Energy storage switching power distribution method and system for different drop depths

Abstract

The present application relates to the technical field of power system, and specifically provides a power distribution method and system for energy storage switching of different drop depths, which comprises the following steps: obtaining a first support power based on multi-stage sag interval and support power setting rules corresponding to each stage of sag interval; obtaining a second support power based on load sensitivity characteristic factor; obtaining a third support power according to the state of charge of energy storage; in the case that the real-time terminal voltage of super capacitor is lower than the preset under-voltage threshold, distributing the third support power to the energy storage battery; obtaining a fourth support power based on the maximum high-frequency output power of super capacitor; distributing the low-frequency component in the fourth support power to the energy storage battery and distributing the high-frequency component in the fourth support power to the super capacitor based on the drop depth of grid voltage. The present application reduces the large current impact of battery in shallow drop through the hierarchical power support, significantly prolongs the service life of battery, and ensures the stability of full-depth sag bus.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method and system for energy storage switching power allocation for different drop depths. Background Technology

[0002] In industrial power grid operation, voltage sags are a core power quality issue causing production equipment shutdowns and production line failures. Energy storage combined with seamless fast switching is currently the mainstream technical approach to address voltage sags and ensure stable operation of the power grid and loads. It can quickly respond to grid voltage anomalies and provide rapid bus voltage support, effectively mitigating the production and operational risks caused by voltage sags. However, related control schemes typically employ fixed control logic, uniformly outputting equipment at its rated full power for voltage stabilization support when a voltage sag occurs. This results in insufficient adaptability and economic efficiency of the overall control strategy, exhibiting several technical shortcomings.

[0003] When facing shallow voltage drops of 10% to 30%, the relevant technical solutions maintain a full-power short-term discharge state, causing frequent high-current surges in the battery and shortening the energy storage cycle life. For deep voltage drops of 30% or more, the system lacks dynamic power expansion and control logic. The fixed full-power output mode cannot provide sufficient voltage support, making it difficult to quickly raise the bus voltage to the safe tolerance range of the load equipment and failing to completely eliminate the safety hazard of equipment shutdown. Furthermore, the relevant technical solutions do not couple the real-time state-of-charge (SOC) constraint power output of the energy storage system. After a fault occurs, regardless of the remaining battery charge, it uniformly discharges at full power. Under low SOC conditions, this easily leads to deep over-discharge of the battery, triggering the battery over-discharge protection mechanism, causing the voltage sag support process to fail midway, significantly reducing the reliability of fault management. In addition, the system lacks a hybrid energy storage power decoupling and distribution logic. All instantaneous surge power and steady-state voltage regulation power are borne solely by the lithium battery energy storage, failing to achieve high- and low-frequency power decoupling and distribution. Instantaneous high-current surges accelerate lithium battery cell degradation, further aggravating the aging and wear of the energy storage equipment. At the same time, the solution lacks a graded fault duration matching strategy adapted to grid operating conditions, and does not dynamically adjust the energy storage power output duration and output capacity based on the actual fault duration of grid reclosing. The energy storage capacity allocation lacks precision, resulting in a waste of energy storage resources. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a power allocation method and system for energy storage switching for different drop depths. This invention solves the technical defects of related technical solutions, such as uniform full-power discharge regardless of drop depth, failure to consider load sensitivity differences, instantaneous compensation failure due to supercapacitor undervoltage, large battery loss, insufficient support for depth sag, failure of sag protection under low charge, and low energy storage capacity utilization.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution: In a first aspect, the present invention provides a method for energy storage switching power allocation for different drop depths, comprising: Based on the pre-divided multi-level sag intervals and the corresponding support power setting rules for each level of sag interval, the first support power is obtained according to the current grid voltage drop depth; When the voltage of the faulty phase does not meet the minimum operating requirements of the load, the first supporting power is corrected based on the preset load sensitivity characteristic factor to obtain the second supporting power. Based on the energy storage state of charge, the second supporting power is corrected to obtain the third supporting power; and when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third supporting power is allocated to the energy storage battery. When the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold, the third supporting power is corrected based on the maximum high-frequency output power of the supercapacitor to obtain the fourth supporting power. Based on the grid voltage drop depth, the low-frequency component of the fourth supporting power is allocated to the energy storage battery, and the high-frequency component of the fourth supporting power is allocated to the supercapacitor.

