Battery voltage flexible acquisition system and implementation method thereof

Abstract

The invention relates to a battery voltage flexible acquisition system and an implementation method thereof. The battery voltage flexible acquisition system comprises a single battery management system, a battery pack and a wire harness, wherein the battery pack consists of a plurality of battery modules; the wire harness is used for connecting the battery modules with the single battery management system; the single battery management system comprises a controller, an A / D module, a switch group and a wire harness interface which are connected in sequence, and a voltage acquisition circuit and an auxiliary circuit are integrated in the single battery management system. On the basis that various complex voltage acquisition wire harnesses are arranged in an energy storage battery box and connecting cables with different lengths are arranged on battery modules, the management of switching different types of battery modules by using the same single battery management system is provided, voltage acquisition nodes are changed, and the voltage acquisition precision is improved; meanwhile, whether the battery voltage is abnormal or not can be judged according to a corresponding algorithm through the read-back numerical value, and a voltage acquisition abnormal circuit can also be identified.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery management, and in particular relates to a battery voltage flexible acquisition system and an implementation method thereof. Background Art

[0002] Lithium-ion batteries have been widely used as energy storage power sources in the fields of communications, power systems, transportation, etc. As an energy supply component, the wiring harness connecting the battery to the battery management system module (single battery management system) plays a bridge role. The correct connection of the wiring harness is directly related to whether the battery voltage acquisition can achieve the required accuracy, affecting the safety and operational reliability of the entire system. In order to improve the correct and convenient connection between the battery pack and the single battery management system, it is very important to arrange the wiring harness structure reasonably and effectively and use a reasonable voltage calculation method.

[0003] At present, there are common customization defects in single-cell battery management systems. One module can only collect the voltage of a battery pack in a single-cell series-parallel mode, and has a fixed voltage collection method. The compatibility between the single-cell battery management system and the energy storage battery module with different numbers of battery strings is poor. In addition, under the conventional single-wire voltage collection method, at least one of the two voltage collection lines of the single cell uses the power line between the single cells to collect the voltage. When calculating the voltage, it is usually necessary to add a compensation value for the voltage drop caused by the current flowing through the power line. In particular, when the battery module is working at a high current, the voltage drop caused by the power line across the two battery modules cannot be accurately calculated, and the corresponding single cell voltage compensation value is difficult to accurately estimate, which reduces the voltage collection accuracy of this type of single cell. Summary of the invention

[0004] The purpose of the present invention is to provide a battery voltage flexible acquisition system and an implementation method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A battery voltage flexible acquisition system, comprising a single battery management system, a battery pack consisting of a plurality of battery modules, and a wiring harness for connecting the battery modules and the single battery management system; the single battery management system comprises a controller, an A / D module, a switch group and a wiring harness interface connected in sequence, and a voltage acquisition circuit is integrated in the single battery management system;

[0007] The controller is used for switching control of the voltage acquisition circuit and battery voltage calculation;

[0008] The A / D module is used for converting voltage analog quantity into digital quantity;

[0009] The switch group is used to turn on or off the corresponding voltage collection circuit according to the controller instruction;

[0010] The wiring harness interface is used to connect the single battery management system and the wiring harness;

[0011] The battery pack is a voltage detection object and generates a voltage analog signal.

[0012] As a further optimization solution of the present invention, an auxiliary circuit is integrated in the single battery management system, and the auxiliary circuit is used for comparing and amplifying voltage signals.

[0013] As a further optimization scheme of the present invention, the switch group, the wiring harness interface and the wiring harness are set based on the management number of the battery module. When the management number of the battery module is an even number, redundancy is added at the even-numbered battery numbers; when the management number of the battery module is an odd number, redundancy is added at the odd-numbered battery numbers.

