Carrier synchronization control method for energy storage system, energy storage system

Abstract

This invention proposes a carrier synchronization control method for energy storage systems. The method includes selecting one branch from N parallel branches as the master branch and the remaining N-1 branches as slave branches; determining the master cabinet from multiple energy storage cabinets within the master branch through a dynamic competition mechanism, and designating the remaining energy storage cabinets within the master branch and all energy storage cabinets within the slave branches as slave cabinets; the master cabinet sending a carrier synchronization signal to all slave cabinets; and the slave cabinets calculating the phase offset between their own carrier and the carrier synchronization signal based on the received carrier synchronization signal, and performing carrier phase compensation accordingly. This invention, by selecting the master branch and having its master cabinet, generated through competition, uniformly distribute the carrier synchronization signal; and by having each slave branch's master cabinet and slave cabinets receive and compensate for the signal, it effectively suppresses common-mode interference and prevents malfunctions in the battery management system and fire suppression system. Furthermore, slave branches can switch to master branches at any time, further enhancing the system's fault-tolerant operation capability.

Description

Technical Field

[0001] This invention relates to the field of energy storage converter technology, and more particularly to a carrier synchronization control method for energy storage systems. Background Technology

[0002] As battery capacity increases year by year, the capacity of a single energy storage cabinet can no longer match the full charging and discharging requirements of battery clusters. Therefore, multi-cabinet parallel solutions are widely used. In existing parallel energy storage cabinet systems, carrier synchronization is usually only achieved for cabinets connected in parallel to AC and DC ports within the same branch, and relies on the central controller to issue synchronization signals, with each cabinet in the branch passively receiving the signals to complete synchronization. However, when multiple branches without communication connections are connected to the AC port, high-frequency circulating currents still exist on the AC side of each branch's energy storage system, causing common-mode interference. This interference can easily trigger malfunctions in the entire battery management system or fire protection system, ultimately causing the energy storage system to fail and shut down. In addition, if the synchronization circuit of the central controller fails, the entire branch's energy storage cabinets will shut down, resulting in a significant lack of system fault tolerance.

[0003] Therefore, a new solution is needed. Summary of the Invention

[0004] To address the problem that traditional multi-branch energy storage systems rely on centralized controller carrier synchronization and cannot self-reset after a fault, resulting in insufficient fault tolerance, this invention provides a carrier synchronization control method for energy storage systems.

[0005] According to one aspect of the present invention, a carrier synchronization control method for an energy storage system is provided, applicable to an energy storage system comprising N parallel branches, each branch including multiple energy storage cabinets, wherein the N parallel branches converge to the same AC bus and there are no direct communication lines between the branches, wherein N≥2, comprising the following steps: Select one branch from the N parallel branches as the main branch, and the remaining N-1 branches as secondary branches; The main cabinet is determined from multiple energy storage cabinets in the main branch through a dynamic competition mechanism, and the remaining energy storage cabinets in the main branch and all energy storage cabinets in the slave branch are determined as slave cabinets. The main cabinet sends a carrier synchronization signal to all slave cabinets; The server rack calculates the phase offset between its own carrier and the carrier synchronization signal based on the received carrier synchronization signal, and performs carrier phase compensation based on the phase offset.

[0006] The carrier synchronization control method for energy storage systems provided by this invention further includes: In response to the detection of a fault in the main rack, a dynamic contention mechanism is triggered within the main branch to re-determine a new main rack from the remaining fault-free racks in the main branch, excluding the faulty rack, and the new main rack takes over the transmission of the carrier synchronization signal.

[0007] The carrier synchronization control method for energy storage systems provided by this invention further includes: A dynamic competition mechanism is used to determine the local master cabinet of each slave branch from among multiple energy storage cabinets in each slave branch. The local master cabinet is used to perform power distribution and current sharing control within its own branch.

[0008] In the carrier synchronization control method for energy storage systems provided by this invention, the dynamic contention mechanism includes: Obtain the preset priority identifier and real-time operating status data of each energy storage cabinet in the main branch; In response to the need to determine the main cabinet, energy storage cabinets with preset priority identifiers that meet preset rules are selected from the energy storage cabinets whose real-time operating status data shows no faults.

[0009] The carrier synchronization control method for energy storage systems provided by this invention further includes: The fault-free rack within the main branch with a priority higher than other slave racks is configured as a backup master rack, and the backup master rack continuously receives and tracks the carrier synchronization signal of the master rack; In response to a failure of the main cabinet, the backup main cabinet automatically takes over as the new main cabinet and sends carrier synchronization signals.

