Short-circuit protection circuit and energy storage system
By designing a short-circuit protection circuit for intelligent fuses in a parallel circuit of multi-cluster batteries, the problem that branch and dry fuses cannot cooperate with each other during dry short circuit is solved, and graded protection is achieved, reducing operation and maintenance costs.
Patent Information
- Application Number
- CN202420857885.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-23
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-04-23
AI Technical Summary
In the parallel circuit of multi-cluster battery, the branch fuse and the dry fuse cannot cooperate with each other to protect each other during the dry circuit short circuit, resulting in "overgraded protection" phenomenon and increasing operation and maintenance costs.
A short-circuit protection circuit is designed, including the dry circuit protection module of the intelligent fuse and n branch fuses. The intelligent fuse is disconnected when the dry circuit is short-circuited to achieve graded protection.
Grade protection of branch and dry fuses is realized, avoiding the phenomenon of "graduation protection" and reducing operation and maintenance costs.
Smart Images
Figure CN222484281U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of automatic control technology, and in particular to a short circuit protection circuit and an energy storage system. Background Art
[0002] With the continuous development of new energy, there are more and more multi-cluster battery parallel circuits. Due to the existence of short circuits and other phenomena, the existing technical solution is to connect a fuse in series in each branch and main circuit to protect the circuit from damage. However, when a short circuit occurs in the main circuit, the fuses in each branch circuit will blow, making it impossible for the fuse in the main circuit to blow, and finally the phenomenon of "override protection" will occur, which cannot achieve the purpose of mutual protection between the branch circuit fuse and the main circuit fuse. In addition, due to the large number of branches, the number of blown fuses is large, which increases the operation and maintenance costs. Utility Model Content
[0003] In view of the above problems, the present application proposes a short circuit protection circuit and an energy storage system.
[0004] The embodiment of the present application provides a short circuit protection circuit, comprising: a main circuit protection module having an intelligent fuse therein and n branch circuit fuses;
[0005] One end of each branch fuse is connected in parallel to the main circuit protection module, and the other end of each branch fuse is used to connect the corresponding external battery, so that the current of each external battery is transmitted to the external circuit connected to the main circuit protection module through the corresponding branch fuse and the main circuit protection module;
[0006] The intelligent fuse is used to disconnect the path between each of the external batteries and the external circuit when a main circuit short circuit occurs.
[0007] Further, in the above-mentioned short-circuit protection circuit, the main circuit protection module includes a main circuit fuse, and the main circuit fuse is connected in parallel with the smart fuse;
[0008] The main circuit fuse is used to blow after the smart fuse is disconnected.
[0009] Furthermore, in the above-mentioned short-circuit protection circuit, the resistance value of the equivalent resistance in the main circuit of the short-circuit protection circuit in which the main circuit fuse is connected in series is greater than the resistance value of the equivalent resistance in the main circuit of the short-circuit protection circuit in which the smart fuse is connected in series.
[0010] Furthermore, in the above short-circuit protection circuit, the short-circuit current of the main circuit fuse is the same as that of each branch circuit fuse.
[0011] Further, in the above-mentioned short-circuit protection circuit, the intelligent fuse is an active fuse, and the active fuse includes an electronic switch, a voltage sensor, a current sensor and a circuit breaker controller; the electronic switch is connected in series to the trunk of the short-circuit protection circuit, and the circuit breaker controller is connected to the voltage sensor and the current sensor respectively; the voltage sensor and the current sensor are used to detect the trunk voltage and the trunk current respectively;
[0012] The circuit breaker controller is used to control the electronic switch to disconnect when it is detected that the main circuit voltage or the main circuit current reaches a corresponding threshold.
[0013] Furthermore, in the above-mentioned short-circuit protection circuit, the intelligent fuse includes an electromagnetic induction microswitch; the electromagnetic induction microswitch is connected in series to the main circuit of the short-circuit protection circuit; when the main circuit of the short-circuit protection circuit is short-circuited, the electromagnetic induction microswitch is disconnected.
[0014] Furthermore, in the above short-circuit protection circuit, the pre-arcing value T of each branch fuse is 2 Equal to the pre-arcing value T of the smart fuse 1 <n*T 2 .
