Overvoltage protection strategy determination method, fault protection method, device, and medium

Abstract

The embodiment of the application provides a kind of overvoltage protection strategy determination method, fault protection method, equipment and medium, belong to equipment protection field.Overvoltage protection strategy determination method includes: multiple impulse voltages are applied to the battery pack of energy storage device, and the impulse voltage critical value of battery pack is determined;A simulation model of energy storage device is constructed;The overvoltage fault simulation of each fault type is carried out to energy storage device using simulation model, and the first electrical change data and the second electrical change data corresponding to each fault type are obtained respectively;According to impulse voltage critical value, first electrical change data and second electrical change data, the protection strategy corresponding to each fault type of energy storage device is determined.Overvoltage condition of battery pack under different grounding states is analyzed through electrical change data, and then the protection strategy corresponding to each fault type is determined, to carry out overvoltage protection to battery pack in energy storage device, avoid overvoltage to cause battery pack damage, improve the security of battery pack.

Description

Technical Field

[0001] This invention relates to the field of equipment protection, and more specifically to an overvoltage protection strategy determination method, a fault protection method, equipment, and medium. Background Technology

[0002] With the rapid development of electric power technology, energy storage devices, including battery packs, are widely used in various scenarios. Typically, energy storage devices consist of DC and AC side systems. When the AC side system experiences asymmetrical short-circuit faults such as single-phase, two-phase, or three-phase short circuits, or when the DC side system experiences a fault, resonant overvoltages will occur in the energy storage device. These overvoltages not only affect the reliable operation of electrical components such as transformers, BMS (Battery Management System), and PCS (Power Conversion System) in the energy storage device, but can even lead to damage to these components.

[0003] Overvoltage protection for electrical components typically involves disconnecting them based on their impact. However, current technology usually only protects the battery pack in cases of short circuits, overcharging, and thermal runaway. After protecting the electrical components within the energy storage device, overvoltage protection for the battery pack itself is no longer provided. Overvoltage in the energy storage device can also affect the reliable operation of the battery pack, leading to damage and consequently, poor battery pack safety. Summary of the Invention

[0004] The purpose of this invention is to provide an overvoltage protection strategy determination method, a fault protection method, equipment, and medium. The overvoltage protection strategy determination method is used to solve the problem of poor safety of battery packs.

[0005] To achieve the above objectives, the first aspect of this application provides a method for determining an overvoltage protection strategy, the method comprising:

[0006] Multiple impulse voltages are applied to the battery pack of the energy storage device to determine the critical value of the impulse voltage of the battery pack. The energy storage device includes a battery pack and a transformer, and the battery pack is grounded.

[0007] Construct a simulation model of the energy storage device;

[0008] The simulation model was used to simulate overvoltage faults of each fault type in the energy storage device, and the first electrical change data and the second electrical change data corresponding to each fault type were obtained. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded.

[0009] Based on the critical value of the impulse voltage, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined.

[0010] In the embodiments of this application, the overvoltage protection strategy determination method further includes:

[0011] Multiple surge currents are applied to the battery pack, and the melting time of the adapter plate corresponding to each surge current is determined.

[0012] Based on the impulse voltage threshold, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined, including:

[0013] Based on the fuse-off time of the adapter piece, the critical value of the impulse voltage, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined.

[0014] In the embodiments of this application, multiple impulse voltages are applied to the battery pack of the energy storage device to determine the impulse voltage critical value of the battery pack, including:

[0015] Multiple impulse voltages are applied to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage.

[0016] Determine the critical value of the battery pack's impact voltage based on energy efficiency.

[0017] In the embodiments of this application, a simulation model is used to simulate overvoltage faults of each fault type in the energy storage device, and first electrical change data and second electrical change data corresponding to each fault type are obtained, including:

[0018] A simulation model was used to simulate an overvoltage-free fault in an energy storage device, and the electrical data of the energy storage device before the fault was obtained.

[0019] The simulation model was used to simulate overvoltage faults of each fault type in the energy storage device, and the first post-fault electrical data corresponding to each fault type was obtained when the transformer was grounded, and the second post-fault electrical data corresponding to each fault type was obtained when the transformer was not grounded.

[0020] The electrical data after each first fault is merged with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type. The electrical data after each second fault is merged with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

[0021] In the embodiments of this application, the energy storage device further includes a battery management device, which is used to control the on / off state of the battery pack;

[0022] If the fault type is an inter-terminal fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-terminal fault is detected.

[0023] When the transformer is grounded, if the fault type is a battery pack polarity fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared.

[0024] In the embodiments of this application, the energy storage device further includes an energy storage converter, which is used to control the current state of the battery pack.

[0025] When the transformer is not grounded, if the fault type is a two-phase short circuit in the transformer, the protection strategy is to perform no-power compensation on the battery management device side.

[0026] When the transformer is not grounded, if the fault type is a three-phase short circuit fault of the transformer, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to constant voltage state in the second time.

[0027] When the transformer is grounded, if the fault type is a single-phase short circuit fault or a three-phase short circuit fault, the protection strategy is to disconnect the transformer from the battery pack.

[0028] When the transformer is grounded, if the fault type is a two-phase short circuit fault, the protection strategy is to switch the state of the energy storage converter to constant voltage state in the second time.

