A method, apparatus and system for arc detection

Abstract

This application discloses a method, apparatus, and system for arcing detection. It acquires the battery voltage of an energy storage converter (PCS), as well as the bus voltage and branch current within the PCS. When an abnormal branch current is detected, the voltage difference between the battery voltage and the bus voltage is acquired. When the voltage difference exceeds a preset threshold, an arcing fault is determined to have occurred in the PCS. The branch experiencing the arcing fault is associated with the branch exhibiting the abnormal current. This application is applicable to PCS with two (or more) branches, capable of monitoring the current in multiple branches and determining whether an arcing fault has occurred via voltage difference. It also supports the location of the branch experiencing the arcing fault. The solution is easy to operate and requires no additional arcing sensors, resulting in lower costs.

Description

Technical Field

[0001] This application relates to the field of energy storage system technology, and in particular to a method, apparatus and system for arc detection. Background Technology

[0002] When grounding faults and short-circuit faults occur in an energy storage system, abnormal current and voltage can occur, and even electric arcs can be generated, affecting the normal operation of the energy storage system. Timely arc detection to locate and eliminate the fault is crucial for the operation of the energy storage system. Arc detection utilizes the characteristics of an electric arc to detect faults. An electric arc is a high-temperature, high-energy discharge phenomenon with high current and voltage. In arc detection, by analyzing parameters such as the current, voltage, and time of the arc, the location and type of the fault can be determined.

[0003] Existing technologies contain numerous researches on arcing detection methods for single-branch energy storage systems. However, due to the circuit differences between dual (multi-branch) energy storage systems and single-branch systems, existing arcing detection methods cannot be directly applied to dual (multi-branch) energy storage systems, thus affecting their safety. Therefore, how to perform arcing detection for dual (multi-branch) energy storage systems is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method, apparatus, and system for arc detection, specifically for arc detection in dual (multi) branch energy storage systems.

[0005] This application discloses a method for arc detection, the method comprising:

[0006] Obtain the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS;

[0007] If the branch current is detected to be abnormal, the voltage difference between the battery voltage and the bus voltage is obtained;

[0008] When the differential pressure is greater than the preset differential pressure, it is determined that the PCS has an arcing fault, wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current.

[0009] Optionally, the PCS includes n branches, and detecting that the branch current is an abnormal current includes:

[0010] When the branch current of the first branch is detected to drop to 0, or when the branch current of the first branch is detected to exceed the threshold, it is determined that the abnormal current has been detected.

[0011] Optionally, determining that the PCS has experienced an arcing fault when the branch current of the first branch is detected to drop to 0 includes:

[0012] The branch in the PCS where the arcing fault occurred is identified as the first branch.

[0013] Optionally, determining that the PCS has experienced an arcing fault when the branch current of the first branch exceeds a threshold includes:

[0014] The branch in the PCS that experienced the arcing fault was identified as the branch connected in parallel with the first branch.

[0015] Optionally, after determining that the PCS has experienced an arcing fault, the method further includes:

[0016] Shut down the PCS.

[0017] Optionally, after obtaining the voltage difference between the battery voltage and the bus voltage, the method further includes:

[0018] When the differential pressure is not greater than the preset differential pressure, it is determined that the PCS has not experienced an arcing fault, and the abnormal current continues to be detected.

[0019] Optionally, the preset differential pressure is 20V.

[0020] Based on the above-mentioned method for arc detection, this application also discloses an apparatus for arc detection, comprising: an acquisition unit and a determination unit;

[0021] The acquisition unit is used to acquire the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS.

[0022] The acquisition unit is also used to acquire the voltage difference between the battery voltage and the bus voltage when the branch current is detected to be an abnormal current.

[0023] The determining unit is used to determine that the PCS has an arcing fault when the pressure difference is greater than a preset pressure difference; wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current.

[0024] Optionally, the PCS contains n branches, and the acquisition unit includes:

[0025] A determination subunit is used to determine that the abnormal current is detected when the branch current of the first branch drops to 0 or the branch current of the first branch exceeds a threshold.

