Method, system, device and medium for reverse power flow handling in a three-phase distribution network

Abstract

The application provides a reverse current processing method, system, device and medium of a three-phase power distribution network, belonging to the technical field of energy storage control. The method is applied to an energy storage system including multiple energy storage devices and a three-phase electric meter, control instructions are issued to the nth energy storage device based on a preset detection sequence to increase the output power; in the case that the nth energy storage device receives the control instructions, the power change data of each phase of the grid side is obtained through the three-phase electric meter, and the access phase corresponding to the nth energy storage device is determined based on the power change data; after determining the access phase of each energy storage device, if a reverse current signal is detected, the energy storage device with the access phase being the reverse current phase is selected based on the corresponding reverse current phase, the reverse current processing strategy is determined, and the operating parameters of the corresponding energy storage device are adjusted. The method realizes accurate identification of the access phase of multiple energy storage devices and reverse current positioning, reduces the phase misjudgment rate, and improves the operating stability and control efficiency in the home energy storage and grid connection scenario.

Description

Technical Field

[0001] This application relates to the field of energy storage control technology, and in particular to a method, system, device and medium for reverse current processing in a three-phase power distribution network. Background Technology

[0002] With the rapid popularization of distributed photovoltaic systems and home energy storage, the parallel application of multiple energy storage devices in three-phase power distribution networks has become an important trend in energy management. In typical residential or small commercial scenarios, users usually connect to the grid through three-phase meters, with each phase carrying independent loads and energy devices (such as photovoltaic inverters, energy storage systems, electric vehicle charging stations, etc.).

[0003] Currently, in order to achieve efficient energy distribution and safe grid operation, home energy storage systems need to accurately identify the phase sequence of their connection (i.e., the grid phases to which the device is connected, such as phase A, phase B, and phase C) and monitor the power flow direction of each phase in real time to prevent reverse current (backflow) from impacting the grid.

[0004] However, existing phase identification methods cannot accurately identify the access phase of different energy storage devices in a three-phase power distribution network where multiple energy storage devices operate in parallel, thus failing to achieve accurate positioning of the reverse phase and significantly increasing the misjudgment rate of the reverse phase. Summary of the Invention

[0005] This application provides a method, system, device, and medium for reverse current processing in a three-phase power distribution network to solve the technical problem that existing phase sequence identification under the condition of multiple energy storage devices operating in parallel cannot accurately identify the access phase of different energy storage devices, thus failing to achieve accurate positioning of the reverse current phase and significantly increasing the misjudgment rate of the reverse current phase.

[0006] In a first aspect, embodiments of this application provide a reverse current processing method for a three-phase power distribution network, applied to an energy storage system. The energy storage system includes multiple energy storage devices and a three-phase electricity meter. The method includes:

[0007] Based on the preset detection sequence of multiple energy storage devices, control commands are sent to the nth energy storage device; where n is a positive integer less than or equal to N, N is the total number of energy storage devices, and the control commands are used to control the energy storage device to increase its output power.

[0008] When the nth energy storage device receives a control command, the power change data of each phase on the grid side is obtained through the three-phase electricity meter.

[0009] For any phase, the power change data of that phase is compared with preset change parameters; the preset change parameters include: preset change amplitude, preset change direction and preset change timing.

[0010] If the change amplitude, change direction, and change timing in the power change data of a phase are consistent with the preset change amplitude, preset change direction, and preset change timing, respectively, the power change data of the phase is determined to conform to the preset change parameters, and the phase is determined to be the access phase of the nth energy storage device.

[0011] If a reverse current signal is detected after determining the access phase of all energy storage devices, the corresponding energy storage devices with the reverse current phase are selected based on the reverse current phase indicated by the reverse current signal.

[0012] Determine the reverse flow processing strategy, and adjust the operating parameters of the corresponding energy storage devices connected to the reverse flow phase according to the reverse flow processing strategy;

[0013] Among them, the change amplitude is the absolute value of the instantaneous active power difference between the phases before and after the control command is executed; the change direction is used to characterize the increase or decrease of the active power of the phases; the change timing includes the start time and duration of the change in the phase power.

[0014] In one possible implementation, based on a preset detection sequence of multiple energy storage devices, the control command is sent to the nth energy storage device, which further includes:

[0015] When the total number N of energy storage devices changes, based on the preset detection sequence of multiple energy storage devices, control commands are issued to the nth energy storage device, and silence commands are issued to the remaining energy storage devices except the nth energy storage device.

[0016] The silent command is used to control the energy storage device to keep its output power constant.

[0017] In one possible implementation, before issuing control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices, the method further includes:

[0018] Each of the multiple energy storage devices is assigned a device code, which is used to distinguish different energy storage devices.

[0019] Based on the device codes of multiple energy storage devices, a preset detection sequence for multiple energy storage devices is generated.

[0020] In one possible implementation, the priority of each energy storage device in a preset detection sequence is adjusted based on at least one of the following:

[0021] Historical test success rate of each energy storage device;

[0022] Communication quality of each energy storage device;

[0023] The phase status of each energy storage device is determined.

[0024] In one possible implementation, determining the reverse flow processing strategy includes:

[0025] When there are multiple reverse-current phases, for any reverse-current phase, determine the total power regulation corresponding to the reverse-current phase, and determine the load power status corresponding to the energy storage device connected to the reverse-current phase respectively.

[0026] Based on the load power status, determine the power allocation ratio of each energy storage device corresponding to the reverse phase;

[0027] Based on the total power regulation and power allocation ratio, the power regulation of each energy storage device corresponding to the reverse phase is determined, and a reverse processing strategy is generated based on the power regulation of each energy storage device.

[0028] The load power status includes: current load power, power fluctuation level, and load adjustment margin.

[0029] Secondly, embodiments of this application provide a reverse current processing device for a three-phase power distribution network, comprising:

[0030] The processing module is used to send control commands to the nth energy storage device based on the preset detection sequence of multiple energy storage devices; where n is a positive integer less than or equal to N, N is the total number of energy storage devices, and the control commands are used to control the energy storage device to increase its output power.

[0031] The acquisition module is used to acquire power change data of each phase on the grid side through three-phase meters when the nth energy storage device receives a control command.

[0032] The processing module is also used to compare the power change data of any phase with preset change parameters for any given phase. The preset change parameters include: preset change amplitude, preset change direction, and preset change timing.

[0033] The processing module is also used to determine that the power change data of a phase conforms to preset change parameters when the change amplitude, change direction, and change timing in the power change data of a phase are consistent with the preset change amplitude, preset change direction, and preset change timing, respectively, and to determine the phase as the access phase of the nth energy storage device.

[0034] If a reverse current signal is detected after determining the access phase of all energy storage devices, the processing module is also used to filter out the energy storage devices whose access phase is the reverse current phase based on the reverse current phase indicated by the reverse current signal.

[0035] The processing module is also used to determine the reverse flow processing strategy and adjust the operating parameters of the corresponding energy storage devices with reverse flow phases according to the reverse flow processing strategy.

[0036] Among them, the change amplitude is the absolute value of the instantaneous active power difference between the phases before and after the control command is executed; the change direction is used to characterize the increase or decrease of the active power of the phases; the change timing includes the start time and duration of the change in the phase power.

[0037] In one possible implementation, the processing module is further configured to, when the total number N of energy storage devices changes, issue control commands to the nth energy storage device based on a preset detection sequence of the multiple energy storage devices, and issue silence commands to the remaining energy storage devices other than the nth energy storage device.