[0029] A second aspect of this application provides a fault protection method, the fault protection method comprising:

[0030] If a fault is detected in the energy storage device, determine the target fault type corresponding to the fault;

[0031] Based on the protection strategy corresponding to the target fault type, fault protection is performed on the energy storage device. The protection strategy is obtained according to the overvoltage protection strategy determination method described above.

[0032] A third aspect of this application provides an overvoltage protection strategy determination device, which includes:

[0033] An impulse voltage application module is used to apply multiple impulse voltages to the battery pack of an energy storage device and determine the critical impulse voltage value of the battery pack. The energy storage device includes a battery pack and a transformer, and the battery pack is grounded.

[0034] The simulation model building module is used to build simulation models of energy storage devices;

[0035] The fault simulation module is used to simulate overvoltage faults of each fault type for the energy storage device using a simulation model, and obtain the first electrical change data and the second electrical change data corresponding to each fault type. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded.

[0036] The protection strategy determination module is used to determine the protection strategy for each fault type of the energy storage device based on the impulse voltage threshold, the first electrical change data, and the second electrical change data.

[0037] In embodiments of this application, the overvoltage protection strategy determination device further includes:

[0038] The fusing time determination module is used to apply multiple impact currents to the battery pack and determine the fusing time of the adapter piece corresponding to each impact current.

[0039] The protection strategy determination module is also used to determine the protection strategy for each fault type of the energy storage device based on the fuse time of the adapter piece, the critical value of the impulse voltage, the first electrical change data and the second electrical change data.

[0040] In embodiments of this application, the impulse voltage application module includes:

[0041] The energy efficiency determination submodule is used to apply multiple impulse voltages to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage.

[0042] The critical value determination submodule is used to determine the critical value of the battery pack's impact voltage based on energy efficiency.

[0043] In the embodiments of this application, the fault simulation module includes:

[0044] The simulation submodule is used to simulate overvoltage faults in energy storage devices using simulation models, and to obtain electrical data of the energy storage devices before the fault.

[0045] The electrical data acquisition submodule is used to simulate overvoltage faults of each fault type in the energy storage device using a simulation model, and to obtain the first post-fault electrical data corresponding to each fault type when the transformer is grounded, and the second post-fault electrical data corresponding to each fault type when the transformer is not grounded.

[0046] The electrical data merging submodule is used to merge the electrical data after each first fault with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type, and to merge the electrical data after each second fault with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

[0047] In the embodiments of this application, the energy storage device further includes a battery management device, which is used to control the on / off state of the battery pack;

[0048] If the fault type is an inter-terminal fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-terminal fault is detected.

[0049] When the transformer is grounded, if the fault type is a battery pack polarity fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared.

[0050] In the embodiments of this application, the energy storage device further includes an energy storage converter, which is used to control the current state of the battery pack.

[0051] When the transformer is not grounded, if the fault type is a two-phase short circuit in the transformer, the protection strategy is to perform no-power compensation on the battery management device side.

[0052] When the transformer is not grounded, if the fault type is a three-phase short circuit fault of the transformer, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to constant voltage state in the second time.

[0053] When the transformer is grounded, if the fault type is a single-phase short circuit fault or a three-phase short circuit fault, the protection strategy is to disconnect the transformer from the battery pack.

[0054] When the transformer is grounded, if the fault type is a two-phase short circuit fault, the protection strategy is to switch the state of the energy storage converter to constant voltage state in the second time.

[0055] A fourth aspect of this application provides a fault protection device, the fault protection device comprising:

[0056] The fault type determination module is used to determine the target fault type corresponding to the fault if a fault is detected in the energy storage device.

[0057] The fault protection module is used to provide fault protection for the energy storage device based on the protection strategy corresponding to the target fault type. The protection strategy is obtained according to the overvoltage protection strategy determination method described above.

[0058] The fifth aspect of this application provides an electrical device, comprising:

[0059] The memory is configured to store instructions; and

[0060] The processor is configured to retrieve instructions from memory and, when executing instructions, to implement the overvoltage protection strategy determination method described above, or to implement the fault protection method described above.

[0061] The sixth aspect of this application provides a machine-readable storage medium storing a computer program, which, when executed by a processor, implements the overvoltage protection strategy determination method described above, or implements the fault protection method described above.

[0062] This application provides a method for determining an overvoltage protection strategy, comprising: applying multiple impulse voltages to the battery pack of an energy storage device to determine the impulse voltage critical value of the battery pack; constructing a simulation model of the energy storage device; using the simulation model to simulate overvoltage faults of each fault type in the energy storage device, obtaining first electrical change data and second electrical change data corresponding to each fault type; and determining the protection strategy for each fault type of the energy storage device based on the impulse voltage critical value, the first electrical change data, and the second electrical change data. The overvoltage situation of the battery pack under different grounding states is analyzed through the first electrical change data and the second electrical change data, thereby determining the protection strategy for each fault type. The determined protection strategy can provide overvoltage protection for the battery pack in the energy storage device, preventing damage to the battery pack due to overvoltage and improving the safety of the battery pack. Attached Figure Description

[0063] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0064] Figure 1 A flowchart of the overvoltage protection strategy determination method provided in an embodiment of this application is shown;

[0065] Figure 2 A flowchart of the fault protection method provided in an embodiment of this application is shown;

[0066] Figure 3 A schematic diagram of the overvoltage protection strategy determination device provided in an embodiment of this application is shown;

[0067] Figure 4 A schematic diagram of the fault protection device provided in an embodiment of this application is shown;

[0068] Figure 5 A schematic diagram of a first structure of the energy storage device provided in an embodiment of this application is shown;

[0069] Figure 6 A second structural schematic diagram of the energy storage device provided in the embodiments of this application is shown. Detailed Implementation

[0070] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the present invention.