[0026] Optionally, when the branch current of the first branch is detected to drop to 0, the determining subunit is used to:

[0027] The branch in the PCS where the arcing fault occurred is identified as the first branch.

[0028] Optionally, if the branch current of the first branch is detected to exceed a threshold, the determining subunit is used to:

[0029] The branch in the PCS that experienced the arcing fault was identified as the branch connected in parallel with the first branch.

[0030] Optionally, after determining that the PCS has experienced an arcing fault, the device is further configured to:

[0031] Shut down the PCS.

[0032] Optionally, after acquiring the voltage difference between the battery voltage and the bus voltage, the device is further configured to:

[0033] When the differential pressure is not greater than the preset differential pressure, it is determined that the PCS has not experienced an arcing fault, and the abnormal current continues to be detected.

[0034] Optionally, the preset differential pressure is 20V.

[0035] Based on the above-mentioned arc detection method, this application also discloses an arc detection system for implementing the above-mentioned method, the system comprising: a sampling module, a battery cluster management system, and a digital signal processor;

[0036] The sampling module is used to acquire the bus voltage and branch current in the energy storage converter PCS. When the branch current is detected to be abnormal, the module sends an abnormal signal and the bus voltage to the digital signal processor. The abnormal signal includes the branch information corresponding to the abnormal current.

[0037] The battery cluster management system is used to collect the battery voltage of the PCS and send the battery voltage to the digital signal processor;

[0038] The digital signal processor is used to respond to the abnormal signal, obtain the voltage difference between the battery voltage and the bus voltage, and compare the voltage difference with a preset voltage difference;

[0039] It is also used to locate the branch where the arcing fault occurs by means of the abnormal signal, wherein the branch where the arcing fault occurs is associated with the branch where the current is the abnormal current.

[0040] Optionally, the system is also configured to: shut down the PCS in response to the abnormal signal.

[0041] This application discloses a method, apparatus, and system for arcing detection. It acquires the battery voltage of an energy storage converter (PCS), as well as the bus voltage and branch current within the PCS. When an abnormal branch current is detected, the voltage difference between the battery voltage and the bus voltage is acquired. When the voltage difference exceeds a preset threshold, an arcing fault is determined to have occurred in the PCS. The branch experiencing the arcing fault is associated with the branch exhibiting the abnormal current. This application is applicable to PCS with two (or more) branches, capable of monitoring the current in multiple branches and determining whether an arcing fault has occurred via voltage difference. It also supports the location of the branch experiencing the arcing fault. The solution is easy to operate and requires no additional arcing sensors, resulting in lower costs. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0043] Figure 1a This is a schematic flowchart of a method for arc detection disclosed in an embodiment of this application;

[0044] Figure 1b This is a schematic diagram of the structure of the dual-branch energy storage converter disclosed in the embodiments of this application;

[0045] Figure 2 This is a flowchart illustrating another arc detection method disclosed in an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of the structure of an arc detection device disclosed in an embodiment of this application;

[0047] Figure 4 This is a schematic diagram of the structure of an arc detection system disclosed in an embodiment of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] In one embodiment, this application discloses a method for arc detection.

[0050] For details, please refer to Figure 1aThe arc detection method disclosed in this embodiment includes the following steps:

[0051] Step 101: Obtain the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS.

[0052] In the method described in this embodiment, as an optional approach, steps 101 to 103 can be implemented using an arc detection system disclosed in this application. Specifically, this can be achieved by continuously acquiring the bus voltage and branch current of each branch in the PCS through a sampling module in the system.

[0053] PCS can be a dual-branch or multi-branch version. Figure 1b This is a schematic diagram of the structure of the dual-branch energy storage converter disclosed in the embodiments of this application, as shown below. Figure 1b As shown, the left side, including RACK1 and RACK2, is the battery side; RACK1 and RACK2 are battery clusters. The right side is the DC side; I1 is one branch in the PCS, and I2 is another branch in the PCS. Among them, FU... +1 and FU +2 FU is the positive electrode fuse. - RS1 and RS2 are the negative electrode fuses, RS1 and RS2 are shunts, and C is the bus capacitor. Correspondingly, in the multi-branch version of the PCS, there are also I3, I4, ... I... n .

