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

Abstract

The invention 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; the anode terminal is connected with the anode of the battery pack, and the cathode terminal is connected with the cathode of the battery pack; a pair of voltage dividing modules which are connected in series are respectively connected between the reference wiring end and any sampling access end; the switch module is used for controlling connection and disconnection between each wiring detection end and the corresponding sampling access end; the input end of the control module is connected with the series connection point in each pair of voltage division modules and used for obtaining corresponding voltage so as to determine the actual corresponding connection relation, and after the first sampling line and the wiring detection end are connected in an out-of-order mode, the actual corresponding connection relation is judged according to the voltage of the wiring detection end. Therefore, battery parameters can be correctly sampled under the condition of out-of-order wiring, repeated wiring is avoided, and the battery installation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a wiring sequence recognition circuit, a sampling circuit, a battery management system and a battery device. Background Art

[0002] Electric two-wheeled vehicles are usually powered by a battery pack, such as a lead-acid battery pack or a lithium-ion battery pack containing a plurality of battery cells.

[0003] When leaving the factory, each battery cell in the lithium-ion battery pack has been connected and fixed according to the designed connection structure. When installing it on an electric two-wheeled vehicle, there is no need to connect and install each battery cell. However, lead-acid battery packs are different from lithium-ion battery packs. When installing and using lead-acid battery packs, operators need to connect and install each battery cell with the lead-acid BMS (Battery Management System). During the installation process, the sampling lines of different battery cells need to be distinguished and connected to the connection points of the power consumption module in the specified order. If the connection is wrong, the lead-acid battery management system will not work properly or even be damaged, and usually requires rewiring.

[0004] The above-mentioned process of installing the lead-acid battery pack is usually difficult to complete efficiently and accurately. This connection method will increase the workload of the installer and result in low installation efficiency. Summary of the invention

[0005] The present invention provides a wiring sequence identification circuit, a sampling circuit, a battery management system and a battery device, which enable the battery cells and the BMS to obtain the actual corresponding connection relationship when they are connected out of order, so that the parameters of the battery pack can be correctly sampled without rewiring, which helps to improve the battery installation efficiency.

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

[0007] N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal and a plurality of voltage divider modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive terminal is used to be connected to the positive electrode of the battery pack, and the negative terminal is used to be connected to the negative electrode 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 the negative terminal or the positive terminal;

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

[0009] A control module is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to respectively obtain the voltage of each wiring detection end when each wiring detection end is respectively connected to the corresponding sampling access end, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the obtained voltage of each wiring detection end.

[0010] In one embodiment, the control module includes a voltage acquisition unit and an identification unit, wherein the voltage acquisition unit is connected between the identification unit and the series connection points in each pair of voltage divider modules, and is used to detect the voltages at each of the series connection points, and output the detected voltages at each of the series connection points to the identification unit; the identification unit is used to determine the voltages of each of the wiring detection terminals according to the voltages at each of the series connection points, and determine the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the voltages 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 in the first range; the first range means that when the corresponding wiring detection terminal is connected to any of the first sampling lines, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy requirements and range requirements of the voltage acquisition unit.

[0012] In one embodiment, the identification unit stores the sampled resistance ratio of each pair of voltage divider modules; when the identification unit determines the voltage of each wiring detection terminal according to the voltage at each of the series connection points, it is specifically used to:

[0013] The voltage of the wiring detection terminal corresponding to the series connection point is determined according to the voltage at each of the series connection points and the sampling resistance ratio of a corresponding pair of voltage dividing 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 a difference between a first preset value and a value of 1; the first preset value is a ratio of a total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to a range of the voltage acquisition unit; the target terminal is an 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 of the battery cell that can be taken by the reference terminal 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 according to the voltage of each of the wiring detection terminals, it is specifically used to:

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

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

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

[0021] In a second aspect, the present invention provides a sampling circuit, comprising the identification circuit described in any one of the first aspects, and a voltage sampling module; a pair of voltage dividing modules connected in series are connected between the negative terminal and the positive terminal; and the control module is further used to obtain the voltage between the positive and negative electrodes of the battery pack when the positive terminal and the negative terminal are connected;

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

[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 in a second range; the second range indicates that the voltage at the series connection point in the voltage divider module in the second group meets the accuracy requirements 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 a difference between a third preset value and a value of 1; the third preset value is a ratio of a total voltage of N battery cells in a battery pack to a 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 according to the voltage of each of the wiring detection terminals and the voltage between the positive and negative electrodes, it is specifically used to:

[0029] Subtracting two adjacent voltages in the sorting result to obtain N-2 subtraction results; the sorting result is the result of taking the absolute value of the voltage of each wiring detection terminal and then sorting the voltage by size;

[0030] Determine the current voltage values ​​of N-1 battery cells in the battery pack except the battery cell corresponding to the target terminal according to the minimum value of the sorting result 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 electrodes 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 used for:

[0033] Determine the battery cell to be discharged according to the current voltage value of each battery cell;

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

[0035] In one embodiment, it also includes: a circuit module connected to the control module and the voltage sampling module, the circuit 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 balance the voltage of each battery cell.

