Clock synchronization method of energy storage system, energy storage converter and energy storage system

Abstract

The embodiment of the invention relates to the technical field of energy storage systems, and provides an energy storage system clock synchronization method, an energy storage converter and an energy storage system.The method comprises the steps that the cable length between a first controller and a second controller closest to the first controller is obtained, and a first cable distance is obtained; determining first delay time at least according to the first cable distance, wherein the first delay time is a phase difference value between a clock of a second controller closest to the first controller and a clock of the first controller; and the first delay time is sent to the second controller within a preset time period, so that the second controller adds the clock of the second controller and the first delay time, and clock synchronization between the first controller and the second controller closest to the first controller is realized. The clock synchronization method of the energy storage system at least can solve the problem of high cost caused by the fact that clock synchronization of a first controller and a second controller in an energy storage system in the prior art needs optical fiber electrical connection.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage systems, and in particular to a clock synchronization method, an energy storage converter, and an energy storage system for an energy storage system. Background Art

[0002] A power conversion system (PCS), also known as an energy storage inverter, is one of the core devices in an energy storage system. It includes power conversion components (such as IGBTs), control components, protection components, a communication module, and a heat dissipation system (such as a radiator, fan, or liquid cooling plate).

[0003] In energy storage converters, a master-slave architecture is typically used to implement distributed control, functional division of labor, and system expansion. The master's functions include system control and management, data processing and analysis, and user interface and interaction, while the slave's functions include local control and execution, as well as collaborative operation. The master and slaves each perform their respective roles in the energy storage converter system: the master is responsible for centralized control, data management, and user interaction, while the slaves are responsible for specific power conversion and local control. Through the collaborative operation of the master and slaves, the energy storage converter system can achieve efficient, flexible, and reliable operation.

[0004] In conventional energy storage systems, optical fibers are often used to electrically connect the first controller and the second controller, resulting in high costs. Summary of the Invention

[0005] The embodiments of the present application provide a clock synchronization method, an energy storage converter, and an energy storage system for an energy storage system, which at least solve the problem that the clock synchronization of the first controller and the second controller in the energy storage system of the prior art requires an optical fiber electrical connection, resulting in high costs.

[0006] According to some embodiments of the present application, on one hand, an embodiment of the present application provides a clock synchronization method for an energy storage system, which is applied to a first controller in the energy storage system, wherein the first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and the second controller electrically connected to the first controller is serially connected to the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, the digital signal processor and the field editable gate array communicate bidirectionally, the field editable gate array of the first controller and the field editable gate array of the first controller are electrically connected using the cable, the first controller is used to centrally control each second controller, and the second controller is used to adjust the power of the energy storage system. The method includes: obtaining a cable length between the first controller and the second controller closest to the first controller to obtain a first cable distance, and determining a first delay time based on at least the first cable distance, the first delay time being a phase difference between a clock of the second controller closest to the first controller and a clock of the first controller; and sending the first delay time to the second controller within a preset time period so that the second controller adds the clock of the second controller to the first delay time, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller.

[0007] In some embodiments, after sending the first delay time to the second controller within a preset time period, the method further includes: when there is at least one faulty device among all the second controllers and the faulty device is the second controller closest to the first controller, issuing a shutdown instruction to the other second controllers except the second controller electrically connected to the first controller to control the shutdown of the other second controllers except the second controller electrically connected to the first controller; when there is at least one faulty device among all the second controllers and the faulty device is not the second controller closest to the first controller, issuing the shutdown instruction to the target controller to control the shutdown of the target controller, which is the other second controllers except the faulty device and all the second controllers between the faulty device and the first controller.

[0008] In some embodiments, after sending the first delay time to the second controller within a preset time period, the method further includes: obtaining the cable length between the first controller and the second controller closest to the first controller after a preset period of time to obtain a current cable distance; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, determining that there is no need to synchronize the second controller again; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, determining the difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance to obtain the current delay time, and sending the current delay time to the second controller within the preset time period so that the second controller adds the clock of the second controller to the current delay time.

[0009] In some embodiments, before sending the first delay time to the second controller within a preset time period, the method further includes: obtaining a first time mapping relationship, which is a mapping relationship between the preset time period and the range of the first cable distance; and determining the corresponding preset time period based on the first time mapping relationship and the first cable distance.

