodiment. The voltage of any battery cell in the battery pack can be obtained through this sampling circuit.

[0107] Figure 2 This is a schematic diagram of a sampling circuit according to an embodiment of the present invention, as shown below. Figure 2As shown, the sampling circuit includes an identification circuit and a voltage sampling module, which is connected to the control module in the identification circuit. Since the voltage of each battery cell in the battery pack needs to be obtained, the voltage between the positive and negative terminals needs to be acquired. To achieve this, a pair of voltage divider modules connected in series can be installed between the positive and negative terminals. The control module can acquire the voltage at this series connection point when the positive and negative terminals are connected, and thus determine the voltage between the positive and negative terminals of the battery pack based on the voltage at this series connection point and the sampling resistance ratio of the pair of voltage divider modules.

[0108] After acquiring the voltage between the positive and negative terminals and the voltage at each connection detection terminal, the control module can send these voltages to the voltage sampling module, which can then determine the voltage of each battery cell based on these voltages.

[0109] like Figure 2 As shown, when N=4, then U B4 U is the voltage between B+ and B-. B4 =U BAT1 +U BAT2 +U BAT3 +U BAT4 U B1 U is the voltage of B1 relative to B-. B1 =U BAT1 U B2 U is the voltage of B2 relative to B-. B2 =U BAT1 +U BAT2 U B3 U is the voltage of B3 relative to B-. B3 =U BAT1 +U BAT2 +U BAT3 Based on the above formula, the expression for calculating the voltage of each battery cell can be determined. Once the actual corresponding connection relationships are determined, U can then be determined. B1 U B2 U B3 The value is used to determine the voltage of each battery cell.

[0110] Figure 3 This is a schematic diagram of another sampling circuit provided in an embodiment of the present invention; as shown below. Figure 3As shown, the control module includes a voltage acquisition unit and an identification unit. The voltage acquisition unit is connected between the identification unit and the series connection point in each pair of voltage divider modules, and is used to detect the voltage at each series connection point and output the detected voltage at each series connection point to the identification unit. The identification unit is used to determine the voltage of each wiring detection terminal based on the voltage at each series connection point, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the voltage at each wiring detection terminal. The voltage sampling module can be connected to the identification unit to acquire the voltage of each wiring detection terminal sent by the identification unit, and to determine the voltage of each battery cell based on the voltage of each wiring detection terminal.

[0111] The present invention provides a sampling circuit, including the identification circuit described in the above embodiments, and a voltage sampling module; a pair of voltage divider modules connected in series between the negative terminal and the positive terminal; the control module is further used to acquire the voltage between the positive and negative terminals of the battery pack when the connection between the positive terminal and the negative terminal is made; the voltage sampling module is connected to the control module, and the voltage sampling module is used to receive the voltage of each of the terminal detection terminals and the voltage between the positive and negative terminals sent by the control module, and to obtain the voltage of each battery cell based on the voltage of each terminal detection terminal and the voltage between the positive and negative terminals. By setting up the sampling circuit, the voltage of each battery cell can be determined based on the voltage sampling module in the sampling circuit, thereby facilitating the relevant operation of any battery cell based on the voltage of each battery cell.

[0112] In one embodiment, the switching module includes: a second switch;

[0113] The second switch is connected between the positive terminal and the negative terminal.

[0114] To obtain the voltage between the positive and negative terminals, the voltage needs to be acquired by the voltage acquisition unit in the control module while the positive and negative terminals are connected. To facilitate control over whether the positive and negative terminals are connected, a second switch can be installed between them. By controlling the closing of the second switch, the positive and negative terminals can be connected, thereby obtaining the voltage between the positive and negative terminals.

[0115] For example, the control module may output an on / off signal to the second switch to control the closing or opening of the second switch.

[0116] By setting a second switch, the positive and negative terminals can be connected by controlling the second switch, without manually connecting or disconnecting the positive terminal from the positive terminal of the battery pack.

[0117] In one embodiment, the voltage divider module connected in series between the positive terminal and the negative terminal belongs to the second group, and the sampling resistance ratio of the voltage divider module in the second group is within a second range; the second range indicates that the voltage at the series connection point of the voltage divider module in the second group meets the accuracy and range requirements of the voltage acquisition unit.