[0006] In some embodiments of the present invention, the pre-divided multi-level descent intervals include: When the voltage drop depth is not less than the first threshold and less than the second threshold, the voltage is in the shallow sag range. When the voltage drop depth is not less than the second threshold and less than the third threshold, the grid voltage is in the moderate sag range. When the voltage drop depth is not less than the third threshold, the voltage is in the deep sag range; The voltage drop depth of the power grid represents the magnitude by which the voltage of the faulted phase deviates from the rated phase voltage; The rules for setting the support power for each descent interval include: The grid voltage in the shallow sag range is supported by a first coefficient multiplied by the rated output power of the energy storage system. The grid voltage in the aforementioned moderate sag range supports a power output equal to the second coefficient multiplied by the rated output power of the energy storage system. The grid voltage within the aforementioned deep sag range supports the rated output power of the energy storage system. Wherein, the first coefficient is less than the second coefficient, and the second coefficient is less than 1.

[0007] In some embodiments of the present invention, before the first supporting power is corrected based on a preset load sensitivity characteristic factor to obtain the second supporting power when the fault phase voltage does not meet the minimum load operating requirements, the method further includes: determining whether the fault phase voltage meets the minimum load operating requirements based on the load sensitivity characteristic factor. Based on the load sensitivity factor, determining whether the voltage of the faulty phase meets the minimum operating requirements of the load includes: If the fault phase voltage is not less than the load sensitivity characteristic factor, it is determined that the fault phase voltage meets the minimum load operating requirements. If the voltage of the faulty phase is less than the load sensitivity factor, it is determined that the voltage of the faulty phase does not meet the minimum operating load requirement.

[0008] In some embodiments of the present invention, based on a preset load sensitivity characteristic factor, the first support power is corrected to obtain a second support power, including: The voltage gap is obtained based on the difference between the load sensitivity characteristic factor and the fault phase voltage. Based on the voltage gap, and combined with the difference between the load sensitivity factor and the rated phase voltage, the second supporting power is calculated.

[0009] In some embodiments of the present invention, the formula for calculating the second support power is as follows: ; in, This is the second supporting power; This is the primary supporting power; This is a voltage gap; This is the rated phase voltage; This is the load-sensitive characteristic factor.

[0010] In some embodiments of the present invention, the second supporting power is modified according to the energy storage state of charge to obtain the third supporting power, including: Based on the pre-defined multi-layer energy storage state of charge and the power correction coefficient corresponding to each layer of energy storage state of charge, the power correction coefficient corresponding to the current energy storage state of charge is obtained. The third supporting power is obtained by multiplying the power correction coefficient corresponding to the current energy storage state of charge by the second supporting power.

[0011] In some embodiments of the present invention, based on the maximum high-frequency output power of the supercapacitor, the third supporting power is power-corrected to obtain a fourth supporting power, including: The maximum high-frequency output power is calculated based on the real-time terminal voltage and power factor of the supercapacitor. The maximum high-frequency output power is added to the third support power to obtain the fourth support power.

[0012] In some embodiments of the present invention, based on the grid voltage sag depth, the low-frequency component of the fourth supporting power is allocated to the energy storage battery, and the high-frequency component of the fourth supporting power is allocated to the supercapacitor, including: The fourth supporting power is input into a first-order low-pass filter to obtain the low-frequency component; wherein, the filtering time constant of the first-order low-pass filter is set according to the grid voltage drop depth; Subtracting the low-frequency component from the fourth support power yields the high-frequency component; The low-frequency component is allocated to the energy storage battery, and the high-frequency component is allocated to the supercapacitor.

[0013] In some embodiments of the present invention, the method further includes: Based on the power allocation results, the energy storage system initiates grid voltage sag power support and simultaneously starts timing. When the timing reaches the preset threshold for the temporary sag of the grid reclosing standard, or when the grid voltage is not less than the load sensitivity factor, the energy storage system withdraws from power support.

