Power circuit open identification method, storage medium, electronic device and energy storage system

Abstract

The application relates to a power loop open circuit identification method, a storage medium, an electronic device and an energy storage system. The method is applied to an internal power loop of a battery cluster of an energy storage system, and steps include: sampling and acquiring voltages and currents of battery cluster ports; according to the working state of an energy storage unit, entering different judgment and identification logics to identify whether the internal power loop of the battery cluster is in open circuit failure; when the energy storage system is in a shutdown state, judging the power loop open circuit according to the collected battery cluster port voltage and the battery cluster port voltage judgment and identification logic; when the energy storage system is in a running state, judging the internal power loop open circuit of the battery cluster according to the collected battery cluster port current and the battery cluster port current judgment and identification logic. Compared with the prior art, the application can timely find the internal power loop open circuit failure of the battery cluster under various working conditions, and ensure the real-time performance and correctness of the failure judgment.

Description

Technical Field

[0001] This invention relates to the field of energy storage system diagnostics, and in particular to a method, apparatus, storage medium, battery management system, and energy storage system for identifying open circuits in power circuits. Background Technology

[0002] Currently, there is no dedicated method for identifying open circuits in the power circuits within battery clusters of energy storage units. The common approach is to trigger an excessive inter-cluster differential current fault to protect the entire system, based on the threshold reached. This method only triggers a fault shutdown when the charging and discharging current of the energy storage unit is high. It cannot determine whether there is an open circuit fault in the power circuit of a battery cluster within the energy storage unit, and it is even more impossible to detect an open circuit fault in the power circuit of a specific battery cluster within the energy storage unit when the charging and discharging current is low. This results in an excessively large deviation in the State of Charge (SOC) between battery clusters within the energy storage unit when the fault is discovered, potentially causing the entire energy storage unit to malfunction. This excessive SOC deviation between battery clusters leads to a longer maintenance and restart cycle. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of the prior art by providing a method, storage medium, device, battery management system, and energy storage system for identifying open circuits in the power circuit of battery clusters within an energy storage system.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] As a first aspect of the present invention, a method for identifying open circuits in a power circuit is provided, the method being applied to the power circuit inside a battery cluster of an energy storage system, the steps of which include:

[0006] The voltage and current at the battery cluster port are sampled and obtained;

[0007] Based on the working status of the energy storage unit, different judgment and identification logics are entered to identify whether there is an open circuit fault in the power circuit inside the battery cluster.

[0008] When the energy storage system is in a shutdown state, the internal power circuit of the battery cluster is determined based on the collected battery cluster port voltage and the battery cluster port voltage judgment and identification logic.

[0009] When the energy storage system is in operation, it uses the collected battery cluster port current and the battery cluster port current judgment and identification logic to determine whether the internal power circuit of the battery cluster is open.

[0010] Furthermore, the logic for determining and identifying the battery cluster port voltage is as follows:

[0011] The ratio of the absolute value of the difference between the accumulated cell voltage and the battery cluster port voltage to the accumulated cell voltage is compared with a set threshold. If the ratio is greater than the set threshold, the power circuit is determined to be open. The determination expression is as follows:

[0012]

[0013] In the formula, BESS.State represents the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation; U Cell_Accu This indicates that the total voltage of this battery cluster is obtained by summing the voltages of each individual cell; U Out This represents the port voltage of this battery cluster directly acquired; Rack.Rack_Open_Circuit.U_Rate_Set is the threshold for comparison using the voltage difference ratio of this cluster.

[0014] Furthermore, the logic for determining and identifying the battery cluster port voltage is as follows:

[0015] The ratio of the absolute value of the difference between the maximum and minimum terminal voltages of all battery clusters within this energy storage unit to the maximum terminal voltage of the battery cluster is compared with a set threshold. If the ratio exceeds the set threshold, the power circuit is determined to be open. The determination expression is as follows:

[0016]

[0017] In the formula, Bess.State represents the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation; U out_Max This represents the maximum port voltage of all battery clusters within this energy storage unit, obtained directly from data collection; U out_min This represents the minimum port voltage among all battery clusters within this energy storage unit, obtained directly from data collection; Bank.Rack_Open_Circuit.U_Rate_Set is the threshold value used for comparison based on the inter-cluster voltage difference ratio.