[0036] In one embodiment, the sampling circuit further includes a power supply module, which is connected to the control module and is also connected to the voltage sampling module, and 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; and the at least two resistors are connected in series, in parallel, or in a mixed manner.

[0038] In a third aspect, the present invention provides a battery management system, comprising a wiring sequence identification circuit as described in any one of the first aspect, and / or a sampling circuit as described in any one of the second aspect.

[0039] In a fourth aspect, the present invention provides a battery device, comprising the 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 unit is a lead-acid battery; and / or the number of the battery units is 3 to 7.

[0041] The present invention provides a wiring sequence identification circuit, a sampling circuit, a battery management system and a battery device, wherein a battery pack comprises a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1; N is the number of the battery cells; the wiring sequence identification circuit comprises: N-1 wiring detection terminals, N-1 sampling access terminals, a positive wiring terminal, a negative wiring terminal and a plurality of voltage dividing modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive wiring terminal is used to be connected to the positive electrode of the battery pack, and the negative wiring terminal is used to be connected to the negative electrode of the battery pack; a pair of voltage dividing modules connected in series are respectively connected between the reference wiring terminal and any of the sampling access terminals; the reference wiring terminal is the negative wiring terminal or the positive wiring terminal; a switch module is arranged 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 terminal to be connected to the corresponding sampling access terminal The control module is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to respectively obtain the voltage of each wiring detection terminal when each wiring detection terminal is respectively connected to the corresponding sampling access terminal, and determine the actual corresponding connection relationship between each wiring detection terminal and each first sampling line according to the voltage of each wiring detection terminal obtained. When the first sampling line is connected to the wiring detection terminal, there is a certain magnitude relationship between the voltages of each wiring detection terminal relative to the same reference point. Therefore, by collecting the voltages of each wiring detection terminal relative to the reference wiring terminal, the actual corresponding connection relationship is judged according to the magnitude relationship of the voltages of each wiring detection terminal obtained, so that the actual corresponding connection relationship can be obtained when the wiring is disordered, 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a 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 A schematic diagram of the structure of a wiring sequence recognition circuit provided by one embodiment of the present invention;

[0044] Figure 2 A schematic diagram of the structure of a sampling circuit provided by an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the structure of another sampling circuit provided by an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of an overall structure for load balancing of battery units provided by an embodiment of the present invention;

[0047] Figure 5 A schematic diagram of the structure of an equalization circuit provided by an embodiment of the present invention.

[0048] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0049] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent 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 is a plurality of 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-wheeled vehicle, the battery pack can provide power for the electric two-wheeled vehicle. Taking lead-acid batteries as an example, when the lead-acid battery pack is installed and used, the operator needs to connect and install each battery cell with the lead-acid battery management system. During the installation process, since the first sampling lines between different battery cells are difficult to quickly and accurately distinguish, the connection and installation efficiency is low or the connection error occurs. Therefore, the present application sets a switch module and a voltage divider module, and designs the connection relationship, so that when the connection is disordered, the voltage data of each wiring detection terminal can be collected and the actual corresponding connection relationship between each first sampling line and each wiring detection terminal can be judged based on the voltage data. After knowing the actual wiring sequence, the battery parameter value can be correctly collected even without rewiring.

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

[0052] N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal and a plurality of voltage divider modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive terminal is used to be connected to the positive electrode of the battery pack, and the negative terminal is used to be connected to the negative electrode 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 the negative terminal or the positive terminal;

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

[0054] A control module is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to respectively obtain the voltage of each wiring detection end when each wiring detection end is respectively connected to the corresponding sampling access end, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the obtained voltage of each wiring detection end.

[0055] Figure 1 A schematic diagram of a wiring sequence recognition circuit provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, BAT1 to BAT N N battery cells are connected in series, B+ is a sampling line connected to the positive electrode of the battery pack, B- is a sampling line connected to the negative electrode 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 is the first sampling line, N is the number of battery cells, the first sampling line is located at the serial connection point of two adjacent battery cells, P1 to P N-1 There are N-1 wiring detection terminals. When installing the battery unit, each first sampling line needs to be manually connected to each wiring detection terminal. The wiring sequence recognition circuit can obtain the actual corresponding connection relationship between each first sampling line and each wiring detection terminal.

[0057] Optionally, a reference terminal may be provided, which may be a negative terminal or a positive terminal of the battery pack. After the reference terminal is determined, a pair of voltage divider modules may be provided between the reference terminal and the sampling access terminal, such as Figure 1 As shown, the sampling access terminals are point A, point B, point C and point D, and the reference terminal is the negative terminal.

