Anti-reverse connection detection method and energy storage system

Abstract

The embodiment of the application discloses a reverse connection prevention detection method and an energy storage system. The detection method comprises the following steps: a stack level controller judges whether positive and negative reverse connection exists between a reference cluster and a bus cabinet under the condition that each main negative relay is closed and a pre-charge circuit in the reference cluster is closed; the stack level controller judges whether positive and negative reverse connection exists between a target cluster and the bus cabinet under the condition that positive and negative reverse connection does not exist between the reference cluster and the bus cabinet; and the stack level controller determines whether positive and negative reverse connection exists according to the judgment result of the target cluster. By introducing a front-checking link of the reference cluster, the effectiveness of the reference is identified at the initial stage of detection, and the systematic misjudgment propagation link caused by the continuous execution of subsequent detection under the condition that the reference is invalid is blocked. By reconstructing the execution order and the condition dependence of the detection logic, the original parallel and / or independent judgment mode of each battery cluster is changed into a progressive judgment mode with cascaded conditions, the detection blind area is eliminated, and the accuracy and robustness are improved.

Description

Technical Field

[0001] This application relates to energy storage technology, including but not limited to a reverse connection detection method and energy storage system. Background Technology

[0002] With the large-scale development of energy storage systems, whether the battery clusters and combiner cabinets are reverse-connected has become an important inspection item for identifying potential safety hazards in energy storage systems. An energy storage system consists of multiple battery clusters and combiner cabinets; each battery cluster includes a pre-charge relay and a negative relay.

[0003] In the existing reverse connection detection scheme, the pre-charge relay and negative relay of each battery cluster are closed in sequence, and the external voltage and internal voltage of each battery cluster are collected and compared. Based on the comparison results, it is determined whether there is a reverse connection between the corresponding battery cluster and the combiner cabinet, thereby completing the reverse connection status determination of all battery clusters one by one. However, the above-mentioned reverse connection detection scheme still has the problem of unreliable detection results in practical applications. Under certain working conditions, even if some battery clusters are actually connected correctly, the detection results will still indicate that the battery cluster has a reverse connection abnormality, resulting in a high false judgment rate, affecting the credibility of reverse connection detection, and thus delaying the investigation of real safety hazards. Summary of the Invention

[0004] In view of this, the reverse connection detection method and energy storage system provided in this application can eliminate detection blind spots and improve the accuracy and robustness of reverse connection detection. The reverse connection detection method and energy storage system provided in this application are implemented as follows: The reverse connection detection method provided in this application embodiment is applied to an energy storage system. The energy storage system includes: a stack-level controller, a combiner cabinet, and multiple battery clusters. Each battery cluster is connected in parallel with the combiner cabinet. Each battery cluster includes: a main negative relay and a pre-charge circuit, with the main negative relay and the pre-charge circuit connected in parallel. Any one of the multiple battery clusters is a reference cluster. The detection method includes: When each of the main negative relays is closed and the pre-charge circuit in the reference cluster is closed, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet. If there is no positive and negative reverse connection between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a positive and negative reverse connection between the target cluster and the combiner cabinet. The target cluster is any one of the other battery clusters besides the reference cluster among the plurality of battery clusters. The stack-level controller determines whether the positive and negative terminals of the energy storage system are reversed based on the judgment result of the target cluster.

[0005] In some possible embodiments, each battery cluster further includes: a battery module and a cluster-level controller; the positive terminal of the battery module is connected to a first terminal of the pre-charge circuit, the negative terminal of the battery module is connected to a first terminal of the main negative relay, the second terminal of the pre-charge circuit is connected to a first positive terminal of the combiner cabinet, the second terminal of the main negative relay is connected to a first negative terminal of the combiner cabinet, and the cluster-level controller is connected to the stack-level controller, the control terminal of the pre-charge circuit, and the control terminal of the main negative relay, respectively; before each main negative relay closes and the pre-charge circuit in the reference cluster closes, the detection method further includes: The stack-level controller sends a high-voltage command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding main negative relay to close according to the high-voltage command; After each of the main negative relays is closed, the stack-level controller sends a first control command to the reference cluster-level controller in the reference cluster; The reference cluster level controller controls the closure of the corresponding pre-charge circuit according to the first control command.

[0006] In some possible embodiments, each battery cluster further includes: a first node and a second node, the first node being located between the second end of the pre-charging circuit and the first positive terminal of the combiner cabinet, and the second node being located between the negative terminal of the battery module and the first end of the main negative relay; the first node, the second node, and the voltage detection module in the combiner cabinet are all connected to the cluster-level controller; the stack-level controller determines whether there is a reverse polarity between the reference cluster and the combiner cabinet, including: The reference cluster level controller acquires a first voltage between a first node and a second node in the reference cluster and sends the first voltage to the stack level controller. The voltage detection module collects the total voltage of the energy storage system and sends the total voltage of the energy storage system to the stack-level controller; The stack-level controller compares the magnitude of the first voltage with the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0007] In some possible embodiments, the stack-level controller compares the magnitude of the first voltage with the total voltage of the energy storage system, including: Calculate the first product of the first voltage and the first preset coefficient; By comparing the total voltage of the energy storage system with the magnitude of the first product, a first comparison result is obtained; In response to the first comparison result indicating that the total voltage of the energy storage system is greater than or equal to the first product result, there is no reverse polarity between the reference cluster and the combiner cabinet; In response to the first comparison result indicating that the total voltage of the energy storage system is less than the first product result, there is a positive and negative reverse connection between the reference cluster and the combiner cabinet.

[0008] In some possible embodiments, the stack-level controller determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet, including: The target cluster-level controller in the target cluster acquires the second voltage between the first node and the second node in the target cluster, and sends the second voltage to the stack-level controller; The stack-level controller compares the magnitudes of the first voltage and the second voltage to determine whether there is a reverse polarity connection between the target cluster and the combiner cabinet.

[0009] In some possible embodiments, the stack-level controller compares the magnitudes of the first voltage and the second voltage, including: Calculate the second product of the first voltage and the second preset coefficient; Compare the second voltage with the result of the second product to obtain a second comparison result; In response to the second comparison result indicating that the second voltage is greater than or equal to the second product result, there is no reverse polarity between the target cluster and the combiner cabinet; In response to the second comparison result indicating that the second voltage is less than the second product result, there is a positive and negative reverse connection between the target cluster and the combiner cabinet.

[0010] In some possible embodiments, when the stack-level controller detects the reverse polarity between the target cluster and the combiner cabinet, the detection method further includes: The stack-level controller sends high-voltage commands to the reference cluster-level controller and the target cluster-level controller in the target cluster, respectively. The reference cluster level controller controls the corresponding pre-charging circuit and the main negative relay to disconnect according to the lower high voltage command; The target cluster-level controller controls the corresponding main negative relay to disconnect according to the high-voltage command.

[0011] In some possible embodiments, the detection method further includes: The stack-level controller sends a first reporting message, which indicates that there is a positive and negative reverse connection between the target cluster and the combiner cabinet.