[0018] Furthermore, the logic for determining and identifying the battery cluster port current is as follows:

[0019] The absolute value of the current change of the battery cluster itself when the total current of the energy storage unit changes is compared with a set threshold. If the value is less than the set threshold, the power circuit is determined to be open. The determination expression is as follows:

[0020]

[0021] In the formula, BESS.State represents the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation; BESS.Current_Changed represents the change in the total current of the energy storage unit within a specified time period, with 0 indicating no change and 1 indicating a change; I Out_kThis represents the operating current value after the change in the total current of the k-th cell in a certain battery cluster, obtained directly from data collection; I out_k-1 This represents the operating current value of a battery cluster before the change of the (k-1)th total current, obtained directly from the data; Rack.Rack_Open_Circuit.I_Value_Set is the threshold for comparison using the current difference of this cluster.

[0022] Furthermore, the logic for determining and identifying the battery cluster port current is as follows:

[0023] When the total current of the energy storage unit changes, the ratio of the absolute value of the difference between the maximum and minimum cluster currents of all battery clusters to the maximum cluster current is compared with a set threshold. If the ratio exceeds the set threshold, the power circuit is determined to be open. The determination expression is as follows:

[0024]

[0025] In the formula, BESS.State represents the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation; BESS.Current_Changed represents the change in the total current of the energy storage unit within a specified time period, with 0 indicating no change and 1 indicating a change; I out_Max This represents the maximum operating current among all directly collected battery clusters; I out_min This represents the minimum operating current among all battery clusters directly collected; Bank.Rack_Open_Circuit.I_Rate_Set is the threshold for comparison using the ratio of current differences between clusters.

[0026] Furthermore, if it is determined that the power circuit of the battery cluster is open, the energy storage system will shut down and send fault information.

[0027] As a second aspect of the invention, a computer-readable storage medium is provided having computer instructions stored thereon.

[0028] When the instruction is executed by the processor, it implements the steps of the power circuit open circuit identification method as described in any of the preceding methods.

[0029] As a third aspect of the present invention, an electronic device includes:

[0030] One or more processors;

[0031] Memory, used to store one or more programs;

[0032] When the one or more programs are executed by the one or more processors, the one or more processors implement the power circuit open circuit identification method as described in any of the preceding claims.

[0033] As a fourth aspect of the present invention, a battery management system, the system comprising:

[0034] Voltage acquisition module, used to acquire the voltage at the battery cluster ports;

[0035] Current acquisition module, used to acquire the current at the battery cluster port;

[0036] The electronic device described above is connected to the voltage acquisition module and the current acquisition module, respectively.

[0037] As a fifth aspect of the present invention, an energy storage system is provided, the energy storage system comprising:

[0038] The energy storage unit consists of multiple battery clusters connected in parallel;

[0039] The energy storage unit control system includes the battery management system described above, wherein the battery management system is used to determine whether the power circuit inside the battery cluster of the energy storage system is open.

[0040] The power circuit open circuit identification method described above is executed cyclically in real time while the energy storage unit control system is energized.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1) The open circuit identification method of the internal power circuit of the battery cluster in the energy storage unit provided by the present invention can detect the open circuit fault of the internal power circuit of the battery cluster in a timely manner under various operating conditions by monitoring and comparing the voltage and current of the battery cluster port after the energy storage unit control system is powered on. The method can report to the monitoring system in a timely manner and stop the entire energy storage unit, thereby enabling timely notification of such faults to maintenance personnel and timely maintenance, reducing the long maintenance and downtime caused by excessive SOC deviation between battery clusters due to failure to detect the open circuit fault of the internal power circuit of the battery cluster in a timely manner.