[0054] Step 102: If the branch current is detected to be abnormal, obtain the voltage difference between the battery voltage and the bus voltage.

[0055] In the method described in this embodiment, when the PCS contains two branches, an abnormal current is detected when the branch current of the first branch drops to 0, or when an abnormal increase in the branch current of the second branch (connected in parallel with the first branch) is detected, for example, when the current changes from half (50%) of the total current to 100% of the total current. Similarly, when the PCS contains n (n>1) branches, an abnormal current is detected when the branch current of the first branch drops to 0, or when an abnormal increase in the branch current of another branch connected in parallel with the first branch is detected, for example, when the current increases from one-nth of the total current to one-n-1th of the total current.

[0056] In actual operation, the branch current of the first branch drops to 0 and the branch current of the second branch connected in parallel with the first branch increases abnormally at the same time. Therefore, in order to avoid either of these situations going undetected, it can be determined that an abnormal current has been detected regardless of which situation is detected.

[0057] In the method described in this embodiment, when an abnormal current is detected in the branch current, the sampling module sends an abnormal signal and the bus voltage to the digital signal processor in the arc detection system disclosed in this application. Optionally, the abnormal signal includes the branch corresponding to the abnormal current.

[0058] In the method described in this embodiment, the battery cluster management system in the arc detection system disclosed in this application can collect the battery voltage of the PCS in real time and send the battery voltage to the digital signal processor. The digital signal processor then responds to the abnormal signal, calculates the difference between the battery voltage and the bus voltage to obtain the differential voltage, which is used for comparison with a preset differential voltage.

[0059] As an alternative method, the battery voltage can be divided by the bus voltage to obtain a quotient, which can then be compared with a preset quotient. The calculation of the battery voltage and bus voltage is not specifically limited here; the goal is simply to obtain a value for comparison with the preset value. Similarly, the form of the preset value is not specifically limited; the goal is simply to enable comparison and obtain a result.

[0060] Step 103: When the differential pressure is greater than the preset differential pressure, it is determined that the PCS has an arcing fault, wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current.

[0061] In the method described in this embodiment, the digital signal processor compares the voltage difference obtained in step 102 with a preset voltage difference. When the voltage difference is greater than the preset voltage difference, it is determined that an arcing fault has occurred in the PCS. The preset voltage difference can be 20V. This is because during normal operation of a dual-branch PCS, the two branches have a certain current sharing characteristic, with each branch receiving half of the current, i.e., I0. 总 = I1 + I2. Assuming I1 in branch A drops to 0, and the total current remains unchanged, all current will be output from branch B, causing I2 in branch B to double. Therefore, a voltage difference appears between branch A and branch B. Based on the research conclusions of single-branch PCS arcing, a voltage difference of over 20V will be generated across the arcing point at the instant of arcing. Therefore, a preset voltage difference of 20V can be set to determine whether an arcing fault has occurred in the PCS.

[0062] As an alternative method, after determining that an arcing fault has occurred in the PCS, the arcing detection system disclosed in this application can also shut down the PCS and provide a reminder through sound, warning light, voice, etc. The reminder operation of the system after shutdown is not specifically limited here; it is sufficient to remind the user that an arcing fault has occurred in the PCS.

[0063] In the method described in this embodiment, the digital signal processor can locate the branch where the arcing fault occurs by parsing the abnormal signal and obtaining the branch corresponding to the abnormal current. Specifically, the first branch, that is, the branch where the branch current drops to 0, is located as the branch where the arcing fault occurs. As an optional method, such as... Figure 1b As shown, when the current of I1 drops to 0 or the current of I1 increases abnormally, I1 is identified as the branch where the arcing occurs.