[0071] The components of the embodiments of the invention described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0072] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of the invention, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0073] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0074] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0075] Example 1

[0076] Please see Figure 1 , Figure 1 A flowchart of the overvoltage protection strategy determination method provided in an embodiment of this application is shown. Figure 1 The methods for determining overvoltage protection strategies include:

[0077] S110, apply multiple impulse voltages to the battery pack of the energy storage device to determine the critical value of the impulse voltage of the battery pack, wherein the energy storage device includes a battery pack and a transformer, and the battery pack is grounded.

[0078] The type of energy storage device is determined according to actual needs and may include energy storage power stations, etc., and is not limited here. The energy storage device includes a DC-side battery pack and an AC-side transformer, and the battery pack is grounded. The type of battery pack is also determined according to actual needs and is not limited here. For ease of understanding, the battery pack in the embodiments of this application is a lithium iron phosphate battery pack.

[0079] A transient impulse voltage is applied to both the positive and negative terminals of the battery pack to ground to determine the critical impulse voltage value. When the impulse voltage experienced by the battery pack exceeds the critical value, it will lead to a decrease in battery pack performance or even damage to the battery pack. When an overvoltage occurs in the energy storage device, overvoltage protection must also be implemented for the battery pack.

[0080] In the embodiments of this application, multiple impulse voltages are applied to the battery pack of the energy storage device to determine the impulse voltage critical value of the battery pack, including:

[0081] Multiple impulse voltages are applied to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage.

[0082] Determine the critical value of the battery pack's impact voltage based on energy efficiency.

[0083] Multiple impulse voltage values ​​are applied to the battery pack of the energy storage device to determine the charge and discharge efficiency of the battery pack under different impulse voltage values, thus obtaining the energy efficiency of the battery pack for each impulse voltage. Based on the energy efficiency of the battery pack for each impulse voltage, the impulse voltage that causes a decrease in the energy efficiency of the battery pack is determined, and thus the critical impulse voltage value of the battery pack is determined. For ease of understanding, the critical impulse voltage value in the embodiments of this application is 500V. An overcurrent in the energy storage device causing the battery pack to be subjected to a sum of instantaneous impulse voltages of 500V will lead to a decrease in the performance of the battery pack, and may even lead to damage to the battery pack.

[0084] S120, construct a simulation model of the energy storage device.

[0085] The energy storage device is simulated, and a simulation model of the energy storage device is constructed. Specifically, MATLAB can be used to construct the simulation model of the energy storage device, which will not be elaborated here. The simulation model is then used to perform simulation analysis on the energy storage device to obtain electrical data of the energy storage device under overvoltage conditions.

[0086] It is important to understand that when the transformer is grounded, the DC and AC sides of the energy storage device typically share a common ground. In this embodiment, the effect of distributed capacitance is considered on the DC side. During simulation analysis, the transformer isolates the DC and AC sides, and a ground is introduced through the distributed capacitance. The DC and AC sides each use a separate ground as a reference.

[0087] S130, use the simulation model to simulate overvoltage faults of each fault type for the energy storage device, and obtain the first electrical change data and the second electrical change data corresponding to each fault type. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded.

[0088] The energy storage device was simulated for each fault type using a simulation model, and the corresponding electrical data of the energy storage device was obtained for each fault type. The electrical data includes, but is not limited to, the battery pack current, positive and negative electrode voltages, positive electrode voltage to ground, and negative electrode voltage to ground, etc., which will not be elaborated here.

[0089] In this embodiment, the battery pack is grounded. If a fault of the same type is detected in the energy storage device, the electrical data of the battery pack differs when the transformer is grounded compared to when the transformer is not grounded. When the transformer is grounded, a simulation model is used to simulate each fault type in the energy storage device, obtaining the first electrical change data corresponding to each fault type. This first electrical change data represents the electrical data of the battery pack when the transformer is grounded. When the transformer is not grounded, a simulation model is used to simulate each fault type in the energy storage device, obtaining the second electrical change data corresponding to each fault type. This second electrical change data represents the electrical data of the battery pack when the transformer is not grounded.

[0090] In the embodiments of this application, a simulation model is used to simulate overvoltage faults of each fault type in the energy storage device, and first electrical change data and second electrical change data corresponding to each fault type are obtained, including:

[0091] A simulation model was used to simulate an overvoltage-free fault in an energy storage device, and the electrical data of the energy storage device before the fault was obtained.

[0092] The simulation model was used to simulate overvoltage faults of each fault type in the energy storage device, and the first post-fault electrical data corresponding to each fault type was obtained when the transformer was grounded, and the second post-fault electrical data corresponding to each fault type was obtained when the transformer was not grounded.