[0015] Furthermore, in the above-mentioned short-circuit protection circuit, the short-circuit current of the intelligent fuse is n times the short-circuit current of the branch fuse.
[0016] Furthermore, in the above-mentioned short-circuit protection circuit, each branch fuse is used to be blown when the corresponding branch is short-circuited.
[0017] Another embodiment of the present application further provides an energy storage system, comprising the above-mentioned short-circuit protection circuit.
[0018] The embodiments of the present application have the following beneficial effects:
[0019] The embodiment of the present application proposes a short-circuit protection circuit, comprising: a main circuit protection module with an intelligent fuse inside and n branch circuit fuses; one end of each branch circuit fuse is connected to the main circuit protection module in parallel, and the other end of each branch circuit fuse is used to connect the corresponding external battery, so that the current of each external battery is transmitted to the external circuit connected to the main circuit protection module through the corresponding branch circuit fuse and the main circuit protection module; the intelligent fuse is used to disconnect the path between each external battery and the external circuit when a main circuit short-circuits. The present application can achieve hierarchical protection and reduce costs by causing the corresponding branch circuit fuse to blow when a branch circuit short-circuits; and by causing the corresponding intelligent fuse to blow when a main circuit short-circuits, thereby achieving hierarchical protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope of protection of the present application. In each of the drawings, similar components are numbered similarly.
[0021] Figure 1 A first structural schematic diagram of a short-circuit protection circuit according to some embodiments of the present application is shown;
[0022] Figure 2 A second structural schematic diagram of a short-circuit protection circuit according to some embodiments of the present application is shown;
[0023] Figure 3 A schematic structural diagram of a main circuit protection module of a short circuit protection circuit in some embodiments of the present application is shown.
[0024] Explanation of main component symbols: 110-main circuit protection module; 120-branch circuit fuse; 111-intelligent fuse; 112-main circuit fuse; 100-short circuit protection circuit; 200-external battery; 300-external circuit. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.
[0026] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.
[0027] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing items.
[0028] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.
[0029] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.
[0030] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0031] Normally, in a circuit with multiple clusters connected in parallel, if a short circuit occurs in the main circuit, the fuse of each branch circuit will be blown. This is because the pre-arc value of the main circuit fuse 112 is larger than the pre-arc value of the branch circuit fuse 120, that is, when a short circuit occurs in the main circuit, both the branch circuit fuse 120 and the main circuit fuse 112 are in the blowing stage, but the main circuit fuse 112 takes more time to blow, while the branch circuit fuse 120 takes less time to blow, resulting in the branch circuit fuse 120 blowing faster and the main circuit fuse 112 blowing slower, and finally causing the branch circuit fuse 120 to blow first and the main circuit fuse 112 failing to blow.
[0032] Therefore, in order to solve the above problem, the present application proposes a short circuit protection circuit 100 .
[0033] Please refer to Figure 1 , is a schematic diagram of a structure of a short circuit protection circuit 100 proposed in an embodiment of the present application. Exemplarily, the short circuit protection circuit 100 is applied in an energy storage system.
[0034] In some embodiments, Figure 1 to Figure 2 As shown, the short-circuit protection circuit 100 includes: a main circuit protection module 110 with an intelligent fuse 111 therein and n branch circuit fuses 120. One end of each branch circuit fuse 120 is connected in parallel to the main circuit protection module 110, and the other end of each branch circuit fuse 120 is used to connect the corresponding external battery 200, so that the current of each external battery 200 is transmitted to the external circuit 300 connected to the main circuit protection module 110 through the corresponding branch circuit fuse 120 and the main circuit protection module 110. When a short circuit occurs in the main circuit, the intelligent fuse 111 is used to disconnect the path between each external battery 200 and the external circuit 300.
[0035] Specifically, each external battery 200 is connected in parallel to gather the electric energy of each battery to power the external circuit 300. The external circuit 300 can be a converter. The converter converts the current gathered by each battery to power the power grid connected to the output interface of the converter. There are many main circuit short circuit situations, including any external battery 200 short circuit. Since each external battery 200 is connected in parallel, when an external battery 200 is short-circuited, all other batteries are short-circuited, which will cause the branch fuse 120 on each branch to be in the initial melting state. In the existing scheme, there are only main circuit fuses 112 on several roads, and the time required for the main circuit fuse 112 to melt is greater than the time for the branch circuit fuse 120 to melt, and finally each branch circuit fuse 120 is melted, and the main circuit fuse 112 is not melted, thereby failing to achieve the original intention of the original design of the main circuit fuse 112. This phenomenon occurs because the pre-arc value and melting heat of the fuse are not taken into account. Fusing heat refers to the heat generated on the resistor, which is used in the fusing process of the fuse.