[0064] The method described in this embodiment is applicable to dual (multi) branch PCS versions. Existing research on arc detection methods for single-branch PCS concludes that a voltage difference exceeding 20V will occur at the moment of an arc fault. However, in dual (multi) branch PCS, the condition for multiple branches to operate simultaneously is that the voltage difference between them should be as small as possible. A large voltage difference will result in a large circulating current at the moment of closing. Generally, the voltage difference range for multiple branches is set between 5-10V, meaning the maximum voltage difference for multiple branches should be less than 10V. Therefore, the conclusion of existing solutions that a voltage difference exceeding 20V will occur at the arc point contradicts the operating conditions of multi-branch PCS, and existing solutions cannot be directly applied to dual (multi) branch PCS versions. The method described in this embodiment can solve the arc detection and location problem for dual (multi) branch PCS versions without requiring additional arc sensors. The method is easy to operate and low in cost.

[0065] In one embodiment, this application discloses another method for arc detection; please refer to [link to relevant documentation]. Figure 2 This embodiment describes the entire process of arc detection and positioning for PCS with dual (multi) branches.

[0066] Step 201: Obtain the battery voltage of the PCS, as well as the bus voltage and branch current in the PCS.

[0067] Step 202: Determine if an abnormal branch current is detected. If yes, proceed to step 203. If no, return to step 201.

[0068] Step 203: Obtain the voltage difference between the battery voltage and the bus voltage.

[0069] Step 204: Determine if the pressure difference is greater than the preset pressure difference. If yes, proceed to step 205. If no, return to step 201.

[0070] Step 205: If a PCS arcing fault is detected, shut down the PCS.

[0071] Step 206: Locate the branch where the arcing occurred based on the branch corresponding to the abnormal current.

[0072] Based on the arc detection method disclosed in the above embodiments, this embodiment correspondingly discloses an arc detection device. Please refer to... Figure 3 The arc detection device includes: an acquisition unit 301 and a determination unit 302;

[0073] The acquisition unit 301 is used to acquire the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS.

[0074] The acquisition unit 301 is also used to acquire the voltage difference between the battery voltage and the bus voltage when the branch current is detected to be an abnormal current.

[0075] The determining unit 302 is used to determine that the PCS has an arcing fault when the pressure difference is greater than a preset pressure difference; wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current.

[0076] Optionally, the PCS includes n branches, and the acquisition unit 301 includes:

[0077] A determination subunit is used to determine that the abnormal current is detected when the branch current of the first branch drops to 0 or the branch current of the first branch exceeds a threshold.

[0078] Optionally, if the branch current of the first branch is detected to drop to 0, it is determined that an arcing fault has occurred in the PCS. The determining subunit is used for:

[0079] The branch in the PCS where the arcing fault occurred is identified as the first branch.

[0080] Optionally, if the branch current of the first branch is detected to exceed a threshold, it is determined that an arcing fault has occurred in the PCS. The determining subunit is used for:

[0081] The branch in the PCS that experienced the arcing fault was identified as the branch connected in parallel with the first branch.

[0082] Optionally, after determining that an arcing fault has occurred in the PCS, the device is further configured to:

[0083] Shut down the PCS.

[0084] Optionally, after acquiring the voltage difference between the battery voltage and the bus voltage, the device is further configured to:

[0085] When the differential pressure is not greater than the preset differential pressure, it is determined that the PCS has not experienced an arcing fault, and the abnormal current continues to be detected.

[0086] Optionally, the preset differential pressure is 20V.

[0087] Based on the above-described arc detection method, this application also discloses an arc detection system for implementing the above method. Please refer to [link to system description]. Figure 4 The system includes: a sampling module 401, a battery cluster management system 402, and a digital signal processor 403;

[0088] The sampling module 401 is used to continuously acquire the bus voltage and branch current in the energy storage converter PCS. When the branch current is detected to be abnormal, it sends an abnormal signal and the bus voltage to the digital signal processor. The abnormal signal includes the branch information corresponding to the abnormal current.