[0093] The electrical data after each first fault is merged with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type. The electrical data after each second fault is merged with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

[0094] The energy storage device is simulated without faults using a simulation model. This means that the energy storage device is simulated and analyzed under fault-free conditions to obtain the electrical data of the energy storage device before the fault. The electrical data before the fault includes the electrical data before the fault when the transformer is grounded and the electrical data before the fault when the transformer is not grounded.

[0095] Overvoltage fault simulations for each fault type of the energy storage device are performed using simulation models. This involves simulating and analyzing the energy storage device under fault conditions to obtain the first post-fault electrical data for each fault type when the transformer is grounded, and the second post-fault electrical data for each fault type when the transformer is not grounded. The pre-fault electrical data when the transformer is grounded is combined with the first post-fault electrical data to obtain the first electrical change data. The pre-fault electrical data when the transformer is not grounded is combined with the second post-fault electrical data to obtain the second electrical change data. By analyzing the electrical change data, the changes in current and voltage, and other electrical data of the battery pack before and after the overvoltage are determined, thereby determining the protection strategy for the energy storage device.

[0096] S140, based on the impulse voltage threshold, the first electrical change data and the second electrical change data, determine the protection strategy for each fault type of the energy storage device.

[0097] By analyzing the electrical change data of the battery pack corresponding to each fault type, the surge voltage experienced by the energy storage device is determined, thereby identifying whether the battery pack experiences a voltage surge exceeding the surge voltage threshold during an overvoltage fault. Based on the surge voltage experienced by the energy storage device, a protection strategy for the battery pack in the energy storage device is determined to provide overvoltage protection.

[0098] The transformer's grounding status includes grounded and ungrounded states. Different grounding statuses result in different electrical change data for the battery pack. By analyzing the first and second electrical change data, the overvoltage situation of the battery pack under different grounding states is determined, thereby identifying the corresponding protection strategy for each fault type. The determined protection strategy can provide overvoltage protection for the battery pack in the energy storage device, preventing damage to the battery pack due to overvoltage and improving the safety of the battery pack.

[0099] In the embodiments of this application, the overvoltage protection strategy determination method further includes:

[0100] Multiple surge currents are applied to the battery pack, and the melting time of the adapter plate corresponding to each surge current is determined.

[0101] Based on the impulse voltage threshold, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined, including:

[0102] Based on the fuse-off time of the adapter piece, the critical value of the impulse voltage, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined.

[0103] When an energy storage device experiences overvoltage due to faults such as short circuits, the battery pack is typically subjected to current surges. Multiple surge currents of different values ​​are applied to the battery pack, and the fuse-breaking time of the adapter plate corresponding to each surge current is determined. For ease of understanding, in the embodiments of this application, the fuse-breaking time of the adapter plate corresponding to a 5000A surge current is determined to be 1.8 seconds; the fuse-breaking time of the adapter plate corresponding to an 8000A surge current is 1.2 seconds; and the fuse-breaking time of the adapter plate corresponding to a 15000A surge current is 0.2 seconds.

[0104] Based on the electrical change data corresponding to the current fault type, determine the magnitude of the inrush current experienced by the battery pack due to the current fault type. Based on this inrush current, determine the protection strategy for the current fault type. For example, if the inrush current experienced by the battery pack due to the current fault type is 15000A, the protection strategy could be to disconnect the battery pack within 0.2 seconds to prevent the adapter from melting due to the inrush current, thus improving the battery pack's safety.

[0105] In the embodiments of this application, the energy storage device further includes a battery management device, which is used to control the on / off state of the battery pack;

[0106] If the fault type is an inter-terminal fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-terminal fault is detected.

[0107] When the transformer is grounded, if the fault type is a battery pack polarity fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared.

[0108] The energy storage device also includes a battery management system (BMS), which controls the on / off state of the battery pack. Specifically, when the BMS detects overcharging or over-discharging of the battery pack, it switches the on / off state of the battery pack to an off state. Typically, both DC-side and AC-side faults in the energy storage device can lead to overvoltage. DC-side faults include inter-terminal faults and ground faults. In this embodiment, by disconnecting the BMS from the battery pack, the on / off state of the battery pack is switched to an off state, thereby protecting the battery pack from DC-side faults.

[0109] When the transformer is not grounded, if the fault type is a battery pack polarity fault, since there is no path for the fault current, the second electrical change data shows that both the positive and negative voltages of the battery pack to ground drop simultaneously; the positive and negative voltages and currents of the battery pack remain almost unchanged. Analysis of the second electrical change data shows that overvoltage protection for the battery pack is not required, meaning there is no protection strategy corresponding to the fault type.

[0110] When a battery pack faces risks such as short circuits, overcharging, or thermal runaway, it will typically perform actions like reclosing to clear the fault. When the transformer is grounded and the fault type is a battery pack polarity fault, although there is no path for the fault current, the polarity fault will cause voltage fluctuations on the AC side, which will then affect the voltage between the positive and negative terminals of the battery pack. When the transformer is grounded, if the fault type is a battery pack polarity fault, the first electrical change data shows that the moment the battery pack clears the fault, both the positive and negative terminal voltages to ground will momentarily increase and exceed the impulse voltage threshold. The battery pack current will also momentarily increase. The protection strategy is to disconnect the battery management device from the battery pack before the fault is cleared, switching the battery pack's on / off state to the off state to prevent damage to the battery pack from the impact during the fault clearing.

