Power line detection method and energy storage equipment

Abstract

The invention relates to the technical field of energy storage, and provides a power line detection method and energy storage equipment, and the method comprises the steps: detecting the power line connection of a plurality of battery branches based on the branch voltages of the plurality of battery branches if one of the plurality of battery branches is in a power-on state; and if at least two battery branches in the plurality of battery branches are in the power-on state, determining the battery branch in the power-on state as a power-on branch, and detecting the power line connection of the power-on branch based on the branch current of the power-on branch and the total current of the plurality of battery branches. By using the method, according to the power-on or power-off states of the plurality of battery branches, different modes are adaptively adopted to detect the power line connection of the battery branches, and the detection accuracy of the power line connection can be ensured, so that the performance and the safety of the parallel energy storage system can be improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a power line detection method and energy storage equipment. Background Art

[0002] With the development of energy storage technology, energy storage systems have been widely used in the fields of grid energy storage, home energy storage, electric vehicles, etc. These fields have high requirements for the capacity, reliability and economy of battery systems. Therefore, parallel energy storage systems have become an important choice to improve the performance of energy storage systems. In a parallel energy storage system, multiple branches of battery packs or battery modules are connected in parallel through power lines. In this connection mode, the positive and negative poles of each battery pack or battery module are connected separately, and they share the current and voltage during the charging or discharging process.

[0003] In a parallel energy storage system, a connection failure of the power line in any branch may affect the performance and stability of the entire battery system, and even cause serious accidents. For example, a short circuit or open circuit in the power line may cause a fire or explosion. Therefore, abnormal detection of the power line is crucial to maintaining the long-term stable operation of the battery system and improving the performance and safety of the parallel energy storage system. Summary of the invention

[0004] In view of this, the present application provides a power line detection method and energy storage device to solve the problem of the need for power line detection in parallel energy storage systems in order to maintain long-term stable operation of the battery system and improve the performance and safety of the parallel energy storage system.

[0005] A first aspect of an embodiment of the present application provides a power line detection method, which is applied to an energy storage device, and the power line detection method includes: the energy storage device includes multiple battery branches connected in parallel, and the multiple battery branches are connected through power lines. The method includes: if there is a battery branch in the multiple battery branches that is in a powered-on state, based on the branch voltage of the multiple battery branches, detecting the power line connection of the multiple battery branches; if there are at least two battery branches in the multiple battery branches that are in a powered-on state, determining the battery branch in the powered-on state as a powered-on branch, and detecting the power line connection of the powered-on branch based on the branch current of the powered-on branch and the total current of the multiple battery branches.

[0006] In some embodiments, the multiple battery branches include at least three battery branches, and the detecting the power line connection of the multiple battery branches based on the branch voltages of the multiple battery branches includes: determining a battery branch in a powered-on state among the multiple battery branches as a powered-on branch, and determining a battery branch in a powered-off state among the multiple battery branches as a powered-off branch; determining the branch voltage of the powered-off branch as a detection voltage; and detecting the power line connection of the multiple battery branches based on the detection voltage.

[0007] In some embodiments, the detecting of the power line connection of the multiple battery branches based on the detection voltage includes: if the detection voltage is within a preset voltage range, determining the lower power branch corresponding to the detection voltage as the first branch; if the detection voltage is not within the preset voltage range, determining the lower power branch corresponding to the detection voltage as the second branch; if the lower power branch includes the first branch and the second branch, determining that the power line connection of the second branch is in an abnormal connection state, and the power line connection of the upper power branch and the first branch is in a normal connection state; if the lower power branches are all the second branches, determining that the power line connection of the upper power branch is in an abnormal connection state; if the lower power branches are all the first branches, determining that the power line connections of the multiple battery branches are all in a normal connection state.

[0008] In some embodiments, the multiple battery branches include two battery branches, and the detecting the power line connection of the multiple battery branches based on the branch voltages of the multiple battery branches includes: determining the branch voltage of the lower power branch among the multiple battery branches as the detection voltage; if the detection voltage is not within a preset voltage range, determining that the power line connection of a battery branch among the multiple battery branches is in an abnormal connection state; if the detection voltage is within the preset voltage range, determining that the power line connections of the multiple battery branches are all in a normal connection state.

[0009] In some embodiments, the power line connection of the power-on branch is detected based on the branch current of the power-on branch and the total current of the multiple battery branches, including: if the branch current satisfies a first condition, the power-on branch corresponding to the branch current is determined as a third branch; if the branch current satisfies a second condition, the power-on branch corresponding to the branch current is determined as a fourth branch; if the total current is greater than a first current threshold and the power-on branch includes the third branch and the fourth branch, it is determined that the power line connection of the fourth branch is in an abnormal connection state.

[0010] In some embodiments, the method further includes: if the branch current is greater than a second current threshold, determining that the branch current satisfies the first condition; if within a first time period, the branch current is continuously within a preset current range, determining that the branch current satisfies the second condition preset current range.

[0011] In some embodiments, the method further includes: if the multiple battery branches are all in a power-off state, determining a target branch from the multiple battery branches based on the branch battery pack voltages of the multiple battery branches; responding to a power-on instruction, controlling the target branch to power on, and determining the powered-on target branch as the powered-on branch.