[0058] Since each wiring detection terminal is connected to each first sampling line, the voltage of each wiring detection terminal may be the voltage of a battery cell, or the sum of the voltages of two, three to N-1 battery cells. For lead-acid batteries, the voltage of a battery cell may be 10V to 14V. When N is equal to 5, the voltage of the wiring detection terminal can reach about 50V. When measuring voltage, due to the small measurement range of the voltage measuring device, it is usually impossible to directly measure the voltage of the wiring detection terminal. Therefore, for the wiring sequence identification circuit, a pair of voltage divider modules are set between the sampling access terminal and the reference wiring terminal, and the control module is connected to the series connection point of each pair of voltage divider modules, so as to obtain the voltage of the series connection point, and then obtain the voltage of the wiring detection terminal.

[0059] Among them, when obtaining the voltage of the wiring detection terminal, in order to obtain the voltage at a series connection point at a certain moment, the on-off between the wiring detection terminal and the sampling access terminal can be controlled by a switch, such as Figure 1 As shown, for P1 to P N-1 Each of the N-1 wiring detection terminals can be provided with a switch, such as switch K1, switch K2, etc. When it is necessary to obtain the voltage of the wiring detection terminal P1, switch K1 can be closed. At this time, the voltage collected is the voltage at the series connection point between R1 and R2, and the voltage at point P1 can be obtained based on this voltage. Similarly, when it is necessary to obtain the voltage at point P2, switch K2 is closed. At this time, the voltage collected is the voltage at the series connection point between R3 and R4, and the voltage at point P2 can be obtained based on this voltage. By adopting the above method of closing each switch in sequence, the voltage of each point P can be obtained, that is, the voltage of each wiring detection terminal.

[0060] Optionally, when controlling the switch module to be closed or opened, the control module may output an on / off signal to the switch module, thereby controlling the closing or opening of the switch module. Exemplarily, when the number of switches in the switch module is N-1, one switch is controlled to be closed and the other switches are controlled to be opened in sequence. Exemplarily, K1 is closed and the other switches are opened, or K2 is closed and the other switches are opened, 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 obtained, the voltage of the wiring detection terminal is the same as the voltage of the connected first sampling line. When the reference wiring terminal is determined, the voltages of each first sampling line have a certain regularity, so the actual corresponding connection relationship between each wiring detection terminal and the first sampling line can be determined according to the voltage of each wiring detection terminal.

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

[0063] 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 the 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 a plurality of voltage divider modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive terminal is used to be connected to the positive electrode of the battery pack, and the negative terminal is used to be connected to the negative electrode 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 the negative terminal or the positive terminal; a switch module is arranged 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 terminal The control module is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to obtain the voltage of each wiring detection terminal when each wiring detection terminal is respectively connected to the corresponding sampling access terminal, and determine the actual corresponding connection relationship between each wiring detection terminal and each first sampling line according to the obtained voltage of each wiring detection terminal. When the first sampling line is connected to the wiring detection terminal, the voltages of each wiring detection terminal have a certain magnitude relationship. The actual corresponding connection relationship is judged according to the magnitude relationship of the voltages of each wiring detection terminal, so that the actual corresponding connection relationship can be obtained when the wiring is disordered, 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.

[0064] In one embodiment, the control module includes a voltage acquisition unit and an identification unit, wherein the voltage acquisition unit is connected between the identification unit and the series connection points in each pair of voltage divider modules, and is used to detect the voltages at each of the series connection points, and output the detected voltages at each of the series connection points to the identification unit; the identification unit is used to determine the voltages of each of the wiring detection terminals according to the voltages at each of the series connection points, and determine the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the voltages 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 in the first range; the first range means that when the corresponding wiring detection terminal is connected to any of the first sampling lines, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy requirements and range requirements of the voltage acquisition unit.

[0066] The function of the control module is to obtain the voltage of each wiring detection terminal and identify the wiring sequence. Therefore, the control module can be composed of a voltage acquisition unit and an identification unit. The voltage acquisition unit can be implemented by an analog-to-digital conversion chip.

[0067] In order to use the same voltage acquisition unit to acquire the voltage of each wiring detection terminal, it is necessary to set the sampling resistance ratio of each pair of voltage divider modules in the first group. Since each wiring detection terminal and each first sampling line are connected in a disorderly order, each wiring 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 requirement 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 requirement of the voltage acquisition unit.

[0068] By setting the sampling resistance ratio of each pair of voltage divider modules as described above, it is possible to use one voltage acquisition unit to accurately acquire the voltage of each wiring detection terminal.

[0069] In one embodiment, the identification unit stores the sampled resistance ratio of each pair of voltage divider modules; when the identification unit determines the voltage of each wiring detection terminal according to the voltage at each of the series connection points, it is specifically used to:

[0070] The voltage of the wiring detection terminal corresponding to the series connection point is determined according to the voltage at each of the series connection points and the sampling resistance ratio of a corresponding pair of voltage dividing modules.