[0111] When the fault type is an inter-electrode fault in the battery pack, the fault current can still create a loop even when the transformer is not grounded. During the inter-electrode fault, the battery pack is constantly affected by the short-circuit current, leading to damage due to thermal runaway. Furthermore, after the battery pack is cleared from the fault, it will experience small-amplitude under-matching oscillations in voltage and current, further affecting the operation of the energy storage device. When the transformer is grounded, the battery pack is also affected by the short-circuit current, and voltage oscillations will occur even after the fault is cleared. If the fault type is an inter-electrode fault, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-electrode fault is detected, preventing the short-circuit current from causing the battery pack's adapter to blow. It should be understood that the first time can be set based on the adapter's blowing time. For example, if the short-circuit current causes the adapter to blow in 0.2 seconds, the first time value can be 0.1 seconds or a value shorter than the adapter's blowing time.

[0112] In the embodiments of this application, the energy storage device further includes an energy storage converter, which is used to control the current state of the battery pack.

[0113] When the transformer is not grounded, if the fault type is a two-phase short circuit in the transformer, the protection strategy is to perform no-power compensation on the battery management device side.

[0114] When the transformer is not grounded, if the fault type is a three-phase short circuit fault of the transformer, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to constant voltage state in the second time.

[0115] When the transformer is grounded, if the fault type is a single-phase short circuit fault or a three-phase short circuit fault, the protection strategy is to disconnect the transformer from the battery pack.

[0116] When the transformer is grounded, if the fault type is a two-phase short-circuit fault, the protection strategy is to switch the state of the energy storage converter to a constant voltage state in the second time. Typically, when the battery pack in an energy storage device is charging and discharging, the energy storage converter is used to control the current state of the battery pack to control its AC / DC conversion. The current state of the battery pack includes both DC and AC states. AC side faults in energy storage devices include single-phase short-circuit faults, two-phase short-circuit faults, and three-phase short-circuit faults in the transformer. In this embodiment, the energy storage converter is used to protect the battery pack during AC side faults.

[0117] When the transformer is not grounded, if the fault type is a single-phase short circuit, analysis of the first electrical change data shows that overvoltage protection for the battery pack is not required; that is, there is no protection strategy corresponding to this fault type. When the transformer is not grounded, if the fault type is a two-phase short circuit, unlike a single-phase short circuit, the electrical data of the battery pack exhibits irregular oscillations during a single-phase short circuit. The protection strategy is to provide no-power compensation to the battery management device side.

[0118] When the transformer is not grounded, if the fault type is a three-phase short circuit fault, the electrical data of the battery pack will exhibit irregular oscillations, requiring power-free compensation on the battery management device side. Simultaneously, when the energy storage device is connected to the grid, it uses the grid's frequency and phase as a reference for constant power control of the transformer. When a three-phase short circuit fault occurs, the disappearance of the grid's three-phase voltage causes the transformer's constant power control to lose its reference. The energy storage converter needs to switch from a constant power state to a constant voltage state, resulting in a protection strategy of power-free compensation on the battery management device side, and switching the energy storage converter's state to a constant voltage state within a second timeframe.

[0119] The positive and negative voltages and currents of the battery pack are not affected by the transformer's grounding status. However, compared to an ungrounded transformer, when the transformer is grounded, single-phase short-circuit faults, three-phase short-circuit faults, and three-phase short-circuit faults all cause significant fluctuations in the positive and negative voltages of the battery pack to ground. When the transformer is grounded, if the fault type is a single-phase or three-phase short-circuit fault, the AC side fault causes DC side oscillations, and the protection strategy is to disconnect the transformer from the battery pack.

[0120] When the transformer is grounded, if the fault type is a two-phase short-circuit fault, the transformer's constant power control loses its reference. The protection strategy is to switch the energy storage converter's state to constant voltage state within a second time period. It is important to understand that the second time period is set according to actual needs. The second time period should be longer than the fault duration, but it should not be too long, so that the energy storage converter's state can be switched back from constant voltage state to constant power state after the fault is recovered.

[0121] This application provides a method for determining an overvoltage protection strategy, comprising: applying multiple impulse voltages to the battery pack of an energy storage device to determine the impulse voltage critical value of the battery pack; constructing a simulation model of the energy storage device; using the simulation model to simulate overvoltage faults of each fault type in the energy storage device, obtaining first electrical change data and second electrical change data corresponding to each fault type; and determining the protection strategy for each fault type of the energy storage device based on the impulse voltage critical value, the first electrical change data, and the second electrical change data. The overvoltage situation of the battery pack under different grounding states is analyzed through the first electrical change data and the second electrical change data, thereby determining the protection strategy for each fault type. The determined protection strategy can provide overvoltage protection for the battery pack in the energy storage device, preventing damage to the battery pack due to overvoltage and improving the safety of the battery pack.

[0122] Example 2

[0123] Please see Figure 2 , Figure 2 A flowchart of the fault protection method provided in an embodiment of this application is shown.