[0043] 2) The open circuit identification method of the internal power circuit of the battery cluster in the energy storage unit provided by the present invention selects to use the battery cluster port voltage judgment logic or the ratio of the difference of the battery cluster current for logical judgment based on the current working state of the energy storage system and the state of the battery cluster connected to the DC bus. Compared with the prior art based on the inter-cluster differential current reaching a threshold to trigger the inter-cluster differential current fault as the judgment basis, it can perform the open circuit judgment of the internal power circuit of the battery cluster in real time, thereby ensuring the real-time performance and accuracy of the fault judgment. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the process of the present invention;

[0045] Figure 2 A block diagram of an electronic device according to one embodiment of the present invention;

[0046] Figure 3 This is a block diagram of a battery management system according to one embodiment of the present invention;

[0047] Figure 4 This is a block diagram of an energy storage system according to one embodiment of the present invention. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0049] Example 1

[0050] As a first embodiment of the present invention, a method for identifying an open circuit in the internal power circuit of a battery cluster in an energy storage system is provided, the specific steps of which are as follows: Figure 1 As shown:

[0051] S1. The Battery Management System (BMS) collects the voltage and current at the battery cluster ports and determines the current operating status of the energy storage unit.

[0052] S2. Based on the working status of the energy storage unit, different identification logics are entered to identify whether there is an open circuit fault in the power circuit.

[0053] S3. When the energy storage system is in a shutdown state, that is, when the battery cluster is not connected to the DC bus, the power circuit is open-circuited based on the collected battery cluster port voltage and the identification logic under this condition.

[0054] S4. When the energy storage system is in operation, and the battery cluster is connected to the DC bus, it is impossible to identify whether the power circuit is open based on the battery cluster port voltage. At this time, the power circuit is determined based on the battery cluster current.

[0055] The above process is executed in real time and cyclically while the energy storage unit control system is energized.

[0056] S5. Issue a shutdown command and send fault information.

[0057] Port voltage determination logic:

[0058] Method 1: The ratio of the absolute value of the difference between the accumulated cell voltage and the battery cluster port voltage to the accumulated cell voltage is compared with a set threshold. If the ratio is greater than the set threshold, the power circuit is considered open. The determination expression is as follows:

[0059]

[0060] Method 2: The ratio of the absolute value of the difference between the maximum and minimum terminal voltages of all battery clusters within this energy storage unit to the maximum terminal voltage of the battery cluster is compared with a set threshold. If the ratio exceeds the set threshold, the power circuit is considered open. The determination expression is as follows:

[0061]

[0062] Battery cluster current determination logic:

[0063] Method 1: Compare the absolute value of the current change of the battery cluster itself when the total current of the energy storage unit changes with a set threshold. If it is less than the set threshold, the power circuit is determined to be open. The determination expression is:

[0064]

[0065] Method 2: When the total current of the energy storage unit changes, the ratio of the absolute value of the difference between the maximum and minimum cluster currents of all battery clusters to the maximum cluster current is compared with a set threshold. If the ratio is greater than the set threshold, the power circuit is considered open. The judgment expression is as follows:

[0066]

[0067] In the above formula:

[0068] BESS.State: Represents the current state of the energy storage unit, 0 for shutdown and 1 for operation;

[0069] BESS.Current_Changed: Indicates the change in the total current of the energy storage unit within a specified time period, 0 for no change and 1 for change;

[0070] U Cell_Accu This indicates that the total voltage of this battery cluster is obtained by summing the voltages of individual cells.

[0071] U Out : This indicates the port voltage of this battery cluster obtained directly from the data.

[0072] U out_Max : This represents the maximum port voltage of all battery clusters within this energy storage unit, obtained directly from data collection.

[0073] U Out_mim : Indicates the minimum port voltage among all battery clusters within this energy storage unit, obtained directly from the data.

[0074] I out_Max : Represents the maximum operating current among all battery clusters directly collected;

[0075] I out_min: Represents the minimum operating current among all battery clusters directly collected;

[0076] I out_k : Represents the k-th operating current sample value in a certain battery cluster obtained directly;

[0077] I Out_k-1 : Represents the (k-1)th operating current sample value in a certain battery cluster obtained directly;

[0078] Rack.Rack_Open_Circuit.U_Rate_Set: The threshold for comparison using the voltage difference ratio of this cluster;

[0079] Bank.Rack_Open_Circuit.U_Rate_Set: The threshold for comparison using the inter-cluster voltage difference ratio;

[0080] Rack.Rack_Open_Circuit.I_Value_Set: The threshold for comparing current differences within this cluster;

[0081] Bank.Rack_Open_Circuit.I_Rate_Set: The threshold for comparison using the ratio of inter-cluster current differences.