[0118] To acquire the voltage between the positive and negative terminals using a single voltage acquisition unit, the sampling resistance ratio of the voltage divider module located between the positive and negative terminals needs to be set. This sampling resistance ratio can be within a second range, ensuring that the accuracy and range requirements of the voltage acquisition unit are met when acquiring the voltage at the series connection point in the voltage divider module. The accuracy of the voltage acquisition unit refers to the voltage corresponding to a single scale division of the voltage acquisition unit.

[0119] For example, when acquiring the voltage at the series connection point, the range of the voltage acquisition unit must not be exceeded to avoid burning out the voltage acquisition unit; at the same time, the accuracy of the voltage acquisition unit must not be less than that of the voltage acquisition unit to avoid failing to acquire an accurate voltage.

[0120] By setting the sampling resistance ratio of the voltage divider module in the second group, the voltage between the positive and negative terminals can be accurately obtained.

[0121] In one embodiment, the second range is determined by a third resistance ratio and a fourth resistance ratio; the third resistance ratio is the difference between a third preset value and a value of 1; the third preset value is the ratio of the total voltage of the N battery cells in the battery pack to the range of the voltage acquisition unit.

[0122] The fourth resistance ratio is the difference between the fourth preset value and the value 1; the fourth preset value is the ratio of the total voltage of the N battery cells in the battery pack to the accuracy of the voltage acquisition unit.

[0123] The second range can be determined by the third resistance ratio and the fourth resistance ratio, that is, the sampling resistance ratio of the voltage divider module in the second group is greater than or equal to the third resistance ratio and less than or equal to the fourth resistance ratio.

[0124] When measuring the total voltage of N battery cells, the sampling resistance ratio needs to meet the measurement range requirements of the voltage acquisition unit. According to the voltage conversion formula V2 = V*R 2N-1 / (R 2N-1 +R 2N Where V2 is the voltage at the series connection point and V is the voltage between the positive and negative terminals, then according to the voltage conversion formula above, R can be determined. 2N / R 2N-1=V / V²-1. Since the total voltage of N battery cells is measured, the third preset value is the ratio of the total voltage of the N battery cells in the battery pack to the range of the voltage acquisition unit. Because the voltage of each battery cell differs between fully charged and depleted states, the total voltage here is the sum of the voltages of all N battery cells when fully charged. For example, when the voltage of each of the N battery cells is in the range of 10V to 14V, where the voltage is 10V in a depleted state and 14V in a fully charged state, then the total voltage of the N battery cells is 14*N.

[0125] Furthermore, when measuring the total voltage of N battery cells, the sampling resistance ratio must also meet the accuracy requirements of the voltage acquisition unit. According to the aforementioned R... 2N / R 2N-1 The calculation formula is V / V²-1. Since the total voltage of N battery cells is measured, the fourth preset value is the ratio of the total voltage of the N battery cells in the battery pack to the accuracy of the voltage acquisition unit.

[0126] By limiting the third and fourth resistance ratios, the voltage acquisition unit can accurately measure the voltage at the series connection point of the voltage divider module in the second group, thereby accurately acquiring the voltage between the positive and negative poles and avoiding problems such as inaccurate voltage measurement or exceeding the measurement range when measuring the voltage at the series connection point.

[0127] In one embodiment, when the voltage sampling module obtains the voltage of each battery cell based on the voltage of each of the wiring detection terminals and the voltage between the positive and negative electrodes, it is specifically used for:

[0128] Subtract two adjacent voltages from the sorting results to obtain N-2 subtraction results; the sorting results are the results of taking the absolute value of the voltage of each of the wiring detection terminals and then sorting them by size.

[0129] The current voltage values ​​of N-1 battery cells in the battery pack, excluding the battery cell corresponding to the target terminal, are determined based on the minimum value of the sorting results and N-2 subtraction results; the target terminal is the end opposite to the reference terminal.

[0130] The difference between the absolute value of the voltage between the positive and negative terminals and the maximum value of the sorting result is determined as the current voltage value of the battery cell corresponding to the target terminal.

[0131] Since the voltage at each detection terminal is relative to the voltage at the reference terminal (which can be either positive or negative), the voltage at each detection terminal may be positive or negative. The closer the detection terminal is to the reference terminal, the smaller the absolute value of its voltage. After obtaining the voltages of N-1 detection terminals, the absolute values ​​of each voltage can be taken and then sorted in ascending order. For example, they can be arranged in ascending order or descending order.