[0014] Secondly, the present invention also provides an energy storage switching power distribution system for different drop depths, the system comprising: The reference support power acquisition module is used to obtain the first support power based on the pre-divided multi-level sag intervals and the support power setting rules corresponding to each level of sag interval, according to the current grid voltage drop depth. The load correction module is used to correct the first support power based on a preset load sensitivity factor to obtain the second support power when the voltage of the faulty phase does not meet the minimum operating load requirements. The energy storage battery correction module is used to correct the second support power according to the energy storage state of charge to obtain the third support power; and when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third support power is allocated to the energy storage battery. The supercapacitor correction module is used to correct the third supporting power based on the maximum high-frequency output power of the supercapacitor, so as to obtain the fourth supporting power, when the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold. The power distribution module is used to allocate the low-frequency component of the fourth supporting power to the energy storage battery and the high-frequency component of the fourth supporting power to the supercapacitor based on the grid voltage drop depth.

[0015] Thirdly, the present invention also provides an electronic device, including: a processor, and a memory storing a program, the program including instructions that, when executed by the processor, cause the processor to perform the above-described energy storage switching power allocation method for different drop depths.

[0016] Fourthly, the present invention also provides a non-transient machine-readable medium storing computer instructions for causing the computer to execute the above-described energy storage switching power allocation method for different drop depths.

[0017] Fifthly, the present invention also provides a computer program product, including a computer program / instruction, characterized in that, when the computer program / instruction is executed by a processor, it implements the above-mentioned energy storage switching power allocation method for different drop depths.

[0018] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: This invention proposes a power allocation method for energy storage switching at different drop depths. Through multi-level sag interval division and graded power support strategies, it actively limits the discharge rate of the energy storage battery during shallow drops, significantly reducing lithium battery cycle degradation caused by high-current impacts. Measured degradation rates are reduced by over 40%, effectively extending battery life and reducing overall lifecycle maintenance costs. Simultaneously, it introduces a load-sensitivity factor and a voltage gap compensation mechanism to ensure that the bus voltage remains stable within a precise load tolerance range under all drop conditions, eliminating downtime risks. Adaptive state-of-charge correction prevents over-discharge protection from malfunctioning at low charge levels, ensuring effective sag protection throughout the entire process. In the hybrid energy storage architecture, the supercapacitor handles high-frequency impact components, while the lithium battery only handles steady-state low-frequency voltage regulation, achieving power decoupling and improving system capacity utilization. The method as a whole considers both power quality management and long-term energy storage operational benefits, reducing capacity loss caused by deep discharge. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other embodiments based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating a power allocation method for energy storage switching at different drop depths provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of an energy storage switching power distribution system for different drop depths provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of the electronic device provided in the embodiment of the present invention. Detailed Implementation

[0021] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0022] like Figure 1 As shown in the figure, this embodiment of the invention provides a flowchart of a power allocation method for energy storage switching based on different drop depths. Figure 1 This is a flowchart illustrating a power allocation method for energy storage switching at different drop depths. This flowchart only shows the logical sequence of the method in this embodiment. In other possible embodiments of the invention, different methods may be used, provided they do not conflict. Figure 1 Complete the steps shown or described in the order indicated.

[0023] See Figure 1 The method of this invention specifically includes the following steps: Step S101: Based on the pre-divided multi-level sag intervals and the corresponding support power setting rules for each level of sag interval, the first support power is obtained according to the current grid voltage drop depth.

[0024] The grid voltage sag depth of this invention is used to characterize the magnitude of the deviation of the fault phase voltage from the rated phase voltage, and is defined as: ;in, This is the rated phase voltage; This is the voltage of the faulty phase.

[0025] The pre-defined multi-level sag intervals include: when the grid voltage drop depth is not less than a first threshold and less than a second threshold, the grid voltage is in a shallow sag interval; when the grid voltage drop depth is not less than a second threshold and less than a third threshold, the grid voltage is in a moderate sag interval; and when the grid voltage drop depth is not less than a third threshold, the grid voltage is in a deep sag interval.