[0010] In some embodiments, determining the first delay time based at least on the first cable distance includes: obtaining a second time mapping relationship, where the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; and determining the corresponding first delay time based on the second time mapping relationship and the first cable distance.

[0011] In some embodiments, determining the first delay time based at least on the first cable distance includes: determining the first delay time based on t=L / v, where t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

[0012] According to some embodiments of the present application, another aspect of the embodiments of the present application provides a clock synchronization method for an energy storage system, which is applied to a second controller in the energy storage system, wherein a first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and the second controller electrically connected to the first controller is connected in series with the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, the digital signal processor and the field editable gate array communicate bidirectionally, the field editable gate array of the first controller and the field editable gate array of the first controller are electrically connected using the cable, the first controller is used to centrally control each second controller, and the second controller is used to adjust the power of the energy storage system, the method comprising: receiving Receive a first delay time sent by the first controller, and add the clock of the second controller to the first delay time, so as to achieve clock synchronization between the first controller and the second controller closest to the first controller; obtain the cable length between the second controller and the next second controller to obtain a second cable distance, and determine a second delay time at least based on the second cable distance, the second delay time is the phase difference between the clock of the second controller and the clock of the next second controller, and the second controller and the next second controller are electrically connected by a cable; send the first delay time to the second controller within a preset time period, so that the next second controller adds the clock of the next second controller to the second delay time, so as to achieve clock synchronization between the second controller and the next second controller.

[0013] In some embodiments, after sending the first delay time to the second controller within a preset time period, the method further includes: receiving a shutdown instruction sent by the first controller, and switching the second controller's own state to a shutdown state, wherein, when there is at least one faulty device among all the second controllers, and the faulty device is the second controller closest to the first controller, the first controller sends a shutdown instruction to the other second controllers except the second controller electrically connected to the first controller, so as to control the shutdown of the other second controllers except the second controller electrically connected to the first controller; when there is at least one faulty device among all the second controllers, and the faulty device is not the second controller closest to the first controller, the first controller sends the shutdown instruction to the target controller to control the shutdown of the target controller, and the target controller is the other second controllers except the faulty device and all the second controllers between the faulty device and the first controller.

[0014] In some embodiments, after sending the first delay time to the next second controller, the method further includes: receiving the current delay time sent by the first controller, adding the clock of the second controller to the current delay time, wherein the first controller obtains the cable length between the first controller and the second controller closest to the first controller after a preset period of time to obtain the current cable distance; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines that there is no need to synchronize the second controller again, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines the phase difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance to obtain the current delay time, and sends the current delay time to the second controller within the preset time period.

[0015] In some embodiments, receiving the first delay time sent by the first controller includes: receiving the first delay time sent by the first controller within the preset time period; wherein, the first controller obtains a first time mapping relationship, the first time mapping relationship is a mapping relationship between the preset time period and the range of the first cable distance, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; the first controller determines the corresponding preset time period based on the first time mapping relationship and the first cable distance; the first controller determines the first delay time based on t=L / v, or the first controller obtains a second time mapping relationship, the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; the first controller determines the corresponding first delay time based on the second time mapping relationship and the first cable distance, wherein t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

[0016] According to some embodiments of the present application, on the other hand, embodiments of the present application provide an energy storage converter, including: an acquisition unit, used to acquire the cable length between a first controller and a second controller closest to the first controller, obtain a first cable distance, and determine a first delay time based at least on the first cable distance, the first delay time being the phase difference between the clock of the second controller closest to the first controller and the clock of the first controller; a first processing unit, used to send the first delay time to the second controller within a preset time period, so that the second controller adds the clock of the second controller to the first delay time, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller.

[0017] In some embodiments, the energy storage converter also includes: a second processing unit, which is used to send the first delay time to the second controller within a preset time period, and when there is at least one faulty device in all the second controllers, and the faulty device is the second controller closest to the first controller, issue a shutdown instruction to the second controllers other than the second controller electrically connected to the first controller to control the shutdown of the second controllers other than the second controller electrically connected to the first controller; a third processing unit, which is used to send the shutdown instruction to the target controller to control the shutdown of the target controller when there is at least one faulty device in all the second controllers, and the faulty device is not the second controller closest to the first controller. The target controller is the second controller other than the faulty device and all the second controllers between the faulty device and the first controller.