[0132] After obtaining the sorting results, the minimum value of the sorting results is determined as the current voltage of the battery cell where the reference terminal is located. The N-2 subtractions between adjacent voltages in the sorting results represent the current voltage values ​​of the remaining N-2 battery cells, excluding the cell corresponding to the target terminal. Furthermore, when determining the current voltage value of the battery cell corresponding to the target terminal, the difference between the absolute value of the voltage between the positive and negative terminals and the maximum value of the sorting results can be calculated; this difference is the current voltage value of the battery cell corresponding to the target terminal.

[0133] like Figure 2 As shown, when N=4, then U B4 U is the voltage between B+ and B-. B4 =U BAT1 +U BAT2 +U BAT3 +U BAT4 ;U B1 U is the voltage of B1 relative to B-. B1 =U BAT1 ;U B2 U is the voltage of B2 relative to B-. B2 =U BAT1 +U BAT2 ;U B3 U is the voltage of B3 relative to B-. B3 =U BAT1 +U BAT2 +U BAT3 Therefore, U B1 B2 B3 B4 , and U BAT1 This represents the minimum absolute voltage value among the voltage values ​​corresponding to each connection detection terminal (point P). U BAT2 =U B2 -U B1 U BAT3 =U B3 -U B2 U BAT4 =U B4 -U​​​B3 . After acquiring the voltage of each P point, for example, the voltage U1 at point P1 is 24V, the voltage U2 at point P2 is 36V, the voltage U3 at point P3 is 12V, and the voltage between the positive and negative electrodes is U B4 which is equal to 48V, then U1, U2, and U3 are sorted in ascending order, and U3<U1<U2 can be obtained. Since U B1 <U B2 <U B3 , it can be known that U3=U B1 , U1=U B2 , U2=U B3 , from which the actual corresponding connection relationship can be obtained as: B1 is connected to P3, B2 is connected to P1, and B3 is connected to P2. Further, U BAT1 =12V, U BAT2 =U1-U3=12V, U BAT3 =U B3 -U B2 =U2-U1=12V, U BAT4 =U B4 -U B3 =12V.

[0134] Through the above method, the current voltage value of each battery cell can be obtained simply and accurately.

[0135] In an embodiment, the voltage sampling module is further configured to: determine a to-be-discharged battery cell according to the current voltage value of each battery cell; wherein the to-be-discharged battery cell is the battery cell with the highest voltage among the N battery cells.

[0136] When determining the to-be-discharged battery cell, the current voltage values of the respective battery cells may be compared to determine the to-be-discharged battery cell. The to-be-discharged battery cell is the battery cell with the highest voltage among the N battery cells. Alternatively, the voltages of the N battery cells are sorted, the battery cell with the highest voltage is taken as a first battery cell, and the battery cell with the second highest voltage is taken as a second battery cell. When the difference between the voltage of the first battery cell and the voltage of the second battery cell is greater than a preset value, the first battery cell is determined as the to-be-discharged battery cell.

[0137] By accurately determining the to-be-discharged battery cell, accurate discharging of the battery cells in the battery pack can be realized.

[0138] Since a battery pack has a plurality of battery cells, when each battery cell supplies power to the outside, there may be a certain battery cell with a relatively high voltage or a relatively large remaining capacity, and the voltages or remaining capacities of different battery cells differ greatly, so it is necessary to discharge part of the battery cells to make the voltage or capacity of the battery cell equivalent to the voltage or capacity of other battery cells, that is, voltage equalization is required to improve the service life of the battery pack.

[0139] Figure 4 This is a schematic diagram of an overall structure for load balancing of battery cells according to an embodiment of the present invention, as shown below. Figure 4 As shown, the positive terminal, each connection detection terminal, and the negative terminal can be connected to the input terminal of the equalization circuit. At the same time, the output terminals of the identification unit and the voltage sampling module are also connected to the input terminal of the equalization circuit. The equalization circuit can receive the battery cell to be discharged from the voltage sampling module, and receive the actual corresponding connection sequence of each connection detection terminal and each of the first sampling lines from the identification unit, and discharge the battery cell to be discharged according to the received information.

[0140] Figure 5 This is a schematic diagram of an equalization circuit according to an embodiment of the present invention. To achieve approximately consistent equalization current when discharging different battery cells, the equalization circuit can be configured as follows: Figure 5 As shown: The equalization circuit includes: N-1 connection detection terminals, N-1 equalization access terminals, positive connection terminal, negative connection terminal, positive access terminal, negative access terminal and multiple discharge modules.