[0012] In some embodiments, determining a target branch from the multiple battery branches based on the branch battery group voltages of the multiple battery branches includes: acquiring the branch battery group voltages of the multiple battery branches to obtain a voltage set; determining a highest voltage from the voltage set; and determining the battery branch corresponding to the highest voltage as the target branch.

[0013] In some embodiments, after determining that the power line connection is in an abnormal connection state, the method also includes: controlling all powered-on branches among the multiple battery branches to power off, and calculating the power-off time; if the power-off time does not reach a second time, prohibiting the multiple battery branches from powering on.

[0014] A second aspect of an embodiment of the present application provides an energy storage device, including a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the processor implements the above-mentioned power line detection method when executing the computer-readable instructions.

[0015] In a power line detection method provided in an embodiment of the present application, for an energy storage device including multiple battery branches in parallel, when one of the multiple battery branches is in a powered-on state, the power line connection of the multiple battery branches is detected based on the branch voltage of the multiple battery branches. In a case where at least two of the multiple battery branches are in a powered-on state, the power line connection of the powered-on branch is detected by determining the battery branch in the powered-on state as the powered-on branch, and based on the branch current of the powered-on branch and the total current of the powered-on branch. By using this method, different methods are adaptively adopted to detect the power line connection of the battery branches according to the powered-on or powered-off state of the multiple battery branches, which can ensure the detection accuracy of the power line connection, thereby helping to improve the performance and safety of the parallel energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 This is an application scenario diagram of the power line detection method provided in an embodiment of the present application.

[0018] Figure 2 It is a flow chart for implementing the power line detection method provided in an embodiment of the present application.

[0019] Figure 3 This is a partial structural example diagram of a battery pack provided in an embodiment of the present application.

[0020] Figure 4 This is an example diagram of an application scenario of the power line detection method provided in an embodiment of the present application.

[0021] Figure 5 This is a partial structural example diagram of a battery pack provided in another embodiment of the present application.

[0022] Figure 6 It is a schematic diagram of the structure of the energy storage device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field in this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. It should be understood that, unless otherwise specified in this application, " / " means or. For example, A / B can represent A or B. "And / or" in this application is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. "At least one" means one or more. "Multiple" means two or more than two. For example, at least one of a, b or c can represent: a, b, c, a and b, a and c, b and c, a, b and c seven situations.

[0026] In a parallel energy storage system, multiple branches of battery packs or battery modules are connected in parallel to increase the total capacity and reliability of the system. In a parallel energy storage system, if the connection of any branch power line fails, it may have a significant impact on the stability of the entire system. For example, if the power line connection of a branch is disconnected, then the branch cannot provide electrical energy, which will result in a reduction in the total capacity of the parallel energy storage system. In extreme cases, if the capacity of the remaining branches is insufficient to meet the needs of the power load, the performance of the parallel energy storage system may degrade or fail to work properly. Therefore, in a parallel energy storage system, power line fault detection is crucial to ensure system performance, stability, etc.

[0027] The embodiment of the present application provides a power line detection method, which adaptively uses different methods to detect the power line connection of the battery branch according to the power-on or power-off status of multiple battery branches, thereby ensuring the detection accuracy of the power line connection, thereby helping to improve the performance and safety of the parallel energy storage system.

[0028] In some embodiments, the parallel energy storage system can be regarded as a large energy storage device. For ease of description, the embodiments of the present application are described by taking the application of the power line detection method to the energy storage device as an example.

[0029] See also Figure 1 , Figure 1 The figure shows an application scenario of the power line detection method provided by the embodiment of the present application. Figure 1 As shown, the energy storage device 100 is electrically connected to the electrical load 200, and the energy storage device 100 provides electrical energy to the electrical load 200. The energy storage device 100 includes battery groups 1 to n connected in parallel, where n is an integer greater than 1. Figure 1 As shown, the branch where each battery group is located is a battery branch, and the battery groups 1 to n are connected in parallel to form a plurality of parallel battery branches.

[0030] In some embodiments, each battery pack in battery packs 1 to n may include a battery management unit, a relay, a positive terminal, a negative terminal, etc. The positive terminals of battery packs 1 to n are interconnected, and the negative terminals are interconnected, and the current flows freely between battery packs 1 to n, so that battery packs 1 to n jointly undertake the task of power supply or charging, thereby improving the total capacity and reliability of the energy storage device. The battery management unit can control the electrical state of the battery branch where the corresponding battery pack is located by controlling the on and off of the relay, and the electrical state includes a power-on state and a power-off state. For example, the battery management unit can make the battery branch where the battery pack is located in the power-on state by controlling the relay in the battery pack to close, and the battery pack in the battery branch can supply power to the power load 200. The battery management unit can make the battery branch where the battery pack is located in the power-off state by controlling the relay in the battery pack to disconnect.

[0031] In other embodiments, the battery packs 1 to n may be communicatively connected via a communication bus, for example, via a controller area network (CAN) bus.

[0032] In another embodiment, a battery pack can be designated as a master from the battery packs 1 to n, and the remaining battery packs can be designated as slaves. The master can obtain the branch voltage, branch current, etc. of the battery branch where the slave is located.