[0026] The rules for setting the supporting power for each sag range are as follows: for grid voltage in a shallow sag range, the supporting power is the first coefficient multiplied by the rated output power of the energy storage system; for grid voltage in a medium sag range, the supporting power is the second coefficient multiplied by the rated output power of the energy storage system; and for grid voltage in a deep sag range, the supporting power is the rated output power of the energy storage system.

[0027] In this embodiment of the invention, the first threshold is 10%, the second threshold is 20%, and the third threshold is 30%. Correspondingly, the first coefficient is set to 0.4, and the second coefficient is set to 0.7.

[0028] The energy storage system of this invention includes an energy storage battery and a supercapacitor. The energy storage battery is a lithium battery, which has the characteristics of high energy density and strong steady-state continuous discharge capability, making it suitable for handling low-frequency steady-state voltage regulation power during voltage sag mitigation. Compared with lithium batteries, supercapacitors have high power density, fast response speed, can output large current instantaneously, and have long cycle life, and can withstand frequent instantaneous charge and discharge shocks. However, their energy density is relatively low, making them unsuitable for long-term continuous discharge.

[0029] The distribution method of this invention outputs a reference support power based on the severity of the voltage drop. A shallow sag avoids direct full-power output and reduces unnecessary high-current surges to the battery; a deep sag directly activates the rated power to ensure the basic voltage support capability.

[0030] Step S102: When the voltage of the faulty phase does not meet the minimum operating requirements of the load, the first supporting power is corrected based on the preset load sensitivity characteristic factor to obtain the second supporting power.

[0031] Before step S102, the method further includes: determining whether the voltage of the faulty phase meets the minimum operating requirements of the load based on the load sensitivity characteristic factor.

[0032] If the fault phase voltage is not less than the load sensitivity factor, the fault phase voltage is determined to meet the minimum load operating requirements; if the fault phase voltage is less than the load sensitivity factor, the fault phase voltage is determined to not meet the minimum load operating requirements.

[0033] The load sensitivity characteristic factor of the present invention characterizes the lowest operating phase voltage that the load can withstand. If the current fault phase voltage is greater than or equal to the load sensitivity characteristic factor, it indicates that no temporary power sag is required at this time, the second support power is set to 0, and no further steps are needed.

[0034] Load sensitivity characteristic factor of the present invention .

[0035] In this embodiment of the invention, the second support power is obtained by power correction of the first support power based on a preset load sensitivity characteristic factor, which may include: The voltage gap is obtained based on the difference between the load sensitivity factor and the fault phase voltage; based on the voltage gap, combined with the difference between the load sensitivity factor and the rated phase voltage, the second supporting power is calculated.

[0036] The formula for calculating the voltage gap is: ; The formula for calculating the second support power is: ; in, This is a voltage gap; This is the second supporting power; This is the primary supporting power.

[0037] After the calculation is completed, an upper limit clamping constraint is applied to the power of the second support, so that... , This is to set the rated output power of the energy storage system to prevent the corrected power command from exceeding the rated output capacity of the energy storage system hardware.

[0038] Step S103: Based on the energy storage state of charge, the second supporting power is corrected to obtain the third supporting power; and when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third supporting power is allocated to the energy storage battery.

[0039] Based on the energy storage state of charge, the second supporting power is corrected to obtain the third supporting power, including: Based on the pre-defined multi-layer energy storage state of charge and the power correction coefficient corresponding to each layer of energy storage state of charge, the power correction coefficient corresponding to the current energy storage state of charge is obtained; the power correction coefficient corresponding to the current energy storage state of charge is multiplied by the second support power to obtain the third support power.

[0040] In this embodiment of the invention, the state of charge of the multi-layer energy storage and the power correction coefficient corresponding to the state of charge of each layer are specifically set as follows: when the state of charge of the energy storage is greater than 40%, the power correction coefficient is 1.0; when the state of charge of the energy storage is not greater than 40% and not less than 20%, the power correction coefficient is 0.5; when the state of charge of the energy storage is less than 20%, the power correction coefficient is 0.2.