[0038] The silent command is used to control the energy storage device to keep its output power constant.

[0039] In one possible implementation, the processing module is further configured to determine the device codes of multiple energy storage devices, the device codes being used to distinguish different energy storage devices.

[0040] The processing module is also used to generate a preset detection sequence for multiple energy storage devices based on the device codes of multiple energy storage devices.

[0041] In one possible implementation, the priority of each energy storage device in a preset detection sequence is adjusted based on at least one of the following:

[0042] Historical test success rate of each energy storage device;

[0043] Communication quality of each energy storage device;

[0044] The phase status of each energy storage device is determined.

[0045] In one possible implementation, the processing module is further configured to, when there are multiple reverse-current phases, determine the total power adjustment amount corresponding to any one reverse-current phase, and determine the load power state corresponding to the energy storage device connected to the reverse-current phase.

[0046] The processing module is also used to determine the power allocation ratio of each energy storage device corresponding to the reverse phase based on the load power status.

[0047] The processing module is also used to determine the single power adjustment amount of each energy storage device corresponding to the reverse phase based on the total power adjustment amount and the power allocation ratio, and to generate a reverse processing strategy based on the single power adjustment amount of each energy storage device.

[0048] The load power status includes: current load power, power fluctuation level, and load adjustment margin.

[0049] Thirdly, embodiments of this application provide an energy storage system, which includes multiple energy storage devices, a three-phase meter, and a control unit;

[0050] The three-phase meter is used to collect power change data from multiple energy storage devices; the control unit is used to execute the first aspect and / or various possible implementations of the first aspect.

[0051] Fourthly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0052] The memory stores instructions that the computer executes;

[0053] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0054] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0055] In a sixth aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0056] The reverse current processing method for a three-phase power distribution network provided in this application issues control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices. Upon receiving the control command, the nth energy storage device acquires power change data for each phase on the grid side using a three-phase meter. For any given phase, the power change data is compared with preset change parameters. If the power change data matches the preset parameters, the phase is designated as the access phase for the nth energy storage device. After determining the access phases for all energy storage devices, if a reverse current signal is detected, the corresponding access phase is selected based on the reverse current phase indicated by the signal. This method identifies energy storage devices connected to the reverse-current phase. When there are multiple reverse-current phases, for any given phase, it determines the total power regulation corresponding to that phase and the load power status of each connected energy storage device in the reverse-current phase. Based on the load power status, it determines the power allocation ratio for each energy storage device in the reverse-current phase. Based on the total power regulation and the power allocation ratio, it determines the individual power regulation of each energy storage device in the reverse-current phase. Based on the individual power regulation of each energy storage device, it generates a reverse-current processing strategy and adjusts the operating parameters of the connected energy storage devices in the reverse-current phase according to this strategy. This method combines ordered power disturbance on the device side, three-phase power sensing on the meter side, phase mapping establishment, and reverse-current closed-loop regulation. It achieves automatic identification of the connected phase in multi-device parallel operation scenarios without adding additional phase detection hardware, significantly improving phase sequence identification accuracy. Furthermore, it solves the signal interference problem in multi-device parallel operation scenarios through a time-division detection mechanism, achieving accurate positioning of the reverse-current phase. Attached Figure Description

[0057] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0058] Figure 1 This is a flowchart illustrating the reverse current processing method for the three-phase power distribution network provided in this application. Figure 1 ;

[0059] Figure 2 This is a flowchart illustrating the reverse current processing method for the three-phase power distribution network provided in this application. Figure 2 ;

[0060] Figure 3 This is a schematic diagram of the reverse current processing device for the three-phase power distribution network provided in this application;

[0061] Figure 4 This is a schematic diagram of the structure of the electronic device provided in this application.

[0062] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0063] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0064] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0065] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0066] It should be noted that 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, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0067] The reverse current processing method for three-phase power distribution networks provided in this application relates to the fields of distributed photovoltaic energy storage and three-phase power distribution network control. This method is particularly suitable for the operation scenario of multiple energy storage devices being connected in parallel to the three-phase power grid in a home energy storage system.

[0068] With the rapid popularization of distributed photovoltaic systems and home energy storage, the parallel application of multiple energy storage devices in three-phase power distribution networks has become an important trend in energy management. In typical residential or small commercial scenarios, users usually connect to the grid through three-phase meters, with each phase carrying independent loads and energy devices (such as photovoltaic inverters, energy storage systems, electric vehicle charging stations, etc.).

[0069] In a typical residential user-side environment, a residential rooftop photovoltaic array, energy storage battery pack, energy storage converter, and three-phase smart meter usually together constitute an energy harvesting, conversion, metering, and dispatch system. The photovoltaic system generates electricity during the day, the energy storage device charges during off-peak electricity prices or when there is surplus power generation, and discharges when household load increases or photovoltaic output is insufficient, in order to maintain a stable power supply to the user-side load.

[0070] With the increase in household energy storage capacity and the growing demand for parallel operation of multiple brands and multiple energy storage devices, systems often need to automatically identify the phase of device connection without adding extra detection hardware, and monitor and control potential backflow of electricity.

[0071] Because the loads on each phase in a three-phase power distribution network are not perfectly balanced, and household power consumption varies frequently over different time periods, the connected phase, output power, and power flow of energy storage devices on the grid side will dynamically change accordingly. Therefore, it is necessary for the electricity meter to continuously collect power information for each phase, and for the control unit to coordinate the operating status of multiple energy storage devices. In this type of scenario, the system must not only meet the flexibility of parallel connection, but also take into account the requirements of low cost, low power consumption, and easy deployment, especially adapting to the usage scenarios of non-professional users such as on-site wiring, capacity expansion, and equipment replacement.

[0072] Currently, in order to achieve efficient energy dispatch and safe grid operation, home energy storage systems need to accurately identify the phase sequence of their connection (i.e., the grid phases to which the equipment is connected, such as phase A, phase B, and phase C) and monitor the power flow direction of each phase in real time to prevent reverse current (reverse flow) from impacting the grid.

[0073] Specifically, for phase sequence identification and reverse current control of energy storage devices in three-phase power distribution networks, solutions based on voltage and current sampling or power characteristic analysis are typically adopted. The former often relies on additional phase detection modules, voltage transformers, or current transformers to infer the phase to which the device is connected by collecting three-phase voltage and current signals and comparing their phases; the latter is usually based on three-phase power data collected by electricity meters, and determines the phase to which the device is connected or the reverse current phase by observing the power change pattern.

[0074] However, in a three-phase power distribution network where multiple energy storage devices operate in parallel, the existing phase identification method cannot accurately identify the connected phase of different energy storage devices due to the uneven distribution of household three-phase loads, the large differences in the power consumption characteristics of each phase, and the fact that the connected phases of multiple devices are not fixed. Insufficient accuracy in identifying the connected phase directly leads to the inability to accurately locate the reverse phase and perform targeted reverse processing, which easily increases the misjudgment rate of the reverse phase.

[0075] At the same time, the device cannot automatically identify its phase sequence after being connected, requiring manual configuration of parameters. This not only makes installation complicated, but also makes the system prone to malfunctions due to wiring errors.