[0033] In the process of realizing power line detection, if there is a battery branch in the power-on state among multiple battery branches, then based on the parallel connection of multiple battery branches, the remaining battery branches can also detect the branch voltage of the battery branch in the power-on state. In this case, the energy storage device 100 can detect the power line connection of multiple battery branches based on the branch voltages of multiple branches. If there are at least two battery branches in the power-on state among multiple battery branches, then there should be branch currents in the at least two battery branches. In this case, the energy storage device 100 can determine the battery branch in the power-on state as the power-on branch, and detect the power line connection of the power-on branch based on the branch current of the power-on branch and the total current of the power-on branch. By detecting the power line connection of the battery branch, it is helpful to improve the performance and safety of the energy storage device 100.

[0034] In some embodiments, the energy storage device 100 may be any one of an energy storage power station and a large uninterruptible power supply (UPS).

[0035] Figure 1The scenarios shown are only illustrative examples, and the power line detection method provided in this application can also be applied in other scenarios. For example, in some scenarios, it can include energy storage devices 100, inverters, and power loads 200; in some scenarios, it can include energy storage devices 100 but not power loads 200; in some scenarios, it can also include other types of devices. The embodiments of this application do not limit the specific application scenarios of the power line detection method.

[0036] See also Figure 2 The figure is a flowchart of the implementation of the power line detection method provided in the embodiment of the present application. The method is applied to energy storage equipment. The embodiment of the present application is applied to the method in Figure 1 The energy storage device 100 in FIG. 1 is used as an example for explanation. The method comprises the following steps.

[0037] S11: Detecting electrical states of multiple battery branches.

[0038] In some embodiments, the electrical state indicates the working condition of the battery branch. The electrical state includes a power-on state and a power-off state. The power-on state indicates that the battery branch supplies power to the outside, or supplies power to the power load connected to the battery branch, and the relay in the battery branch is in a closed state. The power-off state indicates that the battery branch does not supply power to the outside, or does not supply power to the power load connected to the battery branch, and the relay in the battery branch is in an open state.

[0039] S12: If one of the multiple battery branches is in a powered-on state, detecting power line connections of the multiple battery branches based on branch voltages of the multiple battery branches.

[0040] In some embodiments, the branch voltage of the battery branch represents the voltage of the powered branch battery pack detected through the power line.

[0041] See also Figure 3 , Figure 3 The figure shows a partial structural example of a battery pack provided in an embodiment of the present application. Figure 3 As shown, taking battery pack 1 as an example (battery packs 2 to n are similar), battery pack 1 includes a positive terminal BAT+, a negative terminal BAT-, a relay 10, a relay 11, a battery management unit 20, and a voltage sensor 30. The input terminals of the relay 10 and the relay 11 (such as Figure 3 As shown, the left end or inner end of the relay 10 or the relay 11 is electrically connected to the battery management unit 20. The battery management unit 20 can send control signals to the relay 10 and the relay 11 respectively to control the on and off of the relay 10 and the relay 11. Figure 3As shown, the right end or outer end of the relay 10 is electrically connected to the positive terminal BAT+. The output end of the relay 11 is electrically connected to the negative terminal BAT-. One end of the voltage sensor 30 is electrically connected to the output end of the relay 10 and the positive terminal BAT+, and the other end of the voltage sensor 30 is electrically connected to the output end of the relay 11 (as shown in FIG. Figure 3 As shown, the right end or outer end of the relay 11 ) is electrically connected to the negative terminal BAT−, and the voltage sensor 30 is used to detect the branch voltage of the battery branch where the battery pack 1 is located, and send the branch voltage to the battery management unit 20 .

[0042] In some embodiments, the positive terminal BAT+ of battery pack 1 is electrically connected to the positive terminal BAT+ of battery packs 2 to n through a power line, and the negative terminal BAT- of battery pack 1 is electrically connected to the negative terminal BAT- of battery packs 2 to n through a power line, so that battery packs 1 to n are connected in parallel to form multiple battery branches. Therefore, if one of the multiple battery branches is in a powered-on state, and the branch voltage of the powered-on branch is equal to the voltage of the battery pack of the powered-on branch, then the remaining battery branches can also detect the voltage of the battery pack of the powered-on branch through the power line connected to the powered-on branch.

[0043] Figure 3 The illustrated scenario is only an illustrative example. For example, in another application scenario, the number of relays in the battery pack may not be limited to two. In another application scenario, the battery pack may include a positive terminal BAT+, a negative terminal BAT-, a relay 10, a relay 11, and a battery management unit 20, but does not include a voltage sensor 30. The embodiments of the present application do not limit specific application scenarios.

[0044] In some embodiments, the power lines of multiple battery branches in parallel are connected together. If one of the multiple battery branches is in a powered-on state, then when the power line of each battery branch is in a normal connection state (for example, the power line is normally connected and the air switch is open or closed), the remaining battery branches can also detect the branch voltage of the battery branch in the powered-on state. If there is a large difference between the branch voltage of the battery branch and the branch voltage of the battery branch in the powered-on state, it indicates that there is a battery branch with abnormal power line connection (for example, the power line fails or the air switch of the battery branch is disconnected) among the multiple battery branches. Therefore, when one of the multiple battery branches is in a powered-on state, the energy storage device can detect the power line connection of the multiple battery branches based on the branch voltage of the multiple battery branches.

[0045] In other embodiments, the energy storage device may monitor the branch voltage of the battery branch where the battery pack is located through a battery management unit in the battery pack.