[0041] Third Support Power The calculation formula is as follows: ; ; in, This represents the current state of charge of the energy storage. This is the power correction factor.

[0042] The energy storage state-of-charge hierarchical current limiting mechanism in step S103 can automatically reduce the current rating when the remaining battery charge is low, avoid triggering the battery over-discharge protection during the temporary derating process, and prevent the voltage support from failing midway.

[0043] When the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the supercapacitor does not participate in high-frequency impact compensation, and all the supporting power is directly handed over to the energy storage battery.

[0044] Step S104: When the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold, the third supporting power is corrected based on the maximum high-frequency output power of the supercapacitor to obtain the fourth supporting power.

[0045] In this embodiment of the invention, based on the maximum high-frequency output power of the supercapacitor, the third supporting power is power-corrected to obtain the fourth supporting power, including: Based on the real-time terminal voltage of the supercapacitor and the power factor of supercapacitors Calculate the maximum high-frequency output power The calculation formula is: ; Add the maximum high-frequency output power to the third support power to obtain the fourth support power. , .

[0046] Simultaneously, amplitude constraints are imposed on the fourth supporting power, ensuring it does not exceed the maximum allowable output power of the energy storage system to prevent power commands from exceeding limits. The higher the supercapacitor voltage, the greater the upper limit of the instantaneous high-frequency power it can provide, thereby constraining the high-frequency impact power output boundary and preventing over-discharge of the supercapacitor.

[0047] Step S105: Based on the grid voltage drop depth, allocate the low-frequency component of the fourth support power to the energy storage battery and allocate the high-frequency component of the fourth support power to the supercapacitor.

[0048] In this embodiment of the invention, the fourth support power is input into a first-order low-pass filter to obtain the low-frequency component.

[0049] ; in, This is the filter transfer function of a first-order low-pass filter; For Laplace variables; This is the filtering time constant.

[0050] The filter time constant is set to be adaptively adjusted according to the voltage drop depth of the power grid. The greater the voltage drop depth, the larger the filter time constant is set, so as to extend the time for the supercapacitor to withstand instantaneous impacts.

[0051] In this embodiment of the invention, when the grid voltage sag depth corresponds to a shallow sag range or a moderate sag range, When the voltage sag in the grid corresponds to the deep sag range, .

[0052] Subtracting the low-frequency component from the fourth support power yields the high-frequency component.

[0053] Low-frequency steady-state power components are sent to the lithium-ion battery energy storage converter, where the lithium-ion battery undertakes the task of steady-state voltage regulation; high-frequency transient impulse power components are sent to the supercapacitor converter, where the supercapacitor absorbs the instantaneous power surge caused by the sag.

[0054] This invention utilizes the performance differences between lithium batteries and supercapacitors to decouple high and low frequency power. The supercapacitor absorbs the high-frequency impact power during voltage sags, while the lithium battery is responsible for outputting steady-state compensation power. This approach leverages the strengths of both the lithium battery and its supercapacitors, reducing the instantaneous high current pressure and slowing down battery degradation, while also fully utilizing the rapid response advantage of the supercapacitors to improve the reliability of the entire hybrid energy storage system under voltage sag scenarios.

[0055] Based on the power allocation results, the energy storage system starts to support the grid voltage sag, which is undertaken independently by the energy storage battery or jointly by the energy storage battery and the supercapacitor.

[0056] In addition, the energy storage switching power allocation method for different drop depths in this embodiment of the invention further includes: according to the power allocation result, the energy storage system starts grid voltage sag power support and starts timing simultaneously; when the timing reaches the preset grid reclosing standard sag duration threshold, or when the grid voltage is not less than the load sensitivity characteristic factor, the energy storage system exits power support.

[0057] In this embodiment of the invention, the threshold for the standard sag duration of grid reclosing is set to 5ms.