[0012] In some possible embodiments, each battery cluster further includes: a main positive relay, the first terminal of which is connected to the negative terminal of the battery module, the control terminal of which is connected to the cluster-level controller, and the second terminal of which is connected to the first positive terminal of the combiner cabinet; if there is no reverse polarity between the target cluster and the combiner cabinet, the detection method further includes: The stack-level controller sends a second control command to the cluster-level controllers in the other battery clusters; The cluster-level controller in the other battery cluster controls the corresponding pre-charge circuit to close according to the second control command; After a first preset time period, the stack-level controller sends a third control command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding main positive relay to close according to the third control instruction; After a second preset time period, the stack-level controller sends a fourth control command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding pre-charge circuit to disconnect according to the fourth control instruction.

[0013] In some possible embodiments, each battery cluster further includes a cluster-level controller, which is connected to the stack-level controller, the control terminal of the main negative relay, and the control terminal of the pre-charge circuit, respectively. In the event of a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: The stack-level controller sends a fifth control command to the reference cluster-level controller in the reference cluster and the cluster-level controller in the other battery clusters, respectively. The reference cluster level controller controls the corresponding pre-charge circuit and the main negative relay to disconnect according to the fifth control command; The cluster-level controller in the other battery clusters controls the corresponding main negative relay to disconnect according to the fifth control command.

[0014] In some possible embodiments, before the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: The stack controller detects whether the precharge switch in each precharge circuit is a precharge relay and whether each battery cluster includes a battery pack. When the precharge switch is a precharge relay and each battery cluster includes the battery pack, the stack level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0015] The energy storage system provided in this application includes: a stack-level controller, a combiner cabinet, and multiple battery clusters, each battery cluster being connected in parallel with the combiner cabinet; each battery cluster includes: a main negative relay and a pre-charge circuit, the main negative relay being connected in parallel with the pre-charge circuit; any one of the multiple battery clusters is a reference cluster; The stack-level controller is used to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet when each of the main negative relays is closed and the pre-charge circuit in the reference cluster is closed; The stack-level controller is further configured to determine whether there is a positive-negative reverse connection between the target cluster and the combiner cabinet when there is no positive-negative reverse connection between the reference cluster and the combiner cabinet, wherein the target cluster is any one of the other battery clusters besides the reference cluster among the plurality of battery clusters; The stack-level controller is also used to determine whether the positive and negative terminals of the energy storage system are reversed based on the judgment result of the target cluster.

[0016] In some possible embodiments, each battery cluster further includes: a battery module and a cluster-level controller; the positive terminal of the battery module is connected to a first terminal of the pre-charging circuit, the negative terminal of the battery module is connected to a first terminal of the main negative relay, the second terminal of the pre-charging circuit is connected to a first positive terminal of the combiner cabinet, the second terminal of the main negative relay is connected to a first negative terminal of the combiner cabinet, and the cluster-level controller is connected to the stack-level controller, the control terminal of the pre-charging circuit, and the control terminal of the main negative relay, respectively; The stack-level controller is also used to send a high-voltage command to each of the cluster-level controllers; Each of the cluster-level controllers is used to control the closing of the corresponding main negative relay according to the high voltage command; The stack-level controller is also configured to send a first control command to the reference cluster-level controller in the reference cluster after each of the main negative relays is closed; The reference cluster level controller is used to control the closure of the corresponding pre-charging circuit according to the first control command.

[0017] In some possible embodiments, each battery cluster further includes: a first node and a second node, wherein the first node is located between the second end of the pre-charging circuit and the first positive terminal of the combiner cabinet, and the second node is located between the negative terminal of the battery module and the first end of the main negative relay; the first node, the second node, and the voltage detection module in the combiner cabinet are all connected to the cluster-level controller. The reference cluster level controller is also used to acquire a first voltage between a first node and a second node in the reference cluster, and send the first voltage to the stack level controller; The voltage detection module is used to collect the total voltage of the energy storage system and send the total voltage of the energy storage system to the stack-level controller; The stack-level controller is also used to compare the magnitude of the first voltage and the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0018] The reverse connection detection method and energy storage system provided in this application determine whether there is a reverse connection between the reference cluster and the combiner cabinet when each main negative relay is closed and the pre-charge circuit in the reference cluster is closed. If there is no reverse connection between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a reverse connection between the target cluster and the combiner cabinet. The target cluster is any one of the multiple battery clusters other than the reference cluster. Based on the determination result of the target cluster, the stack-level controller determines whether there is a reverse connection in the energy storage system. By introducing a pre-verification step for the reference cluster, this application can identify the validity of the reference reference in the early stage of detection, blocking the systematic misjudgment propagation link caused by the continued execution of subsequent detections when the reference reference fails, and avoiding chain misjudgments of normal battery clusters. Compared with existing reverse connection detection schemes, this application reconstructs the execution order and conditional dependencies of the detection logic, transforming the original parallel and / or independent judgment mode of each battery cluster into a progressive judgment mode with cascading conditions, effectively eliminating detection blind spots and improving the accuracy and robustness of reverse connection detection. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0020] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application; Figure 2 A schematic flowchart of a detection method provided in an embodiment of this application; Figure 3 A flowchart illustrating another detection method provided in an embodiment of this application; Figure 4 A flowchart illustrating another detection method provided in an embodiment of this application; Figure 5 A flowchart illustrating another detection method provided in an embodiment of this application; Figure 6 A flowchart illustrating another detection method provided in an embodiment of this application; Figure 7 A flowchart illustrating another detection method provided in an embodiment of this application; Figure 8 This is a schematic diagram of another detection method provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0023] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0024] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0025] Currently, one existing reverse connection detection scheme achieves distributed offline detection by adding a detection branch and voltage detection unit between the battery-side busbar and the power conversion system (PCS)-side busbar in the combiner cabinet. The specific process is as follows: disconnect all combiner switches (i.e., main circuit switches) in the combiner cabinet, connect each battery cluster to the system one by one, and determine whether a reverse connection exists between the battery cluster and the combiner cabinet by detecting the voltage on the battery-side busbar. After completing the detection and disconnection of the current battery cluster, the next battery cluster is connected, and the process is repeated in a round-robin fashion. The energy storage system includes a battery management system (BMS).

[0026] However, this plan has the following problems: (1) The detection process is independent of the relay power-on sequence of the battery management system (BMS). After the detection is completed, another set of control logic is still required to execute the normal power-on of the system, resulting in redundant and complex control logic.

[0027] (2) Since this scheme relies on the added hardware detection branch and adopts a serial detection process with the main circuit switch disconnected, it is essentially a "pre-inspection" mode in the installation or maintenance phase. Therefore, for large energy storage systems containing dozens of battery clusters, this detection process is cumbersome, time-consuming, and inefficient, and cannot meet the application requirements for rapid response.