[0046] In other embodiments, the battery packs 1 to n may be communicatively connected via a communication bus, for example, via a controller area network (CAN) bus.

[0047] In other embodiments, the energy storage device may designate a battery pack from battery packs 1 to n as a host, and the remaining battery packs as slaves. The slave may send the branch voltage of the battery branch where the slave is located to the host, and the host may detect the power line connection of the multiple battery branches based on the branch voltages of the multiple battery branches.

[0048] In some embodiments of the present application, the multiple battery branches include at least three battery branches, and based on the branch voltages of the multiple battery branches, the power line connections of the multiple battery branches are detected, including: determining a battery branch in a power-off state among the multiple battery branches as a power-off branch; determining the branch voltage of the power-off branch as a detection voltage; and detecting the power line connections of the multiple battery branches based on the detection voltage.

[0049] In some embodiments, the battery branch being in a power-off state indicates that the relay in the battery branch is in a disconnected state and does not supply power to the load. The branch voltage of the power-off branch indicates the voltage of the external power line detected by the power-off branch or the battery pack voltage of the power-off branch detected by the power-off branch. In theory, the branch voltage of the power-off branch is the same as the branch voltage of the power-off branch. However, if there is a large difference between the branch voltage detected by the power-off branch and the branch voltage of the power-off branch, it may indicate that there is a power line connection failure in multiple battery branches.

[0050] In some embodiments, the energy storage device may determine a battery branch in a powered-on state as a powered-on branch. In the case where one of the multiple battery branches is in a powered-on state, the multiple battery branches include one powered-on branch, and the remaining battery branches are all powered-off branches. The powered-on branch is connected in parallel with the powered-off branch, and the energy storage device may detect the power line connection of the multiple battery branches based on the detection voltage of the powered-off branch.

[0051] In some embodiments of the present application, when multiple battery branches include at least three battery branches, based on the detection voltage, the power line connection of the multiple battery branches is detected, including: if the detection voltage is within a preset voltage range, the lower power branch corresponding to the detection voltage is determined as the first branch; if the detection voltage is not within the preset voltage range, the lower power branch corresponding to the detection voltage is determined as the second branch; if the lower power branch includes the first branch and the second branch, it is determined that the power line connection of the second branch is in an abnormal connection state, and the power line connection between the upper power branch and the first branch is in a normal connection state; if the lower power branches are all the second branches, it is determined that the power line connection of the upper power branch is in an abnormal connection state; if the lower power branches are all the first branches, it is determined that the power line connections of the multiple battery branches are all in a normal connection state.

[0052] In some embodiments, the preset voltage range can be customized. For example, the preset voltage range can be set based on the minimum operating voltage of the energy storage device, or based on the branch voltage of the power-on branch. For example, the preset voltage range can be set to a voltage within the range of ±2V of the branch voltage of the power-on branch. The specific setting of the preset voltage range is not limited in the embodiment of the present application. By setting the preset voltage range, it is helpful to improve the system response speed, detection accuracy and resource saving in the power line detection process.

[0053] In some embodiments, the abnormal connection state of the power line connection of the battery branch includes a power line connection failure, or the air switch of the battery branch is disconnected, etc. The normal connection state of the power line connection of the battery branch includes a normal power line connection and a closed air switch of the battery branch.

[0054] In some embodiments, if the detection voltage is within a preset voltage range, it means that the lower power branch corresponding to the detection voltage can detect the branch voltage of the upper power branch. In this case, the energy storage device can determine that the power line connection between the upper power branch and the battery branch corresponding to the detection voltage is in a normal connection state. At this time, the energy storage device can determine the lower power branch corresponding to the detection voltage as the first branch.

[0055] In some embodiments, if the detection voltage is not within the preset voltage range, it means that the lower power branch corresponding to the detection voltage has failed to successfully detect the branch voltage of the upper power branch. In this case, it indicates that the power line connection of the lower power branch corresponding to the detection voltage is in an abnormal connection state or the power line connection of the upper power branch is in an abnormal connection state. At this time, the energy storage device can determine the lower power branch corresponding to the detection voltage as the second branch.

[0056] In order to locate the specific location where the abnormality occurs in the power line connection, in the case where the multiple battery branches include at least three battery branches, if the lower power branch includes the first branch and the second branch, the energy storage device can determine that the power line connection of the second branch is in an abnormal connection state, and the power line connection between the upper power branch and the first branch is in a normal connection state. If the lower power branches are all the second branches, the energy storage device can determine that the power line connection of the upper power branch is in an abnormal connection state. If the lower power branches are all the first branches, the energy storage device can determine that the power line connections of multiple battery branches are all in a normal connection state.

[0057] Take the case where multiple battery branches include three battery branches, such as Figure 4 As shown, battery pack 1, battery pack 2 and battery pack 3 are connected in parallel to form three battery branches, and the battery branch where battery pack 1 is located is in a powered-on state, supplying power to the power load 200. The battery branches where battery pack 2 and battery pack 3 are located are both in a powered-off state. The energy storage device can determine the battery branch where battery pack 1 is located as a powered-on branch, and the battery branches where battery pack 2 and battery pack 3 are located are both powered-off branches. The energy storage device can detect the detection voltage of the powered-off branch where battery pack 2 is located through the voltage sensor 31 in battery pack 2, and detect the detection voltage of the powered-off branch where battery pack 3 is located through the voltage sensor 32 in battery pack 3.