[0014] A method for implementing a battery voltage flexible acquisition system comprises the following steps:

[0015] Configuring parameters of the single battery management system;

[0016] Determine whether the current collected voltage matches the configured parameters. If so, enter voltage collection mode 1; if not, enter voltage collection mode 2;

[0017] In voltage acquisition mode 1, the switch group is executed according to switch group gating mode 1, and in voltage acquisition mode 2, the switch group is executed according to switch group gating mode 2;

[0018] Read the battery voltage analog data, perform A / D conversion, and calculate the output battery voltage value;

[0019] The voltage of each single cell is collected at a preset interval. After the voltage collection is completed, the moving average value of the voltage of each single cell is calculated and compared with the current value to determine whether it exceeds the preset threshold. If so, the voltage collection is started again, and the switch group is executed according to the switch group selection mode 3. If not, the voltage value is output and the current round of collection is completed;

[0020] In switch group selection mode 3, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the threshold is the actual value of the abnormal single cell voltage value of the battery cell; at the same time, the abnormal voltage collection circuit is judged.

[0021] As a further optimization scheme of the present invention, the specific contents of the combination of the voltage acquisition mode 1 and the switch group gating mode 1 are as follows:

[0022] When the single battery management system is used for voltage collection of a single battery module, and the number of batteries in series in the battery module is not greater than the number of voltage collection channels of the single battery management system, the voltage collection mode is defined as voltage collection mode 1; the switch selection mode is that all redundant collection switches remain in a normally open state, and other switches are closed according to control instructions, which is defined as switch group selection mode 1;

[0023] The specific contents of the combination of the voltage acquisition mode 2 and the switch group gating mode 2 are as follows:

[0024] When the single battery management system is used for voltage collection of two or more battery modules, and two or more adjacent battery modules are connected in series to form a group, and the total number of single batteries connected in series in the group is not greater than the number of voltage collection channels of the single battery management system module, the voltage collection mode is defined as voltage collection mode 2; the switch group keeps the corresponding serial number switch at the equal division point of the number of battery modules managed by the single battery management system in a normally closed state, and other switches are closed according to the control command, which is defined as switch selection mode 2;

[0025] The specific contents of switch group gating mode 3 are as follows:

[0026] After the single-cell battery management system completes the single-cell battery voltage collection, it statistically calculates the moving average value of each single-cell battery voltage and compares it with the current value. If the voltage of the mth cell exceeds the threshold, the positive collection circuit switch of the mth cell and the positive collection circuit switch of the m-3th cell are closed at the same time to obtain a voltage value of 1; then the positive collection circuit switch of the m-1th cell and the positive collection circuit switch of the m+2th cell are closed at the same time to obtain a voltage value of 2; during this process, other switches are kept open.

[0027] As a further optimization scheme of the present invention, the number of battery modules managed by the single battery management system in the voltage acquisition mode 2 is determined according to parameter settings.

[0028] As a further optimization solution of the present invention, the switch group gating mode 3 is applicable in both the voltage acquisition mode 1 and the voltage acquisition mode 2.

[0029] As a further optimization solution of the present invention, the preset time is 0.1s.

[0030] As a further optimization scheme of the present invention, the voltage calculation method of the battery voltage flexible acquisition system is specifically as follows:

[0031] The controller compares the numerical accuracy of voltage acquisition of adjacent battery modules, then switches the acquisition mode for the battery modules with abnormal voltage acquisition accuracy, and then calculates the results to obtain the actual voltage.

[0032] As a further optimization scheme of the present invention, the voltage calculation method of the battery voltage flexible acquisition system is generally divided into two types: a normal voltage calculation method and an abnormal voltage calculation method:

[0033] Normal voltage acquisition calculation method: When the battery voltage acquisition is normal, the analog quantity collected by the analog quantity acquisition circuit sampling resistor and amplifier is converted into a digital quantity by the A / D conversion module for linear calculation to obtain the voltage value;

[0034] Abnormal voltage collection and calculation method: When the battery voltage collection value is abnormal, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the preset threshold is the actual value of the abnormal single battery voltage value.