[0028] (3) After the system is powered on and running, if a new wiring error is caused by misoperation during operation and maintenance, the solution cannot automatically detect the wiring abnormality before the system is powered on again, and lacks online protection capability.

[0029] To address the aforementioned issues, another reverse connection detection scheme employs a parallel approach to detect whether battery clusters are reverse connected during high-voltage operation. The specific process involves sequentially closing the pre-charge relay and negative relay of each battery cluster, and comparing the external and internal voltages of each cluster. Based on the comparison results, it is determined whether a reverse connection exists between the corresponding battery cluster and the combiner cabinet, thus completing the reverse connection status determination for all battery clusters one by one.

[0030] However, the above-mentioned reverse connection detection scheme still has the problem of unreliable detection results in practical applications. Under certain working conditions, even if some battery clusters are actually connected correctly, the detection results will still indicate that the battery cluster has a reverse connection abnormality, resulting in a high false judgment rate, affecting the credibility of reverse connection detection, and thus delaying the investigation of real safety hazards, resulting in serious detection blind spots.

[0031] In view of this, embodiments of this application provide a reverse connection detection method, which is applied to an energy storage system. The energy storage system includes: a stack-level controller, a combiner cabinet, and multiple battery clusters. Each battery cluster is connected in parallel with the combiner cabinet. Each battery cluster includes: a main negative relay and a pre-charge circuit, with the main negative relay and the pre-charge circuit connected in parallel. Any one of the multiple battery clusters is a reference cluster. The detection method includes: when each main negative relay is closed and the pre-charge circuit in the reference cluster is closed, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet; when there is no reverse polarity connection between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a reverse polarity connection between a target cluster and the combiner cabinet. The target cluster is any one of the other battery clusters besides the reference cluster. Based on the determination result of the target cluster, the stack-level controller determines whether there is a reverse polarity connection in the energy storage system.

[0032] To better understand the detection method provided in the embodiments of this application, the energy storage system to which the detection method is applied will be described first.

[0033] Please see Figure 1 , Figure 1 This is a schematic diagram of an energy storage system provided in an embodiment of this application. Figure 1As shown, the energy storage system includes: a stack-level controller 200, a combiner cabinet 300, and multiple battery clusters 100.

[0034] Each battery cluster 100 is connected in parallel with the combiner cabinet 300. Each battery cluster 100 includes a main negative relay Q and a pre-charging circuit 110, with the main negative relay Q connected in parallel with the pre-charging circuit 110.

[0035] Among them, any one of the multiple battery clusters 100 is the reference cluster. The target cluster is any one of the other battery clusters besides the reference cluster.

[0036] Each battery cluster 100 is connected in parallel with the combiner cabinet 300, which can be understood as a centralized topology architecture for the energy storage system.

[0037] In some examples, each battery cluster 100 also includes a battery module and a cluster-level controller.

[0038] The positive terminal of the battery module is connected to the first terminal of the pre-charging circuit 110, the negative terminal of the battery module is connected to the first terminal of the main negative relay Q, the second terminal of the pre-charging circuit 110 is connected to the first positive terminal of the combiner cabinet 300, the second terminal of the main negative relay Q is connected to the first negative terminal of the combiner cabinet 300, and the cluster level controller is connected to the stack level controller 200, the control terminal of the pre-charging circuit 110 and the control terminal of the main negative relay Q.

[0039] In some examples, each battery cluster 100 also includes a first node A and a second node B. The first node A is located between the second end of the pre-charging circuit 110 and the first positive terminal of the combiner cabinet 300, and the second node B is located between the negative terminal of the battery module and the first end of the main negative relay Q. The first node A, the second node B, and the voltage detection module 310 in the combiner cabinet 300 are all connected to the cluster-level controller.

[0040] In some examples, each precharge circuit 110 includes a resistor R and a precharge switch K.

[0041] The first end of resistor R is connected to the positive terminal of the battery module, the second end of resistor R is connected to the first end of precharge switch K, the second end of precharge switch K is connected to the first positive terminal of combiner cabinet 300, and the control terminal of precharge switch K is connected to cluster controller.

[0042] In some examples, the combiner cabinet 300 also includes: a battery-side bus, an energy storage inverter-side bus, a third node E, and a fourth node F.

[0043] The positive terminal B+ of the battery-side busbar is connected to the positive terminal P+ of the energy storage inverter-side busbar, and the negative terminal B- of the battery-side busbar is connected to the negative terminal P- of the energy storage inverter-side busbar. The third node E is located between the positive terminal B+ of the battery-side busbar and the positive terminal P+ of the energy storage inverter-side busbar. The fourth node F is located between the negative terminal B- of the battery-side busbar and the negative terminal P- of the energy storage inverter-side busbar. The voltage detection module 310 is connected to the third node E and the fourth node F respectively.

[0044] Among them, the positive electrode B+ of the battery-side busbar is the first positive electrode of the busbar 300, the negative electrode B- of the battery-side busbar is the first negative electrode of the busbar 300, the positive electrode P+ of the energy storage inverter-side busbar is the second positive electrode of the busbar 300, and the negative electrode P- of the energy storage inverter-side busbar is the second negative electrode of the busbar 300.

[0045] The voltage detection module collects the voltage U between the third node E and the fourth node F. EF That is, the total voltage of the energy storage system is collected.

[0046] In some examples, the energy storage system also includes: Energy Storage Inverter (PCS) 400.

[0047] The energy storage inverter 400 is connected to the positive terminal P+ and the negative terminal P- of the energy storage inverter side bus, respectively.

[0048] In some examples, each battery cluster 100 also includes a main positive relay M.

[0049] The first terminal of the main positive relay M is connected to the negative terminal of the battery module, the control terminal of the main positive relay M is connected to the cluster controller, and the second terminal of the main positive relay M is connected to the first positive terminal of the combiner cabinet 300.

[0050] In some examples, each battery cluster 100 also includes a cluster-level controller.

[0051] The cluster-level controller is connected to the stack-level controller 200, the control terminal of the main negative relay Q, and the control terminal of the pre-charging circuit 110, respectively.

[0052] In each battery cluster 100, the main positive relay M, the pre-charging circuit 110, and the main negative relay Q constitute a high-voltage box.

[0053] For illustrative purposes, this application embodiment uses battery cluster 100-1 as the base cluster and battery clusters 110-2 to 110-N as target clusters. That is, cluster-level controller 1 is the base cluster-level controller, and cluster-level controllers 2 to N are the target cluster-level controllers.

[0054] This application first determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet 300. If there is no reverse polarity connection, it further determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet 300. Therefore, based on the determination result of the target cluster, it is determined whether there is a reverse polarity connection in the energy storage system. By introducing a pre-verification step for the reference cluster, this application can identify the validity of the reference in the early stages of detection, blocking the propagation chain of systematic misjudgments caused by the continued execution of subsequent detections when the reference is invalid, thus avoiding a chain reaction of misjudgments of normal battery clusters. Compared with existing reverse polarity detection schemes, this application reconstructs the execution order and conditional dependencies of the detection logic, transforming the original parallel and / or independent judgment mode of each battery cluster into a progressive judgment mode with cascading conditions, effectively eliminating detection blind spots and improving the accuracy and robustness of reverse polarity detection.