[0010] The carrier synchronization control method for energy storage systems provided by this invention further includes: In response to the faulty cabinet returning to normal operation, the priority of the energy storage cabinet that has returned to normal operation and the current standby cabinet are re-evaluated according to the preset rules. In response to the fact that the energy storage cabinet that has been restored to normal operation has a higher priority than the current backup cabinet, the restored cabinet is configured as the new backup cabinet.

[0011] The carrier synchronization control method for energy storage systems provided by the present invention further includes: in response to detecting that the main branch is completely unusable or that all energy storage cabinets in the main branch are unable to perform the main cabinet function, isolating the main branch and selecting one branch from the remaining N-1 secondary branches as a new main branch. The new main branch determines the new host cabinet according to the dynamic competition mechanism, and the new host cabinet sends carrier synchronization signals to each energy storage cabinet in the remaining branches.

[0012] According to another aspect of the present invention, an energy storage system is also provided, characterized in that it comprises: N parallel branches, each branch containing one or more energy storage cabinets, the N parallel branches converge to the same AC bus and there is no direct communication line between the branches, where N≥2; Each of the energy storage cabinets is equipped with a controller configured to perform the carrier synchronization control method described above.

[0013] According to another aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the carrier synchronization control method for an energy storage system as described above.

[0014] The carrier synchronization control system method for energy storage systems implemented in this invention has the following beneficial effects: This invention discloses a carrier synchronization method and system for parallel multi-branch energy storage cabinets on the AC side, aiming to solve the problems of insufficient fault tolerance and high-frequency circulating current interference caused by traditional reliance on centralized controllers; by selecting a main branch and introducing a dynamic competition mechanism within it to generate a master cabinet, a unified carrier synchronization signal is sent to all slave branches; simultaneously, when the master cabinet fails, it is seamlessly taken over by a hot-backup backup, and the cabinet re-competes for backup status after the failure; when the entire main branch fails, the system automatically isolates and switches any slave branch to become the new master branch to take over the synchronization responsibility; this invention achieves full-system carrier synchronization without a dedicated controller through a decentralized dynamic master selection and multi-level hot standby mechanism, eliminates high-frequency circulating current paths, and greatly improves the system's self-healing and fault tolerance capabilities under multiple faults. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort: Figure 1 The diagram shown is a connection schematic of the energy storage system provided by the present invention; Figure 2 The diagram shows a flowchart of the carrier synchronization control method for energy storage systems provided by the present invention. Detailed Implementation

[0016] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Typical embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0018] Figure 1 The diagram shown is a connection schematic of the energy storage system provided by this invention. Figure 1 The connection diagram of the energy storage system is shown below. The system includes N parallel branches (branch 1, branch 2, ..., branch N), where N ≥ 2. Each branch contains multiple energy storage cabinets; for example, branch 1 contains cabinets A1, A2, ..., Am, branch 2 contains cabinets B1, B2, ..., Bn, and so on. The AC outputs of all branches are connected to the same AC bus, and there are no direct communication lines between the branches. Each energy storage cabinet contains a controller, which includes, but is not limited to, hardware devices with computing and control functions such as digital signal processors, microcontrollers, and field-programmable gate arrays. The controllers exchange information via power line carrier communication, but there are no dedicated synchronization signal lines between branches.

[0019] Example 1 Figure 2 The diagram shows a flowchart of a carrier synchronization control method for an energy storage system provided by the present invention. Figure 2 As shown, the carrier synchronization control method for energy storage systems provided by the present invention includes the following steps: Step S1: Select one branch from the N parallel branches as the main branch, and the remaining N-1 branches as secondary branches; Specifically, in this embodiment, after the system is powered on and initialized, one branch is selected from N parallel branches as the main branch, and the remaining N-1 branches are selected as slave branches. The selection of the main branch can be based on preset rules, such as selecting the branch with the smallest branch number, or selecting the branch that completed initialization first. In this embodiment, it is preferable to select the fault-free branch with the smallest branch number as the main branch.

[0020] Step S2: Determine the main energy storage cabinet from among the multiple energy storage cabinets in the main branch through a dynamic competition mechanism, and determine the remaining energy storage cabinets in the main branch and all energy storage cabinets in the slave branch as slave cabinets; Specifically, in this embodiment, the main cabinet is determined through a dynamic competition mechanism within the main branch. Specifically, each cabinet within the main branch monitors its own operating status in real time and broadcasts its status information to other cabinets within the branch. When it is necessary to determine the main cabinet (e.g., during system initialization, main cabinet failure, etc.), each cabinet competes according to preset priority rules. Therefore, in this embodiment, firstly, the preset priority identifier and real-time operating status data of each energy storage cabinet within the main branch are obtained; in response to the need to determine the main cabinet, from the energy storage cabinets whose real-time operating status data shows no faults, the energy storage cabinet with the preset priority identifier conforming to the preset rules is selected as the main cabinet.