[0035] The beneficial effects of the present invention are:

[0036] Based on the fact that there are multiple complex voltage collection harnesses and connecting cables of different lengths on the battery modules in the energy storage battery box, the present invention proposes a method of using the same single battery management system to switch the management of different types of battery modules, and changing the voltage collection nodes to improve the voltage collection accuracy; at the same time, it is also possible to determine whether there is a battery voltage abnormality based on the corresponding algorithm through the read-back value, and to identify the voltage collection abnormal circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0038] Figure 2 It is a schematic diagram of the switch group structure of the present invention;

[0039] Figure 3 is a software control flow chart of an embodiment of the present invention;

[0040] Figure 4 is a structural block diagram of a first single-cell battery management system according to an embodiment of the present invention;

[0041] Figure 5 It is a structural block diagram of a second single-cell battery management system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0043] A battery voltage flexible acquisition system, comprising a single battery management system, a battery pack consisting of a plurality of battery modules, and a wiring harness for connecting the battery modules and the single battery management system; the single battery management system comprises a controller, an A / D module, a switch group and a wiring harness interface connected in sequence, and a voltage acquisition circuit is integrated in the single battery management system;

[0044] The controller is used for switching control of the voltage acquisition circuit and battery voltage calculation;

[0045] The A / D module is used for converting voltage analog quantity into digital quantity;

[0046] The switch group is used to turn on or off the corresponding voltage collection circuit according to the controller instruction;

[0047] The wiring harness interface is used to connect the single battery management system and the wiring harness;

[0048] The battery pack is a voltage detection object and generates a voltage analog signal.

[0049] The single battery management system is integrated with an auxiliary circuit, which is used for comparing and amplifying voltage signals.

[0050] The switch group, the wiring harness interface and the wiring harness are set based on the management quantity of the battery module. When the management quantity of the battery module is an even number, redundancy is added at the even-numbered battery numbers; when the management quantity of the battery module is an odd number, redundancy is added at the odd-numbered battery numbers.

[0051] A method for implementing a battery voltage flexible acquisition system comprises the following steps:

[0052] Configuring parameters of the single battery management system;

[0053] Determine whether the current collected voltage matches the configured parameters. If so, enter voltage collection mode 1; if not, enter voltage collection mode 2;

[0054] In voltage acquisition mode 1, the switch group is executed according to switch group gating mode 1, and in voltage acquisition mode 2, the switch group is executed according to switch group gating mode 2;

[0055] Read the battery voltage analog data, perform A / D conversion, and calculate the output battery voltage value;

[0056] The voltage of the single cell is collected at a preset interval, and the preset time is 0.1s. After the voltage collection is completed, the moving average value of the voltage of each single cell is calculated and compared with the current value to determine whether it exceeds the preset threshold; if so, the voltage collection is started again, and the switch group is executed according to the switch group selection mode 3; if not, the voltage value is output and the current round of collection is completed;

[0057] In switch group selection mode 3, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the threshold is the actual value of the abnormal single cell voltage value; at the same time, the abnormal voltage collection circuit is judged.

[0058] The specific contents of the combination of the voltage acquisition mode 1 and the switch group gating mode 1 are as follows:

[0059] When the single battery management system is used for voltage collection of a single battery module, and the number of batteries in series in the battery module is not greater than the number of voltage collection channels of the single battery management system, the voltage collection mode is defined as voltage collection mode 1; the switch selection mode is that all redundant collection switches remain in a normally open state, and other switches are closed according to control instructions, which is defined as switch group selection mode 1;

[0060] The specific contents of the combination of the voltage acquisition mode 2 and the switch group gating mode 2 are as follows:

[0061] When the single battery management system is used for voltage collection of two or more battery modules, and two or more adjacent battery modules are connected in series to form a group, and the total number of single batteries connected in series in the group is not greater than the number of voltage collection channels of the single battery management system module, the voltage collection mode is defined as voltage collection mode 2; the switch group keeps the corresponding serial number switch at the equal division point of the number of battery modules managed by the single battery management system in a normally closed state, and other switches are closed according to the control command, which is defined as switch selection mode 2;