[0055] Please see Figure 2 , Figure 2 This is a schematic flowchart of a detection method provided in an embodiment of this application. Figure 2 As shown, the detection method includes: S201. When each main negative relay is closed and the pre-charge circuit in the reference cluster is closed, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0056] When each main negative relay is closed and the pre-charge circuit in the reference cluster is closed, it means that the energy storage system is in the pre-charge phase of applying high voltage. Reverse polarity refers to the connection of the positive terminal of the reference cluster to the first negative terminal of the combiner cabinet, and vice versa. Whether there is reverse polarity between the reference cluster and the combiner cabinet essentially refers to whether there is reverse polarity between the high-voltage box in the reference cluster and the combiner cabinet.

[0057] When there is no reverse polarity connection between the reference cluster and the combiner cabinet, the connection between them is considered normal. Conversely, if there is a reverse polarity connection, the connection is considered abnormal.

[0058] S202. If there is no reverse polarity between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a reverse polarity between the target cluster and the combiner cabinet.

[0059] The target cluster is any one of the battery clusters other than the reference cluster.

[0060] Specifically, if there is no reverse polarity connection between the target cluster and the combiner cabinet, the connection status of the target cluster can be considered normal. If there is a reverse polarity connection between the target cluster and the combiner cabinet, the connection status of the target cluster can be considered abnormal.

[0061] In this method, if there is no reverse polarity between the reference cluster and the combiner cabinet, it can determine whether there is a reverse polarity between the target cluster and the combiner cabinet. This can avoid subsequent detection of the target cluster's connection status when the connection status of the reference cluster is abnormal. This completely solves the blind reliance on the connection status of a single battery cluster in the existing solution and effectively avoids the chain of misjudgments of other normal battery clusters caused by the reverse polarity of the reference cluster.

[0062] S203. Based on the judgment result of the target cluster, the stack-level controller determines whether there is a reverse connection between the positive and negative poles of the energy storage system.

[0063] Specifically, if the target cluster is determined to have no reverse polarity connection (meaning that any other battery cluster does not have reverse polarity connection), then the energy storage system is determined to have no reverse polarity connection. Conversely, if the target cluster is determined to have reverse polarity connection (meaning that any other battery cluster has reverse polarity connection), then the energy storage system is determined to have reverse polarity connection.

[0064] If the energy storage system has no reverse polarity connection, it can be interpreted as the reverse polarity protection test passing. If the energy storage system has reverse polarity connection, it can be interpreted as the reverse polarity protection test failing.

[0065] Simultaneously, during the pre-charging phase of the energy storage system before it reaches high voltage, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet. If there is no reverse polarity connection between the reference cluster and the combiner cabinet, it then determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet. Based on this, the reverse polarity detection is completed synchronously with the normal high-voltage connection sequence of the energy storage system, significantly improving the real-time performance and efficiency of the detection.

[0066] In this embodiment, when each main negative relay is closed and the pre-charge circuit in the reference cluster is closed, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet. If there is no reverse polarity connection between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet. The target cluster is any one of the multiple battery clusters other than the reference cluster. Based on the determination result of the target cluster, the stack-level controller determines whether there is a reverse polarity connection in the energy storage system. By introducing a pre-verification step for the reference cluster, this application can identify the validity of the reference reference in the early stages of detection, blocking the propagation chain of systematic misjudgments caused by continuing subsequent detection when the reference reference fails, thus avoiding a chain reaction of misjudgments of normal battery clusters. Compared with existing reverse polarity detection schemes, this application reconstructs the execution order and conditional dependencies of the detection logic, transforming the original parallel and / or independent judgment mode of each battery cluster into a progressive judgment mode with cascading conditions, effectively eliminating detection blind spots and improving the accuracy and robustness of reverse polarity detection.

[0067] In some possible embodiments, please refer to Figure 3 , Figure 3 A schematic flowchart of another detection method provided in an embodiment of this application. Before each main negative relay closes and the pre-charge circuit in the reference cluster closes, the detection method further includes: S301, the stack-level controller sends a high-voltage command to each cluster-level controller.

[0068] Before sending the high-voltage command, the energy storage system is in the power-on phase. During the power-on phase, the battery management system in the energy storage system powers on and completes a self-test.

[0069] S302. Each cluster-level controller controls the corresponding main negative relay to close according to the high voltage command.

[0070] This can be understood as all cluster-level controllers controlling their respective main negative relays to close according to the high-voltage command, so that all main negative relays are in the closed state.

[0071] For example, cluster controller 1 controls the main negative relay Q1 to close according to the high voltage command, cluster controller 2 controls the main negative relay Q2 to close according to the high voltage command, until cluster controller N controls the main negative relay QN to close according to the high voltage command.

[0072] S303. After each main negative relay is closed, the stack-level controller sends the first control command to the reference cluster-level controller in the reference cluster.

[0073] For example, the stack-level controller sends a first control command to the cluster-level controller 1.

[0074] S304, the reference cluster level controller controls the corresponding pre-charge circuit to close according to the first control command.

[0075] For example, cluster-level controller 1 controls the pre-charge circuit 110-1 to close according to a first control command.

[0076] In this embodiment, the stack-level controller sends a high-voltage command to each cluster-level controller; each cluster-level controller controls the corresponding main negative relay to close according to the high-voltage command; after each main negative relay closes, the stack-level controller sends a first control command to the reference cluster-level controller in the reference cluster; the reference cluster-level controller controls the corresponding pre-charge circuit to close according to the first control command, so that each main negative relay closes and the pre-charge circuit in the reference cluster closes. Based on this, the voltage polarity reference of the reference cluster can be pre-established using the inherent power-on sequence of the energy storage system. Thus, during the pre-charge phase of high-voltage charging of the energy storage system, it is possible to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0077] In some possible embodiments, please refer to Figure 4 , Figure 4 This is a schematic flowchart illustrating another detection method provided in an embodiment of this application. Figure 4 As shown, the reactor-level controller in S201 above determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet, including: S401, the reference cluster level controller acquires the first voltage between the first node and the second node in the reference cluster and sends the first voltage to the stack level controller.

[0078] For example, the cluster-level controller 1 acquires the first voltage U between the first node A and the second node B in the battery cluster 100-1. BC-1 .

[0079] S402, The voltage detection module collects the total voltage of the energy storage system and sends the total voltage of the energy storage system to the stack-level controller.

[0080] S403. The stack-level controller compares the magnitude of the first voltage with the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0081] In some examples, the implementation process of S403 above includes: calculating the first product result of the first voltage and the first preset coefficient; comparing the total voltage of the energy storage system with the magnitude of the first product result to obtain a first comparison result; in response to the first comparison result indicating that the total voltage of the energy storage system is greater than or equal to the first product result, there is no positive and negative reverse connection between the reference cluster and the combiner cabinet; in response to the first comparison result indicating that the total voltage of the energy storage system is less than the first product result, there is a positive and negative reverse connection between the reference cluster and the combiner cabinet.