[0082] The open-circuit diagnostic method provided by this invention selects either battery cluster port voltage judgment logic or battery cluster current judgment logic based on the current working state of the energy storage system and the state of the battery cluster connected to the DC bus, and performs open-circuit judgment of the internal power circuit of the battery cluster in real time, thereby ensuring the real-time performance and accuracy of the fault judgment.

[0083] Example 2

[0084] As a second aspect of the present invention, this application also provides a computer-readable storage medium storing computer instructions thereon, which, when executed by a processor, implement the above-described method for identifying open circuits in the internal power circuit of a battery cluster. The computer-readable storage medium can be an internal storage unit of any device with data processing capabilities as described in the foregoing embodiments, such as a hard disk or memory. The computer-readable storage medium can also be an external storage device, such as a plug-in hard disk, smart media card (SMC), SD card, flash card, etc., equipped on the device. Furthermore, the computer-readable storage medium can include both internal storage units of any device with data processing capabilities and external storage devices. The computer-readable storage medium is used to store the computer program and other programs and data required by the device with data processing capabilities, and can also be used to temporarily store data that has been output or will be output.

[0085] Example 3

[0086] As a third aspect of the present invention, this application also provides an electronic device, comprising: one or more processors 11; a memory 12 for storing one or more programs; when the one or more programs are executed by the one or more processors 11, the one or more processors 11 implement the above-described method for identifying open circuits in the internal power circuit of a battery cluster. Figure 2 The diagram shown is a hardware structure diagram of any device with data processing capabilities for identifying open circuits in the internal power circuit of a battery cluster, as provided in this embodiment of the invention. (Except for...) Figure 3 In addition to the processor, memory, and network interface shown, any data processing device in the embodiment may also include other hardware depending on the actual function of the data processing device, which will not be described in detail here.

[0087] Example 4

[0088] As a fourth aspect of the present invention, this application also provides a battery management system comprising:

[0089] Voltage acquisition module, used to acquire the voltage at the battery cluster ports;

[0090] Current acquisition module, used to acquire the current at the battery cluster port;

[0091] The electronic device described in the above embodiment is connected to the voltage acquisition module and the current acquisition module, respectively.

[0092] Figure 3 This is a block diagram of a battery management system according to an embodiment of the present invention, such as... Figure 3 As shown, the battery management system 20 of this embodiment includes a voltage acquisition module 21, a current acquisition module, and the electronic device described in the above embodiment.

[0093] The voltage acquisition module 21 is used to acquire the voltage at the battery cluster port; the current acquisition module 22 is used to acquire the current at the battery cluster port; the electronic device is connected to the voltage acquisition module and the current acquisition module respectively.

[0094] According to the battery management system 20 of the present invention, the voltage and current of the battery cluster port are sampled by the voltage acquisition module 21 and the current acquisition module, respectively; the open circuit of the battery pack circuit is determined by the open circuit identification method of the internal power circuit of the battery cluster as described in the above embodiment; the open circuit judgment of the internal power circuit of the battery cluster is performed in real time, thereby ensuring the real-time performance and accuracy of the fault judgment.

[0095] Example 5

[0096] As a fifth aspect of the present invention, this application also provides a battery management system comprising:

[0097] An energy storage unit is composed of multiple battery clusters connected in parallel.

[0098] The energy storage unit control system includes the battery management system described in the above embodiment. The battery management system is used to determine whether the power circuit inside the battery cluster of the energy storage system is open. The power circuit open circuit identification method described above is executed in real time and cyclically when the energy storage unit control system is energized.

[0099] Figure 4 This is a block diagram of an energy storage system according to an embodiment of the present invention. The energy storage system 30 of the present invention includes an energy storage unit 31 and a battery management system 20.

[0100] Among them, such as Figure 4 As shown, the battery pack 31 has multiple battery clusters 32 connected in parallel; the battery management system 20 is used to diagnose whether the internal power circuit of the battery clusters in the energy storage system is open.