[0124] Figure 2 The fault protection methods include:

[0125] S210, If a fault is detected in the energy storage device, determine the target fault type corresponding to the fault.

[0126] During the operation of the energy storage device, it is continuously monitored for faults. If a fault is detected, the target fault type is determined. Different fault types will result in differences in the electrical change data of the battery pack. Real-time monitoring of the battery pack's electrical change data is used to determine whether the energy storage device is faulty. If a fault is detected, the target fault type is identified.

[0127] S220, based on the protection strategy corresponding to the target fault type, performs fault protection on the energy storage device, wherein the protection strategy is obtained according to the overvoltage protection strategy determination method described above.

[0128] Having determined the protection strategy for each fault type of the energy storage device, and after identifying the target fault type, the corresponding protection strategy is queried. Based on the protection strategy corresponding to the target fault type, fault protection is implemented for the energy storage device. Overvoltage protection is provided for the battery pack in the energy storage device through the protection strategy, preventing damage to the battery pack due to overvoltage and improving the safety of the battery pack.

[0129] Example 3

[0130] Please see Figure 3 , Figure 3 A schematic diagram of the overvoltage protection strategy determination device provided in an embodiment of this application is shown. Figure 3 The overvoltage protection strategy determination device 300 includes:

[0131] The impulse voltage application module 310 is used to apply multiple impulse voltages to the battery pack of the energy storage device and determine the impulse voltage critical value of the battery pack. The energy storage device includes a battery pack and a transformer, and the battery pack is grounded.

[0132] Simulation model building module 320 is used to build simulation models of energy storage devices;

[0133] The fault simulation module 330 is used to simulate overvoltage faults of each fault type in the energy storage device using a simulation model, and obtain the first electrical change data and the second electrical change data corresponding to each fault type. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded.

[0134] The protection strategy determination module 340 is used to determine the protection strategy for each fault type of the energy storage device based on the impulse voltage threshold, the first electrical change data and the second electrical change data.

[0135] In embodiments of this application, the overvoltage protection strategy determination device 300 further includes:

[0136] The fusing time determination module is used to apply multiple impact currents to the battery pack and determine the fusing time of the adapter piece corresponding to each impact current.

[0137] The protection strategy determination module 340 is also used to determine the protection strategy for each fault type of the energy storage device based on the fuse time of the adapter piece, the critical value of the impulse voltage, the first electrical change data and the second electrical change data.

[0138] In embodiments of this application, the impulse voltage application module 310 includes:

[0139] The energy efficiency determination submodule is used to apply multiple impulse voltages to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage.

[0140] The critical value determination submodule is used to determine the critical value of the battery pack's impact voltage based on energy efficiency.

[0141] In the embodiments of this application, the fault simulation module 330 includes:

[0142] The simulation submodule is used to simulate overvoltage faults in energy storage devices using simulation models, and to obtain electrical data of the energy storage devices before the fault.

[0143] The electrical data acquisition submodule is used to simulate overvoltage faults of each fault type in the energy storage device using a simulation model, and to obtain the first post-fault electrical data corresponding to each fault type when the transformer is grounded, and the second post-fault electrical data corresponding to each fault type when the transformer is not grounded.

[0144] The electrical data merging submodule is used to merge the electrical data after each first fault with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type, and to merge the electrical data after each second fault with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

[0145] In the embodiments of this application, the energy storage device further includes a battery management device, which is used to control the on / off state of the battery pack;

[0146] If the fault type is an inter-terminal fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-terminal fault is detected.

[0147] When the transformer is grounded, if the fault type is a battery pack polarity fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared.

[0148] In the embodiments of this application, the energy storage device further includes an energy storage converter, which is used to control the current state of the battery pack.

[0149] When the transformer is not grounded, if the fault type is a two-phase short circuit in the transformer, the protection strategy is to perform no-power compensation on the battery management device side.

[0150] When the transformer is not grounded, if the fault type is a three-phase short circuit fault of the transformer, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to constant voltage state in the second time.

[0151] When the transformer is grounded, if the fault type is a single-phase short circuit fault or a three-phase short circuit fault, the protection strategy is to disconnect the transformer from the battery pack.

[0152] When the transformer is grounded, if the fault type is a two-phase short circuit fault, the protection strategy is to switch the state of the energy storage converter to constant voltage state in the second time.

[0153] The overvoltage protection strategy determination device 300 is used to execute the corresponding steps in the above-described overvoltage protection strategy determination method. The specific implementation of each function will not be described in detail here. In addition, the optional examples in Embodiment 1 are also applicable to the overvoltage protection strategy determination device 300 in Embodiment 2.

[0154] Example 4

[0155] Please see Figure 4 , Figure 4 A schematic diagram of the fault protection device provided in an embodiment of this application is shown. Figure 4 The fault protection device 400 includes:

[0156] A fourth aspect of this application provides a fault protection device 400, which includes:

[0157] The fault type determination module 410 is used to determine the target fault type corresponding to the fault if a fault is detected in the energy storage device.

[0158] The fault protection module 420 is used to perform fault protection on the energy storage device based on the protection strategy corresponding to the target fault type, wherein the protection strategy is obtained according to the overvoltage protection strategy determination method described above.