[0082] For example, the value range of the first preset coefficient is 0.89-1. For instance, the first preset coefficient is 0.9.

[0083] For example, when U EF ≥k1×U BC-1 At this time, there is no reverse polarity between the reference cluster and the combiner cabinet, meaning the connection between the high-voltage box in the reference cluster and the combiner cabinet is normal. When U EF <k1×U BC-1 At this time, there is a reverse polarity between the reference cluster and the combiner cabinet, which means that the connection between the high voltage box in the reference cluster and the combiner cabinet is abnormal.

[0084] Among them, U EF U is the total voltage of the energy storage system, k1 is the first preset coefficient, and U BC-1 This is the first voltage.

[0085] In this embodiment, the first voltage is acquired by a reference cluster-level controller, and the total voltage of the energy storage system is acquired by a voltage detection module. Then, the stack-level controller compares the first voltage with the total voltage of the energy storage system to determine if there is a reverse polarity connection between the reference cluster and the combiner cabinet. Therefore, there is no need to add an additional independent detection branch, which reduces the number of components in the energy storage system, lowers hardware material costs, and has a significant advantage of zero cost.

[0086] In some possible embodiments, please refer to Figure 5 , Figure 5 This is a flowchart illustrating another detection method provided in an embodiment of this application. The stack-level controller in S202 above determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet, including: S501, The target cluster level controller in the target cluster acquires the second voltage between the first node and the second node in the target cluster and sends the second voltage to the stack level controller.

[0087] For example, the target cluster-level controller acquires the second voltage U between the first node A and the second node B in the target cluster. BC-i For example, when the target cluster is battery cluster 110-2, the target cluster-level controller is cluster-level controller 2. When the target cluster is battery cluster 110-N, the target cluster-level controller is cluster-level controller N.

[0088] S502. The stack-level controller compares the magnitudes of the first voltage and the second voltage to determine whether there is a reverse polarity connection between the target cluster and the combiner cabinet.

[0089] In some examples, the implementation process of S502 above includes: calculating the second product result of the first voltage and the second preset coefficient; comparing the magnitude of the second voltage and the second product result to obtain a second comparison result; in response to the second comparison result indicating that the second voltage is greater than or equal to the second product result, there is no positive and negative polarity reversal between the target cluster and the combiner cabinet; in response to the second comparison result indicating that the second voltage is less than the second product result, there is a positive and negative polarity reversal between the target cluster and the combiner cabinet.

[0090] For example, the value range of the second preset coefficient is 0.79-1. For instance, the second preset coefficient is 0.8.

[0091] For example, when U BC-i ≥k2×U BC-1 At this time, there is no reverse polarity between the target cluster and the combiner cabinet, meaning the connection between the high-voltage box in the target cluster and the combiner cabinet is normal. When U BC-i <k2×U BC-1 At this time, there is a reverse polarity between the target cluster and the combiner cabinet, which means that the connection between the high-voltage box in the target cluster and the combiner cabinet is abnormal.

[0092] Among them, U BC-i U is the second voltage, k2 is the second preset coefficient, and U BC-1 This is the first voltage.

[0093] In this embodiment, the second voltage is acquired by reusing the cluster-level controller (i.e., the target cluster-level controller) in another battery cluster. Then, the stack-level controller compares the magnitudes of the first and second voltages to determine whether there is a reverse polarity connection between the target cluster and the combiner cabinet. Therefore, no new dedicated detection branch is needed, further reducing the number of components in the energy storage system and lowering hardware material costs, resulting in a significant advantage of zero cost.

[0094] In some possible embodiments, please refer to Figure 6 , Figure 6 This is a schematic flowchart illustrating another detection method provided in an embodiment of this application. Figure 6 As shown, when there is a reverse polarity connection between the target cluster and the combiner cabinet, the detection method also includes: S601 and the stack-level controller send high-voltage commands to the reference cluster-level controller and the target cluster-level controller in the target cluster, respectively.

[0095] For example, when there is a reverse polarity connection between the battery cluster 100-2 and the combiner cabinet, the stack-level controller sends a high-voltage command to the cluster-level controller 1, cluster-level controller 2 to cluster-level controller N respectively.

[0096] S602, the reference cluster level controller controls the corresponding pre-charge circuit and main negative relay to disconnect according to the high voltage command.

[0097] For example, cluster-level controller 1 controls the pre-charging circuit 110-1 and the main negative relay Q1 to disconnect according to the lower high voltage command.

[0098] S603, the target cluster level controller controls the corresponding main negative relay to disconnect according to the high voltage command.

[0099] For example, cluster-level controllers 2 to N control their respective main negative relays (i.e., main negative relays Q2 to QN) to disconnect according to the high voltage command.

[0100] In some examples, the heap level controller sends the first reporting information.

[0101] The first reported information is used to indicate that there is a reverse polarity connection between the target cluster and the combiner cabinet.

[0102] Among them, a fault in which the target cluster and the combiner cabinet are connected in reverse polarity can be defined as a level one fault.

[0103] For example, when there is a reverse polarity connection between the positive and negative terminals of the battery cluster 100-2 and the combiner cabinet, the stack level controller sends a first reporting message to indicate that a level one fault has occurred in the battery cluster 100-2.

[0104] In particular, by sending reporting information, the system clearly informs the operation and maintenance personnel that there is a level one fault in the energy storage system, and provides clear fault location and troubleshooting basis, which effectively improves the operation and maintenance efficiency and maintainability of the energy storage system.

[0105] In this embodiment, when there is a reverse polarity connection between the target cluster and the combiner cabinet, the stack-level controller sends high-voltage reduction commands to both the reference cluster-level controller and the target cluster-level controller within the target cluster. The reference cluster-level controller then controls the corresponding pre-charge circuit and main negative relay to disconnect according to the high-voltage reduction command; the target cluster-level controller also controls the corresponding main negative relay to disconnect according to the high-voltage reduction command, causing each battery cluster to perform a high-voltage reduction operation. Thus, the energy storage system is in a high-voltage reduction state.

[0106] In some possible embodiments, please refer to Figure 7 , Figure 7 This is a schematic flowchart illustrating another detection method provided in an embodiment of this application. Figure 7 As shown, when there is no reverse polarity connection between the target cluster and the combiner cabinet, the detection method also includes: S701, the stack-level controller sends a second control command to the cluster-level controller in other battery clusters.

[0107] S702, the cluster-level controller in other battery clusters controls the corresponding pre-charge circuit to close according to the second control command.

[0108] For example, cluster controllers 2 to N control the closure of their respective pre-charging circuits (i.e., pre-charging circuits 110-1 to 110-N) according to the second control command. At this time, all pre-charging circuits in the energy storage system are in a closed state.