[0062] The specific contents of switch group gating mode 3 are as follows:

[0063] After the single-cell battery management system completes the single-cell battery voltage collection, it statistically calculates the moving average value of each single-cell battery voltage and compares it with the current value. If the voltage of the mth cell exceeds the threshold, the positive collection circuit switch of the mth cell and the positive collection circuit switch of the m-3th cell are closed at the same time to obtain a voltage value of 1; then the positive collection circuit switch of the m-1th cell and the positive collection circuit switch of the m+2th cell are closed at the same time to obtain a voltage value of 2; during this process, other switches are kept open.

[0064] The number of battery modules managed by the single battery management system in the voltage acquisition mode 2 is determined according to parameter settings.

[0065] The switch group gating mode 3 is applicable in both the voltage acquisition mode 1 and the voltage acquisition mode 2.

[0066] The specific contents of the voltage calculation method of the battery voltage flexible acquisition system are as follows:

[0067] The controller compares the numerical accuracy of voltage acquisition of adjacent battery modules, then switches the acquisition mode for the battery modules with abnormal voltage acquisition accuracy, and then calculates the results to obtain the actual voltage.

[0068] The voltage calculation method of the battery voltage flexible acquisition system is generally divided into two types: normal voltage calculation method and abnormal voltage calculation method:

[0069] Normal voltage acquisition calculation method: When the battery voltage acquisition is normal, the analog quantity collected by the analog quantity acquisition circuit sampling resistor and amplifier is converted into a digital quantity by the A / D conversion module for linear calculation to obtain the voltage value.

[0070] Abnormal voltage collection and calculation method: When the battery voltage collection value is abnormal, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the preset threshold is the actual value of the abnormal single cell voltage value.

[0071] In this embodiment:

[0072] The technical problem to be solved by the present invention is: to enable the same type of single-cell battery management system to use a battery voltage flexible acquisition system composed of a compatible voltage acquisition harness, interface, and controller, adopt different voltage acquisition control modes and different voltage calculation methods to achieve voltage acquisition when battery modules with different numbers of battery strings are combined into a battery pack.

[0073] 1. Hardware, such as Figure 1 As shown in the figure, the battery voltage flexible acquisition system is mainly composed of a controller, an A / D module, a switch group, an auxiliary circuit, a wiring harness interface, a wiring harness and a battery pack. Among them, the controller, A / D module, switch group, wiring harness interface and auxiliary circuit (not shown in the figure) are all integrated in the single battery management system; the battery pack is composed of multiple battery modules of the same type, and the battery modules are flexibly connected; the single battery management system and the battery pack are connected by a wiring harness.

[0074] The controller is responsible for the gating control of the voltage acquisition circuit switch group and the battery voltage calculation;

[0075] The A / D module is responsible for the conversion of voltage analog and digital quantities;

[0076] The switch group is responsible for turning on or off the corresponding voltage collection circuit according to the controller instruction;

[0077] The auxiliary circuit is responsible for comparing and amplifying the voltage signal;

[0078] The wiring harness interface is used to connect the single battery management system module and the wiring harness, which is convenient for installation and maintenance;

[0079] The wiring harness is an extension of the voltage acquisition circuit outside the single battery management system module, and is used to connect the single battery in the battery pack and the single battery management system;

[0080] The battery pack is the voltage detection object and generates a voltage analog signal.

[0081] The switch group, harness interface and harness collection line number need to be designed together according to the battery module management quantity. When the management quantity is an even number, redundancy needs to be added at the even-numbered battery numbers. When the management quantity is an odd number, redundancy needs to be added at the odd-numbered battery numbers.