[0159] The fault protection device 400 is used to perform the corresponding steps in the fault protection method described above. The specific implementation of each function will not be described in detail here. In addition, the optional examples in Embodiment 2 are also applicable to the fault protection device 400 in Embodiment 4.

[0160] This application embodiment also provides a control device, including:

[0161] The memory is configured to store instructions; and

[0162] The processor is configured to retrieve instructions from memory and, when executing the instructions, to implement the overvoltage protection strategy determination method according to Embodiment 1, or the fault protection method according to Embodiment 2.

[0163] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured; adjusting kernel parameters can address issues related to poor battery pack safety.

[0164] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0165] This application also provides an embodiment of a power device, including:

[0166] The memory is configured to store instructions; and

[0167] The processor is configured to retrieve instructions from memory and, when executing instructions, to implement the overvoltage protection strategy determination method described above, or to implement the fault protection method described above.

[0168] Please see Figure 5 , Figure 5 A schematic diagram of a first structure of the energy storage device provided in an embodiment of this application is shown.

[0169] In this embodiment, the power equipment also includes an energy storage device 500, which includes a battery pack 510 and a transformer 520. The energy storage device 500 is used to connect to the power grid, the battery pack 510 is used for charging and discharging, and the transformer 520 is used for voltage transformation of the energy storage device 500. The control device is configured to: apply multiple impulse voltages to the battery pack 510 of the energy storage device 500 to determine the impulse voltage threshold value of the battery pack 510; construct a simulation model of the energy storage device 500; use the simulation model to simulate overvoltage faults of each fault type in the energy storage device 500, obtaining first electrical change data and second electrical change data corresponding to each fault type; and determine the protection strategy of the energy storage device 500 for each fault type based on the impulse voltage threshold value, the first electrical change data, and the second electrical change data. Please refer to [link to relevant documentation]. Figure 6 , Figure 6 A second structural schematic diagram of the energy storage device provided in the embodiments of this application is shown.

[0170] The energy storage device 500 also includes a battery management device 530 and an energy storage inverter 540, both of which are connected to the battery pack 510. Protection strategies include disconnecting the battery management device 530 from the battery pack 510, performing no-power compensation on the battery management device 530 side, and switching the energy storage inverter 540 to a constant voltage state. These protection strategies provide overvoltage protection for the battery pack 510 in the energy storage device 500, preventing damage to the battery pack 510 due to overvoltage and improving the safety of the battery pack 510.

[0171] This application also provides a machine-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the overvoltage protection strategy determination method according to embodiment 1, or the fault protection method according to embodiment 2.

[0172] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0173] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0174] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0175] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0176] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0177] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0178] Machine-readable storage media include both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0179] It should also be noted that 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 process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0180] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for determining an overvoltage protection strategy, characterized in that, The overvoltage protection strategy determination method includes: Multiple impulse voltages are applied to the battery pack of the energy storage device to determine the critical value of the impulse voltage of the battery pack. The energy storage device includes a battery pack, a transformer, a battery management device, and an energy storage converter. The battery pack is grounded. The battery management device is used to control the on / off state of the battery pack, and the energy storage converter is used to control the current state of the battery pack. Construct a simulation model of the energy storage device; The simulation model is used to simulate overvoltage faults of each fault type in the energy storage device, and the first electrical change data and the second electrical change data corresponding to each fault type are obtained respectively. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded. Based on the threshold value of the impulse voltage, the first electrical change data, and the second electrical change data, the protection strategy of the energy storage device for each fault type is determined; Wherein, if the fault type is an inter-electrode fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack as soon as the inter-electrode fault is detected; When the transformer is grounded, if the fault type is a battery pack polarity fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared. When the transformer is not grounded, if the fault type is a two-phase short circuit of the transformer, the protection strategy is to perform no-power compensation on the battery management device side. When the transformer is not grounded, if the fault type is a three-phase short circuit fault of the transformer, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to constant voltage state in the second time period. When the transformer is grounded, if the fault type is a single-phase short circuit fault or a three-phase short circuit fault of the transformer, the protection strategy is to disconnect the transformer from the battery pack. When the transformer is grounded, if the fault type is a two-phase short-circuit fault of the transformer, the protection strategy is to switch the state of the energy storage converter to a constant voltage state in the second time period.

2. The overvoltage protection strategy determination method according to claim 1, characterized in that, The overvoltage protection strategy determination method further includes: Multiple surge currents are applied to the battery pack, and the melting time of the adapter plate corresponding to each surge current is determined. The step of determining the protection strategy for each fault type of the energy storage device based on the impulse voltage threshold, the first electrical change data, and the second electrical change data includes: Based on the fuse-off time of the adapter piece, the critical value of the impact voltage, the first electrical change data, and the second electrical change data, the protection strategy for each fault type of the energy storage device is determined.

3. The overvoltage protection strategy determination method according to claim 1, characterized in that, The process of applying multiple impulse voltages to the battery pack of the energy storage device and determining the impulse voltage critical value of the battery pack includes: Multiple impulse voltages are applied to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage. Based on the energy efficiency, the critical value of the impact voltage of the battery pack is determined.