[0109] S703, after a first preset time period, the stack-level controller sends a third control command to each cluster-level controller.

[0110] For example, the first preset duration is, for instance, 3 seconds.

[0111] S704. Each cluster-level controller controls the corresponding main positive relay to close according to the third control instruction.

[0112] For example, cluster-level controller 1, cluster-level controller 2 to cluster-level controller N control their respective main positive relays (i.e., main positive relays M1, M2 to MN) to close according to the third control command. At this time, all the main positive relays in the energy storage system are in the closed state.

[0113] S705, after a second preset time period, the stack-level controller sends a fourth control command to each cluster-level controller.

[0114] For example, the second preset duration is 1 second.

[0115] S706, Each cluster-level controller controls the corresponding pre-charge circuit to disconnect according to the fourth control instruction.

[0116] For example, cluster controller 1, cluster controller 2 to cluster controller N control their respective pre-charging circuits (i.e., pre-charging circuits 110-1, 110-2 to 110-N) to close according to the fourth control command. At this time, all pre-charging circuits in the energy storage system are in the open state.

[0117] In this embodiment, when there is no reverse polarity connection between the target cluster and the combiner cabinet, the stack-level controller sends a second control command to the cluster-level controllers in other battery clusters. The cluster-level controllers in the other battery clusters control the corresponding pre-charge circuit to close according to the second control command. After a first preset time, the stack-level controller sends a third control command to each cluster-level controller. Each cluster-level controller controls the corresponding main positive relay to close according to the third control command. After a second preset time, the stack-level controller sends a fourth control command to each cluster-level controller. Each cluster-level controller controls the corresponding pre-charge circuit to open according to the fourth control command. Based on this, after the reverse polarity detection passes, the energy storage system can enter the high-voltage power-on stage to complete the high-voltage connection.

[0118] In some possible embodiments, when there is a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: the stack-level controller sending a fifth control command to the reference cluster-level controller in the reference cluster and the cluster-level controllers in other battery clusters respectively; the reference cluster-level controller controlling the corresponding pre-charge circuit and main negative relay to disconnect according to the fifth control command; and the cluster-level controllers in other battery clusters controlling the corresponding main negative relay to disconnect according to the fifth control command.

[0119] For example, cluster-level controller 1 controls the pre-charge circuit 110-1 and the main negative relay Q1 to disconnect according to the fifth control command. Cluster-level controllers 2 to N control their respective main negative relays (i.e., main negative relays Q1 to QN) to disconnect according to the fifth control command. At this time, all pre-charge circuits and main negative relays in the energy storage system are in the disconnected state. This stage can be understood as all battery clusters performing a high-voltage operation.

[0120] In some examples, the stack-level controller sends a second reporting message to indicate that there is a reverse polarity connection between the reference cluster and the combiner cabinet.

[0121] For example, when there is a reverse polarity connection between the battery cluster 100-1 and the combiner cabinet, the stack level controller sends a second reporting message to determine that the connection between the battery cluster 100-1 and the combiner cabinet is abnormal.

[0122] In this implementation, when there is a reverse polarity connection between the reference cluster and the combiner cabinet, the stack-level controller sends a fifth control command to the reference cluster-level controller in the reference cluster and the cluster-level controllers in other battery clusters. The reference cluster-level controller, according to the fifth control command, controls the corresponding pre-charge circuit and main negative relay to disconnect; the cluster-level controllers in other battery clusters, according to the fifth control command, control the corresponding main negative relays to disconnect. Based on this, upon detecting a reverse polarity connection between the reference cluster and the combiner cabinet, all battery clusters in the energy storage system perform a high-voltage down-voltage operation, placing the energy storage system in a high-voltage down-voltage state.

[0123] In some possible embodiments, before the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: the stack-level controller detecting whether the precharge switch in each precharge circuit is a precharge relay and whether each battery cluster includes a battery pack; and the stack-level controller determining whether there is a reverse polarity connection between the reference cluster and the combiner cabinet when the precharge switch is a precharge relay and each battery cluster includes a battery pack.

[0124] Specifically, when the pre-charge switch in each pre-charge circuit is a pre-charge relay, it can be understood that the energy storage system has an independently controllable pre-charge circuit. When the pre-charge switch in each pre-charge circuit is not a pre-charge relay, it can be understood that the energy storage system does not have an independently controllable pre-charge circuit.

[0125] When each battery cluster includes a battery pack, the energy storage system's topology can be understood as a three-tier architecture. When each battery cluster does not include a battery pack, the energy storage system's topology can be understood as a two-tier architecture.

[0126] In this embodiment, the stack-level controller detects whether the pre-charge switch in each pre-charge circuit is a pre-charge relay and whether each battery cluster includes a battery pack. If the pre-charge switch is a pre-charge relay and each battery cluster includes a battery pack, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet. Based on this pre-hardware verification logic, the corresponding reverse polarity detection process can be adaptively initiated according to the energy storage system's topology and hardware configuration, achieving intelligent identification and compatibility with energy storage systems of various topologies. This significantly improves the robustness and versatility of the reverse polarity detection logic.

[0127] Please see Figure 8 , Figure 8 This is a schematic flowchart of another detection method provided in an embodiment of this application. (Combined with...) Figure 8The following will describe an exemplary application of the embodiments of this application in a real-world application scenario.

[0128] Once the energy storage system is started, the battery management system within the system powers on and completes a self-test.

[0129] S801, the stack-level controller sends a high-voltage command to each cluster-level controller, and each cluster-level controller controls the corresponding main negative relay to close according to the high-voltage command.

[0130] In all battery clusters, the main negative relay is in the closed state.

[0131] S802. After each main negative relay is closed, the stack-level controller sends a first control command to the reference cluster-level controller in the reference cluster; the reference cluster-level controller controls the corresponding pre-charge circuit to close according to the first control command.

[0132] S803, Stack-level controller compares the total voltage U of the energy storage system EF Is it greater than or equal to the first product of the first voltage and the first preset coefficient, k1×U? BC-1 .

[0133] S804, the total voltage U of the energy storage system EF The product of the first voltage and the first preset coefficient, k1×U, is greater than or equal to the result. BC-1 In this case, the stack controller compares the second voltage U BC-i Is it greater than or equal to the second product of the first voltage and the second preset coefficient, k2×U? BC-1 .

[0134] S805, at the second voltage U BC-i The result of the second product k2×U, which is greater than or equal to the first voltage and the second preset coefficient, is also greater than or equal to this product. BC-1 In this case, the stack-level controller sends a second control command to the cluster-level controllers in other battery clusters, and the cluster-level controllers in other battery clusters control the closing of the corresponding pre-charge circuit according to the second control command.

[0135] Among them, when the second voltage U BC-i The result of the second product k2×U, which is greater than or equal to the first voltage and the second preset coefficient, is also greater than or equal to this product. BC-1 When this happens, it means that the reverse connection protection test of the energy storage system has passed.