[0141] Each of the aforementioned wiring detection terminals is used to connect to one of the first sampling lines, the positive terminal is used to connect to the positive terminal of the battery pack, and the negative terminal is used to connect to the negative terminal of the battery pack; a discharge module is connected in series between the positive terminal and each of the aforementioned equalization terminals, between the negative terminal and each of the aforementioned equalization terminals, and between any two of the aforementioned equalization terminals.

[0142] A switch module is disposed between the N-1 wiring detection terminals, the positive terminal and the negative terminal and the N-1 equalization access terminals, the positive access terminal and the negative access terminal. The switch module is used to control the connection and disconnection between the positive terminal and the positive access terminal, between the negative terminal and the negative access terminal, and between any one of the wiring detection terminals and any one of the equalization access terminals.

[0143] Among them, the discharge modules adjacent to the positive terminal or the negative terminal belong to the first group, and the discharge modules not adjacent to either the positive terminal or the negative terminal belong to the second group. The difference in the equivalent resistance values ​​of each discharge module in the first group is less than a first preset difference threshold. The difference in the equivalent resistance values ​​of each discharge module in the second group is less than the first preset difference threshold, and the difference in the equivalent resistance values ​​of discharge modules in different groups is greater than a second preset difference threshold. The second preset difference threshold is greater than the first preset difference threshold.

[0144] To achieve the above objectives, the equivalent resistance values ​​of each discharge module can be set so that the load impedance is approximately equal when voltage balancing is applied to any battery cell. That is, the equivalent resistance values ​​of each discharge module in the first group are approximately equal, the equivalent resistance values ​​of each discharge module in the second group are approximately equal, and the equivalent resistance values ​​of each discharge module in the first group are not equal to those in the second group. This ensures that the load impedance is approximately equal when discharging any battery cell.

[0145] The following description uses four battery cells as an example to illustrate the implementation of this invention. Of course, the number of battery cells can also be three, five, six, seven, etc. Figure 5 As shown in the diagram, B1, B2, and B3 are the first sampling lines. When the number of battery cells is 4, there are 3 first sampling lines. P1, P2, and P3 are the wiring detection terminals. The first sampling lines and wiring detection terminals can be connected in random order. Points B, C, and D in the diagram are the equalization access terminals, point E is the positive terminal, and point A is the negative terminal. In order to achieve voltage equalization of each battery cell, a discharge module is set between any two points (except for the combination of points A and E), resulting in 9 discharge modules. R1, R4, R5, R6, R8, and R9 are the discharge modules in the first group, and R2, R3, and R7 are the discharge modules in the second group. Therefore, the resistance values ​​of R1, R4, R5, R6, R8, and R9 are approximately equal, the resistance values ​​of R2, R3, and R7 are approximately equal, and the resistance values ​​of the discharge modules in the first group are different from those in the second group.

[0146] When equalizing the voltage of a battery cell, since the first sampling lines and equalization access terminals are connected out of order, once the actual corresponding connection relationship between the first sampling lines and equalization access terminals is determined, the switch that needs to be turned on can be determined when a certain battery cell needs to be discharged. By turning on the switch, the voltage of the battery cell can be equalized.

[0147] For example, see again Figure 2 When the actual corresponding connection relationship is: B3 is connected to P3, B2 is connected to P2, and B1 is connected to P1, when it is necessary to control the discharge of battery BAT1, the switches that need to be turned on are K1 and K2; when it is necessary to control the discharge of battery BAT2, the switches that need to be turned on are K2 and K3; when it is necessary to control the discharge of battery BAT3, the switches that need to be turned on are K3 and K4; and when it is necessary to control the discharge of battery BAT4, the switches that need to be turned on are K4 and K5.

[0148] In one embodiment, the system further includes a circuit module connected to the control module and the voltage sampling module. The circuit module is configured to receive the actual corresponding connection relationship sent by the control module and the battery cell to be discharged sent by the voltage sampling module, so as to discharge the battery cell to be discharged according to the actual corresponding connection relationship to balance the voltage of each battery cell.

[0149] In addition, a circuit module can be set in the sampling circuit. The circuit module can receive the actual corresponding connection relationship sent by the control module, and can also receive the battery cells to be discharged sent by the voltage sampling module. The circuit module can perform preset control on each battery cell according to the received information, such as charging or discharging the battery cells.