[0071] A sampling resistance ratio needs to be set for each pair of voltage divider modules. Exemplarily, 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 of the second voltage divider module to the first voltage divider module. The first voltage divider module is the voltage divider module adjacent to the reference terminal.

[0072] According to the wiring sequence identification circuit, there is a 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 end, R1 is the first voltage divider module, and R2 is the second voltage divider module. According to the above voltage conversion formula, it can be determined that R2 / R1 = V / V1-1. Therefore, after setting the sampling resistance ratio, the identification unit can store each sampling resistance ratio, so that after obtaining the voltage at the corresponding series connection point, the voltage at the corresponding wiring detection end can be calculated based on the above formula. That is, the sampling resistance ratio is the resistance ratio of the second voltage divider module to the first voltage divider module.

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

[0074] When calculating the voltage at point P2, the control module can first control K2 to close, and then control K1, K3 to K N-1 The voltage V1 obtained by the voltage acquisition unit is the voltage at the series connection point between R3 and R4. The voltage at point P2 can be determined based on the voltage and the sampling resistance ratio, that is, V = V1 + V 1* R4 / R3.

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

[0076] In addition, the sampling resistance ratio may also be the resistance ratio of the first voltage dividing module to the second voltage dividing module.

[0077] The sampling resistance ratio is stored by the identification unit, so that after the voltage at each series connection point is obtained, the voltage at the wiring detection end can be determined based on the voltage at the series connection point. There is no need to set the sampling resistance ratio of each group of voltage divider modules to be the same, thereby 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 a difference between a first preset value and a value of 1; the first preset value is a ratio of a total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to a range of the voltage acquisition unit; the target terminal is an 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 of the battery cell that can be taken by the reference terminal to the accuracy of the voltage acquisition unit.

[0080] Since each first sampling line and each wiring detection terminal can be connected in random order, each wiring detection terminal may be connected to B N-1 The two first sampling lines B1 or B2 are connected, and for each sampled resistance ratio, there is a 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 other than the battery 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, when measuring except BAT N When the voltage of N-1 battery cells other than the target terminal is measured, that is, the voltage measured by the voltage acquisition unit at this time is the maximum measurement voltage, the sampling resistance ratio needs to meet the measurement range requirement of the voltage acquisition unit, that is, the first resistance ratio is the difference between the first preset value and the value 1, and the first preset value is the ratio of the total voltage of N-1 battery cells except 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] Exemplarily, when the voltages of N-1 battery cells are all in the range of 10V to 14V, where the voltage is 10V in a low-power state and 14V in a fully-charged state, then the total voltage of the 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, V / V1 is recorded as the voltage division ratio. When the voltage at the wiring detection end is 48V at most, when the voltage division ratio is 3:1, V1 is 16V; when the voltage division ratio is 20:1, V1 is 2.4V; therefore, when the voltage division ratio is smaller, V1 is larger, which may exceed the range of the voltage acquisition unit, thereby burning the voltage acquisition unit. Therefore, the sampling resistance ratio must be greater than the first resistance ratio.

[0084] When measuring the voltage of the battery cell corresponding to the reference terminal, if the reference terminal is the negative terminal, then BAT1 is the battery cell corresponding to the negative terminal, then when measuring the voltage of the battery cell BAT1, that is, the voltage measured by the voltage acquisition unit at this time is the minimum measurement voltage, then the sampling resistance ratio needs to meet the measurement accuracy requirements of the voltage acquisition unit, that is, the second resistance ratio is the difference between the second preset value and the value 1, and the second preset value is the ratio of the minimum value of the battery cell corresponding to the reference terminal to the accuracy of the voltage acquisition unit. The minimum value of the possible values ​​of the battery cell corresponding to the reference terminal refers to the minimum value of the possible values ​​of the battery cell. Exemplarily, the voltage of the battery cell is 10V to 14V, wherein the voltage is 10V in the low-power state and 14V in the full-power state. The minimum value of the possible values ​​of the battery cell is 10V.

[0085] The second resistance ratio is the maximum value of the sampling resistance ratio. When the minimum value of the possible value of the battery cell is 12V, when the voltage division ratio is 3:1, V1 is 4V; when the voltage division ratio is 20:1, V1 is 0.6V; therefore, when the voltage division ratio is larger, V1 is smaller, and the actual accuracy of the voltage acquisition unit after the voltage division circuit may be less than the accuracy requirement of the sampling circuit to obtain the battery cell voltage in the engineering design, so that it cannot be accurately measured. Therefore, the sampling resistance ratio should be smaller 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 of each series connection point, thereby accurately acquiring the voltage of each wiring detection terminal, avoiding the problem of inaccurate voltage measurement or exceeding the measurement range when measuring the voltage of 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 larger the sampling resistance ratio is, the lower the measurement accuracy is. For example, when the maximum voltage at the wiring detection end is 48V, when the voltage division ratio is 3:1, V1 is 16V; when the voltage division ratio is 20:1, V1 is 2.4V. It can be seen that when the voltage division ratio is larger, that is, the sampling resistance ratio is larger, the accuracy of measuring voltage is lower. The first resistance ratio is the minimum value of the sampling resistance ratio. In order to improve the measurement accuracy of the voltage acquisition unit, the sampling resistance ratio of each pair of voltage division 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 one embodiment, when determining the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the voltages of each of the wiring detection terminals, the recognition unit is specifically configured to:

[0091] Sort the voltages of each of the wiring detection terminals 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 the recognition unit obtains the voltages of each of the wiring detection terminals, it can sort the voltages of each of the wiring detection terminals, and the actual corresponding connection relationship can be obtained according to the sorting result.

[0093] Exemplarily, when the reference wiring terminal is the negative wiring terminal, the voltages of B1 to B N-1 are all positive values, and the voltages from B1 to B N-1 increase in sequence. Since each of the first sampling lines (each B point) is connected to each of the wiring detection terminals (each P point), the voltage of each of the wiring detection terminals is equal to the voltage of each of the first sampling lines. Since there is a certain pattern in the magnitudes of the voltages of each of the first sampling lines, by sorting the voltages of each of the wiring detection terminals, the actual corresponding connection relationship can be determined.

[0094] Exemplarily, when the reference wiring terminal is the negative wiring terminal and N is 4, that is, when there are 4 battery cells connected in series, then 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 obtaining the voltages of each P point, if the voltage U1 of the P1 point is 24V, the voltage U2 of the P2 point is 36V, and the voltage U3 of the P3 point is 12V, then sorting U1, U2, and U3 from smallest to largest 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 , thus 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 connection terminal is the positive connection terminal, BAT N is the battery unit corresponding to the positive connection terminal of the battery pack, and BAT1 is the battery unit corresponding to the negative connection terminal of the battery pack. The voltages of B1 to B N-1 are all negative values, and U B1 is the voltage of B1 relative to B+, and U B2 is the voltage of B2 relative to B+. Since the voltages of each B point are negative values, the voltages from B1 to B N-1 increase in sequence. When N is equal to 4, the voltages from B1 to B3 increase in sequence. After obtaining the voltages of each P point, such as the voltage U1 of P1 point is -24V, the voltage U2 of P2 point is -36V, and the voltage U3 of P3 point is -12V, then sorting U1, U2, U3 from small to large, we can get 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 , thus 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 elaborated here.

[0097] By sorting the voltages of the obtained connection detection terminals, the magnitude relationship of the voltages corresponding to each first sampling line is obtained according to the reference connection terminal, so as to determine the actual corresponding connection relationship between each first sampling line and each connection 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 connection 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 on-off between each wiring detection terminal and the corresponding sampling access terminal. Since the number of wiring detection terminals is N-1, the switch module may include N-1 first switches. One end of each first switch may be connected to a wiring detection terminal, and the other end of the first switch may be connected to a sampling access terminal.

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

[0102] The present invention also provides a sampling circuit, comprising the identification circuit described in any of the above embodiments, and a voltage sampling module; a pair of voltage dividing modules connected in series are connected between the negative terminal and the positive terminal; the control module is also used to obtain the voltage between the positive and negative electrodes of the battery pack when the positive terminal and the negative terminal are connected;

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

[0104] For a battery pack with multiple battery cells connected in series, the voltages of the individual battery cells may be different. When the voltage of one of the battery cells is higher, the battery cell needs to be discharged to make the voltage of the battery cell equal to that of the other battery cells, that is, voltage balancing is required.

[0105] When voltage balancing is performed on battery cells in a battery pack, it is necessary to first determine the battery cells to be discharged. When determining the battery cells to be discharged, it is necessary to determine based on the voltages of the individual battery cells, so it is necessary to obtain the voltages of the individual battery cells in 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, and the voltage of any battery cell in the battery pack can be obtained through the sampling circuit.

[0107] Figure 2 A schematic diagram of a sampling circuit according to an embodiment of the present invention is shown in FIG. Figure 2As shown, the sampling circuit includes an identification circuit and a voltage sampling module, and the voltage sampling module is connected to the control module in the identification circuit. Since the voltage of each battery cell in the battery pack is to be obtained, it is necessary to obtain the voltage between the positive and negative electrodes. In order to obtain the voltage between the positive and negative electrodes, a pair of voltage dividing modules connected in series can be set between the positive terminal and the negative terminal. The control module can obtain the voltage of the series connection point when the positive terminal and the negative terminal are connected, so as to determine the voltage between the positive and negative electrodes of the battery pack according to the voltage of the series connection point and the sampling resistance ratio of the pair of voltage dividing modules.

[0108] After obtaining the voltage between the positive and negative electrodes and the voltage of each wiring detection terminal, the control module can send the above voltage to the voltage sampling module, and the voltage sampling module can determine the voltage of each battery unit based on the above voltages.