[0018] In some embodiments, the energy storage converter further includes: a fourth processing unit, configured to send the first delay time to the second controller within a preset time period, and then obtain the cable length between the first controller and the second controller closest to the first controller after a preset period of time to obtain the current cable distance; a first determination unit, configured to determine that there is no need to synchronize the second controller again when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference; a second determination unit, configured to determine the difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference to obtain the current delay time, and send the current delay time to the second controller within the preset time period so that the second controller adds the clock of the second controller to the current delay time.

[0019] In some embodiments, the energy storage converter also includes: a fifth processing unit, used to obtain a first time mapping relationship before sending the first delay time to the second controller within a preset time period, the first time mapping relationship being a mapping relationship between the preset time period and the first cable; a sixth processing unit, used to determine the corresponding preset time period based on the first time mapping relationship and the first cable distance.

[0020] According to some embodiments of the present application, on the other hand, embodiments of the present application provide an energy storage system, including: a first controller and multiple second controllers, the first controller is electrically connected to one of all the second controllers in the energy storage system by a cable, the second controller electrically connected to the first controller and the other second controllers are connected in series by the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor, a field editable gate array, and the digital signal processor and the field editable gate array can communicate bidirectionally, the field editable gate array of the first controller and the field editable gate array of the first controller are electrically connected by the cable, the first controller is used to centrally control the second controllers, the second controller is used to adjust the power of the energy storage system, the first controller is used to execute any one of the methods described, and each second controller is used to execute any one of the methods described.

[0021] The technical solution provided by the embodiments of the present application has at least the following advantages: the transmission speed of the signal in the cable is much lower than the speed of light, and the specific value depends on the material and structure of the cable. At least the first delay time is determined based on the first cable distance, and the estimated first delay time for the signal to be transmitted from the first controller to the second controller can be calculated; by using such a delay compensation mechanism when calculating the delay, the required first delay time can be automatically calculated and applied according to the length of the cable. When the signal reaches the second controller, due to the compensation sent in advance, the second controller can receive the signal on time and achieve synchronization. In a parallel architecture of multiple second controllers, the signal is transmitted from the first controller to the first second controller, then from the first second controller to the second second controller, and so on, and all devices can achieve accurate clock synchronization. Although using cables instead of optical fibers will increase the signal transmission delay, this problem can be overcome by introducing a delay compensation mechanism. Compared with optical fibers, the cost of cables is significantly reduced, thereby solving the problem of high cost caused by the need for optical fiber electrical connection for clock synchronization between the first and second controllers in energy storage systems of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplified by the figures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the flow of the clock synchronization method of the first energy storage system;

[0024] Figure 2 It is a structural diagram of an energy storage converter;

[0025] Figure 3 Schematic diagram of the flow of the clock synchronization method of the first energy storage system;

[0026] Figure 4 Schematic diagram of the structure of an energy storage system;

[0027] Figure 5 A schematic diagram of the principle of an energy storage system. DETAILED DESCRIPTION

[0028] As can be seen from the background technology, in the energy storage converter, the architecture of the host and the slave is usually used to realize functions such as distributed control, functional division and system expansion. The functions of the host include system control and management, data processing and analysis, user interface and interaction, and the functions of the slave include local control and execution and collaborative operation. The host and the slave each have their own functions in the energy storage converter system. The host is responsible for centralized control, data management and user interaction, and the slave is responsible for specific power conversion and local control. Through the collaborative work of the host and the slave, the energy storage converter system can achieve efficient, flexible and reliable operation. In the energy storage system of the prior art, optical fiber is often used to electrically connect the first controller and the second controller, resulting in high costs. In order to solve the problem that the clock synchronization of the first controller and the second controller in the energy storage system of the prior art requires optical fiber electrical connection, resulting in high costs, the embodiment of the present application provides a clock synchronization method, energy storage converter and energy storage system for an energy storage system.

[0029] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0030] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0032] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0033] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0034] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0035] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) as being on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or a third component may be present between the two components. Conversely, when describing a component as being on the surface of another component or as being formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0036] In the description of the embodiments of this application, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them) or another component can be present between them. In addition, when a component such as a layer, film, region, or plate is "directly on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located between them.