[0076] To address the aforementioned issues, this application provides a reverse current processing method for three-phase power distribution networks. This method is applied to energy storage systems comprising multiple energy storage devices and three-phase meters. It utilizes grid power changes as the identification basis, sequentially controlling individual energy storage devices to release fixed amounts of electrical energy for short periods. Combined with time-sharing detection of multiple energy storage devices via cloud computing, the corresponding access phase of each device can be uniquely determined based on power change data. After determining the phase of all energy storage devices in the three-phase power distribution network, if a reverse current signal is detected, the corresponding energy storage device is selected based on the reverse current phase indicated by the signal, and a corresponding reverse current processing strategy is determined. The operating parameters of the energy storage device corresponding to the reverse current phase are adjusted according to this strategy. This method leverages the existing collaborative control relationship between energy storage devices and three-phase meters. Through detection sequence management, power change analysis, and reverse current phase association positioning, it forms a phase sequence identification and reverse current processing mechanism for multi-device parallel operation scenarios. This provides a foundation for subsequent low-cost, low-interference, and scalable home energy storage operation control, avoiding signal conflicts during multi-device parallel operation and ensuring high accuracy and stability of phase sequence identification.

[0077] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0078] Figure 1 A flowchart illustrating the reverse current processing method for a three-phase power distribution network provided in this application embodiment. Figure 1 The executing entity in this embodiment can be, for example, the control unit of an energy storage system. Figure 1 As shown, the reverse current processing method for a three-phase power distribution network provided in this embodiment includes:

[0079] S101: Based on the preset detection sequence of multiple energy storage devices, send control commands to the nth energy storage device.

[0080] Where n is a positive integer less than or equal to N, N is the total number of energy storage devices, and the control command is used to control the energy storage devices to increase their output power.

[0081] In this embodiment, the three-phase power distribution network is a three-phase AC power distribution environment on the home or user side. The energy storage system is deployed in the three-phase power distribution network. The energy storage system includes multiple energy storage devices, three-phase meters, and control units that are communicatively connected to the energy storage devices and three-phase meters.

[0082] Specifically, the energy storage device is a combination of battery energy storage units and energy storage converters that can output or absorb electrical energy from the grid. Each energy storage device has an independent device identifier, communication interface, and adjustable output power. The three-phase meter is an intelligent metering device that can independently collect and transmit the grid-side power of phases A, B, and C. The control unit can be deployed as a home energy management controller, a local gateway, a processor integrated into the energy storage host, or a cloud-local collaborative management platform.

[0083] In one possible implementation, the control unit first discovers and files the energy storage devices. It acquires the online status, device code, rated power, current output power, charge / discharge permit status, and communication quality parameters of each energy storage device via a local area network bus, wireless communication link, or power line carrier communication. It also reads the real-time power sampling capability and data refresh cycle of the three-phase electricity meter. Based on this, the control unit determines the device identifiers of multiple energy storage devices to generate corresponding detection queues, i.e., obtains a preset detection order for the corresponding multiple energy storage devices. This preset detection order can, for example, be arranged in ascending order according to the device identifiers to form a stable device detection sequence.

[0084] Understandably, the preset detection sequence is used to constrain the action order of multiple energy storage devices during the access phase identification stage, so that only one energy storage device performs power disturbance at the same time, thereby avoiding detection aliasing caused by multiple devices changing at the same time.

[0085] In one possible implementation, the control command may specifically be a detection start message, which includes a target power increment, power increase duration, start execution timestamp, execution confirmation field, and abnormal rollback parameters; wherein, the target power increment is used to enable the nth energy storage device to generate a power disturbance on its connected phase that can be observed by the three-phase electricity meter, and the duration is used to ensure that the three-phase electricity meter stably captures the change within at least one or more sampling periods.

[0086] To avoid interference from other devices with the test results, the control unit can send silent control information to other energy storage devices while issuing control commands. This allows other energy storage devices to maintain their current output state, not to perform power ramp-up, not to participate in power balancing regulation, and not to respond to unnecessary energy dispatch requests during the target device's test. This ensures that any new power changes on the grid side are contributed by a single device as much as possible, facilitating subsequent phase-specific analysis.

[0087] In this embodiment of the application, for the target power increment in the control command, the corresponding detection disturbance magnitude can be adaptively determined based on the load fluctuation level and the resolution of the three-phase electricity meter in the three-phase power distribution network.

[0088] If the current load of the three-phase power grid is relatively stable, a small fixed increment can be used, such as a certain percentage of the rated output power of the energy storage device as the detection power. If the load fluctuates greatly or the photovoltaic output changes significantly, the detection increment can be increased and the detection duration can be extended in order to form a significant change characteristic higher than the noise threshold.

[0089] In addition, the power increment needs to meet two types of constraints at the same time: one is that it can be reliably identified by the three-phase electricity meter, and the other is that it does not cause power supply disturbance on the user side or exceed the safe operation boundary of the equipment.

[0090] In one possible implementation, the control unit can also check the current battery state of charge, inverter temperature, discharge permission flag and grid-connected operation status of the nth energy storage device before sending control commands. The detection is only initiated when the device meets the conditions for performing power enhancement actions. If the conditions are not met, the current device is skipped and the reason is recorded, and it will be added back to the detection queue later.

[0091] For example, when the phase detection process of the current energy storage device reaches the nth energy storage device, the control unit sends a control command to the nth energy storage device; after receiving the control command, the nth energy storage device first performs message verification and execution feasibility judgment, and returns a receipt confirmation information to the control unit; subsequently, the energy storage converter inside the energy storage device adjusts the AC side output command value according to the target power increment, so that the device can increase the output power in a short time, and the control unit enters the sampling and monitoring stage according to the receipt confirmation result and execution timestamp.

[0092] Understandably, by triggering controllable power disturbances in energy storage devices one by one under the constraints of a preset detection sequence, the outputs of multiple devices that were originally difficult to distinguish in complex parallel operation scenarios are decomposed into identifiable events of a single device and a single time period. This suppresses the phase identification error caused by the superposition of disturbances from multiple devices from the source. At the same time, there is no need to add voltage transformers, current transformers or dedicated phase detection modules. Therefore, it is possible to establish the foundation for subsequent phase identification and reverse current processing with low hardware dependence and low deployment cost.

[0093] In one possible implementation, before issuing control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices, device codes for each of the multiple energy storage devices are determined. These device codes are used to distinguish different energy storage devices. Based on the device codes of the multiple energy storage devices, a preset detection sequence for the multiple energy storage devices is generated.

[0094] Understandably, the device code is used to distinguish different energy storage devices; it is a unique identifier for each energy storage device, such as a serial number, serial number, factory serial number, or communication address. This code is read or received by the control unit during the energy storage system registration process and associated with the online status, rated parameters, and communication address of the corresponding energy storage device to accurately distinguish different energy storage devices within the same system.

[0095] By using device codes to establish distinguishable identifiers among multiple energy storage devices, and then forming a sequential detection relationship based on these identifiers, the control unit can schedule each energy storage device to participate in phase identification under unified rules. By first creating files, then sorting, and then issuing control commands, a preset detection sequence can be automatically formed in scenarios where multiple energy storage devices are operated in parallel, reducing the workload of manual configuration and ensuring the determinism and traceability of the detection process. This reduces the probability of device confusion and duplicate detection, improves the accuracy of control command issuance and the orderliness of the detection process, thereby enhancing the adaptability and deployment efficiency of the entire reverse flow processing method.