[0082] The switch group structure is shown in Figure 2 , composed of multiple controlled switches. Taking the single battery management system with 9 voltage collection channels as an example, the controlled switches B1-, B2+, B4+, B6+, B8+ and other even-numbered switches are connected to bus 1, and the controlled switches B1+, B3+, B5+, B7+, B9+ and other odd-numbered switches are connected to bus 2. When collecting battery voltage, the battery analog signal is connected through bus 1 and bus 2. A redundant channel B7- is added between the collection channels corresponding to the controlled switches B6+ and B7+.

[0083] 2. In terms of software control, the controller adopts corresponding voltage acquisition control methods according to the above-mentioned different battery module combinations, realizes accurate acquisition of battery voltages with direct cable connection between modules, and eliminates voltage drops caused by high current operation. See the software control process for details. Figure 3 , specifically follow the steps below:

[0084] Step 1: Configure the single battery management system parameters according to the actual battery management situation;

[0085] Step 2: The software determines whether the current collected voltage is normal and whether it matches the configuration parameters. If it matches, it enters voltage collection mode 1; otherwise, it enters voltage collection mode 2.

[0086] Step 3, the switch group is executed according to gating mode 1 in voltage acquisition mode 1, and the switch group is executed according to gating mode 2 in voltage acquisition mode 2;

[0087] Step 4, read the battery voltage analog data, perform A / D conversion, and calculate the output battery voltage value;

[0088] Step 5, collect the single cell voltage every 0.1s. After completing the voltage collection, calculate the moving average value of each single cell voltage (the moving average filter period is 1s) and compare it with the current value to determine whether it exceeds the threshold; if it exceeds the threshold, enter the voltage collection again, and the switch group executes according to the selection mode 3 and enters step 6; otherwise, output the voltage value and complete this round of collection.

[0089] Step 6, in switch group selection mode 3, collect the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point once, and then subtract the voltage values ​​of the remaining two batteries respectively. The voltage whose difference with the voltage moving average value is within the threshold is the actual value of the abnormal single cell voltage value; at the same time, it can be determined which voltage collection circuit is abnormal.

[0090] Among them, the voltage acquisition mode corresponds to the switch group gating mode, which is divided into the following three types:

[0091] (1) Combination of voltage acquisition mode 1 and switch group selection mode 1

[0092] When the single battery management system module is used for voltage collection of a single battery module, and the number of batteries in series in the battery module is not greater than the number of voltage collection channels of the single battery management system module, the voltage collection mode is defined as voltage collection mode 1; the switch gating mode is that all redundant collection switches remain in a normally open state, and other switches are closed according to control instructions, which is defined as switch gating mode 1.

[0093] (2) Combination of voltage acquisition mode 2 and switch group selection mode 2

[0094] When the single battery management system module is used for voltage collection of two or more battery modules, and two or more adjacent battery modules are connected in series to form a group, and the total number of single batteries connected in series in the group is not greater than the number of voltage collection channels of the single battery management system module, the voltage collection mode is defined as voltage collection mode 2; at this time, the number of battery modules managed by the single battery management system is determined according to the parameter setting; the switch group keeps the serial number switch corresponding to the point where the number of battery modules managed by the single battery management system is equally divided, and the other switches are closed according to the control instruction, which is defined as switch selection mode 2.

[0095] (3) Switch group selection mode 3 (at this time, voltage acquisition mode 1 or voltage acquisition mode 2 is applicable)

[0096] After the single cell battery management system completes the single cell battery voltage collection, it calculates the moving average value of each single cell battery voltage and compares it with the current value. If the voltage of the mth cell battery exceeds the threshold, the positive collection circuit switch of the mth cell battery and the positive collection circuit switch of the m-3th cell battery are closed at the same time to obtain a voltage value of 1; then the positive collection circuit switch of the m-1th cell battery and the positive collection circuit switch of the m+2th cell battery are closed at the same time to obtain a voltage value of 2. In this process, other switches are kept open.