[0021] Furthermore, in this embodiment, the preset rule is: the rack with the smallest number among the fault-free racks is selected as the master rack. For example, if there are racks 1, 2, and 3 in the main branch, and rack 2 fails, then rack 1 and rack 3 compete for the master rack. Since the number of rack 1 is smaller than that of rack 3, rack 1 is selected as the master rack, and rack 3 and the recovered rack 2 become slave racks.

[0022] Step S3: The main cabinet sends a carrier synchronization signal to all slave cabinets; Specifically, in this embodiment, the main cabinet generates a carrier synchronization signal and broadcasts the signal to all cabinets within the branch. The carrier synchronization signal can be a high-precision synchronization pulse or a digital message containing phase information.

[0023] Step S4: The server rack calculates the phase offset between the local carrier and the carrier synchronization signal based on the received carrier synchronization signal, and performs carrier phase compensation based on the phase offset.

[0024] Specifically, in this embodiment, each rack within a branch receives a carrier synchronization signal from the main rack. The controller of each rack calculates the phase offset between its internal carrier and the received carrier synchronization signal, and then adjusts its own carrier phase based on the offset to achieve carrier synchronization across all racks in the system.

[0025] The carrier synchronization control method for energy storage systems provided in this embodiment constructs a decentralized hierarchical synchronization architecture through the selection of main branches and the dynamic competition mechanism of main cabinets. It can achieve carrier synchronization of the entire system without relying on a dedicated centralized controller. The main cabinet, as the only synchronization signal source, ensures that the carrier phase reference of all cabinets is consistent, thus eliminating the high-frequency circulation path caused by carrier asynchrony at the physical level.

[0026] Example 2 Furthermore, in this embodiment, the method further includes: configuring a fault-free rack within the main branch with a priority higher than other slave racks as a backup master rack, wherein the backup master rack continuously receives and tracks the carrier synchronization signal of the master rack; in response to a failure of the master rack, the backup master rack automatically takes over as a new master rack to send the carrier synchronization signal; in response to detecting a failure of the master rack, triggering a dynamic contention mechanism within the main branch, re-determining a new master rack from the remaining fault-free racks within the main branch excluding the faulty rack, and having the new master rack take over sending the carrier synchronization signal.

[0027] In this embodiment, while determining the main rack, a fault-free rack within the main branch with a priority higher than other slave racks is configured as a backup main rack. The backup main rack continuously receives and tracks the carrier synchronization signal sent by the main rack, maintaining carrier phase synchronization with the main rack and remaining in a hot backup state.

[0028] For example, in a main branch circuit, there are cabinets 1, 2, 3, and 4. If cabinet 2 fails, cabinet 1 is selected as the primary cabinet. Cabinets 3 and 4 compete for the backup primary cabinet position, so cabinet 3 is configured as the backup primary cabinet. Cabinet 3 synchronizes its carrier phase with cabinet 1 in real time, so it can immediately take over if cabinet 1 fails.

[0029] In this embodiment, the hot backup mechanism of the backup main cabinet enables microsecond-level rapid takeover in the event of a main cabinet failure. The switching process is transparent to the slave cabinet, ensuring the continuity of carrier synchronization and avoiding system oscillations caused by synchronization source interruption.

[0030] Example 3 Furthermore, in this embodiment, the method further includes: in response to the faulty cabinet returning to normal operation, re-determining the priority of the energy storage cabinet that has returned to normal operation and the current backup cabinet according to the preset rules; in response to the energy storage cabinet that has returned to normal operation having a higher priority than the current backup cabinet, configuring the restored cabinet as the new backup cabinet.

[0031] In this embodiment, the mechanism of fault recovery cabinets re-competing for the qualification of backup cabinets enables them to smoothly reconnect to the system in hot backup state without downtime or manual intervention, which significantly improves the maintainability and availability of the system.

[0032] The following details the switching process in case of a main unit cabinet failure.

[0033] Assuming that in the initial state, cabinet 1 in the main branch is the main cabinet, cabinet 3 is the backup main cabinet, and the remaining cabinets are slave cabinets.