[0136] S806. After a first preset time period, the stack-level controller sends a third control command to each cluster-level controller, and each cluster-level controller controls the corresponding main positive relay to close according to the third control command.

[0137] S807 After a second preset time, the stack level controller sends a fourth control command to each cluster level controller, and each cluster level controller controls the corresponding pre-charge circuit to disconnect according to the fourth control command.

[0138] At this point, the energy storage system completes the connection to the high voltage.

[0139] S808, the total voltage U of the energy storage system EF The product of the first voltage and the first preset coefficient, k1×U, is less than the result of the first product. BC-1 In this case, the stack-level controller sends a second reporting message.

[0140] Among them, the second reporting message indicates that there is a positive and negative reverse connection between the reference cluster and the combiner cabinet, that is, there is a positive and negative reverse connection between the battery cluster 100-1 and the combiner cabinet.

[0141] S809, at the second voltage U BC-i The result of the second product k2×U, which is greater than or equal to the first voltage and the second preset coefficient, is also greater than or equal to this product. BC-1 In this case, the stack-level controller sends the first reporting information.

[0142] The second reporting message indicates that there is a reverse polarity connection between the target cluster and the combiner cabinet, that is, any one of the battery clusters 100-2 to 100-N has a reverse polarity connection with the combiner cabinet.

[0143] If there is a reverse polarity connection between the target cluster and the combiner cabinet, and a reverse polarity connection between the reference cluster and the combiner cabinet, all battery clusters will perform a high-voltage operation, causing all main negative relays and pre-charge circuits to be disconnected.

[0144] It should be understood that although the steps in the above flowcharts are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the above flowcharts may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0145] Based on the foregoing embodiments, this application provides an energy storage system. For example... Figure 1As shown, the energy storage system includes: a stack-level controller 200, a combiner cabinet 300, and multiple battery clusters 100, each battery cluster 100 being connected in parallel with the combiner cabinet 300; each battery cluster 100 includes: a main negative relay Q and a pre-charge circuit 110, the main negative relay Q being connected in parallel with the pre-charge circuit 110; any one of the multiple battery clusters 100 is the reference cluster.

[0146] The stack-level controller 200 is used to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet 300 when each main negative relay Q is closed and the pre-charge circuit in the reference cluster is closed.

[0147] The stack level controller 200 is also used to determine whether there is a positive or negative reverse connection between the target cluster and the combiner cabinet 300 when there is no positive or negative reverse connection between the reference cluster and the combiner cabinet 300. The target cluster is any one of the other battery clusters 100 besides the reference cluster.

[0148] The stack-level controller 200 is also used to determine whether the positive and negative terminals of the energy storage system are reversed based on the judgment result of the target cluster.

[0149] In some possible embodiments, each battery cluster 100 further includes: a battery module and a cluster-level controller; the positive terminal of the battery module is connected to the first terminal of the pre-charging circuit 110, the negative terminal of the battery module is connected to the first terminal of the main negative relay Q, the second terminal of the pre-charging circuit 110 is connected to the first positive terminal of the combiner cabinet 300, the second terminal of the main negative relay Q is connected to the first negative terminal of the combiner cabinet 300, and the cluster-level controller is connected to the control terminal of the stack-level controller 200, the control terminal of the pre-charging circuit 110, and the control terminal of the main negative relay Q.

[0150] The stack-level controller 200 is also used to send high-voltage commands to each cluster-level controller.

[0151] Each cluster-level controller is used to control the closing of the corresponding main negative relay Q according to the high voltage command.

[0152] The stack-level controller 200 is also used to send a first control command to the reference cluster-level controller in the reference cluster after each main negative relay Q is closed.

[0153] A reference cluster-level controller is used to control the closing of the corresponding pre-charge circuit according to the first control command.

[0154] In some possible embodiments, each battery cluster 100 further includes: a first node A and a second node B, the first node A being located between the second end of the pre-charging circuit 110 and the first positive terminal of the combiner cabinet 300, the second node B being located between the negative terminal of the battery module and the first end of the main negative relay Q, and the first node A, the second node B, and the voltage detection module 310 in the combiner cabinet 300 being connected to the cluster-level controller.

[0155] The reference cluster level controller is also used to acquire the first voltage between the first node and the second node in the reference cluster and send the first voltage to the stack level controller 200.

[0156] The voltage detection module 310 is used to collect the total voltage of the energy storage system and send the total voltage of the energy storage system to the stack-level controller 200.

[0157] The stack-level controller 200 is also used to compare the magnitude of the first voltage and the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet 300.

[0158] The descriptions of the above energy storage system embodiments are similar to those of the above detection method embodiments, and have similar beneficial effects. For technical details not disclosed in the energy storage system embodiments of this application, please refer to the descriptions of the detection method embodiments of this application for understanding.

[0159] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0160] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0161] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0162] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting reverse connection, characterized in that, The detection method is applied to an energy storage system, which includes a stack-level controller, a combiner cabinet, and multiple battery clusters. Each battery cluster is connected in parallel with the combiner cabinet. Each battery cluster includes a main negative relay and a pre-charge circuit, with the main negative relay connected in parallel with the pre-charge circuit. Any one of the multiple battery clusters serves as a reference cluster. The detection method includes: When each of the main negative relays is closed and the pre-charge circuit in the reference cluster is closed, the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet. If there is no positive and negative reverse connection between the reference cluster and the combiner cabinet, the stack-level controller determines whether there is a positive and negative reverse connection between the target cluster and the combiner cabinet. The target cluster is any one of the other battery clusters besides the reference cluster among the plurality of battery clusters. The stack-level controller determines whether the positive and negative terminals of the energy storage system are reversed based on the judgment result of the target cluster.

2. The detection method according to claim 1, characterized in that, Each battery cluster further includes: a battery module and a cluster-level controller; the positive terminal of the battery module is connected to a first terminal of the pre-charging circuit, the negative terminal of the battery module is connected to a first terminal of the main negative relay, the second terminal of the pre-charging circuit is connected to a first positive terminal of the combiner cabinet, the second terminal of the main negative relay is connected to a first negative terminal of the combiner cabinet, and the cluster-level controller is connected to the stack-level controller, the control terminal of the pre-charging circuit, and the control terminal of the main negative relay respectively; before each main negative relay closes and the pre-charging circuit in the reference cluster closes, the detection method further includes: The stack-level controller sends a high-voltage command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding main negative relay to close according to the high-voltage command; After each of the main negative relays is closed, the stack-level controller sends a first control command to the reference cluster-level controller in the reference cluster; The reference cluster level controller controls the closure of the corresponding pre-charge circuit according to the first control command.