[0058] If the detection voltage of the lower electrical branch where battery pack 2 is located and the detection voltage of the lower electrical branch where battery pack 3 is located are both within the preset voltage range, the energy storage device can determine that the power line connections of the three battery branches are all in a normal connection state. If the detection voltage of the lower electrical branch where battery pack 2 is located and the detection voltage of the lower electrical branch where battery pack 3 is located are not within the preset voltage range, the energy storage device can determine that the power line connection of the battery branch where battery pack 1 is located is in an abnormal connection state. If the detection voltage of the lower electrical branch where battery pack 2 is located is within the preset voltage range, and the detection voltage of the lower electrical branch where battery pack 3 is located is not within the preset voltage range, the energy storage device can determine that the power line connection of the battery branch where battery pack 3 is located is in an abnormal connection state, and the power line connection between the battery branch where battery pack 1 is located and the lower electrical branch where battery pack 2 is located is in a normal connection state. If the detection voltage of the lower power branch where battery group 2 is located is not within the preset voltage range, and the detection voltage of the lower power branch where battery group 3 is located is within the preset voltage range, the energy storage device can determine that the power line connection of the battery branch where battery group 2 is located is in an abnormal connection state, and the power line connection between the battery branch where battery group 1 is located and the lower power branch where battery group 3 is located is in a normal connection state.

[0059] In other embodiments, the energy storage device can detect the branch voltage of the lower branch where the battery pack 2 is located through the battery management unit 20 in the battery pack 2. The energy storage device can detect the branch voltage of the lower branch where the battery pack 3 is located through the battery management unit 20 in the battery pack 3.

[0060] In the power line detection method provided in the embodiment of the present application, by detecting the power line connection of the multiple battery branches based on the detection voltage of the power-off branch, the battery branch with abnormal power line connection can be accurately located, which facilitates the maintenance of the power line.

[0061] In some embodiments of the present application, when the multiple battery branches include two battery branches, the power line connections of the multiple battery branches are detected based on the branch voltages of the multiple battery branches, including: determining the branch voltage of the lower power branch among the multiple battery branches as the detection voltage; if the detection voltage is not within a preset voltage range, determining that the power line connection of a battery branch among the multiple battery branches is in an abnormal connection state; if the detection voltage is within the preset voltage range, determining that the power line connections of the multiple battery branches are all in a normal connection state.

[0062] In some embodiments, when the multiple battery branches include two battery branches, if one of the multiple battery branches is in a powered-on state, and the lower powered branch does not detect the branch voltage of the powered-on branch (for example, the detection voltage is not within a preset voltage range), the energy storage device can determine that the power line connection of the battery branch among the multiple battery branches is in an abnormal connection state.

[0063] In some embodiments, when the multiple battery branches include two battery branches, if one of the multiple battery branches is in a powered-on state, and the lower powered branch detects the branch voltage of the powered-on branch, the energy storage device can determine that the power line connections of the multiple battery branches are all in a normal connection state.

[0064] In some embodiments of the present application, after determining that the power line connection is in an abnormal connection state, the energy storage device can control all powered-on branches among multiple battery branches to power off and calculate the power-off duration; if the power-off duration does not reach the second duration, powering on multiple battery branches is prohibited.

[0065] In some embodiments, when the power line connection of the battery branch is in an abnormal connection state, if the energy storage device continues to work and supplies power to the electrical load, it may cause damage to the battery pack in the battery branch, affect the performance of the energy storage device, and even cause a safety accident. Therefore, in order to ensure the performance stability and safety of the energy storage device, after determining that the power line connection is in an abnormal connection state, the energy storage device can control all powered-on branches in multiple battery branches to be powered off.

[0066] In some embodiments, to ensure that sufficient time is provided for power line maintenance, the energy storage device can be set to a second time period. After controlling all powered-on branches among multiple battery branches to be powered-off, the energy storage device calculates the power-off time period. If the power-off time period does not reach the second time period, the energy storage device prohibits the multiple battery branches from being powered-on.

[0067] In other embodiments, the energy storage device can also be connected to the terminal device for communication. After determining that the power line connection is in an abnormal connection state, the energy storage device can send relevant information (such as the abnormal location, etc.) of the abnormal connection state of the power line to the terminal device to prompt the user to maintain the power line.

[0068] S13: If at least two of the multiple battery branches are in a powered-on state, the battery branches in the powered-on state are determined as powered-on branches, and based on the branch current of the powered-on branch and the total current of the multiple battery branches, the power line connection of the powered-on branch is detected.

[0069] In some embodiments, when at least two of the multiple battery branches are in a powered-on state, accurate detection of the power line connection cannot be achieved by detecting the power line connection of the multiple battery branches based on the branch voltages of the multiple battery branches. For example, since at least two of the multiple battery branches are in a powered-on state, regardless of whether the power line connection of the powered-on branch is abnormal, the energy storage device can detect the branch voltage of the powered-on branch, and the branch voltage is within a preset range, so that it is impossible to determine whether the power line connection of the powered-on branch is abnormal based on the branch voltages of the multiple battery branches.