[0037] The terms used herein in the description of the various embodiments described above are intended only to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "above-mentioned parts" are intended to include plural forms unless the context clearly indicates otherwise. A component includes a layer, film, region, or plate, among other components.

[0038] The following detailed description of the various embodiments of the present application is provided in conjunction with the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in the various embodiments of the present application to facilitate a better understanding of the present application. However, even without these technical details and the various variations and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0039] The present application provides a clock synchronization method for an energy storage system, which is applied to a first controller in the energy storage system, wherein the first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and the second controller electrically connected to the first controller is connected in series with the other second controllers using the cable, and the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, and the digital signal processor and the field editable gate array can communicate bidirectionally, and the field editable gate array of the first controller is electrically connected to the field editable gate array of the first controller using the cable, the first controller is used to centrally control the second controllers, and the second controller is used to adjust the power of the energy storage system, such as Figure 1 As shown, the method includes:

[0040] Step S101: Obtain a cable length between the first controller and the second controller closest to the first controller to obtain a first cable distance, and determine a first delay time based at least on the first cable distance, where the first delay time is a phase difference between a clock of the second controller closest to the first controller and a clock of the first controller;

[0041] Step S102, sending the first delay time to the second controller within a preset time period, so that the second controller adds the clock of the second controller to the first delay time, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller.

[0042] In the above steps, the signal transmission speed in the cable is far lower than the speed of light, and the specific value depends on the cable material and structure. By determining the first delay time based on at least the first cable distance, an estimated first delay time for the signal to be transmitted from the first controller to the second controller can be calculated. By using a delay compensation mechanism during the delay calculation, the required first delay time can be automatically calculated and applied based on the cable length. When the signal reaches the second controller, due to the compensation sent in advance, the second controller can receive the signal on time and achieve synchronization. In a parallel architecture with multiple second controllers, the signal travels from the first controller to the first second controller, then from the first second controller to the second second controller, and so on, achieving precise clock synchronization for all devices. Although using cables instead of optical fibers increases signal transmission delay, this problem can be overcome by introducing a delay compensation mechanism. Compared to optical fibers, cables are significantly less expensive, thus solving the problem of the high cost of optical fiber electrical connection for clock synchronization between the first and second controllers in existing energy storage systems.

[0043] In some embodiments, after sending the first delay time to the second controller within a preset time period, the method further includes: when there is at least one faulty device among all the second controllers, and the faulty device is the second controller closest to the first controller, issuing a shutdown instruction to the second controllers other than the second controller electrically connected to the first controller to control the shutdown of the second controllers other than the second controller electrically connected to the first controller; when there is at least one faulty device among all the second controllers, and the faulty device is the second controller not closest to the first controller, issuing the shutdown instruction to the target controller to control the shutdown of the target controller, which is the second controller other than the faulty device and all the second controllers between the faulty device and the first controller.

[0044] This application also provides a specific use case for the faulty device handling process: in a large distributed photovoltaic power plant, multiple PCSs (power storage converters) are interconnected by cables to form a highly coordinated group. Carrier synchronization and interrupt synchronization are required between these converters to ensure uniform power conversion and grid stability. The power plant's control system consists of a master (first controller) and multiple slaves (second controllers). The master is responsible for monitoring and managing the operating status of the entire PCS group.

[0045] Detailed process: When the system monitoring detects a fault in the slave (secondary controller) closest to the host, the host immediately recognizes this situation. Taking into account factors such as cable transmission and signal delays, the host will send a shutdown command to all slaves except the nearest slave, ensuring that these devices are not affected by the erroneous signal from the faulty slave and produce uncoordinated actions, thereby preventing the entire system from falling into chaos. If the faulty device is not the slave closest to the host, but is located elsewhere in the system, the host adopts a more sophisticated strategy. It only sends a shutdown command to the target controller, that is, all slaves except the faulty device and all slaves between the faulty device and the host. In this way, the system can minimize the impact of the faulty device on the overall system operation and maintain the maximum range of system functionality.