3. The detection method according to claim 2, characterized in that, Each battery cluster further includes: a first node and a second node, the first node being located between the second end of the pre-charging circuit and the first positive terminal of the combiner cabinet, and the second node being located between the negative terminal of the battery module and the first end of the main negative relay. The first node, the second node, and the voltage detection module in the combiner cabinet are all connected to the cluster-level controller. The stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet, including: The reference cluster level controller acquires a first voltage between a first node and a second node in the reference cluster and sends the first voltage to the stack level controller. The voltage detection module collects the total voltage of the energy storage system and sends the total voltage of the energy storage system to the stack-level controller; The stack-level controller compares the magnitude of the first voltage with the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

4. The detection method according to claim 3, characterized in that, The stack-level controller compares the magnitude of the first voltage with the total voltage of the energy storage system, including: Calculate the first product of the first voltage and the first preset coefficient; By comparing the total voltage of the energy storage system with the magnitude of the first product, a first comparison result is obtained; In response to the first comparison result indicating that the total voltage of the energy storage system is greater than or equal to the first product result, there is no reverse polarity between the reference cluster and the combiner cabinet; In response to the first comparison result indicating that the total voltage of the energy storage system is less than the first product result, there is a positive and negative reverse connection between the reference cluster and the combiner cabinet.

5. The detection method according to claim 3, characterized in that, The stack-level controller determines whether there is a reverse polarity connection between the target cluster and the combiner cabinet, including: The target cluster-level controller in the target cluster acquires the second voltage between the first node and the second node in the target cluster, and sends the second voltage to the stack-level controller; The stack-level controller compares the magnitudes of the first voltage and the second voltage to determine whether there is a reverse polarity connection between the target cluster and the combiner cabinet.

6. The detection method according to claim 5, characterized in that, The stack-level controller compares the magnitudes of the first voltage and the second voltage, including: Calculate the second product of the first voltage and the second preset coefficient; Compare the second voltage with the result of the second product to obtain a second comparison result; In response to the second comparison result indicating that the second voltage is greater than or equal to the second product result, there is no reverse polarity between the target cluster and the combiner cabinet; In response to the second comparison result indicating that the second voltage is less than the second product result, there is a positive and negative reverse connection between the target cluster and the combiner cabinet.

7. The detection method according to claim 2, characterized in that, In the event that the target cluster and the combiner cabinet have reversed polarity, the detection method further includes: The stack-level controller sends high-voltage commands to the reference cluster-level controller and the target cluster-level controller in the target cluster, respectively. The reference cluster level controller controls the corresponding pre-charging circuit and the main negative relay to disconnect according to the lower high voltage command; The target cluster-level controller controls the corresponding main negative relay to disconnect according to the high-voltage command.

8. The detection method according to claim 7, characterized in that, The detection method further includes: The stack-level controller sends a first reporting message, which indicates that there is a positive and negative reverse connection between the target cluster and the combiner cabinet.

9. The detection method according to claim 2, characterized in that, Each battery cluster further includes: a main positive relay, the first terminal of which is connected to the negative terminal of the battery module, the control terminal of which is connected to the cluster-level controller, and the second terminal of which is connected to the first positive terminal of the combiner cabinet; in the case that there is no reverse polarity between the target cluster and the combiner cabinet, the detection method further includes: The stack-level controller sends a second control command to the cluster-level controllers in the other battery clusters; The cluster-level controller in the other battery cluster controls the corresponding pre-charge circuit to close according to the second control command; After a first preset time period, the stack-level controller sends a third control command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding main positive relay to close according to the third control instruction; After a second preset time period, the stack-level controller sends a fourth control command to each of the cluster-level controllers; Each cluster-level controller controls the corresponding pre-charge circuit to disconnect according to the fourth control instruction.

10. The detection method according to any one of claims 1-9, characterized in that, Each battery cluster further includes a cluster-level controller, which is connected to the stack-level controller, the control terminal of the main negative relay, and the control terminal of the pre-charge circuit. In the event of a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: The stack-level controller sends a fifth control command to the reference cluster-level controller in the reference cluster and the cluster-level controller in the other battery clusters, respectively. The reference cluster level controller controls the corresponding pre-charge circuit and the main negative relay to disconnect according to the fifth control command; The cluster-level controller in the other battery clusters controls the corresponding main negative relay to disconnect according to the fifth control command.

11. The detection method according to any one of claims 2-9, characterized in that, Before the stack-level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet, the detection method further includes: The stack controller detects whether the precharge switch in each precharge circuit is a precharge relay and whether each battery cluster includes a battery pack. When the precharge switch is a precharge relay and each battery cluster includes the battery pack, the stack level controller determines whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

12. An energy storage system, characterized in that, include: The stack-level controller, the combiner cabinet, and multiple battery clusters, each of the battery clusters being connected in parallel with the combiner cabinet; Each of the battery clusters includes: a main negative relay and a pre-charging circuit, wherein the main negative relay is connected in parallel with the pre-charging circuit; any one of the plurality of battery clusters is a reference cluster; The stack-level controller is used to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet when each of the main negative relays is closed and the pre-charge circuit in the reference cluster is closed; The stack-level controller is further configured to determine whether there is a positive-negative reverse connection between the target cluster and the combiner cabinet when there is no positive-negative reverse connection between the reference cluster and the combiner cabinet, wherein the target cluster is any one of the other battery clusters besides the reference cluster among the plurality of battery clusters; The stack-level controller is also used to determine whether the positive and negative terminals of the energy storage system are reversed based on the judgment result of the target cluster.

13. The energy storage system according to claim 12, characterized in that, Each battery cluster further includes: a battery module and a cluster-level controller; the positive terminal of the battery module is connected to the first terminal of the pre-charging circuit, the negative terminal of the battery module is connected to the first terminal of the main negative relay, the second terminal of the pre-charging circuit is connected to the first positive terminal of the combiner cabinet, the second terminal of the main negative relay is connected to the first negative terminal of the combiner cabinet, and the cluster-level controller is connected to the stack-level controller, the control terminal of the pre-charging circuit, and the control terminal of the main negative relay, respectively; The stack-level controller is also used to send a high-voltage command to each of the cluster-level controllers; Each of the cluster-level controllers is used to control the closing of the corresponding main negative relay according to the high voltage command; The stack-level controller is also configured to send a first control command to the reference cluster-level controller in the reference cluster after each of the main negative relays is closed; The reference cluster level controller is used to control the closure of the corresponding pre-charging circuit according to the first control command.

14. The energy storage system according to claim 13, characterized in that, Each battery cluster further includes: a first node and a second node, wherein the first node is located between the second end of the pre-charging circuit and the first positive terminal of the combiner cabinet, and the second node is located between the negative terminal of the battery module and the first end of the main negative relay. The first node, the second node, and the voltage detection module in the combiner cabinet are all connected to the cluster-level controller. The reference cluster level controller is also used to acquire a first voltage between a first node and a second node in the reference cluster, and send the first voltage to the stack level controller; The voltage detection module is used to collect the total voltage of the energy storage system and send the total voltage of the energy storage system to the stack-level controller; The stack-level controller is also used to compare the magnitude of the first voltage and the total voltage of the energy storage system to determine whether there is a reverse polarity connection between the reference cluster and the combiner cabinet.

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