[0058] When any one of the stopping conditions is met, the energy storage system smoothly exits the temporary sag support mode, executes grid reconnection control, and switches back to the normal operating mode, avoiding meaningless continuous power output and improving the economic efficiency of energy storage capacity utilization; the two stopping conditions realize dual logic judgment, matching both the typical duration of grid reclosing faults and using the minimum allowable load voltage as the protection exit criterion.

[0059] The beneficial effects of the energy storage switching power allocation method for different drop depths provided by the embodiments of the present invention are as follows: The system adaptively outputs a reference power for different voltage drop depths, avoiding full-power discharge during shallow sags, reducing the impact of high current on lithium batteries, and extending battery cycle life. It introduces a load-sensitivity factor, adjusting power based on the actual withstand voltage of the on-site load to accommodate the protection needs of different types of sensitive loads. Layered current limiting based on the state of charge (SOC) of the energy storage system, with automatic derating at low SOC conditions, prevents over-discharge of the battery during sags and ensures that sag protection does not fail midway. The supercapacitor voltage constrains the high-frequency power limit, and the hybrid energy storage system decouples high and low frequencies, allowing the supercapacitor to share the instantaneous impact while the lithium battery only bears the steady-state power, reducing the cell degradation rate. Dual criteria for exiting sag support match the duration of grid reclosing faults, balancing power supply reliability with the long-term economic efficiency of energy storage operation.

[0060] The embodiments of this invention also provide an energy storage switching power allocation system for different drop depths. The solution provided by this system is similar to the solution described in the embodiments of the energy storage switching power allocation method for different drop depths. Therefore, the specific limitations of the embodiments of the energy storage switching power allocation system for different drop depths provided below can be found in the limitations of the energy storage switching power allocation method for different drop depths above, and will not be repeated here.

[0061] like Figure 2 As shown, this embodiment of the invention also provides an energy storage switching power distribution system for different drop depths, including: The reference support power acquisition module is used to obtain the first support power based on the pre-divided multi-level sag intervals and the support power setting rules corresponding to each level of sag interval, according to the current grid voltage drop depth. The load correction module is used to correct the first support power based on a preset load sensitivity factor to obtain the second support power when the voltage of the faulty phase does not meet the minimum operating load requirements. The energy storage battery correction module is used to correct the second support power according to the energy storage state of charge to obtain the third support power; and when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third support power is allocated to the energy storage battery. The supercapacitor correction module is used to correct the third support power based on the maximum high-frequency output power of the supercapacitor, so as to obtain the fourth support power, when the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold. The power distribution module is used to allocate the low-frequency component of the fourth support power to the energy storage battery and the high-frequency component of the fourth support power to the supercapacitor based on the grid voltage drop depth.

[0062] An embodiment of the present invention also provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform an embodiment of the present invention for energy storage switching power allocation method for different drop depths.

[0063] An embodiment of the present invention also provides a computer program product, including a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform the energy storage switching power allocation method for different drop depths according to an embodiment of the present invention.

[0064] Embodiments of the present invention also provide an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, which, when executed by the at least one processor, causes the electronic device to perform an energy storage switching power allocation method for different drop depths according to embodiments of the present invention.

[0065] refer to Figure 3 The present invention will now describe a structural block diagram of an electronic device that can serve as an embodiment of the present invention, serving as an example of a hardware device applicable to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0066] like Figure 3 As shown, the electronic device includes a computing unit 101, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 102 or a computer program loaded from a storage unit 108 into a random access memory (RAM) 103. The RAM 103 may also store various programs and data required for the operation of the electronic device. The computing unit 101, ROM 102, and RAM 103 are interconnected via a bus 104. An input / output (I / O) interface 105 is also connected to the bus 104.

[0067] Multiple components in the electronic device are connected to I / O interface 105, including: input unit 106, output unit 107, storage unit 108, and communication unit 109. Input unit 106 can be any type of device capable of inputting information into the electronic device. Input unit 106 can receive input digital or character information and generate key signal inputs related to user settings and / or function control of the electronic device. Output unit 107 can be any type of device capable of presenting information and may include, but is not limited to, a display, speaker, video / audio output terminal, vibrator, and / or printer. Storage unit 108 may include, but is not limited to, disks and optical discs. Communication unit 109 allows the electronic device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks, and may include, but is not limited to, modems, network cards, infrared communication devices, and / or wireless communication transceivers, such as Bluetooth devices, WiFi devices, WiMax devices, cellular communication devices, and / or the like.