[0101] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for identifying open circuits in a power circuit, characterized in that, The method is applied to the internal power circuit of a battery cluster in an energy storage system, and the steps include: The voltage and current at the battery cluster port are sampled and obtained; Based on the working status of the energy storage unit, different judgment and identification logics are entered to identify whether there is an open circuit fault in the power circuit inside the battery cluster. When the energy storage system is in a shutdown state, the internal power circuit of the battery cluster is determined based on the collected battery cluster port voltage and the battery cluster port voltage judgment and identification logic. The logic for determining and identifying the battery cluster port current is as follows: The absolute value of the current change of the battery cluster itself when the total current of the energy storage unit changes is compared with a set threshold. If the value is less than the set threshold, the power circuit is determined to be open. The determination expression is as follows: In the formula, This indicates the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation. This indicates the change in the total current of the energy storage unit within a specified time period, with 0 indicating no change and 1 indicating a change. This indicates the first cell in a battery cluster obtained through direct sampling. k The operating current value after the total current change; This indicates the first cell in a battery cluster obtained through direct sampling. k-1 The operating current value before the total current change; The threshold for comparing the current difference of this cluster; Alternatively, when the total current of the energy storage unit changes, the ratio of the absolute value of the difference between the maximum and minimum cluster currents of all battery clusters to the maximum cluster current can be compared with a set threshold. If the ratio is greater than the set threshold, the power circuit is considered open-circuited. The determination expression is as follows: In the formula, This indicates the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation. This indicates the change in the total current of the energy storage unit within a specified time period, with 0 indicating no change and 1 indicating a change. This represents the maximum operating current among all battery clusters directly collected; This represents the minimum operating current among all battery clusters directly collected; The threshold for comparing the ratio of inter-cluster current differences; When the energy storage system is in operation, it uses the collected battery cluster port current and the battery cluster port current judgment and identification logic to determine whether the internal power circuit of the battery cluster is open.

2. The method for identifying open circuits in a power circuit according to claim 1, characterized in that, The logic for determining and identifying the battery cluster port voltage is as follows: The ratio of the absolute value of the difference between the accumulated cell voltage and the battery cluster port voltage to the accumulated cell voltage is compared with a set threshold. If the ratio is greater than the set threshold, the power circuit is determined to be open. The determination expression is as follows: In the formula, This indicates the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation. This indicates that the total voltage of this battery cluster is obtained by summing the voltages of each individual cell. This represents the port voltage of this battery cluster obtained directly from the data acquisition. This is the threshold for comparing the voltage difference ratio of this cluster.

3. The method for identifying open circuits in a power circuit according to claim 1, characterized in that, The logic for determining and identifying the battery cluster port voltage is as follows: The ratio of the absolute value of the difference between the maximum and minimum terminal voltages of all battery clusters within this energy storage unit to the maximum terminal voltage of the battery cluster is compared with a set threshold. If the ratio exceeds the set threshold, the power circuit is determined to be open. The determination expression is as follows: In the formula, This indicates the current state of the energy storage unit, with 0 indicating shutdown and 1 indicating operation. This represents the maximum port voltage of all battery clusters within this energy storage unit, obtained directly from data collection. This represents the minimum port voltage among all battery clusters within this energy storage unit, obtained directly from data collection. This is the threshold for comparing the ratio of inter-cluster voltage differences.

4. The method for identifying open circuits in a power circuit according to claim 1, characterized in that, When it is determined that the power circuit of the battery cluster is open, the energy storage system shuts down and sends out fault information.

5. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the instruction is executed by the processor, it implements the steps of the power circuit open circuit identification method as described in any one of claims 1-4.

6. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the power circuit open circuit identification method as described in any one of claims 1-4.

7. A battery management system, characterized in that, The system includes: Voltage acquisition module, used to acquire the voltage at the battery cluster ports; Current acquisition module, used to acquire the current at the battery cluster port; The electronic device as described in claim 6 is connected to the voltage acquisition module and the current acquisition module, respectively.

8. An energy storage system, characterized in that, The energy storage system includes: The energy storage unit consists of multiple battery clusters connected in parallel; An energy storage unit control system includes a battery management system as described in claim 7, wherein the battery management system is used to determine whether the internal power circuit of the battery cluster of the energy storage system is open. The power circuit open circuit identification method as described in any one of claims 1-4 is executed in real time and cyclically while the energy storage unit control system is energized.

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