[0096] For example, after multiple energy storage devices are connected, the control unit first performs identity verification on each energy storage device, then obtains its device code and writes it into the local device table; then, the control unit generates a preset detection sequence based on the device code. The generation process can be completed based on the numerical value of the device code, lexicographical order, or preset mapping rules, thereby forming a stable detection queue, so that each energy storage device enters the detection state in a predetermined order; the detection sequence can also be adjusted in combination with the order of device access, communication stability, or historical identification records, so that the detection task is distributed in an orderly manner among multiple energy storage devices.

[0097] Once the preset detection sequence is generated, the control unit can issue control commands to the corresponding nth energy storage device in that sequence, while preventing other energy storage devices from participating in the detection simultaneously. This reduces the risk of power disturbance superposition in the case of multiple devices operating in parallel. Since the detection sequence is automatically generated based on the device code, the energy storage system does not need to manually configure the order of the target devices one by one, thereby improving deployment efficiency and reducing detection deviations caused by manual input errors.

[0098] In one possible implementation, the preset detection order can also be combined with information such as historical detection success rate, communication latency, number of retransmissions, reliability of the device's most recent phase identification result, and installation time to rearrange the detection queue so that devices that have not yet been successfully identified or whose communication is unstable can enter the detection first. For devices that have completed phase identification and whose wiring has not changed recently, the possibility of repeated detection can be reduced, and unnecessary power disturbances and communication overhead can be reduced.

[0099] S102: When the nth energy storage device receives the control command, the power change data of each phase on the grid side is obtained through the three-phase electricity meter, and the access phase corresponding to the nth energy storage device is determined based on the power change data of each phase.

[0100] Understandably, the power change data refers to the power changes of phases A, B, and C collected by the three-phase meters before and after the target energy storage device performs a power disturbance. It can include at least the instantaneous active power value of each phase, the difference between adjacent sampling times, the direction of change, the duration of change, and the time correspondence between the change and the time when the control command is issued. The access phase refers to phase A, phase B, or phase C in the three-phase power distribution network that the nth energy storage device is actually connected to. The determination result serves as the basis for subsequent reverse current positioning and equipment screening.

[0101] In one possible implementation, the control unit can read three-phase power data from the three-phase meter for several sampling periods before issuing control commands to the nth energy storage device, as baseline data before disturbance. This baseline data can be preprocessed, for example, by using moving average, exponential smoothing, or median filtering, to reduce the impact of instantaneous load fluctuations, communication jitter, and metering noise.

[0102] This application does not impose special restrictions on baseline data.

[0103] Understandably, when energy storage devices supply power to the grid-side load and reduce the power drawn from the public grid by that phase, the power meter of the connected phase will change in the direction of reducing the purchased power or increasing the reverse power supply. Therefore, the connected phase of the target device can be identified by the absolute value of the difference, its positive or negative direction, and its degree of synchronization with the command time.

[0104] After the nth energy storage device receives and executes the corresponding control command, the control unit continues to read the real-time power data of the three-phase meters within the disturbance window to form a post-disturbance sampling sequence; the control unit calculates the power difference of phase A, phase B and phase C before and after the disturbance to obtain the corresponding power change.

[0105] The control unit compares the three-phase power change with preset identification thresholds. If the change of a certain phase exceeds the threshold and is significantly greater than the changes of the other two phases, then that phase is identified as the access phase of the nth energy storage device.

[0106] The preset identification threshold can be dynamically set according to the measurement accuracy of the three-phase electricity meter, the fluctuation range of the household load background, and the target power increment set by the current control command. For example, when the sampling resolution of the three-phase electricity meter is high and the on-site load is relatively stable, the threshold can be set to a smaller value to improve the detection sensitivity. When there are frequent start-ups and shutdowns of high-power loads on-site, the threshold can be increased accordingly to suppress false judgments.

[0107] If the three-phase changes are close to or do not exceed the threshold, the control unit can determine that the current identification confidence is insufficient and trigger the compensation detection process, such as re-issuing a control command with a larger magnitude, extending the disturbance holding time, or detecting again after the load fluctuation weakens.

[0108] In one possible implementation, in order to further improve the anti-interference capability, the control unit can also normalize the power change data; specifically, the power difference during the disturbance of each phase is divided by the average load power, rated load limit or statistical standard deviation of the corresponding phase before the disturbance, thereby weakening the influence of the load imbalance of the three phases on the judgment result.

[0109] In another possible implementation, the control unit can also read the phase voltage, current or power factor data synchronously provided by the three-phase meters to cross-verify the conclusions on active power changes.

[0110] If a phase meets the threshold condition in terms of active power change, and its current change trend is consistent with the power increase action of the target equipment, then the reliability of the phase identification is further improved.

[0111] In scenarios where photovoltaic grid connection exists, the control unit can also synchronously acquire the output information of the photovoltaic inverter and remove the impact of rapid photovoltaic fluctuations on the identification window from the power meter sequence.

[0112] In one possible implementation, once the access phase of the nth energy storage device is determined, the control unit establishes a mapping relationship between the device code and the corresponding phase, writes it into the local configuration table or cloud device file, and may also store information such as identification time, disturbance power used during identification, threshold parameters, and identification confidence level; at the same time, the control unit notifies the nth energy storage device to exit the detection state and return to the original scheduling mode, and then selects the next device that has not completed identification from the detection queue, repeating the above process until the access phase of all energy storage devices is determined.

[0113] S103: If a reverse current signal is detected when the access phase of all energy storage devices is determined, the energy storage devices whose access phase is the reverse current phase are selected based on the reverse current phase indicated by the reverse current signal.

[0114] Understandably, the reverse flow signal is a signal detected by the three-phase meter that represents the reverse flow of electrical energy from the user side to the upper-level power grid. For example, it can be manifested as a negative power value of a certain phase, below the zero threshold, or, after combining the installation direction agreement, as the reverse power supply exceeding the preset threshold. The reverse flow phase is the phase in which the reverse flow phenomenon occurs, used to associate the reverse flow phenomenon with the established equipment access phase mapping relationship, thereby quickly narrowing down the range of equipment to be processed.

[0115] After completing the phase identification of all energy storage devices, the control unit can continuously obtain real-time three-phase power data from the three-phase meters and continuously detect the reverse current signal of each phase.

[0116] After detecting the reverse current signal, the control unit determines the phase corresponding to the reverse current signal and obtains the reverse current phase. The control unit queries the device phase mapping table formed in the previous stage and filters out all energy storage devices with the same access phase and reverse current phase to form a candidate device set.

[0117] In one possible implementation, if only one energy storage device is connected to a phase, that device is directly identified as the target device associated with the current reverse phase; if multiple parallel energy storage devices exist in a phase, the control unit further refines the judgment by combining the current output power of each device, the power change trend over a recent period, the state of charge, the scheduling task, and the historical reverse processing records.

[0118] For example, the determination of the energy storage device corresponding to the countercurrent phase can be based on the current discharge power ratio of each candidate device to determine its contribution to the formation of the countercurrent. The higher the output power of the device and the closer it is to the time when the countercurrent occurs, the greater the probability that it will be identified as the main source of the countercurrent. If multiple devices cause the countercurrent together, these devices can be included in the subsequent processing objects.

[0119] In one possible implementation, the identification of reverse current signals can also be combined with a comprehensive judgment of the household load power status and photovoltaic output status. For example, when there is high photovoltaic output and low load on the reverse current phase, the reverse current is not necessarily caused entirely by the energy storage device. Therefore, the control unit can compare the balance between the photovoltaic power generation of that phase, the total output power of the energy storage device, and the power consumed by the load to identify the set of energy storage devices that need to be regulated.