[0097] 3. In terms of software voltage calculation method, the controller first compares the numerical accuracy of adjacent battery voltage collection, then switches the collection method for batteries with abnormal voltage collection accuracy, and then calculates the result to obtain the actual voltage, thereby realizing battery identification with abnormal battery voltage collection and actual voltage collection of the battery. The software voltage calculation method is generally divided into two types: normal voltage calculation method and abnormal voltage calculation method:

[0098] (1) Normal voltage acquisition calculation method

[0099] When the battery voltage is collected normally, the analog quantity collected by the analog quantity collection circuit sampling resistor, amplifier, etc. is converted into a digital quantity by the A / D conversion module for linear calculation to obtain the voltage value.

[0100] (2) Abnormal voltage collection and calculation method

[0101] When the battery voltage acquisition value is abnormal, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the threshold is the actual value of the abnormal single cell voltage value; at the same time, it can be determined which voltage acquisition circuit is abnormal.

[0102] Specific implementation method, taking a single battery management system that supports up to 18 voltage acquisition channels as an example, there are two ways to connect the battery pack control separately:

[0103] Method 1: 3 6-string battery packs are connected to a single battery management system module voltage acquisition interface with a wiring harness, and the controller controls the switches corresponding to the B10-, B10-, and B13- lines to be closed, such as Figure 4 shown.

[0104] Method 2: Two 9-cell battery packs are connected to a single battery management system module voltage acquisition interface with a wiring harness. The software controls the switch corresponding to the B10-line to close and the switches corresponding to the B7- and B13-lines to open. Figure 5 shown.

[0105] The main innovative points of the present invention are as follows:

[0106] 1. In terms of hardware, redundant voltage acquisition lines, acquisition interfaces and switch circuits are set between adjacent batteries with specific serial numbers to be compatible with the combination of modules with different numbers of battery strings in series to form a battery pack;

[0107] 2. In terms of software control, the controller adopts corresponding voltage acquisition control methods according to the above-mentioned different battery module combinations, realizes accurate acquisition of battery voltages with direct cable connection between modules, and eliminates voltage drops caused by high current operation;

[0108] 3. In terms of software voltage calculation method, the controller first compares the numerical accuracy of adjacent battery voltage acquisition, then switches the acquisition method for the battery with abnormal voltage acquisition accuracy, and then calculates the result to obtain the actual voltage, thereby realizing the battery identification with abnormal battery voltage acquisition and the actual voltage acquisition of the battery.

[0109] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A battery voltage flexible acquisition system, characterized in that: It includes a single battery management system, a battery pack consisting of multiple battery modules, and a wiring harness for connecting the battery module and the single battery management system; the single battery management system includes a controller, an A / D module, a switch group and a wiring harness interface connected in sequence, and a voltage acquisition circuit is integrated in the single battery management system; The controller is used for switching control of the voltage acquisition circuit and battery voltage calculation; The A / D module is used for converting voltage analog quantity into digital quantity; The switch group is used to turn on or off the corresponding voltage collection circuit according to the controller instruction; The wiring harness interface is used to connect the single battery management system and the wiring harness; The battery pack is a voltage detection object and generates a voltage analog signal.

2. A battery voltage flexible acquisition system according to claim 1, characterized in that: The single cell battery management system is integrated with an auxiliary circuit, which is used for comparing and amplifying voltage signals.

3. A battery voltage flexible acquisition system according to claim 1, characterized in that: The switch group, the wiring harness interface and the wiring harness are set based on the management quantity of the battery module. When the management quantity of the battery module is an even number, redundancy is added at the even-numbered battery numbers; when the management quantity of the battery module is an odd number, redundancy is added at the odd-numbered battery numbers.