[0089] The battery cluster management system 402 is used to collect the battery voltage of the PCS in real time and send the battery voltage to the digital signal processor;

[0090] The digital signal processor 403 is used to respond to the abnormal signal, obtain the voltage difference between the battery voltage and the bus voltage, and compare the voltage difference with a preset voltage difference;

[0091] It is also used to locate the branch where the arcing fault occurs by means of the abnormal signal, wherein the branch where the arcing fault occurs is associated with the branch where the current is the abnormal current.

[0092] Optionally, the system is also configured to: shut down the PCS in response to the abnormal signal.

[0093] The embodiments in this specification are described in a progressive manner. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant details can be found in the method section.

[0094] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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. Without further limitations, 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 said element.

[0095] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0096] The features described in the embodiments of this specification can be substituted for or combined with each other, so that those skilled in the art can implement or use this application.

[0097] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for arc detection, characterized in that, include: Obtain the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS; If the branch current is detected to be abnormal, the voltage difference between the battery voltage and the bus voltage is obtained; When the differential pressure is greater than the preset differential pressure, it is determined that the PCS has an arcing fault, wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current; The PCS contains n branches, and detecting abnormal current in the branch includes: When the branch current of the first branch is detected to drop to 0, or when the branch current of the first branch is detected to exceed the threshold, it is determined that the abnormal current has been detected.

2. The method according to claim 1, characterized in that, The determination that the PCS has experienced an arcing fault when the branch current of the first branch is detected to drop to 0 includes: The branch in the PCS where the arcing fault occurred is identified as the first branch.

3. The method according to claim 1, characterized in that, The determination that the PCS has experienced an arcing fault when the branch current of the first branch exceeds a threshold includes: The branch in the PCS that experienced the arcing fault was identified as the branch connected in parallel with the first branch.

4. The method according to claim 1, characterized in that, After determining that the PCS has experienced an arcing fault, the method further includes: Shut down the PCS.

5. The method according to claim 1, characterized in that, After obtaining the voltage difference between the battery voltage and the bus voltage, the method further includes: When the differential pressure is not greater than the preset differential pressure, it is determined that the PCS has not experienced an arcing fault, and the abnormal current continues to be detected.

6. The method according to claim 1, characterized in that, The preset differential pressure is 20V.

7. A device for arc detection, characterized in that, include: Acquiring and determining units; The acquisition unit is used to acquire the battery voltage of the energy storage converter PCS, as well as the bus voltage and branch current in the PCS. The acquisition unit is also used to acquire the voltage difference between the battery voltage and the bus voltage when the branch current is detected to be an abnormal current. The determining unit is used to determine that an arcing fault has occurred in the PCS when the pressure difference is greater than a preset pressure difference; wherein the branch where the arcing fault occurs is related to the branch where the current is the abnormal current; The PCS contains n branches. The acquisition unit detects that the branch current is abnormal. Specifically, it is used to determine that the abnormal current is detected when the branch current of the first branch drops to 0 or the branch current of the first branch exceeds a threshold.

8. A system for arc detection, characterized in that, The system for implementing the methods of claims 1-6 includes: a sampling module, a battery cluster management system, and a digital signal processor; The sampling module is used to acquire the bus voltage and branch current in the energy storage converter PCS. When the branch current is detected to be abnormal, the module sends an abnormal signal and the bus voltage to the digital signal processor. The abnormal signal includes the branch information corresponding to the abnormal current. The battery cluster management system is used to collect the battery voltage of the PCS and send the battery voltage to the digital signal processor; The digital signal processor is used to respond to the abnormal signal, obtain the voltage difference between the battery voltage and the bus voltage, and compare the voltage difference with a preset voltage difference; It is also used to locate the branch where the arcing fault occurs by means of the abnormal signal.

9. The system according to claim 8, characterized in that, The system is also used to: shut down the PCS in response to the abnormal signal.

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