[0120] Understandably, this step utilizes the pre-established access phase mapping relationship to quickly convert the reverse current detection result from the grid-side phase to the device-side control object, avoiding the need for complex source location on the fly after a reverse current occurs, thus significantly shortening the reverse current response time. At the same time, in scenarios where multiple devices are connected in parallel and in the same phase, by combining the device output status for secondary screening, the accuracy of identifying the responsible reverse current device can be improved, reducing the risk of system efficiency degradation due to mis-adjustment of other devices.

[0121] In one possible implementation, to avoid false triggering caused by short-term meter fluctuations, reverse current detection can be performed by using both duration threshold and amplitude threshold. That is, when the power value of a certain phase is below the zero threshold for several consecutive sampling periods and its absolute value reaches the minimum reverse current identification threshold, the control unit determines that there is reverse current in that phase and generates a reverse current signal.

[0122] The zero threshold can be set to a strict zero value, or it can be set to a compensation threshold slightly below or slightly above zero to account for measurement errors, harmonic disturbances, and sampling offsets.

[0123] In addition, for situations where the net power fluctuates repeatedly near zero, the control unit can introduce a hysteresis region to prevent frequent switching between reverse flow and non-reverse flow states.

[0124] S104: Determine the reverse flow processing strategy, and adjust the operating parameters of the corresponding energy storage devices connected to the reverse flow phase according to the reverse flow processing strategy.

[0125] Understandably, the reverse flow processing strategy is a power regulation scheme formulated for the reverse flow phase and its corresponding energy storage device; the operating parameters are controllable quantities such as the output power, power limit, charging and discharging power level, power distribution ratio, or regulation execution sequence of the energy storage device.

[0126] The goal of the reverse flow handling strategy is to reduce the reverse power on the reverse phase to within the allowable range, thereby restoring the power balance and grid-connected operation stability of the three-phase power distribution network, while meeting equipment safety constraints and system operation constraints.

[0127] For example, if the three-phase meter displays a negative P real-time power for a certain phase, it indicates that there is a reverse current of P in that phase. The control unit can use this reverse current as the basic adjustment target and combine it with the safety margin (the safety margin is used to compensate for sampling delay, power ramp-up response lag, and load transient fluctuations, to prevent the power from remaining near zero after adjustment and causing reverse current to occur again) to generate a target reduction value. Subsequently, the control unit allocates the total adjustment amount according to the number of candidate energy storage devices and their current status. If only one energy storage device corresponds to the reverse current phase, it can directly issue a command to reduce the output power or limit the discharge power, so that the output of the device drops to a level that does not generate reverse current. If multiple devices are connected to the same reverse current phase, the control unit can distribute the total adjustment amount according to the device's rated power, current output ratio, battery state of charge, available capacity, temperature rise status, and health status to form a coordinated adjustment scheme.

[0128] For example, the control unit can use a method of allocating power according to the current output power ratio, so that the equipment with higher output can bear more reduction, thereby quickly suppressing reverse current; or it can use a method of allocating power according to the remaining adjustment margin, prioritizing the adjustment of equipment that still has a large reduction space, thereby reducing the impact on the operational stability of low-power equipment; after determining the reverse current handling strategy, the energy storage equipment connected to the reverse current phase updates the inverter control target according to the operating parameters received by each phase, and performs power reduction, charging and discharging limit contraction, or switches from the discharging state to the standby or light charging state.

[0129] In one possible implementation, for short-term reverse current caused by sudden changes in user load, the control unit can adopt a graded adjustment mechanism, first performing a small step for rapid reduction, and then deciding whether to continue to increase the adjustment amount based on subsequent meter feedback, so as to avoid excessive adjustment causing the local load to switch back to drawing large amounts of power.

[0130] In abnormal situations, such as when a target energy storage device experiences a communication interruption, refuses to execute commands, or is restricted by a protection state from reducing its output power, the control unit can redistribute the unfinished adjustment amount to other energy storage devices in the same phase, or trigger a higher-level protection strategy at the system level, such as limiting the overall grid-connected output, sending alarm information, and recording fault events, to ensure that the reverse flow processing has fault tolerance capabilities.

[0131] Understandably, this step establishes a closed-loop control relationship between the reverse flow phase and the corresponding energy storage device's operating parameters, transforming reverse flow suppression from simple detection into an executable, feedback-enabled, and iteratively correctable control process. This not only rapidly reduces the risk of backflow of electricity but also takes into account the differences in device capabilities and operating boundaries in multi-device parallel operation scenarios, achieving a stable and low-interference reverse flow control effect.

[0132] The reverse current processing method for three-phase power distribution networks provided in this embodiment is applied to an energy storage system containing multiple energy storage devices and three-phase meters. It issues control commands to the nth energy storage device based on a preset detection sequence, causing the device to temporarily increase its output power. Power change data for each phase on the grid side is obtained through the three-phase meters, and the corresponding access phase of the energy storage device is determined based on this data. After the access phases of all energy storage devices are determined, the reverse current signal output by the three-phase meters is continuously monitored, and energy storage devices corresponding to the access phases are selected based on the reverse current phase. This generates a reverse current processing strategy and adjusts the operating parameters of the relevant energy storage devices. This method combines ordered power disturbance on the device side, three-phase power sensing on the meter side, phase mapping establishment, and reverse current closed-loop adjustment. Without adding additional phase detection hardware, it achieves automatic identification of the access phase and rapid location of the reverse current phase in scenarios where multiple energy storage devices are connected in parallel. This reduces system hardware costs and on-site deployment complexity, reduces the risk of misjudgment caused by simultaneous operation of multiple devices, and improves the accuracy of reverse current location and processing response speed.

[0133] Figure 2 A flowchart illustrating the reverse current processing method for a three-phase power distribution network provided in this application embodiment. Figure 2 .like Figure 2 As shown, in this embodiment... Figure 1 Based on the embodiments, the reverse current processing method for three-phase power distribution networks is described in detail. The reverse current processing method for three-phase power distribution networks shown in this embodiment includes:

[0134] S201: Based on the preset detection sequence of multiple energy storage devices, control commands are sent to the nth energy storage device.

[0135] When the phase detection process of the current energy storage device reaches the nth energy storage device, the control unit issues a control command to the nth energy storage device.

[0136] In one possible implementation, while issuing control commands to the nth energy storage device, a silence command is also issued to the remaining energy storage devices other than the nth energy storage device.

[0137] The silent command is used to control the energy storage device to keep its output power constant.

[0138] In this embodiment, the silence command is a hold-type control signal sent by the control unit to the energy storage devices other than the one being tested in the current test. Its function is to lock the output state of devices not being tested in the current test within the testing window to prevent them from participating in power disturbances.

[0139] For example, while issuing control commands to the nth energy storage device, a silence command is issued to the remaining energy storage devices to ensure that the output power of the remaining energy storage devices remains unchanged. That is, the corresponding energy storage converter maintains the current charging and discharging power setting value and does not perform increase or decrease adjustment.

[0140] In another possible implementation, after the control unit detects a change in the number of connected devices, it regenerates the current set of devices that can participate in the detection and maintains the original or updated preset detection order based on the set. When the control unit issues a control command to the nth energy storage device, it simultaneously issues a silence command to the other energy storage devices so that the other energy storage devices maintain their current grid-connected power, operating mode and power direction unchanged during the detection period.