[0070] To solve the above problem, if at least two of the multiple battery branches are powered on, the energy storage device can detect the power line connection of the powered branch based on the branch current of the powered branch and the total current of the multiple battery branches.

[0071] In some embodiments, the branch current may be a charging current or a discharging current of a powered-on branch. Since the relay in the battery branch is usually disconnected when the battery branch is in a powered-off state, there is no charging current or discharging current in the battery branch. The total current of multiple battery branches may also be referred to as the total current of the powered-on branch, and the total current represents the sum of the branch currents of the powered-on branch.

[0072] In some embodiments, the branch current and the total current can be detected by a current sensor, or by a battery management unit in a battery pack. The embodiment of the present application does not limit the detection method of the branch current and the total current.

[0073] In some embodiments, Figure 1As shown, battery packs 1 to n can be connected via a communication bus. For example, they can be connected via a controller area network bus. The energy storage device can designate a battery pack from battery packs 1 to n as a host, and the remaining battery packs as slaves. The host can obtain the total current of multiple battery branches, and the slave can send the branch current of the battery branch where the slave is located to the host. The host can detect the power line connection of the powered branch based on the branch current of the powered branch and the total current of multiple battery branches.

[0074] In some embodiments of the present application, based on the branch current of the powered branch and the total current of multiple battery branches, the power line connection of the powered branch is detected, including: if the branch current satisfies a first condition, the powered branch corresponding to the branch current is determined as the third branch; if the branch current satisfies a second condition, the powered branch corresponding to the branch current is determined as the fourth branch; if the total current is greater than the first current threshold and the powered branch includes the third branch and the fourth branch, it is determined that the power line connection of the fourth branch is in an abnormal connection state.

[0075] In some embodiments, if the branch current is greater than a second current threshold, it is determined that the branch current satisfies the first condition; if the branch current is continuously within a preset current range within a first time period, it is determined that the branch current satisfies the second condition.

[0076] In some embodiments, the energy storage device can predict the first current threshold value based on the performance parameters (e.g., capacity, historical current data, etc.) of the battery pack in the power-on branch, and the first current threshold value can be determined based on the performance parameters of the battery pack in the power-on branch. The first current threshold value is not limited in the embodiment of the present application. For example, the first current threshold value can be set to 10A.

[0077] In some embodiments, the second current threshold, the preset current range, and the preset duration can be customized, and the second current threshold is less than the first current threshold. For example, the second current threshold can be set to 5A, the preset current range can be set to current equal to 0.1A or 0A, etc., and the preset duration can be set to 1 minute. The embodiment of the present application does not limit the specific settings of the second current threshold, the preset current range, and the first duration.

[0078] In some embodiments, the sum of the branch currents of all powered branches in multiple battery branches in parallel is equal to the total current of multiple battery branches. If there is a branch in the powered branch that continuously discharges at a large current, and at the same time, there is a branch whose discharge current is continuously zero, it can be determined that the branch whose discharge current is continuously zero is that the power line is not connected. In order to accurately locate the powered branch with an abnormal power line connection, if the branch current meets the first condition, the energy storage device determines the powered branch corresponding to the branch current as the third branch; if the branch current meets the second condition, the energy storage device determines the powered branch corresponding to the branch current as the fourth branch. In the case where the total current is greater than the first current threshold and the powered branch includes the third branch and the fourth branch, the energy storage device can determine that the power line connection of the fourth branch is in an abnormal connection state.

[0079] For example, assuming that the first current threshold is set to 10A, the second current threshold is set to 5A, the preset current range is set to the discharge current of 0A, and the preset duration is set to 1 minute. If there are three power-on branches among the multiple battery branches, namely, power-on branch a, power-on branch b and power-on branch c, and the total discharge current of the multiple battery branches is 15A, the branch current (discharge current) of power-on branch a is 10A, the branch current (discharge current) of power-on branch b is 5A, and within 1 minute, the branch current (discharge current) of power-on branch c continues to be 0A, then the energy storage device can determine that the total current of the multiple battery branches is greater than the first current threshold, the branch current of power-on branch a meets the first condition, power-on branch a is the third branch, the branch current of power-on branch c meets the second condition, power-on branch c is the fourth branch, so it can be determined that the power line connection of power-on branch c is in an abnormal connection state.

[0080] In some embodiments of the present application, if multiple battery branches are in a power-off state, a target branch is determined from the multiple battery branches based on the branch battery pack voltages of the multiple battery branches; in response to a power-on instruction, the target branch is controlled to power on, and the target branch after power-on is determined as a powered-on branch.

[0081] In some embodiments, the branch battery pack voltage of the battery branch represents the voltage of the battery pack when the battery branch is in a power-off state. Figure 5 As shown, taking battery pack 1 as an example (battery packs 2 to n are similar), the voltage sensor 33 can detect the relay input terminal ( Figure 5 In some other embodiments, the battery pack 1 can detect the branch battery pack voltage through the battery control unit 20. The embodiment of the present application does not limit the method of obtaining the branch battery pack voltage.

[0082] In some embodiments, a target branch is determined from multiple battery branches based on branch battery pack voltages of multiple battery branches, including: acquiring branch battery pack voltages of multiple battery branches to obtain a voltage set; determining a highest voltage from the voltage set; and determining the battery branch corresponding to the highest voltage as the target branch.