[0034] Time T0: Rack 1 is operating normally and periodically sends carrier synchronization signals to all racks in the system. Rack 3, acting as the backup main rack, continuously receives and tracks the carrier synchronization signal of rack 1, maintaining its own carrier phase in sync with rack 1.

[0035] Time T1: Rack 1 malfunctions and stops sending carrier synchronization signals.

[0036] Time T2: Rack 3 detects an interruption in the synchronization signal of rack 1, or receives a fault broadcast from rack 1. Since rack 3 is always in hot backup mode, its carrier phase is consistent with the phase of rack 1 just before the fault.

[0037] At time T3: Rack 3 automatically takes over as the new master rack and immediately begins sending carrier synchronization signals to all racks in the system. Due to the continuity of the carrier phase before and after the takeover, no significant adjustments are required to the slave racks.

[0038] Time T4: Rack 1 fault resolved, back to normal operation.

[0039] At time T5: Rack 1 rejoins the main branch and determines its priority according to preset rules (lowest number). At this time, the primary rack is rack 3, and the backup rack is idle. Since rack 1's number is lower than rack 3's, rack 1 replaces the original rack 3 as the new backup rack and enters hot backup mode. Rack 3 continues to serve as the primary rack.

[0040] Example 4 Furthermore, in this embodiment, the method further includes: determining the local master cabinet of each slave branch among multiple energy storage cabinets in each slave branch through a dynamic competition mechanism, wherein the local master cabinet is used to perform power distribution and current sharing control within the branch.

[0041] In this embodiment, each slave branch has an independently configured local host cabinet. The local host cabinet is responsible for power distribution and current sharing control within its own branch, but does not participate in the generation of system-level carrier synchronization signals. Specifically, each cabinet in a slave branch receives the carrier synchronization signal sent by the main branch host cabinet and uses this as a reference for carrier phase compensation. After carrier synchronization is completed, the local host cabinet in each slave branch coordinates the output power of each cabinet through internal branch communication according to the power requirements of its branch, thereby achieving current sharing control within the branch.

[0042] This embodiment adopts a hierarchical control architecture, decoupling system-level carrier synchronization from tributary-level power control. This ensures a unified carrier reference for the entire system while giving each tributary independent power scheduling capabilities. The local host cabinet of each tributary shares the computational tasks of power allocation and current sharing control, avoiding the computational bottleneck of the host cabinet. At the same time, the power control within each tributary does not affect system synchronization, realizing functional layering and fault isolation, and improving the overall reliability and control flexibility of the system.

[0043] Example 5 Furthermore, in this embodiment, the method further includes: in response to detecting a complete failure of the main branch or that all energy storage cabinets in the main branch are unable to perform the main cabinet function, isolating the main branch and selecting one branch from the remaining N-1 secondary branches as a new main branch; the new main branch determines a new main cabinet according to the dynamic competition mechanism, and the new main cabinet sends a carrier synchronization signal to each energy storage cabinet in the remaining branches.

[0044] The following details the switching process when the main branch fails as a whole.

[0045] Step S201: The system is running normally. The current main branch is branch 1, and its internal cabinet 1 is the main cabinet.

[0046] Step S202: Detect the status of the main branch. The system continuously monitors the overall operation of branch 1, including the connection status between the branch and the AC bus, and the fault status of all cabinets within the branch.

[0047] Step S203: Determine if the main branch circuit has failed entirely. If the AC circuit breaker of branch 1 trips, or all cabinets within branch 1 fail and are unable to perform their main cabinet functions, then the main branch circuit is determined to have failed entirely. If it has not failed, return to step S202 to continue monitoring.

[0048] Step S204: Isolate the faulty main branch. The system issues a command to isolate branch 1 from the AC bus (e.g., disconnect the AC circuit breaker) to prevent the faulty branch from affecting the other branches.

[0049] Step S205: Select a new main branch. The system selects one of the remaining secondary branches (branch 2, branch 3, ..., branch N) as the new main branch. The selection rule can be the same as the initial main branch selection rule, for example, selecting the fault-free branch with the smallest number among the remaining branches.

[0050] Step S206: New main branch competes for server racks. According to the server rack competition mechanism, a new server rack (let's say rack 2-1) is generated within the new main branch (let's say branch 2).

[0051] Step S207: The new main rack sends a synchronization signal. Rack 2-1, acting as the new system main rack, broadcasts a carrier synchronization signal to all racks in all remaining branches, establishing a new synchronization domain.