[0046] A specific use case for the faulty device handling process demonstrates its beneficial effects: By quickly isolating the faulty device and shutting down the affected equipment, the propagation of fault signals can be effectively prevented, avoiding system-wide instability or safety incidents. This is particularly important for large-scale power facilities such as photovoltaic power plants, where even a minor fault can have serious consequences. While isolating the faulty device, the system can maintain normal operation of most other equipment, reducing unnecessary energy loss and avoiding the economic losses caused by a complete system shutdown. For equipment not directly affected by the faulty device, continued operation ensures power supply continuity and economic benefits. Shutting down only the affected equipment clearly defines the fault area, making it easier for maintenance personnel to quickly locate and repair the fault. This approach simplifies the fault recovery process, shortens the time it takes to restore normal operation, and improves maintenance efficiency. In the event of partial equipment downtime, the system can automatically adjust the load distribution of the remaining equipment to ensure that the overall output power remains close to the target, optimizing resource utilization efficiency. This dynamic scheduling capability is particularly important in emergency situations. During system expansion or equipment layout changes, this hierarchical fault management mechanism allows for local adjustments or repairs without affecting the majority of equipment, enhancing the system's adaptability and flexibility in dynamic environments.

[0047] In some embodiments, after sending the above-mentioned first delay time to the above-mentioned second controller within a preset time period, the above-mentioned method also includes: obtaining the cable length between the above-mentioned first controller and the above-mentioned second controller closest to the above-mentioned first controller after the preset time period to obtain the current cable distance; when the absolute value of the difference between the above-mentioned current cable distance and the above-mentioned first cable distance is less than or equal to the preset difference, determining that there is no need to synchronize the above-mentioned second controller again; when the absolute value of the difference between the above-mentioned current cable distance and the above-mentioned first cable distance is less than or equal to the preset difference, determining the difference between the clock of the above-mentioned second controller closest to the above-mentioned first controller and the clock of the above-mentioned first controller at least based on the above-mentioned current cable distance to obtain the current delay time, and sending the above-mentioned current delay time to the above-mentioned second controller within the above-mentioned preset time period so that the above-mentioned second controller adds the clock of the above-mentioned second controller to the above-mentioned current delay time.

[0048] Reference for the preset differential value: Assume the system requires a clock synchronization accuracy of 10 microseconds, the signal transmission speed in copper cables is 200,000 km / s (approximately 67% the speed of light), and the cable length measurement error is 0.1 meter. Based on the signal transmission time calculation formula t = L / v, it can be calculated that a 1-meter change in cable length causes a change in signal transmission time of approximately 5 microseconds. To account for measurement errors and system stability, the preset differential value can be set to 2 meters. This ensures that even if the cable length changes by 2 meters, the change in signal delay does not exceed the required clock synchronization accuracy, while also avoiding excessive signal delay adjustments.

[0049] This application also provides a specific use case where the effect of cable length is ignored. In a certain energy storage system, carrier signal synchronization is required between the master (first controller) and the slave (second controller) to ensure consistent power conversion operations across all PCS devices. The cable length between the master and slave is originally fixed, but during system maintenance or expansion, the cable length may be adjusted. For example, to optimize the system layout or add more equipment, the cable may be shortened or lengthened.

[0050] Specific operation process: At system startup or when the cable length is initially set, the master reads and stores the cable length information (the first cable distance), calculates the signal transmission delay (the first delay time) based on the cable length, and sends this delay time to the slave. The slave adjusts its clock synchronization based on the received delay time. After the system has been running for a period of time, the master periodically (for example, every 24 hours or less) rechecks the cable length (the current cable distance). If the difference between the current cable distance and the stored first cable distance is less than or equal to a preset difference (for example, the preset difference may be 3 meters, indicating that the effect of cable length changes on signal delay is negligible), the system determines that resynchronization is not necessary because the change in cable length will not significantly affect signal transmission delay. If the difference between the current cable distance and the first cable distance exceeds the preset difference, the master recalculates the signal transmission delay time (the current delay time) and sends it to the slave. The slave adjusts its own clock signal based on the received current delay time to ensure synchronization with the master's clock.