4. The overvoltage protection strategy determination method according to claim 1, characterized in that, The simulation model is used to simulate overvoltage faults of each fault type in the energy storage device, and the first electrical change data and the second electrical change data corresponding to each fault type are obtained respectively, including: The simulation model was used to simulate an overvoltage fault in the energy storage device to obtain the electrical data of the energy storage device before the fault. The simulation model is used to simulate overvoltage faults of each fault type in the energy storage device, and the first post-fault electrical data corresponding to each fault type when the transformer is grounded is obtained, and the second post-fault electrical data corresponding to each fault type when the transformer is not grounded is obtained. Each electrical data after the first fault is merged with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type. Then, each electrical data after the second fault is merged with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

5. A fault protection method, characterized in that, The fault protection method includes: If a fault is detected in the energy storage device, the target fault type corresponding to the fault is determined; Based on the protection strategy corresponding to the target fault type, the energy storage device is subjected to fault protection, wherein the protection strategy is obtained according to the overvoltage protection strategy determination method as described in any one of claims 1 to 4.

6. An overvoltage protection strategy determination device, characterized in that, The overvoltage protection strategy determination device includes: An impulse voltage application module is used to apply multiple impulse voltages to the battery pack of an energy storage device and determine the impulse voltage critical value of the battery pack. The energy storage device includes a battery pack, a transformer, a battery management device, and an energy storage converter. The battery pack is grounded. The battery management device is used to control the on / off state of the battery pack, and the energy storage converter is used to control the current state of the battery pack. The simulation model building module is used to build a simulation model of the energy storage device. The fault simulation module is used to simulate overvoltage faults of each fault type for the energy storage device using the simulation model, and obtain the first electrical change data and the second electrical change data corresponding to each fault type. The first electrical change data is the electrical data of the battery pack when the transformer is grounded, and the second electrical change data is the electrical data of the battery pack when the transformer is not grounded. The protection strategy determination module is used to determine the protection strategy for each fault type of the energy storage device based on the impulse voltage threshold, the first electrical change data, and the second electrical change data. If the fault type is an inter-electrode fault of the battery pack, the protection strategy is to disconnect the battery management device from the battery pack within the first time after detecting the inter-electrode fault. When the transformer is grounded, if the fault type is a battery pack ground fault, the protection strategy is to disconnect the battery management device from the battery pack before the battery pack fault is cleared. When the transformer is not grounded, if the fault type is a two-phase short circuit of the transformer, the protection strategy... The protection strategy involves performing no-power compensation on the battery management device side. When the transformer is not grounded, if the fault type is a three-phase short-circuit fault, the protection strategy is to perform no-power compensation on the battery management device side and switch the state of the energy storage converter to a constant voltage state within a second time period. When the transformer is grounded, if the fault type is a single-phase short-circuit fault or a three-phase short-circuit fault, the protection strategy is to disconnect the transformer from the battery pack. When the transformer is grounded, if the fault type is a two-phase short-circuit fault, the protection strategy is to switch the state of the energy storage converter to a constant voltage state within a second time period.

7. The overvoltage protection strategy determination device according to claim 6, characterized in that, The overvoltage protection strategy determination device further includes: The fusing time determination module is used to apply multiple impact currents to the battery pack and determine the fusing time of the adapter piece corresponding to each impact current. The protection strategy determination module is further configured to determine the protection strategy of the energy storage device for each fault type based on the fuse-breaking time of the adapter piece, the critical value of the impulse voltage, the first electrical change data, and the second electrical change data.

8. The overvoltage protection strategy determination device according to claim 6, characterized in that, The impulse voltage application module includes: The energy efficiency determination submodule is used to apply multiple impulse voltages to the battery pack of the energy storage device to obtain the energy efficiency of the battery pack for each impulse voltage. The critical value determination submodule is used to determine the critical value of the impact voltage of the battery pack based on the energy efficiency.

9. The overvoltage protection strategy determination device according to claim 6, characterized in that, The fault simulation module includes: The simulation submodule is used to simulate the energy storage device without overvoltage faults using the simulation model, and to obtain the electrical data of the energy storage device before the fault. The electrical data acquisition submodule is used to simulate overvoltage faults of each fault type for the energy storage device using the simulation model, and to obtain the first post-fault electrical data corresponding to each fault type when the transformer is grounded, and the second post-fault electrical data corresponding to each fault type when the transformer is not grounded. The electrical data merging submodule is used to merge each of the electrical data after the first fault with the electrical data before the fault to obtain the first electrical change data corresponding to each fault type, and to merge each of the electrical data after the second fault with the electrical data before the fault to obtain the second electrical change data corresponding to each fault type.

10. A fault protection device, characterized in that, The fault protection device includes: The fault type determination module is used to determine the target fault type corresponding to the fault if a fault is detected in the energy storage device. The fault protection module is used to perform fault protection on the energy storage device based on the protection strategy corresponding to the target fault type, wherein the protection strategy is obtained according to the overvoltage protection strategy determination method as described in any one of claims 1 to 4.

11. An electrical device, characterized in that, include: The memory is configured to store instructions; as well as The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the overvoltage protection strategy determination method according to any one of claims 1 to 4, or to implement the fault protection method according to claim 5.

12. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores a computer program, which, when executed by a processor, implements the overvoltage protection strategy determination method according to any one of claims 1 to 4, or the fault protection method according to claim 5.

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