[0083] In some embodiments, the battery management unit predicts the remaining power of the battery pack in the battery branch based on the branch battery pack voltage of the battery branch. Generally, the higher the branch battery pack voltage, the more remaining power the battery pack in the battery branch has. Therefore, after receiving the power-on instruction, the energy storage device can select the battery branch corresponding to the highest voltage from multiple battery branches as the target branch according to the branch battery pack voltages of multiple battery branches, so as to ensure that the energy storage device has high discharge efficiency, performance and stability, while being able to protect the battery branch with a lower branch battery pack voltage.

[0084] In some embodiments, if there is one powered branch among multiple battery branches, the energy storage device can detect the power line connection of multiple battery branches based on the branch voltages of the multiple battery branches; if there are at least two powered branches among the multiple battery branches, the energy storage device can detect the power line connection of the powered branch based on the branch current of the powered branch and the total current of the powered branch.

[0085] In some embodiments of the present application, after determining that the power line connection is in an abnormal connection state, the energy storage device can control all powered-on branches among multiple battery branches to power off and calculate the power-off duration; if the power-off duration does not reach the preset duration, powering on multiple battery branches is prohibited.

[0086] In some embodiments, when the power line connection of the battery branch is in an abnormal connection state, if the energy storage device continues to work and supplies power to the electrical load, it may cause damage to the battery pack in the battery branch, affect the performance of the energy storage device, and even cause a safety accident. Therefore, in order to ensure the performance stability and safety of the energy storage device, after determining that the power line connection is in an abnormal connection state, the energy storage device can control all powered-on branches in multiple battery branches to be powered off.

[0087] In some embodiments, to ensure that sufficient time is provided for power line maintenance, the energy storage device can set a preset time. After controlling all powered-on branches among multiple battery branches to power off, the energy storage device calculates the power-off time. If the power-off time does not reach the preset time, the energy storage device prohibits multiple battery branches from powering on.

[0088] In other embodiments, the energy storage device can also be connected to the terminal device for communication. After determining that the power line connection is in an abnormal connection state, the energy storage device can send relevant information (such as the abnormal location, etc.) of the abnormal connection state of the power line to the terminal device to prompt the user to maintain the power line.

[0089] In a power line detection method provided in an embodiment of the present application, for an energy storage device including multiple battery branches in parallel, when one of the multiple battery branches is in a powered-on state, the power line connection of the multiple battery branches is detected based on the branch voltage of the multiple battery branches. In a case where at least two of the multiple battery branches are in a powered-on state, the power line connection of the powered-on branch is detected by determining the battery branch in the powered-on state as the powered-on branch, and based on the branch current of the powered-on branch and the total current of the powered-on branch. By using this method, different methods are adaptively adopted to detect the power line connection of the battery branches according to the powered-on or powered-off state of the multiple battery branches, which can ensure the detection accuracy of the power line connection, thereby helping to improve the performance and safety of the parallel energy storage system.

[0090] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the 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 the present application.

[0091] See also Figure 6 , Figure 6 The diagram is a schematic diagram of the structure of an energy storage device provided in an embodiment of the present application. The network where the energy storage device 100 is located includes but is not limited to the Internet, a wide area network, a metropolitan area network, a local area network, a virtual private network (VPN), etc.

[0092] like Figure 6 As shown, the energy storage device 100 includes a communication module 101, a memory 102, a processor 103, an input / output interface 104 and a bus 105. The processor 103 is coupled to the communication module 101, the memory 102 and the input / output interface 104 through the bus 105.

[0093] The communication module 101 may be a wireless communication module or a mobile communication module. The wireless communication module may provide wireless communication solutions including wireless local area networks (WLAN) (e.g., wireless fidelity (Wi-Fi) network), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication technology (NFC), infrared technology (IR), etc., applied to the energy storage device 100. The mobile communication module may provide wireless communication solutions including 2G / 3G / 4G / 5G, etc., applied to the energy storage device 100.

[0094] The memory 102 may include one or more random access memories (RAM) and one or more non-volatile memories (NVM). The random access memory can be directly read and written by the processor 103, and can be used to store executable programs (such as machine instructions) of the operating system or other running programs, and can also be used to store user and application data. The random access memory may include static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM, for example, the fifth generation DDR SDRAM is generally referred to as DDR5 SDRAM), etc.

[0095] The non-volatile memory may also store executable programs and user and application data, etc., and may be loaded into the random access memory in advance for direct reading and writing by the processor 103. The non-volatile memory may include a disk storage device and a flash memory.

[0096] The memory 102 is used to store one or more computer programs. The one or more computer programs are configured to be executed by the processor 103. The one or more computer programs include a plurality of instructions, and when the plurality of instructions are executed by the processor 103, the power line detection method executed on the energy storage device 100 can be implemented.

[0097] In other embodiments, the energy storage device 100 further includes an external memory interface for connecting to an external memory to expand the storage capacity of the energy storage device 100 .

[0098] The processor 103 may include one or more processing units, for example, the processor 103 may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0099] The processor 103 provides computing and control capabilities. For example, the processor 103 is used to execute a computer program stored in the memory 102 to implement the above-mentioned power line detection method.