[0141] Specifically, for devices whose current output power is already stable, the silence command allows them to continue using the original settings; for devices in charge / discharge scheduling, the silence command is used to freeze their scheduling corrections to prevent power superposition from affecting the three-phase meters' recognition of power changes in the target device.

[0142] It is understandable that control commands and silence commands can be issued through local gateways, energy managers, or cloud-edge collaborative control platforms. Communication methods can include local area networks, wireless links, or power line communication. This application does not impose any special restrictions on the transmission of control commands and silence commands.

[0143] Based on this, the energy storage system can maintain the consistency of the detection sequence and the power stability within the detection window even when the number of devices changes, reduce signal aliasing caused by multiple devices operating simultaneously, improve the accuracy of phase identification, and reduce operational fluctuations and communication interference caused by repeated disturbances. For home energy storage scenarios with frequent changes in the scale of parallel operation, this solution can enhance the adaptability and stability of the detection process.

[0144] In one possible implementation, the priority of each energy storage device in a preset detection sequence is adjusted based on at least one of the following: the historical detection success rate of each energy storage device; the communication quality of each energy storage device; and the phase determination status of each energy storage device.

[0145] The priority of the preset detection sequence is used to characterize the order in which each energy storage device is detected.

[0146] It is understandable that the historical detection success rate is used to characterize the proportion of each energy storage device whose phase identification was successfully determined in previous access phase identification tasks. The control unit can count the number of successful tests for each energy storage device and the total number of tests, and write the statistical results into the device file. The communication quality is used to characterize the stability of the communication link between the energy storage device and the control unit. The control unit can form a comprehensive evaluation value based on signal strength, message loss rate, round-trip time delay, and retransmission count. The phase identification status is used to characterize whether the energy storage device has completed access phase identification and whether the identification result needs to be verified. The control unit can record the statuses such as "not determined", "determined", and "pending verification" in the mapping table and adjust the subsequent detection arrangements accordingly.

[0147] During the generation of the preset detection sequence, the control unit first forms an initial detection queue based on the device code, and then rearranges the initial queue according to at least one of the above indicators. For example, for energy storage devices with a low historical detection success rate, the control unit can move them forward to prioritize the processing of devices that may have abnormal wiring, parameter drift, or unstable identification. For energy storage devices with poor communication quality, the control unit can detect them earlier to reduce the risk of detection interruption caused by further deterioration of subsequent communication. For energy storage devices whose phases have not yet been determined or whose phases have been determined but have conflict records, the control unit can increase their priority to ensure that the phase mapping table is completed as soon as possible.

[0148] If multiple indicators exist simultaneously, the control unit can assign weights to each indicator and calculate a comprehensive priority value, and then sort them according to the comprehensive priority value to obtain a detection queue that better matches the on-site conditions.

[0149] For example, the control unit can establish a communication connection with each energy storage device through a local gateway and periodically refresh the above indicators. The detection order is regenerated after changes in the number of devices, communication status, or replacement of some devices. This means that the generation of the preset detection order no longer depends on the device code sorting, but is dynamically adjusted according to the current detectability and recognition reliability of the devices. This ensures that high recognition efficiency and stability are maintained when multiple energy storage devices are connected in parallel. For example, devices with low historical detection success rates but stable communication can be prioritized for detection, and devices with degraded communication can be identified as early as possible before losing contact. Devices that have been stably identified can reduce the frequency of repeated detection, thereby reducing invalid power disturbances.

[0150] In one possible implementation, adjusting the priority of each energy storage device in the preset detection sequence based on the communication quality of each energy storage device can be achieved by the control unit periodically refreshing the communication quality indicators of each energy storage device through the local gateway, including signal strength, message loss rate, round-trip time, and retransmission count; based on the refreshed communication quality data, the control unit dynamically adjusts the detection queue, prioritizing devices with poor communication quality to reduce the risk of detection interruption caused by subsequent communication deterioration.

[0151] S202: When the nth energy storage device receives a control command, the power change data of each phase on the grid side is obtained through the three-phase electricity meter.

[0152] S203: For any phase, compare the phase power change data with the preset change parameters.

[0153] Understandably, the preset variation parameters are used to characterize the power disturbance characteristics caused by the energy storage device connecting to a certain phase on the three-phase meter side. These include, for example, the variation amplitude, variation direction, and variation timing, and the three together constitute the determination constraint for the connected phase. The power variation data is collected by the three-phase meter from phases A, B, and C respectively, and is used to reflect the increase or decrease of active power in each phase after the control command is triggered and the timing of its occurrence. The control command is used to drive the nth energy storage device to increase its output power for a short time, so that an identifiable power change is formed on its connected phase, which facilitates subsequent phase matching.

[0154] In one possible implementation, the preset variation parameters include: a preset variation amplitude, a preset variation direction, and a preset variation timing; determining the variation amplitude, variation direction, and variation timing of the power variation data for each phase; comparing the variation amplitude, variation direction, and variation timing corresponding to each phase with the preset variation amplitude, preset variation direction, and preset variation timing, respectively. If the variation amplitude matches the preset variation amplitude, the variation direction matches the preset variation direction, and the variation timing matches the preset variation timing, the power variation data for that phase is determined to conform to the preset variation parameters.

[0155] Among them, the change amplitude is the absolute value of the instantaneous active power difference between the phases before and after the control command is executed; the change direction is used to characterize the increase or decrease of the active power of the phases; the change timing includes the start time and duration of the change in the phase power.

[0156] Understandably, instantaneous active power refers to the actual active power value output by the three-phase meter at the corresponding sampling time, used to characterize the true power state of each phase during the detection period; the time interval before and after the execution of the control command is divided by the time when the control unit issues the control command, forming a reference sampling window and a disturbance sampling window respectively, thus providing a unified reference for the calculation of the change amplitude and change timing; the preset change amplitude is used to limit the power disturbance intensity that the target phase should reach, the preset change direction is used to limit the power of the phase to increase or decrease, and the preset change timing is used to limit the change to occur within the expected response window and last for the corresponding duration, so as to eliminate the interference of background load fluctuations on the judgment results.

[0157] After receiving the execution trigger signal corresponding to the control command, the control unit first reads several sampling points of the target phase before the command is executed and calculates the average active power during that period as a reference value. Then, it reads several sampling points after the command is executed and calculates the active power value after the disturbance. The absolute value of the difference between the two is determined as the change amplitude. If the power after the disturbance is higher than the reference value, the change direction is recorded as increasing, and vice versa. The change timing is obtained by recording the starting time when the power first deviates from the reference range and the length of time when the power remains in the change state. The control unit then compares the change amplitude, change direction, and change timing with the preset change amplitude, preset change direction, and preset change timing, respectively. When all three match, it is determined that the power change data of the phase conforms to the preset change parameters, and the correlation between the phase and the detected object is confirmed accordingly.

[0158] In this embodiment, by breaking down power changes into three dimensions—amplitude, direction, and timing—for joint determination, phase identification no longer relies on a single threshold. Instead, it simultaneously examines the intensity of change, the trend of change, and the response time characteristics. This effectively reduces the probability of misjudgment caused by random load fluctuations, sampling noise, and short-term interference, and improves the accuracy and stability of phase identification in scenarios where multiple energy storage devices are connected in parallel.

[0159] S204: If the power change data of a phase meets the preset change parameters, the phase will be determined as the access phase of the nth energy storage device.