[0109] like Figure 2 As shown, when N = 4, then 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 According to the above formula, the expression for calculating the voltage of each battery cell can be determined. After the actual corresponding connection relationship is determined, U B1 , U B2 , U B3 The value of the battery is used to determine the voltage of each battery cell.

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

[0111] A sampling circuit provided by the present invention comprises the identification circuit described in the above embodiment, and a voltage sampling module; a pair of voltage dividing modules connected in series are connected between the negative terminal and the positive terminal; the control module is also used to obtain the voltage between the positive and negative electrodes of the battery pack when the positive terminal and the negative terminal are connected; the voltage sampling module is connected to the control module, and the voltage sampling module is used to receive the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes sent by the control module, and obtain the voltage of each battery cell according to the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes. By setting the sampling circuit, the voltage of each battery cell can be determined based on the voltage sampling module in the sampling circuit, so as to facilitate related operations on any battery cell according to the voltage of each battery cell.

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

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

[0114] In order to obtain the voltage between the positive and negative electrodes, it is necessary to obtain the voltage through the voltage acquisition unit in the control module when the positive electrode terminal and the negative electrode terminal are connected. In order to facilitate the control of whether the positive electrode terminal and the negative electrode terminal are connected, a second switch can be set between the positive electrode terminal and the negative electrode terminal, and the positive electrode terminal and the negative electrode terminal are connected by controlling the closing of the second switch, so as to obtain the voltage between the positive and negative electrodes.

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

[0116] By providing the second switch, the second switch can be controlled to connect the positive terminal and the negative terminal without manually connecting or disconnecting the positive terminal to the positive electrode 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 in a second range; the second range indicates that the voltage at the series connection point in the voltage divider module in the second group meets the accuracy requirements and range requirements of the voltage acquisition unit.

[0118] In order to use a voltage acquisition unit to acquire the voltage between the positive and negative electrodes, it is necessary to set the sampling resistance ratio of the voltage divider module arranged between the positive terminal and the negative terminal. The sampling resistance ratio can be in the second range, so that when the voltage at the series connection point in the voltage divider module is collected, the accuracy requirement and range requirement of the voltage acquisition unit can be met. The accuracy of the voltage acquisition unit represents the voltage corresponding to the unit scale of the voltage acquisition unit.

[0119] For example, when acquiring the voltage at the series connection point, the range of the voltage acquisition unit cannot be exceeded to avoid burning the voltage acquisition unit; at the same time, when acquiring the voltage at the series connection point, the accuracy of the voltage acquisition unit cannot be less than that to avoid failure to acquire 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 electrodes 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 a difference between a third preset value and a value of 1; the third preset value is a ratio of a total voltage of N battery cells in a battery pack to a 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 may be determined by the third resistance ratio and the fourth resistance ratio, that is, the sampling resistance ratio of the voltage divider modules 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 electrodes. According to the above voltage conversion formula, R 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. Since the voltages of each battery cell are different in a fully charged state and a low-power state, the total voltage here is the sum of the voltages of the N battery cells in a fully charged state. Exemplarily, when the voltages of the N battery cells are in the range of 10V to 14V, wherein the voltage in the low-power state is 10V and the voltage in the fully charged state is 14V, then the total voltage of the N battery cells is 14*N.

[0125] In addition, when measuring the total voltage of N battery cells, the sampling resistance ratio also needs to meet the accuracy requirements of the voltage acquisition unit. 2N / R 2N-1 =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 resistance ratio and the fourth resistance ratio, 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 electrodes, avoiding the problem of 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 according to the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes, it is specifically used to:

[0128] Subtracting two adjacent voltages in the sorting result to obtain N-2 subtraction results; the sorting result is the result of taking the absolute value of the voltage of each wiring detection terminal and then sorting the voltage by size;

[0129] Determine the current voltage values ​​of N-1 battery cells in the battery pack except the battery cell corresponding to the target terminal according to the minimum value of the sorting result 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 electrodes 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 of each wiring detection terminal is relative to the voltage of the reference terminal, the reference terminal can be a positive terminal or a negative terminal. Therefore, the voltage of each wiring detection terminal may be positive or negative. Among them, the absolute value of the voltage corresponding to the wiring detection terminal closer to the reference terminal is smaller. After obtaining the voltages of N-1 wiring detection terminals, the absolute values ​​of the voltages of the N-1 wiring detection terminals obtained can be taken respectively, and the voltages after taking the absolute values ​​can be sorted in order of size. Exemplarily, they can be arranged in order from small to large, or in order from large to small.