4. A method for implementing the battery voltage flexible acquisition system according to any one of claims 1 to 3, characterized in that: The following steps are involved: Configuring parameters of the single battery management system; Determine whether the current collected voltage matches the configured parameters. If so, enter voltage collection mode 1; If not, enter voltage acquisition mode 2; In voltage acquisition mode 1, the switch group is executed according to switch group gating mode 1, and in voltage acquisition mode 2, the switch group is executed according to switch group gating mode 2; Read the battery voltage analog data, perform A / D conversion, and calculate the output battery voltage value; The voltage of each single cell is collected at a preset interval. After the voltage collection is completed, the moving average value of the voltage of each single cell is calculated and compared with the current value to determine whether it exceeds the preset threshold. If so, the voltage collection is started again, and the switch group is executed according to the switch group selection mode 3. If not, the voltage value is output and the current round of collection is completed; In switch group selection mode 3, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the threshold is the actual value of the abnormal single cell voltage value of the battery cell; at the same time, the abnormal voltage collection circuit is judged.

5. The implementation method of a battery voltage flexible acquisition system according to claim 4 is characterized in that: The specific contents of the combination of the voltage acquisition mode 1 and the switch group gating mode 1 are as follows: When the single battery management system is used for voltage collection of a single battery module, and the number of batteries in series in the battery module is not greater than the number of voltage collection channels of the single battery management system, the voltage collection mode is defined as voltage collection mode 1; the switch selection mode is that all redundant collection switches remain in a normally open state, and other switches are closed according to control instructions, which is defined as switch group selection mode 1; The specific contents of the combination of the voltage acquisition mode 2 and the switch group gating mode 2 are as follows: When the single battery management system is used for voltage collection of two or more battery modules, and two or more adjacent battery modules are connected in series to form a group, and the total number of single batteries connected in series in the group is not greater than the number of voltage collection channels of the single battery management system module, the voltage collection mode is defined as voltage collection mode 2; the switch group keeps the corresponding serial number switch at the equal division point of the number of battery modules managed by the single battery management system in a normally closed state, and other switches are closed according to the control command, which is defined as switch selection mode 2; The specific contents of switch group gating mode 3 are as follows: After the single-cell battery management system completes the single-cell battery voltage collection, it statistically calculates the moving average value of each single-cell battery voltage and compares it with the current value. If the voltage of the mth cell exceeds the threshold, the positive collection circuit switch of the mth cell and the positive collection circuit switch of the m-3th cell are closed at the same time to obtain a voltage value of 1; then the positive collection circuit switch of the m-1th cell and the positive collection circuit switch of the m+2th cell are closed at the same time to obtain a voltage value of 2; during this process, other switches are kept open.

6. The implementation method of a battery voltage flexible acquisition system according to claim 5, characterized in that: The number of battery modules managed by the single battery management system in the voltage acquisition mode 2 is determined according to parameter settings.

7. The implementation method of a battery voltage flexible acquisition system according to claim 5, characterized in that: The switch group gating mode 3 is applicable in both the voltage acquisition mode 1 and the voltage acquisition mode 2.

8. The implementation method of a battery voltage flexible acquisition system according to claim 4, characterized in that: The preset time is 0.1s.

9. The implementation method of a battery voltage flexible acquisition system according to claim 4, characterized in that: The specific contents of the voltage calculation method of the battery voltage flexible acquisition system are as follows: The controller compares the numerical accuracy of voltage acquisition of adjacent battery modules, then switches the acquisition mode for the battery modules with abnormal voltage acquisition accuracy, and then calculates the results to obtain the actual voltage.

10. The implementation method of a battery voltage flexible acquisition system according to claim 9, characterized in that: The voltage calculation method of the battery voltage flexible acquisition system is generally divided into two types: normal voltage calculation method and abnormal voltage calculation method: Normal voltage acquisition calculation method: When the battery voltage acquisition is normal, the analog quantity collected by the analog quantity acquisition circuit sampling resistor and amplifier is converted into a digital quantity by the A / D conversion module for linear calculation to obtain the voltage value; Abnormal voltage collection and calculation method: When the battery voltage collection value is abnormal, the total voltage of three consecutive batteries in series with the abnormal battery voltage channel as the starting point and the end point is collected once each, and then the voltage values ​​of the remaining two batteries are subtracted respectively. The voltage whose difference with the voltage moving average value is within the preset threshold is the actual value of the abnormal single battery voltage value.

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