[0160] For example, before receiving the control command for the nth energy storage device, the control unit first reads the three-phase power of several sampling periods as baseline data and filters the baseline data to reduce the impact of load fluctuations and metering noise. After the control command takes effect, the control unit continues to collect the three-phase power sequence and calculates the difference of any phase before and after the disturbance to obtain the power change data of that phase. The control unit compares the change data with preset change parameters. Specifically, if the change amplitude of a certain phase reaches a preset threshold, the change direction is consistent with the power change direction corresponding to the increased output of the energy storage device, and the change timing matches the time when the control command is issued, then the phase is determined to meet the preset change parameters, and the phase is determined as the access phase of the nth energy storage device.

[0161] In one possible implementation, the power change data can also be the instantaneous change of the three-phase electricity meter; based on the instantaneous change, the power change value and direction of the corresponding energy storage device under the current control command can be directly determined, which can be used for comparison with preset change parameters to quickly locate the phase of the current energy storage device.

[0162] In this embodiment, the preset change parameters can be configured based on the metering accuracy of the three-phase electricity meter, the on-site load fluctuation level, and the disturbance power set by the control command. This ensures that the phase identification has sufficient sensitivity while suppressing environmental interference. By comparing the change parameters of each phase one by one, and confirming the connected phase only when the power change data matches the preset change parameters (there is a unique connected phase for the energy storage device), the power disturbance on the device side can be accurately mapped to the phase characteristics on the grid side. This reduces the dependence on additional phase detection hardware, improves the accuracy and stability of connected phase identification in scenarios where multiple energy storage devices are connected in parallel, and provides a reliable foundation for subsequent reverse positioning and operating parameter adjustment.

[0163] S205: If a reverse current signal is detected when the access phase of all energy storage devices is determined, the energy storage devices whose access phase is the reverse current phase are selected based on the reverse current phase indicated by the reverse current signal.

[0164] Step S205 is similar to step S103 above, and will not be described again here.

[0165] S206: When there are multiple reverse-current phases, for any reverse-current phase, determine the total power regulation corresponding to the reverse-current phase, and determine the load power status corresponding to the energy storage device connected to the reverse-current phase.

[0166] S207: Based on the load power status, determine the power allocation ratio of each energy storage device corresponding to the reverse phase.

[0167] S208: Based on the total power regulation and power allocation ratio, determine the single power regulation of each energy storage device corresponding to the reverse phase, and generate a reverse processing strategy based on the single power regulation of each energy storage device.

[0168] S209: Adjust the operating parameters of the energy storage devices connected to the reverse flow phase according to the reverse flow processing strategy.

[0169] The load power status includes: current load power, power fluctuation level, and load adjustment margin.

[0170] Understandably, the total power regulation is used to characterize the total amount of power that needs to be uniformly reduced or recovered for a certain reverse-current phase. For example, it can be determined by the reverse-current power of that phase, the upper limit of grid connection, and the safety margin. The current load power is used to reflect the current actual load level of that phase, the power fluctuation degree is used to reflect the degree of drastic change in the load in a short period of time, and the load regulation margin is used to characterize the space that that phase can participate in regulation without affecting the stability of power supply. The control unit can calculate and update the above parameters based on the real-time sampling results of the three-phase meters.

[0171] When there are multiple reverse-current phases, for any reverse-current phase, determine the total power regulation corresponding to that reverse-current phase, and determine the load power status corresponding to the energy storage device connected to that reverse-current phase.

[0172] During the generation of the reverse flow processing strategy, the control unit first calculates the power allocation ratio of each energy storage device based on the total power adjustment amount on the reverse flow phase and the load power status of the corresponding energy storage device. For example, a higher ratio can be allocated to energy storage devices with higher current power, smaller fluctuations, and larger adjustment margins; a lower ratio can be allocated to energy storage devices with power close to the boundary, larger fluctuations, or smaller adjustment margins.

[0173] After determining the power allocation ratio of each energy storage device, the control unit divides the total power regulation proportionally to obtain the power regulation of each energy storage device. It then converts the power regulation of each device into the corresponding output power limit value, discharge reduction value, or charge / discharge switching command, thereby forming a reverse current processing strategy that can be directly issued. According to the reverse current processing strategy, the operating parameters of the corresponding energy storage devices connected to the reverse current phase are adjusted.

[0174] Understandably, determining the reverse current handling strategy for any phase and further decomposing the overall regulation task within the phase to each energy storage device enables different devices to collaboratively undertake the regulation task according to their respective load states. This avoids a single device bearing excessive power correction pressure, allowing the reverse current suppression process to no longer rely on the centralized regulation of a single device, but to be finely allocated among multiple reverse current phases and multiple devices. This improves the balance, response speed, and execution reliability of reverse current handling, and helps reduce power fluctuations on the grid side, improving the overall operating effect in scenarios where multiple energy storage devices are connected in parallel.

[0175] In this embodiment, the reverse flow processing strategy is generated for a single reverse flow phase, and the reverse flow processing strategies for different reverse flow phases are different.

[0176] In one possible implementation, the power allocation ratio is calculated based on the following formula:

[0177]

[0178] in, Let i be the power regulation of the i-th energy storage device. This refers to the total power regulation of the counter-current phase. Let be the power fluctuation coefficient of the i-th energy storage device.

[0179] In one possible implementation, the power fluctuation coefficient Let be the ratio of the power fluctuation level of the i-th energy storage device to the load regulation margin.

[0180] For example, after analyzing the power change data obtained in the current detection, the power fluctuation level of the i-th energy storage device is found to be 20kW. The load regulation margin that this device can currently use to respond to disturbance commands is 100kW. Therefore, the power fluctuation coefficient corresponding to this energy storage device is... The ratio of power fluctuation range to load regulation margin is 0.2.

[0181] In one possible implementation, for the nth energy storage device, if the power change data of each phase does not conform to the preset change parameters, the control command for the nth energy storage device is regenerated and issued to perform a second phase determination for the energy storage device; if the power change data of each phase obtained during the second determination process still does not conform to the preset change parameters, the energy storage device is marked as faulty and a corresponding fault prompt message is generated, which is used to prompt the user that the corresponding energy storage device has a fault.

[0182] The reverse current processing method for a three-phase power distribution network provided in this embodiment issues control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices. Upon receiving the control command, the nth energy storage device acquires power change data for each phase on the grid side using a three-phase meter. For any given phase, the power change data is compared with preset change parameters. If the power change data matches the preset parameters, the phase is determined as the access phase for the nth energy storage device. After determining the access phases for all energy storage devices, if a reverse current signal is detected, the corresponding access phase is selected based on the reverse current signal indicating the reverse current phase. This method identifies energy storage devices connected in a reverse-current phase. When there are multiple reverse-current phases, for any given phase, the total power regulation corresponding to that phase is determined, and the load power status of each connected energy storage device in a reverse-current phase is also determined. Based on the load power status, the power allocation ratio of each energy storage device in the reverse-current phase is determined. Based on the total power regulation and the power allocation ratio, the individual power regulation of each energy storage device in the reverse-current phase is determined. Based on the individual power regulation of each energy storage device, a reverse-current processing strategy is generated. The operating parameters of the connected energy storage devices in the reverse-current phase are adjusted according to this strategy. This method combines ordered power disturbance on the device side, three-phase power sensing on the meter side, phase mapping establishment, and reverse-current closed-loop regulation. It achieves automatic identification of the connected phase in a multi-device parallel operation scenario without adding additional phase detection hardware, significantly improving phase sequence identification accuracy. Furthermore, a time-division detection mechanism solves the signal interference problem in a multi-device parallel operation scenario, achieving accurate positioning of the reverse-current phase.