[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, and the two adjacent voltages in the sorting results are subtracted. The N-2 subtraction results are the current voltage values ​​of the N-2 battery cells in the remaining battery cells except the battery cell corresponding to the target terminal. In addition, 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 electrodes and the maximum value of the sorting results can be calculated, and the 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 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 Therefore, U B1 B2 B3 B4 , and U BAT1 It is the minimum value among the absolute values ​​of the voltages corresponding to each wiring detection terminal (point P). BAT2 =U B2 -U B1 , U BAT3 =U B3 -U B2 , U BAT4 =U B4 -U​​​B3 After obtaining the voltages of each P point, for example, the voltage U1 at P1 is 24V, the voltage U2 at P2 is 36V, the voltage U3 at P3 is 12V, and the voltage between the positive and negative poles is U B4 equals 48V. Then, sort U1, U2, and U3 from smallest to largest, and we get U3 < U1 < U2. Since U B1 < U B2 < U B3 , so we know that U3 = U B1 , U1 = U B2 , U2 = U B3 . From this, we can obtain the actual corresponding connection relationship: B1 is connected to P3, B2 is connected to P1, and B3 is connected to P2. Furthermore, 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 values of each battery cell can be obtained simply and accurately.

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

[0136] When determining the battery cell to be discharged, the current voltage values of each battery cell can be compared to determine the battery cell to be discharged. The battery cell to be discharged is the battery cell with the highest voltage among the N battery cells. Alternatively, sort the voltages of the N battery cells. The battery cell with the highest voltage is the first battery cell, and the battery cell with the second highest voltage is the 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, then the first battery cell is determined as the battery cell to be discharged.

[0137] Accurately determining the battery cell to be discharged can achieve accurate discharge of the battery cells in the battery pack.

[0138] Since there are multiple battery cells in the battery pack, when each battery cell supplies power externally, there may be a situation where the voltage of a certain battery cell is relatively high or the remaining power is relatively large, and the voltages or remaining powers of different battery cells vary greatly. Then, it is necessary to discharge some battery cells so that the voltage or power of this battery cell is equivalent to the voltage or power of other battery cells, that is, voltage equalization is required to improve the service life of the battery pack.

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

[0140] Figure 5 FIG. 1 is a schematic diagram of a structure of a balancing circuit provided by an embodiment of the present invention. In order to achieve that the balancing current is approximately consistent when discharging different battery cells, the balancing circuit can be configured as follows: Figure 5 As shown: the balancing circuit includes: N-1 wiring detection terminals, N-1 balancing access terminals, a positive wiring terminal, a negative wiring terminal, a positive access terminal, a negative access terminal and multiple discharge modules.

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

[0142] A switch module is provided between the N-1 wiring detection terminals, the positive wiring terminal, the negative wiring terminal and the N-1 balancing access terminals, the positive access terminal and the negative access terminal, and the switch module is used to control the on-off between the positive wiring terminal and the positive access terminal, between the negative wiring terminal and the negative access terminal, and between any one of the wiring detection terminals and any one of the balancing access terminals;

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

[0144] In order to achieve the above purpose, the equivalent resistance value of each discharge module can be set, and when voltage balancing is performed on any battery unit, the load impedance can be made approximately equal. 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 the equivalent resistance values ​​of each discharge module in the second group, so that when discharging any battery unit, the load impedance is approximately equal.

[0145] The following will take four battery cells as an example to illustrate the implementation of the present invention. Of course, the number of battery cells can also be 3, 5, 6, 7, etc. Figure 5 As shown, B1, B2 and B3 in the figure are the first sampling lines. When the number of battery cells is 4, the number of first sampling lines is 3. P1, P2 and P3 are wiring detection terminals, and each first sampling line and each wiring detection terminal can be connected in a random order. In the figure, points B, C and D are balancing access terminals, point E is the positive access terminal, and point A is the negative access terminal. In order to achieve voltage balancing of each battery cell, a discharge module is set between any two points among points A, B, C, D and E (except the combination of points A and E), and there are 9 discharge modules. R1, R4, R5, R6, R8, and R9 are discharge modules in the first group, and R2, R3, and R7 are 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 value of the discharge module in the first group is different from the resistance value of the discharge module in the second group.

[0146] When voltage balancing is performed on the battery cells, since the first sampling lines and the balancing access terminals are connected in disorder, after the actual corresponding connection relationship between the first sampling lines and the balancing access terminals is determined, when a battery cell is to be discharged, the switch that needs to be turned on can be determined, and the voltage of the battery cells can be balanced by turning on the switch.

[0147] For example, see 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; 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, it also includes: a circuit module connected to the control module and the voltage sampling module, the circuit 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 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 cell.

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

[0151] In addition, a power supply module may be provided in the above sampling circuit, and the power supply module may 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; and the at least two resistors are connected in series, in parallel, or in a mixed manner.

[0153] Each voltage divider module may be composed of one resistor or at least two resistors. If it is composed of at least two resistors, they may be connected in series, in parallel or in a mixed manner.

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

[0155] The present invention further provides a battery management system, comprising the wiring sequence identification circuit as described in the above embodiment, and / or the sampling circuit as described in the above embodiment.