[0036] When the current exceeds the short-circuit current of the fuse, the resistor will generate heat, and the fuse can cut off the current by melting the fuse element on the metal electrode. Pre-arc refers to the state in which the fuse is in a closed state when it is working. In the closed state, there is a very high current between the metal electrodes of the fuse, which will cause an arc to be generated between the electrode and the contact surface through which the current passes. In the pre-arc state, the arc formed between the electrodes will generate heat, which will be used for the melting process of the fuse. Under the same current, the larger the pre-arc value, the longer the melting process takes, and the slower the melting. In order to ensure the normal operation of the circuit, the short-circuit current of the main circuit fuse 112 is not less than the sum of the short-circuit currents of each branch fuse 120, and the pre-arc value of the main circuit fuse 112 is greater than the pre-arc value of the branch fuse 120, so that the time required for melting is longer, causing the branch fuse 120 to melt first. The main circuit protection module 110 in this embodiment will be cut off when the main circuit is short-circuited, so that each branch circuit fuse 120 will not be blown, which greatly reduces the cost.
[0037] In addition, each branch fuse 120 is used to fuse when the corresponding branch is short-circuited, and when the main circuit is short-circuited, the intelligent fuse 111 in the main circuit protection module 110 on the main circuit is disconnected, thereby effectively achieving the purpose of hierarchical protection. Among them, the short-circuit current can be a current that exceeds the fuse and begins to enter the pre-arcing state. Among them, n is a positive integer, for example, it can be 10 or 20, etc., of course, it can also be other numbers, depending on the specific usage scenario, and there is no limitation here.
[0038] In some embodiments of the short circuit protection circuit 100, as Figure 3As shown, the main circuit protection module 110 further includes a main circuit fuse 112 , and the main circuit fuse 112 is connected in parallel with the smart fuse 111 .
[0039] Specifically, the main circuit fuse 112 is used to blow after the smart fuse 111 is disconnected. Considering that the total current on the main circuit is large and the breaking capacity of the smart fuse 111 is limited, a main circuit fuse 112 needs to be connected in parallel for current diversion.
[0040] In some embodiments of the short circuit protection circuit 100 , the resistance of the equivalent resistor in the main circuit of the protection circuit connected in series with the main circuit fuse 112 is greater than the resistance of the equivalent resistor in the main circuit of the protection circuit connected in series with the smart fuse 111 .
[0041] Specifically, when the trunk line is short-circuited, in order to make the smart fuse 111 blow first and the trunk line fuse 112 blow later, it is necessary that more than half of the total current on the trunk line needs to pass through the smart fuse 111, and a small part of the current passes through the trunk line fuse 112. Therefore, the resistance value of the equivalent resistance of the smart fuse 111 connected in series in the trunk line must be much smaller than the resistance value of the equivalent resistance of the trunk line fuse 112 connected in series in the trunk line. For example, if the short-circuit current of several lines is 2000A, 90% of the current needs to pass through the smart fuse 111 and 10% of the current needs to pass through the trunk line fuse 112. Then, the resistance value of the equivalent resistance of the trunk line fuse 112 connected in series in the trunk line is 9 times the resistance value of the equivalent resistance of the smart fuse 111 connected in series in the trunk line. Then, the current passing through the smart fuse 111 is 1800A, and the current passing through the trunk line fuse 112 is 200A.
[0042] In some embodiments of the short circuit protection circuit 100 , the pre-arcing value T2 of each branch fuse 120 is equal, and the pre-arcing value T1 of the smart fuse 111 is less than n*T2.
[0043] Specifically, since the smart fuse 111 is connected in series to the main circuit, if the model of each branch fuse 120 is the same, the current passing through each branch fuse 120 is I, and the current on the main circuit is nI. Therefore, when the main circuit is short-circuited, the smart fuse 111 will blow first. Under the premise that the current is nI, the corresponding pre-arc value must be less than n*T2, so that it can blow before the branch fuse 120 blows.