[0183] Figure 3 This is a schematic diagram of the reverse current processing device for the three-phase power distribution network provided in this application. Figure 3 As shown, this application provides a reverse current processing device for a three-phase power distribution network. The reverse current processing device 300 for the three-phase power distribution network includes:

[0184] The processing module 301 is used to send control commands to the nth energy storage device based on the preset detection sequence of multiple energy storage devices; where n is a positive integer less than or equal to N, N is the total number of energy storage devices, and the control commands are used to control the energy storage device to increase its output power.

[0185] The acquisition module 302 is used to acquire power change data of each phase on the grid side through a three-phase meter when the nth energy storage device receives a control command.

[0186] The processing module 301 is also used to compare the power change data of any phase with preset change parameters for any phase; the preset change parameters include: preset change amplitude, preset change direction and preset change timing.

[0187] The processing module 301 is also used to determine that the power change data of the phase conforms to the preset change parameters when the change amplitude, change direction and change timing in the power change data of the phase are consistent with the preset change amplitude, preset change direction and preset change timing, respectively, and to determine the phase as the access phase of the nth energy storage device.

[0188] If a reverse current signal is detected after determining the access phase of all energy storage devices, the processing module 301 is further used to filter out the energy storage devices whose access phase is a reverse current phase based on the reverse current phase indicated by the reverse current signal.

[0189] The processing module 301 is also used to determine the reverse flow processing strategy and adjust the operating parameters of the energy storage device whose access phase is the reverse flow phase according to the reverse flow processing strategy.

[0190] Among them, the change amplitude is the absolute value of the instantaneous active power difference between the phases before and after the control command is executed; the change direction is used to characterize the increase or decrease of the active power of the phases; the change timing includes the start time and duration of the change in the phase power.

[0191] In one possible implementation, the processing module 301 is further configured to, when the total number N of energy storage devices changes, issue control commands to the nth energy storage device based on the preset detection sequence of the multiple energy storage devices, and issue silence commands to the remaining energy storage devices other than the nth energy storage device.

[0192] The silent command is used to control the energy storage device to keep its output power constant.

[0193] In one possible implementation, the processing module 301 is further configured to determine the device codes of multiple energy storage devices, the device codes being used to distinguish different energy storage devices.

[0194] The processing module 301 is also used to generate a preset detection sequence for multiple energy storage devices based on the device codes of multiple energy storage devices.

[0195] In one possible implementation, the priority of each energy storage device in a preset detection sequence is adjusted based on at least one of the following:

[0196] Historical test success rate of each energy storage device;

[0197] Communication quality of each energy storage device;

[0198] The phase status of each energy storage device is determined.

[0199] In one possible implementation, the processing module 301 is further configured to, when there are multiple reverse-current phases, determine the total power adjustment amount corresponding to any one reverse-current phase, and determine the load power state corresponding to the energy storage device connected to the reverse-current phase.

[0200] The processing module 301 is also used to determine the power allocation ratio of each energy storage device corresponding to the reverse phase based on the load power status.

[0201] The processing module 301 is also used to determine the single power adjustment amount of each energy storage device corresponding to the reverse phase based on the total power adjustment amount and the power allocation ratio, and to generate a reverse processing strategy based on the single power adjustment amount of each energy storage device.

[0202] The load power status includes: current load power, power fluctuation level, and load adjustment margin.

[0203] The reverse current processing device for the three-phase power distribution network provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0204] Figure 4 A schematic diagram of the structure of the electronic device provided in this application. Figure 4 As shown, the electronic device 400 provided in this embodiment includes at least one processor 401 and a memory 402. Optionally, the device 400 further includes a communication component 403. The processor 401, memory 402, and communication component 403 are connected via a bus 404.

[0205] In a specific implementation, at least one processor 401 executes computer execution instructions stored in memory 402, causing at least one processor 401 to perform the above-described method.

[0206] The specific implementation process of processor 401 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0207] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0208] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0209] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0210] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0211] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0212] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0213] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0214] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0215] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0216] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0217] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0218] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0219] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for handling reverse current in a three-phase power distribution network, characterized in that, Applied to an energy storage system, the energy storage system comprising multiple energy storage devices and a three-phase electricity meter, the method includes: Based on the preset detection sequence of multiple energy storage devices, a control command is sent to the nth energy storage device; where n is a positive integer less than or equal to N, and N is the total number of energy storage devices. The control command is used to control the energy storage device to increase its output power. When the nth energy storage device receives the control command, the power change data of each phase on the grid side is obtained through the three-phase meter; For any phase, the power change data of that phase is compared with preset change parameters; the preset change parameters include: preset change amplitude, preset change direction, and preset change timing. If the change amplitude, change direction, and change sequence in the power change data of the phase are consistent with the preset change amplitude, the preset change direction, and the preset change sequence, respectively, it is determined that the power change data of the phase conforms to the preset change parameters, and the phase is determined as the access phase of the nth energy storage device; If a reverse current signal is detected, and the corresponding access phase of all the energy storage devices is determined, the energy storage devices whose access phase is the reverse current phase are selected based on the reverse current phase indicated by the reverse current signal. Determine the reverse flow processing strategy, and adjust the operating parameters of the energy storage devices whose access phase is the reverse flow phase according to the reverse flow processing strategy; Wherein, the change amplitude is the absolute value of the instantaneous active power difference of the phase before and after the execution of the control command; the change direction is used to characterize the increase or decrease of the active power of the phase; the change timing includes the start time and duration of the change in the phase power.

2. The method according to claim 1, characterized in that, The step of issuing control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices further includes: Send a silence command to all energy storage devices except the nth energy storage device; The silent command is used to control the output power of the energy storage device to remain constant.

3. The method according to claim 1, characterized in that, Before issuing control commands to the nth energy storage device based on a preset detection sequence of multiple energy storage devices, the method further includes: Each of the multiple energy storage devices is assigned a device code, which is used to distinguish different energy storage devices. Based on the device codes of the multiple energy storage devices, a preset detection sequence for the multiple energy storage devices is generated.

4. The method according to claim 3, characterized in that, The priority of each energy storage device in the preset detection sequence is adjusted based on at least one of the following: The historical test success rate of each energy storage device; Communication quality of each energy storage device; The phase status of each energy storage device is determined separately.

5. The method according to claim 1, characterized in that, The determination of the reverse flow processing strategy includes: When there are multiple reverse flow phases, for any one of the reverse flow phases, the total power adjustment corresponding to the reverse flow phase is determined, and the load power status corresponding to the energy storage device connected to the reverse flow phase is determined respectively. Based on the load power status, determine the power allocation ratio of each energy storage device corresponding to the reverse phase; Based on the total power regulation amount and the power allocation ratio, the power regulation amount of each energy storage device corresponding to the reverse flow phase is determined, and the reverse flow processing strategy is generated based on the power regulation amount of each energy storage device. The load power status includes: current load power, power fluctuation level, and load adjustment margin.

6. An energy storage system, characterized in that, The energy storage system includes multiple energy storage devices, a three-phase electricity meter, and a control unit; The three-phase meter is used to collect power change data of the multiple energy storage devices; the control unit is used to execute the method described in any one of claims 1-5.

7. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-5.

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