[0156] The present invention provides a battery device, comprising the 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 unit is a lead-acid battery; and / or the number of the battery units is 3 to 7.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A wiring sequence recognition circuit, characterized in that: The battery pack includes a first sampling line located between two adjacent battery cells, the number of the first sampling lines is N-1; N is the number of the battery cells, and N is an integer greater than or equal to 3; the wiring sequence identification circuit includes: N-1 wiring detection terminals, N-1 sampling access terminals, a positive terminal, a negative terminal and a plurality of voltage divider modules; each of the wiring detection terminals is used to be connected to any one of the first sampling lines; the positive terminal is used to be connected to the positive electrode of the battery pack, and the negative terminal is used to be connected to the negative electrode 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 the negative terminal or the positive terminal; A switch module is provided between the N-1 wiring detection terminals and the N-1 sampling access terminals, and the switch module is used to control the connection and disconnection between each wiring detection terminal and the corresponding sampling access terminal; A control module is connected to the switch module and is used to output an on-off signal to the switch module. The input end of the control module is connected to the series connection point in each pair of voltage divider modules, and is used to respectively obtain the voltage of each wiring detection end when each wiring detection end is respectively connected to the corresponding sampling access end, and determine the actual corresponding connection relationship between each wiring detection end and each first sampling line according to the obtained voltage of each wiring detection end.

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 points in each pair of voltage divider modules, and is used to detect the voltages at each of the series connection points, and output the detected voltages at each of the series connection points to the identification unit; the identification unit is used to determine the voltages of each of the wiring detection terminals according to the voltages at each of the series connection points, and determine the actual corresponding connection relationship between each of the wiring detection terminals and each of the first sampling lines according to the voltages at each of the wiring detection terminals; 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 in the first range; the first range means that when the corresponding wiring detection terminal is connected to any of the first sampling lines, the voltage at the series connection point in the corresponding pair of voltage divider modules meets the accuracy requirements 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 sampled resistance ratio of each pair of voltage divider modules; when the identification unit determines the voltage of each wiring detection terminal according to the voltage at each of the series connection points, it is specifically used to: The voltage of the wiring detection terminal corresponding to the series connection point is determined according to the voltage at each of the series connection points and the sampling resistance ratio of a corresponding pair of voltage dividing 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 a difference between a first preset value and a value of 1; the first preset value is a ratio of a total voltage of N-1 battery cells other than the battery cell corresponding to the target terminal to a range of the voltage acquisition unit; The target terminal is an 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 of the battery cell that can be taken by the reference terminal 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 the identification unit determines 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, it is specifically used to: The voltages of the wiring detection terminals are sorted to obtain a sorting result, and the actual corresponding connection relationship between the wiring detection terminals and the first sampling lines is determined according to the sorting result.

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

8. A sampling circuit, characterized in that: The invention comprises an identification circuit as claimed in any one of claims 1 to 7, and a voltage sampling module; a pair of voltage dividing modules connected in series are connected between the negative terminal and the positive terminal; and the control module is further used to obtain the voltage between the positive and negative electrodes of the battery pack when the positive terminal and the negative terminal are connected; The voltage sampling module is connected to the control module, and is used to receive the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes sent by the control module, and obtain the current voltage value of each battery cell based on the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes.

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 in the second range; the second range indicates that the voltage at the series connection point in the voltage divider module in the second group meets the accuracy requirements 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 a difference between a third preset value and a value 1; the third preset value is a ratio of a total voltage of N battery cells in a battery pack to a 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 according to the voltage of each wiring detection terminal and the voltage between the positive and negative electrodes, it is specifically used to: Subtracting two adjacent voltages in the sorting result to obtain N-2 subtraction results; the sorting result is the result of taking the absolute value of the voltage of each wiring detection terminal and then sorting the voltage by size; Determine the current voltage values ​​of N-1 battery cells in the battery pack except the battery cell corresponding to the target terminal according to the minimum value of the sorting result 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 electrodes 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: Determine the battery cell to be discharged according to the current voltage value of each battery cell; The battery cell to be discharged is the battery cell with the largest 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, the circuit module is used to receive the actual corresponding connection relationship sent by the control module, and the battery unit to be discharged sent by the voltage sampling module, so as to discharge the battery unit to be discharged according to the actual corresponding connection relationship to balance the voltages of each battery unit.

15. The sampling circuit according to any one of claims 8 to 14, characterized in that: The sampling circuit further comprises a power supply module, wherein the power supply module is connected to the control module and is also connected to the voltage sampling module, and 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 to 14, characterized in that: 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, in parallel or in a mixed manner.

17. A battery management system, characterized in that: It comprises a wiring sequence identification circuit as described in any one of claims 1 to 7, and / or a sampling circuit as described in any one of claims 8 to 16.

18. A battery device, characterized in that: The battery management system according to 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 cells are lead-acid batteries; and / or the number of the battery cells is 3 to 7.

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