[0150] In one embodiment, the sampling circuit further includes a power supply module connected to the control module and also connected to the voltage sampling module. The power supply module is used to supply power to the control module and the voltage sampling module.

[0151] In addition, a power supply module can be set in the above sampling circuit to supply power to the control module and the voltage sampling module.

[0152] In one embodiment, the voltage divider module includes a resistor; or, the voltage divider module includes at least two resistors; the at least two resistors are connected in series, parallel, or mixed connection.

[0153] Each voltage divider module can consist of one resistor or at least two resistors. If it consists of at least two resistors, they can be connected in series, parallel, or a combination of both.

[0154] For example, such as Figure 2 As shown, the discharge module R1 can be a single resistor with a resistance of 30Ω, or it can be composed of two or more resistors. The equivalent resistance of the two or more resistors connected in series, parallel or mixed is equal to 30Ω.

[0155] The present invention also provides a battery management system, including a wiring sequence identification circuit as described in the foregoing embodiments, and / or a sampling circuit as described in the foregoing embodiments.

[0156] The present invention provides a battery device, including a battery management system as described above and a plurality of battery cells, wherein the battery management system and the plurality of battery cells are electrically connected.

[0157] In one embodiment, the battery cell is a lead-acid battery; and / or, the number of battery cells is 3 to 7.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A wiring sequence identification circuit, characterized in that, The battery pack includes a first sampling line located between two adjacent battery cells, and the number of the first sampling lines is N-1; N is the number of battery cells, and N is an integer greater than or equal to 3; the wiring sequence identification circuit includes: The system comprises N-1 connection detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal, and multiple voltage divider modules; each of the connection detection terminals is used to connect to any one of the first sampling lines; the positive terminal is used to connect to the positive terminal of the battery pack, and the negative terminal is used to connect to the negative terminal of the battery pack; a pair of voltage divider modules connected in series are respectively connected between the reference terminal and any of the sampling access terminals; the reference terminal is either the negative terminal or the positive terminal; A switch module is disposed between the N-1 wiring detection terminals and the N-1 sampling access terminals. The switch module is used to control the connection and disconnection between each wiring detection terminal and the corresponding sampling access terminal. The control module, connected to the switch module, is used to output on / off signals to the switch module. The input terminal of the control module is connected to the series connection point in each pair of voltage divider modules. It is used to obtain the voltage of each of the wiring detection terminals when each wiring detection terminal is connected to the corresponding sampling access terminal, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the obtained voltage of each wiring detection terminal.

2. The wiring sequence identification circuit according to claim 1, characterized in that, The control module includes a voltage acquisition unit and an identification unit. The voltage acquisition unit is connected between the identification unit and the series connection point in each pair of voltage divider modules. It is used to detect the voltage at each series connection point and output the detected voltage at each series connection point to the identification unit. The identification unit is used to determine the voltage of each wiring detection terminal based on the voltage at each series connection point, and to determine the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the voltage at each wiring detection terminal. Among them, a pair of voltage divider modules adjacent to any sampling access terminal belongs to the first group; the sampling resistance ratio of any pair of voltage divider modules in the first group is within a first range; the first range indicates that when any of the first sampling lines is connected to the corresponding wiring detection terminal, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy and range requirements of the voltage acquisition unit.

3. The wiring sequence identification circuit according to claim 2, characterized in that, The identification unit stores the sampling resistance ratio of each pair of voltage divider modules; when determining the voltage of each wiring detection terminal based on the voltage at each of the series connection points, the identification unit is specifically used for: The voltage at the connection detection terminal corresponding to each series connection point is determined based on the voltage at each of the series connection points and the sampling resistance ratio of the corresponding pair of voltage divider modules.

4. The wiring sequence identification circuit according to claim 3, characterized in that, The first range is determined by a first resistance ratio and a second resistance ratio; the first resistance ratio is the difference between a first preset value and a value of 1; the first preset value is the ratio of the total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to the range of the voltage acquisition unit; The target terminal is the end opposite to the reference terminal; The second resistance ratio is the difference between the second preset value and the value 1; the second preset value is the ratio of the minimum value that the battery cell corresponding to the reference terminal can take to the accuracy of the voltage acquisition unit.

5. The wiring sequence identification circuit according to claim 4, characterized in that, The sampling resistance ratio of each pair of voltage divider modules in the first group is equal to the first resistance ratio.