[0051] Ignoring the effects of cable length in a specific usage scenario offers a beneficial effect: Dynamically monitoring cable length changes and automatically adjusting clock synchronization allows the system to adapt to various layout requirements and operating environment changes, improving the system's overall adaptability and flexibility. In the event of minor changes in cable length, there's no need to re-perform complex clock synchronization adjustments, reducing maintenance and debugging workload and lowering system maintenance costs. Through regular monitoring and immediate adjustments when necessary, the system ensures that carrier signal synchronization remains within an acceptable error range despite changes in cable length, ensuring the real-time and stable operation of the system. When the system needs to expand, new devices can be quickly added and synchronization adjusted without the need to manually reconfigure the synchronization parameters of all devices, improving the efficiency and convenience of system expansion. Compared to using optical fiber or other high-cost, low-latency transmission media, the dynamic cable length compensation mechanism allows the use of lower-cost cables while maintaining the synchronization accuracy required by the system, achieving an optimal balance between cost and performance.

[0052] In some embodiments, before sending the above-mentioned first delay time to the above-mentioned second controller within the preset time period, the above-mentioned method also includes: obtaining a first time mapping relationship, the above-mentioned first time mapping relationship is a mapping relationship between the above-mentioned preset time period and the range of the above-mentioned first cable distance; according to the above-mentioned first time mapping relationship and the above-mentioned first cable distance, determining the corresponding above-mentioned preset time period.

[0053] Specifically, there is a direct relationship between cable length and signal transmission delay. By establishing a mapping relationship, the system can accurately calculate signal transmission delay based on different cable lengths, allowing for more precise adjustment of the preset time period and ensuring high-precision clock synchronization between devices. This is crucial for power electronics equipment that require precise control of signal phase and frequency. When cables in the system change due to equipment additions, layout adjustments, or maintenance needs, the mapping relationship allows for rapid adjustment of the preset time period, ensuring that the system maintains stable synchronization even with cable length changes. This dynamic adjustment capability enables the system to adapt to changing operating environments, improving overall flexibility and adaptability. During the system design phase, establishing a mapping relationship allows for pre-calculation of the required preset time period for different cable lengths, reducing the complexity of the system synchronization circuitry. This approach simplifies system design, reduces R&D costs and design cycles, and also reduces the demand for real-time computing resources during system operation. Small changes in cable length can result in significant differences in signal delay, which in turn affects system synchronization performance. By promptly adjusting the preset time period through the mapping relationship, synchronization errors caused by cable length changes can be effectively avoided, reducing system failure rates and improving overall operational reliability. When determining the preset time period, the system can rationally allocate signal processing and data transmission resources based on the mapping between actual cable length and time delay, avoiding resource waste while ensuring efficient execution of critical synchronization operations. This mapping allows the system to automatically adapt to changes in cable length, reducing the maintenance and debugging workload associated with these changes. This not only saves maintenance time and costs, but also improves system maintainability and long-term economic benefits.

[0054] In some embodiments, determining the first delay time at least based on the first cable distance includes: obtaining a second time mapping relationship, where the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; and determining the corresponding first delay time based on the second time mapping relationship and the first cable distance.

[0055] Specifically, the second time mapping relationship accounts for multiple variables that affect signal transmission, making delay calculation more detailed and closer to actual values. For example, for the same cable length, the impact of different temperature conditions on signal transmission speed can be taken into account, resulting in a more accurate delay time. By considering multiple factors, including environmental factors and cable characteristics, the system can better withstand the impact of fluctuating external conditions and ensure stability under different operating conditions. This is particularly important in scenarios with significant climate change or harsh operating environments. The second time mapping relationship allows the system to automatically adjust the delay time based on real-time cable characteristics and environmental conditions without manual intervention. This automated adaptability greatly improves the operational convenience and efficiency of power electronics systems that require long-term stable operation. During the initial system design phase, designers can use the second time mapping relationship to perform more precise timing planning and circuit design, ensuring the coordinated operation of all devices under different operating conditions and avoiding design defects caused by inaccurate signal delay estimates. Delay adjustment based on the second time mapping relationship reduces uncertainty during the commissioning process, allowing the system to reach a stable operating state more quickly after deployment. Furthermore, because the system can automatically adapt to environmental changes, maintenance workload and time are reduced.