[0052] In this embodiment, when the entire main branch fails due to extreme conditions, the system can automatically isolate the faulty branch and elect a new main branch to take over the synchronization responsibility, thus achieving fault tolerance at the branch level. The switching process is executed autonomously without external intervention, effectively preventing the entire system from shutting down due to the spread of local faults. This mechanism improves the fault tolerance capability of the system from the single cabinet level to the branch level, greatly enhancing the survivability of the energy storage system under complex operating conditions.

[0053] This invention achieves carrier synchronization of multi-branch energy storage systems without a dedicated centralized controller through a decentralized dynamic competition mechanism, fundamentally eliminating high-frequency circulating current paths caused by carrier asynchrony and avoiding their interference with the battery management system and fire protection system. At the same time, through real-time competitive switching of main cabinets within the branch, smooth reconnection of fault recovery cabinets, and autonomous isolation and replacement of branch-level faults, a multi-level fault-tolerant system from single unit to the entire branch is constructed, effectively solving the problem of system downtime caused by a single fault in traditional solutions, and significantly improving the reliability and availability of the system.

[0054] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0055] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0056] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0057] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0058] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0059] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

Claims

1. A carrier synchronization control method for an energy storage system, applied to an energy storage system comprising N parallel branches, each branch including multiple energy storage cabinets, wherein the N parallel branches converge to the same AC bus and there are no direct communication lines between the branches, wherein N≥2, characterized in that, Includes the following steps: Select one branch from the N parallel branches as the main branch, and the remaining N-1 branches as secondary branches; The main cabinet is determined from multiple energy storage cabinets in the main branch through a dynamic competition mechanism, and the remaining energy storage cabinets in the main branch and all energy storage cabinets in the slave branch are determined as slave cabinets. The main cabinet sends a carrier synchronization signal to all slave cabinets; The server rack calculates the phase offset between its own carrier and the carrier synchronization signal based on the received carrier synchronization signal, and performs carrier phase compensation based on the phase offset.

2. The carrier synchronization control method for an energy storage system according to claim 1, characterized in that, Also includes; In response to the detection of a fault in the main rack, a dynamic contention mechanism is triggered within the main branch to re-determine a new main rack from the remaining fault-free racks in the main branch, excluding the faulty rack, and the new main rack takes over the transmission of the carrier synchronization signal.

3. The carrier synchronization control method for an energy storage system according to claim 1, characterized in that, Also includes: A local master cabinet for each slave branch is determined from multiple energy storage cabinets within each slave branch through a dynamic competition mechanism. The local master cabinet is used to perform power distribution and current sharing control within its own branch.

4. The carrier synchronization control method for an energy storage system according to any one of claims 1 to 3, characterized in that, The dynamic competition mechanism includes: Obtain the preset priority identifier and real-time operating status data of each energy storage cabinet in the main branch; In response to the need to determine the main cabinet, energy storage cabinets with preset priority identifiers that meet preset rules are selected from the energy storage cabinets whose real-time operating status data shows no faults.

5. The carrier synchronization control method for an energy storage system according to claim 4, characterized in that, Also includes: The fault-free rack within the main branch with a priority higher than other slave racks is configured as a backup master rack, and the backup master rack continuously receives and tracks the carrier synchronization signal of the master rack; In response to a failure of the main cabinet, the backup main cabinet automatically takes over as the new main cabinet and sends carrier synchronization signals.

6. The carrier synchronization control method for an energy storage system according to claim 5, characterized in that, Also includes: In response to the faulty cabinet returning to normal operation, the priority of the energy storage cabinet that has returned to normal operation and the current standby cabinet are re-evaluated according to the preset rules. In response to the fact that the energy storage cabinet that has been restored to normal operation has a higher priority than the current backup cabinet, the restored cabinet is configured as the new backup cabinet.

7. The carrier synchronization control method for an energy storage system according to claim 6, characterized in that, Also includes: In response to the detection of a complete failure of the main branch or the inability of all energy storage cabinets in the main branch to perform the main cabinet function, the main branch is isolated, and one branch is selected from the remaining N-1 branch branches as the new main branch. The new main branch determines the new host cabinet according to the dynamic competition mechanism, and the new host cabinet sends carrier synchronization signals to each energy storage cabinet in the remaining branches.

8. An energy storage system, characterized in that, include: N parallel branches, each branch containing one or more energy storage cabinets, the N parallel branches converge to the same AC bus and there is no direct communication line between the branches, where N≥2; Each of the energy storage cabinets is provided with a controller configured to perform the carrier synchronization control method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the carrier synchronization control method for energy storage systems as described in any one of claims 1 to 7.

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