Sampling structure of battery module of energy storage system

Abstract

The utility model discloses a sampling structure of a battery module of an energy storage system, which comprises an MCU controller, an AFE module and a plurality of battery modules, the AFE module is connected with the plurality of battery modules, the MCU controller is connected with the AFE module, one battery module comprises a plurality of mutually connected battery cells, the plurality of battery modules are connected in series through conductive connecting pieces, and the plurality of battery modules are connected in series through conductive connecting pieces. Each battery cell is connected with a voltage sampling line, and the voltage sampling line is connected with the AFE module; the conductive connecting piece is connected with a voltage acquisition input line, and the voltage acquisition input line is connected with the AFE module; or two voltage collecting and sampling lines are connected to the conductive connecting piece, the two voltage collecting and sampling lines are connected with the MCU controller, and a voltage sampling module is arranged in the MCU controller. According to the utility model, the structure is relatively simple, the voltage acquisition precision is improved, effective compensation can be carried out, and the battery can be better protected.

Description

Technical Field

[0001] This utility model belongs to the field of power storage technology, specifically a sampling structure for a battery module of an energy storage system. Background Technology

[0002] With the rapid development of the world economy, energy has become a major issue facing all countries. In recent years, in particular, energy storage has become an unavoidable topic for the development of enterprises and the lives of residents in various countries, with the supply of electricity being a particularly important and prominent issue.

[0003] Solar power generation and energy storage have seen rapid development in both technology and market in recent years, which can effectively address the urgent needs of some countries and regions around the world, especially in Europe, America, and Africa, where there is a pressing need for solar and energy storage products and equipment.

[0004] As customer demand continues to rise, the required capacity for energy storage systems is increasing, while common battery modules are increasingly unable to meet these needs. Therefore, increasing battery capacity means placing more cells within the same battery enclosure, which in turn requires more series-parallel combinations of batteries. Series connection between battery modules has become the primary choice for many designers.

[0005] However, connecting modules in series increases the need for additional series cables or copper busbars, which introduces challenges to sampling. Because these cables and busbars contain impedance, this impedance can be superimposed on the sampling data of a particular cell, affecting the cell sampling data and causing software misjudgments. This introduces uncertainty and error into OCV (Open Circuit Voltage) lookup, voltage protection, and SOC (State of Charge) determination. Inaccurate sampling data makes accurate judgment impossible. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a sampling structure for a battery module in an energy storage system.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A sampling structure for a battery module in an energy storage system includes an MCU controller, an AFE module, and several battery modules. The AFE module is connected to the several battery modules, and the MCU controller is connected to the AFE module. Each battery module contains several interconnected cells. The several battery modules are connected in series through conductive connectors. Each cell is connected to a voltage sampling line, which is connected to the AFE module.

[0009] Connect a voltage acquisition input line to the conductive connector, and this voltage acquisition input line is connected to the AFE module; or connect two voltage acquisition sampling lines to the conductive connector, and both voltage acquisition sampling lines are connected to the voltage sampling module, which is connected to the MCU controller.

[0010] As a further improvement, the conductive connector is a copper busbar or a busbar, and a conductive connector is provided between two adjacent battery modules for connection.

[0011] As a further improvement, several cells in the battery modules are connected in series or in parallel.

[0012] As a further improvement, in several battery modules, the number of battery cells contained in different battery modules is the same.

[0013] As a further improvement, in several battery modules, some battery modules contain the same number of battery cells, while the remaining battery modules contain different numbers of battery cells.

[0014] As a further improvement, the number of channels of the AFE module is greater than or equal to the sum of the number of voltage sampling lines and the number of voltage acquisition input lines.

[0015] As a further improvement, the voltage sampling module is located separately outside the MCU controller.

[0016] As a further improvement, the voltage sampling module is integrated into the MCU controller.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The overall structure is relatively simple. It only requires the acquisition and control of the AFE module and MCU controller, and the addition of acquisition lines to improve the accuracy of cell voltage acquisition, perform precise compensation, and improve battery stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the battery module connection of this utility model;

[0020] Figure 2 This is a circuit connection diagram of Embodiment 1 of the present invention;

[0021] Figure 3 This is a circuit connection diagram of Embodiment 2 of the present invention. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that if terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0025] like Figure 1 As shown, a sampling structure for a battery module in an energy storage system includes an MCU controller, an AFE module, and several battery modules. The AFE module is connected to the battery modules, and the MCU controller is connected to the AFE module. Each battery module contains several interconnected cells. The battery modules are connected in series via conductive connectors. Each cell is connected to a voltage sampling line, which is connected to the AFE module. The conductive connector is a copper busbar or a busbar, and a conductive connector is provided between two adjacent battery modules for connection. The AFE module has a voltage sampling function, transmitting the collected voltage to the MCU controller for corresponding compensation based on the data.

[0026] For ease of description, the following explanation will use the example of setting up four battery modules, each containing four battery cells.

[0027] There are four battery modules: Pack1, Pack2, Pack3, and Pack4.

[0028] Pack 1 contains 4 battery cells: 1#, 2#, 3#, and 4#.

[0029] Pack 2 contains four battery cells: #5, #6, #7, and #8.

[0030] Pack 3 contains four battery cells: 9#, 10#, 11#, and 12#.

[0031] Pack 4 contains four battery cells: 13#, 14#, 15#, and 16#.