6. The wiring sequence identification circuit according to claim 2, characterized in that, When determining the actual corresponding connection relationship between each wiring detection terminal and each of the first sampling lines based on the voltage of each wiring detection terminal, the identification unit is specifically used for: The voltages of each of the wiring detection terminals are sorted by magnitude to obtain a sorting result, and the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines is determined based on the sorting result.

7. The wiring sequence identification circuit according to any one of claims 1-6, characterized in that, The switching module includes: N-1 first switches; One end of each of the first switches is connected to one of the wiring detection terminals, and the other end of each of the first switches is connected to one of the sampling access terminals.

8. A sampling circuit, characterized in that, The device includes the identification circuit described in any one of claims 1-7, and a voltage sampling module; a pair of voltage divider modules connected in series between the negative terminal and the positive terminal; the control module is also used to acquire the voltage between the positive and negative terminals of the battery pack when the connection between the positive terminal and the negative terminal is made; The voltage sampling module is connected to the control module. The voltage sampling module is used to receive the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals sent by the control module, and to obtain the current voltage value of each battery cell based on the voltage of each of the wiring detection terminals and the voltage between the positive and negative terminals.

9. The sampling circuit according to claim 8, characterized in that, The switch module includes: a second switch; The second switch is connected between the positive terminal and the negative terminal.

10. The sampling circuit according to claim 8, characterized in that, The voltage divider module connected in series between the positive terminal and the negative terminal belongs to the second group, and the sampling resistance ratio of the voltage divider module in the second group is within the second range; the second range indicates that the voltage at the series connection point of the voltage divider module in the second group meets the accuracy and range requirements of the voltage acquisition unit.

11. The sampling circuit according to claim 10, characterized in that, The second range is determined by a third resistance ratio and a fourth resistance ratio; the third resistance ratio is the difference between a third preset value and a value of 1; the third preset value is the ratio of the total voltage of the N battery cells in the battery pack to the range of the voltage acquisition unit. The fourth resistance ratio is the difference between the fourth preset value and the value 1; the fourth preset value is the ratio of the total voltage of the N battery cells in the battery pack to the accuracy of the voltage acquisition unit.

12. The sampling circuit according to claim 8, characterized in that, When the voltage sampling module obtains the current voltage value of each battery cell based on the voltage at each of the wiring detection terminals and the voltage between the positive and negative electrodes, it is specifically used for: Subtract two adjacent voltages from the sorting results to obtain N-2 subtraction results; the sorting results are the results of taking the absolute value of the voltage of each of the wiring detection terminals and then sorting them by size. The current voltage values ​​of N-1 battery cells in the battery pack, excluding the battery cell corresponding to the target terminal, are determined based on the minimum value of the sorting results and N-2 subtraction results; the target terminal is the end opposite to the reference terminal. The difference between the absolute value of the voltage between the positive and negative terminals and the maximum value of the sorting result is determined as the current voltage value of the battery cell corresponding to the target terminal.

13. The sampling circuit according to claim 12, characterized in that, The voltage sampling module is also used for: The battery cell to be discharged is determined based on the current voltage value of each battery cell; The battery cell to be discharged is the battery cell with the highest voltage among the N battery cells.

14. The sampling circuit according to claim 13, characterized in that, Also includes: A circuit module connected to the control module and the voltage sampling module is used to receive the actual corresponding connection relationship sent by the control module and the battery cell to be discharged sent by the voltage sampling module, so as to discharge the battery cell to be discharged according to the actual corresponding connection relationship to equalize the voltage of each battery cell.

15. The sampling circuit according to any one of claims 8-14, characterized in that, The sampling circuit also includes a power supply module, which is connected to the control module and the voltage sampling module. The power supply module is used to supply power to the control module and the voltage sampling module.

16. The sampling circuit according to any one of claims 8-14, characterized in that, The voltage divider module includes one resistor; or, the voltage divider module includes at least two resistors; the at least two resistors are connected in series, parallel or mixed connection.

17. A battery management system, characterized in that, Includes the wiring sequence identification circuit as described in any one of claims 1-7, and / or the sampling circuit as described in any one of claims 8-16.

18. A battery device, characterized in that, It includes the battery management system as described in claim 17 and a plurality of battery cells, wherein the battery management system and the plurality of battery cells are electrically connected.

19. The battery device according to claim 18, characterized in that, The battery cell is a lead-acid battery; and / or, the number of battery cells is 3 to 7.

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