[0044] Exemplarily, if the pre-arcing value of each branch fuse 120 is a, there are 20 branches in total, and each branch has a branch fuse 120, then the pre-arcing value of the smart fuse 111 is less than 20a.
[0045] In some embodiments of the short-circuit protection circuit 100 , the short-circuit current of the smart fuse 111 is n times the short-circuit current of the branch fuse 120 .
[0046] Specifically, if the short-circuit current of the smart fuse 111 is too small, the entire circuit cannot operate; if the short-circuit current is too large, the smart fuse 111 cannot be blown before the main fuse 112 is blown.
[0047] For example, if the short-circuit current of each branch is 100A, there are 10 branches in total, and the short-circuit current of the smart fuse 111 is 800A. Assuming that the current of each branch is 90A, according to the design concept, this is a normal working state. However, since the current on the main line reaches 900A, which exceeds the short-circuit current of the smart fuse 111, the smart fuse 111 will be blown and cannot work normally. Therefore, the selection of the short-circuit current of the smart fuse 111 is particularly important.
[0048] In some embodiments of the short circuit protection circuit 100 , the short circuit current of the main fuse 112 and each branch fuse 120 is the same.
[0049] Specifically, since the main circuit fuse 112 exists mainly to make up for the defect of limited segmentation capacity of the smart fuse 111. Therefore, when the main circuit is short-circuited, after the smart fuse 111 is blown, the main circuit fuse 112 must also be able to blow immediately, and must blow before the branch circuit fuse 120 is blown. Therefore, the selection of the main circuit fuse 112 is also very important. The model of the main circuit fuse 112 can be the same as the model of the branch circuit fuse 120. In this way, when the smart fuse 111 is blown, the total current on the main circuit passes through the main circuit fuse 112. Since the total current at this time far exceeds the short-circuit current of the main circuit fuse 112, the main circuit fuse 112 is quickly blown. Of course, the model of the main circuit fuse 112 can also be other, for example, the short-circuit current of the main circuit fuse 112 can also be slightly higher than the short-circuit current of the branch circuit fuse 120. For example, the short-circuit current of the branch fuse 120 is 250A, and the short-circuit current of the main circuit fuse 112 is in the range of 250 to 500A. Of course, it can also be in other ranges, which are not limited here. The short-circuit current selection of the main circuit fuse 112 is also related to the main circuit short-circuit current. In short, the main circuit short-circuit current is smaller than the main circuit short-circuit current.
[0050] In some embodiments of the short-circuit protection circuit 100, the smart fuse 111 is an active fuse, which includes an electronic switch, a voltage sensor, a current sensor, and a circuit breaker controller; the electronic switch is connected in series to the trunk of the short-circuit protection circuit 100, and the circuit breaker controller is connected to the voltage sensor and the current sensor respectively; the voltage sensor and the current sensor are used to detect the trunk voltage and the trunk current. The circuit breaker controller is used to control the electronic switch to disconnect when it is detected that the trunk voltage or the trunk current reaches the corresponding threshold.
[0051] Specifically, the smart fuse 111 can be active or passive. This embodiment proposes an active type. When a system circuit fails or is overloaded, the current and voltage will change. The active fuse can monitor these signals in real time through current sensors and voltage sensors, and transmit them to the circuit breaker controller for analysis and processing. If the current or voltage of the system circuit exceeds the set threshold, the circuit breaker controller will control the electronic switch to cut off the circuit to protect the electrical equipment from damage. Among them, the electronic switch can be cut off by the fuse blowing, etc., which is not limited here.
[0052] In some embodiments of the short-circuit protection circuit 100, the smart fuse 111 includes an electromagnetic induction microswitch; the electromagnetic induction microswitch is connected in series to the main circuit of the protection circuit; when the main circuit of the protection circuit is short-circuited, the electromagnetic induction microswitch is disconnected.
[0053] Specifically, the smart fuse 111 in this embodiment is a passive fuse, which does not require an additional controller to control the switch to be turned off. Instead, it uses the principle of electromagnetic induction. When the current on the main line reaches a certain value, the electromagnetic induction micro switch will automatically disconnect.