[0032] Each cell is equipped with a voltage sampling line. For cells #1 to #6, the voltage sampling lines are C1-C16 respectively. C5 is the voltage sampling line between cells #4 and #5, C9 is between cells #8 and #9, and C13 is between cells #12 and #13. Pack 1, Pack 2, Pack 3, and Pack 4 are four independent battery packs. The cells within these packs are connected in series, and the cells themselves are also connected in series, forming 16 cells in series. However, Pack 1, Pack 2, Pack 3, and Pack 4 are connected in series using busbars. The connection between Pack 1 and Pack 2 is defined as Busbar 1, Pack 2 and Pack 3 as Busbar 2, and Pack 3 and Pack 4 as Busbar 3. Because these are series connections between battery modules, the required busbar length is longer than the direct connection traces between the cells within each battery module. Therefore, each busbar will have a certain impedance.

[0033] Therefore, the voltage sampling of voltage sampling line C5 includes Busbar1, the voltage sampling of voltage sampling line C9 includes Busbar2, and the voltage sampling of voltage sampling line C13 includes Busbar3. When a large current flows through the entire battery string, a certain voltage drop will be formed on Busbar1, Busbar2, and Busbar3.

[0034] Therefore, during the charging and discharging phase, the sampling voltage of each cell is forced to be increased by the busbar voltage. Cell sampling voltage = actual cell voltage + busbar voltage. However, this busbar voltage causes the cell sampling voltage to be too high, resulting in inaccurate voltages for C5, C9, and C13. This affects various calculations of the battery system, leading to deviations, including inaccurate OCV calibration, inaccurate SOC calculation, and inaccurate voltage protection point. Therefore, this influencing factor needs to be filtered out to obtain accurate voltage measurements.

[0035] To solve this technical problem, this application adopts the following two different embodiments.

[0036] Example 1

[0037] refer to Figure 1 and 2 As shown, an additional voltage acquisition input line is connected to the AFE chip on Busbar1, Busbar2, and Busbar3. For the four battery modules, three additional voltage acquisition input lines are required. It is necessary to ensure that the AFE module has 19 channels so that the voltage on Busbar1, Busbar2, and Busbar3 can be detected, sampled, and then transmitted to the MCU controller for compensation processing.

[0038] In Implementation Example 1, this problem can be solved without adding too many extra circuits and electrical sampling lines, and the changes to the system are not too significant. The changes are relatively small and easy to implement.

[0039] Example 2

[0040] refer to Figure 1 , 3 As shown, voltage sampling lines 2 are individually connected to Busbar1, Busbar2, and Busbar3 and input to the MCU controller. A voltage sampling module is configured, and sampling lines 2 are connected to the module. Real-time calculations of the voltages on Busbar1, Busbar2, and Busbar3 are performed and used as compensation values. Internally, the MCU controller subtracts VBusbar1, VBusbar2, and VBusbar3 from the original sampled voltages VC5, VC9, and VC13, respectively, to obtain new values ​​VC5-1, VC9-1, and VC13-1, which are then used to calculate the relevant battery parameters. In these parameters, VC5, VC9, and VC13 refer to the voltages sampled by sampling lines C5, C9, and C13, respectively; VBusbar1, VBusbar2, and VBusbar3 refer to the voltages sampled by Busbar1, Busbar2, and Busbar3, respectively.

[0041] That is, the new cell voltage:

[0042] VC5-1 = VC5 - VBusbar1

[0043] VC9-1 = VC9 - Vbusbar2

[0044] VC13-1 = VC13-VBusbar3.

[0045] This part of the circuit and voltage acquisition sampling line can be added independently on the original basis. The voltage acquisition sampling line can also be connected to the circuit board with the AFE chip by a separate connector without affecting the original circuit function and sampling line function.

[0046] The voltage sampling of other cells in the system remains unchanged, and only these three channels need to be processed separately.

[0047] Furthermore, in the case of a total of 16 cells, this application exemplifies a battery module containing four cells, and all four battery modules maintain the same number of four cells. This approach can also be applied in other situations. For example:

[0048] (1) Two of the battery modules contain three cells, and the other two battery modules contain five cells, for a total of 16 cells, or other cell combinations.

[0049] (2) In a system with parallel battery cells, even if more battery cells are used, the number of cells is still 16, such as 3+3+5+5, and this principle is still followed.

[0050] There are only two battery modules, each with eight cells. The two P battery modules can also be processed in the manner described in the above embodiment to achieve accurate cell voltage sampling.

[0051] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sampling structure for a battery module in an energy storage system, characterized in that, It includes an MCU controller, an AFE module, and several battery modules. The AFE module is connected to the several battery modules, and the MCU controller is connected to the AFE module. Each battery module contains several interconnected cells. The several battery modules are connected in series through conductive connectors. Each cell is connected to a voltage sampling line, which is connected to the AFE module. Connect a voltage acquisition input line to the conductive connector, and this voltage acquisition input line is connected to the AFE module; or connect two voltage acquisition sampling lines to the conductive connector, and both voltage acquisition sampling lines are connected to the voltage sampling module, which is connected to the MCU controller.

2. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, The conductive connector is a copper busbar or a busbar, and a conductive connector is provided between two adjacent battery modules for connection.

3. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, The battery modules consist of several cells connected in series or in parallel.

4. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, In several battery modules, the number of battery cells contained in different battery modules is the same.

5. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, In several battery modules, some battery modules contain the same number of battery cells, while the remaining battery modules contain different numbers of battery cells.

6. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, The number of channels in the AFE module is greater than or equal to the sum of the number of voltage sampling lines and the number of voltage acquisition input lines.

7. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, The voltage sampling module is set up separately outside the MCU controller.

8. The sampling structure of the energy storage system battery module according to claim 1, characterized in that, The voltage sampling module is integrated into the MCU controller.

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