[0100] The input / output interface 104 is used to provide a channel for user input or output. For example, the input / output interface 104 can be used to connect various input and output devices, such as a mouse, keyboard, touch device, display screen, etc., so that the user can enter information or visualize information.

[0101] The bus 105 is at least used to provide a channel for mutual communication among the communication module 101 , the memory 102 , the processor 103 , and the input / output interface 104 in the energy storage device 100 .

[0102] It is to be understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the energy storage device 100. In other embodiments of the present application, the energy storage device 100 may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0103] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program includes program instructions. The method implemented when the program instructions are executed can refer to the power line detection method in the above-mentioned embodiments of the present application.

[0104] The computer-readable storage medium may be an internal memory of the energy storage device described in the above embodiment, such as a hard disk or memory of the energy storage device. The computer-readable storage medium may also be an external storage device of the energy storage device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc., equipped on the energy storage device.

[0105] Furthermore, the computer-readable storage medium may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, etc.; the data storage area may store data created according to the use of the energy storage device, etc.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A power line detection method, applied to energy storage equipment, characterized in that: The energy storage device comprises a plurality of battery branches connected in parallel, wherein the plurality of battery branches are connected via power lines, and the method comprises: If one of the multiple battery branches is in a powered-on state, detecting power line connections of the multiple battery branches based on branch voltages of the multiple battery branches; If at least two of the multiple battery branches are in a powered-on state, the battery branches in the powered-on state are determined as powered-on branches, and the power line connection of the powered-on branch is detected based on the branch current of the powered-on branch and the total current of the multiple battery branches.

2. The power line detection method according to claim 1, characterized in that: The plurality of battery branches include at least three battery branches, and the detecting the power line connection of the plurality of battery branches based on the branch voltages of the plurality of battery branches includes: Determine the battery branches in the power-on state among the multiple battery branches as the power-on branches, and determine the battery branches in the power-off state among the multiple battery branches as the power-off branches; Determining the branch voltage of the power-down branch as the detection voltage; Based on the detected voltage, power line connections of the plurality of battery branches are detected.

3. The power line detection method according to claim 2, characterized in that: The detecting the power line connection of the plurality of battery branches based on the detection voltage includes: If the detection voltage is within a preset voltage range, determining the power-down branch corresponding to the detection voltage as the first branch; If the detection voltage is not within the preset voltage range, determining the power-down branch corresponding to the detection voltage as the second branch; If the down-powered branch includes the first branch and the second branch, it is determined that the power line connection of the second branch is in an abnormal connection state, and the power line connection of the up-powered branch and the first branch is in a normal connection state; If the lower power branches are all the second branches, determining that the power line connection of the upper power branch is in an abnormal connection state; If the down-power branches are all the first branches, it is determined that the power line connections of the multiple battery branches are all in a normal connection state.

4. The power line detection method according to claim 1, characterized in that: The plurality of battery branches include two battery branches, and the detecting the power line connection of the plurality of battery branches based on the branch voltages of the plurality of battery branches includes: Determining a branch voltage of a lower power branch among the plurality of battery branches as a detection voltage; If the detected voltage is not within the preset voltage range, determining that a power line connection of a battery branch among the multiple battery branches is in an abnormal connection state; If the detected voltage is within the preset voltage range, it is determined that the power line connections of the plurality of battery branches are all in a normal connection state.

5. The power line detection method according to claim 1, characterized in that: The detecting the power line connection of the powered-on branch based on the branch current of the powered-on branch and the total current of the plurality of battery branches comprises: If the branch current satisfies the first condition, determining the powered-on branch corresponding to the branch current as the third branch; If the branch current satisfies the second condition, determining the powered-on branch corresponding to the branch current as the fourth branch; If the total current is greater than a first current threshold and the powered-on branch includes the third branch and the fourth branch, it is determined that the power line connection of the fourth branch is in an abnormal connection state.

6. The power line detection method according to claim 5, characterized in that: The method further comprises: If the branch current is greater than a second current threshold, determining that the branch current satisfies the first condition; If the branch current is continuously within the preset current range within the first time period, it is determined that the branch current satisfies the second condition.

7. The power line detection method according to claim 1, characterized in that: The method further comprises: If the plurality of battery branches are all in a power-off state, determining a target branch from the plurality of battery branches according to branch battery pack voltages of the plurality of battery branches; In response to the power-on instruction, the target branch is controlled to be powered on, and the powered-on target branch is determined as the powered-on branch.

8. The power line detection method according to claim 1, characterized in that: The determining a target branch from the plurality of battery branches according to the branch battery pack voltages of the plurality of battery branches comprises: Obtaining branch battery group voltages of the plurality of battery branches to obtain a voltage set; determining a highest voltage from the set of voltages; The battery branch corresponding to the highest voltage is determined as the target branch.

9. The power line detection method according to claim 3 or 4, characterized in that: After determining that the power line connection is in an abnormal connection state, the method further includes: Controlling all powered-on branches in the plurality of battery branches to be powered-off, and calculating the power-off duration; If the power-off time does not reach the second time, the plurality of battery branches are prohibited from being powered on.

10. An energy storage device, characterized in that: The method comprises a memory, a processor and computer-readable instructions stored in the memory and executable on the processor, wherein the computer-readable instructions, when executed by the processor, implement the power line detection method according to any one of claims 1 to 9.

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