[0054] The embodiment of the present application proposes a short circuit protection circuit 100, comprising: a main circuit protection module 110 with an intelligent fuse 111 therein and n branch circuit fuses 120; one end of each branch circuit fuse 120 is connected in parallel to the main circuit protection module 110, and the other end of each branch circuit fuse 120 is used to connect the corresponding external battery 200, so that the current of each external battery 200 is transmitted to the external circuit 300 connected to the main circuit protection module 110 through the corresponding branch circuit fuse 120 and the main circuit protection module 110; the intelligent fuse 111 is used to disconnect the path between each external battery 200 and the external circuit 300 when a main circuit short circuit occurs. The present application can melt the corresponding branch circuit fuse 120 when the branch circuit is short-circuited; and the corresponding intelligent fuse 111 melts when the main circuit is short-circuited, so as to achieve hierarchical protection and reduce costs.
[0055] Another embodiment of the present application further provides an energy storage system, including the above-mentioned short-circuit protection circuit 100 .
[0056] It can be understood that the short-circuit protection circuit of this embodiment corresponds to the short-circuit protection circuit 100 in the above embodiment, wherein the options of the above short-circuit protection circuit 100 are also applicable to this embodiment and will not be described repeatedly here.
[0057] In several embodiments provided in the present application, it should be understood that the disclosed device can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a part of the module, program segment or code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow diagram, and the combination of boxes in the structure diagram and / or the flow diagram, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.
[0058] In addition, the functional modules or units in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
[0059] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.
[0060] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.
Claims
1. A short circuit protection circuit, characterized in that: include: It is equipped with a main circuit protection module of an intelligent fuse and n branch circuit fuses; One end of each branch fuse is connected in parallel to the main circuit protection module, and the other end of each branch fuse is used to connect the corresponding external battery, so that the current of each external battery is transmitted to the external circuit connected to the main circuit protection module through the corresponding branch fuse and the main circuit protection module; The intelligent fuse is used to disconnect the path between each of the external batteries and the external circuit when a main circuit short circuit occurs.
2. The short circuit protection circuit according to claim 1, characterized in that: The main circuit protection module includes a main circuit fuse, and the main circuit fuse is connected in parallel with the smart fuse; The main circuit fuse is used to blow after the smart fuse is disconnected.
3. The short circuit protection circuit according to claim 2, characterized in that: The resistance value of the equivalent resistor in the main circuit of the short-circuit protection circuit in which the main circuit fuse is connected in series is greater than the resistance value of the equivalent resistor in the main circuit of the short-circuit protection circuit in which the smart fuse is connected in series.
4. The short circuit protection circuit according to claim 2, characterized in that: The short-circuit current of the main fuse is the same as that of each of the branch fuses.
5. The short circuit protection circuit according to claim 1, characterized in that: The intelligent fuse is an active fuse, which includes an electronic switch, a voltage sensor, a current sensor and a circuit breaker controller; the electronic switch is connected in series to the trunk of the short-circuit protection circuit, and the circuit breaker controller is connected to the voltage sensor and the current sensor respectively; the voltage sensor and the current sensor are used to detect the trunk voltage and the trunk current respectively; The circuit breaker controller is used to control the electronic switch to disconnect when it is detected that the main circuit voltage or the main circuit current reaches a corresponding threshold.
6. The short circuit protection circuit according to claim 1, characterized in that: The intelligent fuse includes an electromagnetic induction micro switch; the electromagnetic induction micro switch is connected in series to the main circuit of the short-circuit protection circuit; when the main circuit of the short-circuit protection circuit is short-circuited, the electromagnetic induction micro switch is disconnected.
7. The short circuit protection circuit according to claim 1, characterized in that: The pre-arcing value T2 of each branch fuse is equal, and the pre-arcing value T1 of the intelligent fuse is less than n*T2.
8. The short circuit protection circuit according to claim 1, characterized in that: The short-circuit current of the intelligent fuse is n times the short-circuit current of the branch fuse.
9. The short circuit protection circuit according to claim 1, characterized in that: Each branch fuse is used to fuse when the corresponding branch is short-circuited.
10. An energy storage system, characterized in that: A short-circuit protection circuit comprising any one of claims 1 to 9.