[0056] Other factors, combined with cable length, contribute to the first delay: Temperature: Temperature changes affect the dielectric constant of the cable material, thereby affecting signal transmission speed. When determining the first delay, real-time temperature data collected by a temperature sensor can be combined to adjust for the effect of cable length on delay using a lookup table or function calculation. Cable type and material: Different cable types (such as coaxial, twisted pair, and fiber optic) and materials significantly affect signal transmission speed. The second time mapping relationship can include the relationship between different cable types and delay times to accurately calculate delay for different cable types. Signal frequency: High-frequency signals are attenuated more severely in cables than low-frequency signals, which can cause delay variations. Therefore, signal frequency can also be considered when determining the first delay, especially when the system operates in different frequency modes. Cable aging: Over time, cables may naturally age, causing changes in their characteristics, which can affect signal transmission. Regularly testing the cable's impedance and delay characteristics and updating the mapping relationship can compensate for delay changes caused by cable aging. Electromagnetic interference: External electromagnetic interference can affect signal transmission, resulting in additional delay. Adding the relationship between the EMI level and the delay time to the second time mapping relationship enables the system to maintain good synchronization performance in a strong EMI environment.

[0057] In some embodiments, determining the first delay time at least based on the first cable distance includes: determining the first delay time based on t=L / v, wherein t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

[0058] Specifically, the formula t=L / v is based on the theory of electromagnetic wave propagation in media. Its application ensures scientific and accurate calculation of signal transmission delay. The propagation velocity v of electromagnetic waves is not only related to the physical properties of the medium, such as the dielectric constant and magnetic permeability of the cable, but is also affected by environmental factors such as temperature and humidity. Understanding and applying these theories helps to more accurately estimate signal delay. This formula directly converts cable length L into signal transmission delay time t, eliminating the need for complex simulations or experimental testing. This simplifies delay calculation during system design and debugging, reducing development costs. In a multi-machine parallel system, accurately calculating signal delay is crucial for achieving synchronization between devices. Using the t=L / v formula ensures that the signal delay received by each slave controller is accurately calculated based on the actual cable length between it and the master controller, thereby improving overall system synchronization accuracy and ensuring stable and efficient system performance. During system operation, cable lengths may change due to equipment layout adjustments, fault repairs, or system expansion. Through the formula t=L / v, the system can quickly respond to changes in cable length, recalculate signal delays, ensure dynamic adjustment of synchronization between devices, and enhance the flexibility and adaptability of the system.

[0059] According to some embodiments of the present application, another aspect of the present application provides an energy storage converter, such as Figure 2 Shown, including:

[0060] an acquiring unit 21 configured to acquire a cable length between a first controller and a second controller closest to the first controller to obtain a first cable distance, and determine a first delay time based at least on the first cable distance, where the first delay time is a phase difference between a clock of the second controller closest to the first controller and a clock of the first controller;

[0061] The first processing unit 22 is used to send the above-mentioned first delay time to the above-mentioned second controller within a preset time period, so that the above-mentioned second controller adds the clock of the above-mentioned second controller to the above-mentioned first delay time, thereby realizing clock synchronization between the above-mentioned first controller and the above-mentioned second controller closest to the above-mentioned first controller.

[0062] By acquiring the first cable distance and determining the first delay time based on it, the energy storage converter ensures that the signal transmission delay between the second controller and the first controller is accurately calculated and compensated. This enables the second controller to precisely adjust its clock phase to maintain synchronization with the first controller, thereby optimizing signal coordination and power conversion in the parallel system and improving overall system efficiency. In a multi-controller parallel system, poor clock synchronization can lead to signal inconsistencies, which in turn can cause power conversion imbalances or voltage and current fluctuations. Using a synchronization mechanism based on the first cable distance and the first delay time can effectively prevent these issues, ensuring stable system operation and avoiding system failures or safety hazards caused by signal coordination errors. During the system design phase, traditional methods of estimating signal delay based on cable length often require extensive experimental verification and correction. By directly acquiring the first cable distance and calculating the first delay time through the acquisition unit, system designers can more easily design the clock synchronization circuit, reduce debugging workload, and accelerate system development. In actual applications, cable layouts may change due to equipment relocation, system expansion, or fault repair. By sending the first delay time to the second controller within a preset time period, the system automatically adapts to changes in cable layout and maintains the continued effectiveness of clock synchronization between devices. In the event of a system failure, maintenance personnel can quickly locate the problem by checking cable length and the first delay time, without the need for complex signal analysis or circuit diagnosis. During fault recovery, clock synchronization can be quickly restored by resending the first delay time, as long as the first cable distance measurement is accurate.