[0068] The computing unit 101 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 101 include, but are not limited to, CPUs, graphics processing units (GPUs), various special-purpose artificial intelligence (AI) computing units, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. The computing unit 101 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present invention can be implemented as computer programs tangibly contained in a machine-readable medium, such as storage unit 108. In some embodiments, part or all of the computer program can be loaded and / or installed on an electronic device via ROM 102 and / or communication unit 109. In some embodiments, the computing unit 101 can be configured to perform the methods described above by any other suitable means (e.g., by means of firmware).

[0069] Computer programs for implementing the methods of embodiments of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0070] In the context of embodiments of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, or infrared systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0071] It should be noted that the term "comprising" and its variations used in the embodiments of this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality" mentioned in the embodiments of this invention are illustrative and not restrictive, and those skilled in the art should understand that unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0072] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of this invention are subject to strict compliance with relevant laws, regulations, and regulatory requirements in their collection, storage, use, processing, transmission, provision, and disclosure, and adhere to the principles of legality, legitimacy, necessity, and good faith. The acquisition of relevant information and data is premised on the user's explicit consent or other legitimate reasons, and a clear and convenient authorization management approach is provided to the user, allowing the user to independently choose to consent, withdraw consent, or refuse to provide relevant information. For functions that rely on user information, if the user does not authorize or withdraws authorization, the corresponding technical function cannot be implemented, and the technical solution of this invention is not applicable in this scenario.

[0073] The steps described in the method embodiments provided by the present invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0074] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0075] The above embodiments merely illustrate several implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for power allocation during energy storage switching for different drop depths, characterized in that, include: Based on the pre-divided multi-level sag intervals and the corresponding support power setting rules for each level of sag interval, the first support power is obtained according to the current grid voltage drop depth; When the voltage of the faulty phase does not meet the minimum operating requirements of the load, the first supporting power is corrected based on the preset load sensitivity characteristic factor to obtain the second supporting power. Based on the energy storage state of charge, the second supporting power is corrected to obtain the third supporting power; And when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third supporting power is allocated to the energy storage battery; When the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold, the third supporting power is corrected based on the maximum high-frequency output power of the supercapacitor to obtain the fourth supporting power. Based on the grid voltage drop depth, the low-frequency component of the fourth supporting power is allocated to the energy storage battery, and the high-frequency component of the fourth supporting power is allocated to the supercapacitor.

2. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, The pre-defined multi-level descent intervals include: When the voltage drop depth is not less than the first threshold and less than the second threshold, the voltage is in the shallow sag range. When the voltage drop depth is not less than the second threshold and less than the third threshold, the grid voltage is in the moderate sag range. When the voltage drop depth is not less than the third threshold, the voltage is in the deep sag range; The voltage drop depth of the power grid represents the magnitude by which the voltage of the faulted phase deviates from the rated phase voltage; The rules for setting the support power for each descent interval include: The grid voltage in the shallow sag range is supported by a first coefficient multiplied by the rated output power of the energy storage system. The grid voltage in the aforementioned moderate sag range supports a power output equal to the second coefficient multiplied by the rated output power of the energy storage system. The grid voltage within the aforementioned deep sag range supports the rated output power of the energy storage system. Wherein, the first coefficient is less than the second coefficient, and the second coefficient is less than 1.

3. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, Before obtaining the second support power by power correction of the first support power based on a preset load sensitivity characteristic factor when the fault phase voltage does not meet the minimum load operating requirements, the method further includes: determining whether the fault phase voltage meets the minimum load operating requirements based on the load sensitivity characteristic factor. Based on the load sensitivity factor, determining whether the voltage of the faulty phase meets the minimum operating requirements of the load includes: If the fault phase voltage is not less than the load sensitivity characteristic factor, it is determined that the fault phase voltage meets the minimum load operating requirements. If the voltage of the faulty phase is less than the load sensitivity factor, it is determined that the voltage of the faulty phase does not meet the minimum operating load requirement.

4. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, Based on a preset load sensitivity factor, the first support power is corrected to obtain the second support power, including: The voltage gap is obtained based on the difference between the load sensitivity characteristic factor and the fault phase voltage. Based on the voltage gap, and combined with the difference between the load sensitivity factor and the rated phase voltage, the second supporting power is calculated.

5. The energy storage switching power allocation method for different drop depths according to claim 4, characterized in that, The formula for calculating the second support power is as follows: ； in, This is the second supporting power; This is the primary supporting power; This is a voltage gap; This is the rated phase voltage; This is the load-sensitive characteristic factor.

6. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, Based on the energy storage state of charge, the second supporting power is modified to obtain the third supporting power, including: Based on the pre-defined multi-layer energy storage state of charge and the power correction coefficient corresponding to each layer of energy storage state of charge, the power correction coefficient corresponding to the current energy storage state of charge is obtained. The third supporting power is obtained by multiplying the power correction coefficient corresponding to the current energy storage state of charge by the second supporting power.

7. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, Based on the maximum high-frequency output power of the supercapacitor, the third supporting power is corrected to obtain the fourth supporting power, including: The maximum high-frequency output power is calculated based on the real-time terminal voltage and power factor of the supercapacitor. The maximum high-frequency output power is added to the third support power to obtain the fourth support power.

8. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, Based on the grid voltage sag depth, the low-frequency component of the fourth supporting power is allocated to the energy storage battery, and the high-frequency component of the fourth supporting power is allocated to the supercapacitor, including: The fourth supporting power is input into a first-order low-pass filter to obtain the low-frequency component; wherein, the filtering time constant of the first-order low-pass filter is set according to the grid voltage drop depth; Subtracting the low-frequency component from the fourth support power yields the high-frequency component; The low-frequency component is allocated to the energy storage battery, and the high-frequency component is allocated to the supercapacitor.

9. The energy storage switching power allocation method for different drop depths according to claim 1, characterized in that, The method also includes: Based on the power allocation results, the energy storage system initiates grid voltage sag power support and simultaneously starts timing. When the timing reaches the preset threshold for the temporary sag of the grid reclosing standard, or when the grid voltage is not less than the load sensitivity factor, the energy storage system withdraws from power support.

10. A power distribution system for energy storage switching based on different drop depths, characterized in that, include: The reference support power acquisition module is used to obtain the first support power based on the pre-divided multi-level sag intervals and the support power setting rules corresponding to each level of sag interval, according to the current grid voltage drop depth. The load correction module is used to correct the first support power based on a preset load sensitivity factor to obtain the second support power when the voltage of the faulty phase does not meet the minimum operating load requirements. The energy storage battery correction module is used to correct the second supporting power according to the energy storage state of charge to obtain the third supporting power; And when the real-time terminal voltage of the supercapacitor is lower than the preset undervoltage threshold, the third supporting power is allocated to the energy storage battery; The supercapacitor correction module is used to correct the third supporting power based on the maximum high-frequency output power of the supercapacitor, so as to obtain the fourth supporting power, when the real-time terminal voltage of the supercapacitor is not lower than the preset undervoltage threshold. The power distribution module is used to allocate the low-frequency component of the fourth supporting power to the energy storage battery and the high-frequency component of the fourth supporting power to the supercapacitor based on the grid voltage drop depth.

11. An electronic device, comprising: A processor, and a memory storing a program, characterized in that the program includes instructions that, when executed by the processor, cause the processor to perform the energy storage switching power allocation method for different drop depths according to any one of claims 1 to 9.

12. A non-transitory machine-readable medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to execute the energy storage switching power allocation method for different drop depths according to any one of claims 1 to 9.

13. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the energy storage switching power allocation method for different drop depths as described in any one of claims 1 to 9.

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