[0063] In some embodiments, the energy storage converter further includes: a second processing unit for sending the first delay time to the second controller within a preset time period, and when there is at least one faulty device among all the second controllers, and the faulty device is the second controller closest to the first controller, issuing a shutdown instruction to the second controllers other than the second controller electrically connected to the first controller, so as to control the shutdown of the second controllers other than the second controller electrically connected to the first controller; a third processing unit for sending the shutdown instruction to the target controller, and when there is at least one faulty device among all the second controllers, and the faulty device is the second controller not closest to the first controller, so as to control the shutdown of the target controller, the target controller being the second controllers other than the faulty device and all the second controllers between the faulty device and the first controller.

[0064] This application also provides a specific use case for the faulty device handling process: in a large distributed photovoltaic power plant, multiple PCSs (power storage converters) are interconnected by cables to form a highly coordinated group. Carrier synchronization and interrupt synchronization are required between these converters to ensure uniform power conversion and grid stability. The power plant's control system consists of a master (first controller) and multiple slaves (second controllers). The master is responsible for monitoring and managing the operating status of the entire PCS group.

[0065] Detailed process: When the system monitoring detects a fault in the slave (secondary controller) closest to the host, the host immediately recognizes this situation. Taking into account factors such as cable transmission and signal delays, the host will send a shutdown command to all slaves except the nearest slave, ensuring that these devices are not affected by the erroneous signal from the faulty slave and produce uncoordinated actions, thereby preventing the entire system from falling into chaos. If the faulty device is not the slave closest to the host, but is located elsewhere in the system, the host adopts a more sophisticated strategy. It only sends a shutdown command to the target controller, that is, all slaves except the faulty device and all slaves between the faulty device and the host. In this way, the system can minimize the impact of the faulty device on the overall system operation and maintain the maximum range of system functionality.

[0066] A specific use case for the faulty device handling process demonstrates its beneficial effects: By quickly isolating the faulty device and shutting down the affected equipment, the propagation of fault signals can be effectively prevented, avoiding system-wide instability or safety incidents. This is particularly important for large-scale power facilities such as photovoltaic power plants, where even a minor fault can have serious consequences. While isolating the faulty device, the system can maintain normal operation of most other equipment, reducing unnecessary energy loss and avoiding the economic losses caused by a complete system shutdown. For equipment not directly affected by the faulty device, continued operation ensures power supply continuity and economic benefits. Shutting down only the affected equipment clearly defines the fault area, making it easier for maintenance personnel to quickly locate and repair the fault. This approach simplifies the fault recovery process, shortens the time it takes to restore normal operation, and improves maintenance efficiency. In the event of partial equipment downtime, the system can automatically adjust the load distribution of the remaining equipment to ensure that the overall output power remains close to the target, optimizing resource utilization efficiency. This dynamic scheduling capability is particularly important in emergency situations. During system expansion or equipment layout changes, this hierarchical fault management mechanism allows for local adjustments or repairs without affecting the majority of equipment, enhancing the system's adaptability and flexibility in dynamic environments.

[0067] In some embodiments, the energy storage converter further includes: a fourth processing unit, configured to send the first delay time to the second controller within a preset time period, and then obtain the cable length between the first controller and the second controller closest to the first controller after a preset time period to obtain the current cable distance; a first determination unit, configured to determine that there is no need to synchronize the second controller again when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference; a second determination unit, configured to determine the difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference to obtain the current delay time, and send the current delay time to the second controller within the preset time period so that the second controller adds the clock of the second controller to the current delay time.

[0068] This application also provides a specific use case where the effect of cable length is ignored. In a certain energy storage system, carrier signal synchronization is required between the master (first controller) and the slave (second controller) to ensure consistent power conversion operations across all PCS devices. The cable length between the master and slave is originally fixed, but during system maintenance or expansion, the cable length may be adjusted. For example, to optimize the system layout or add more equipment, the cable may be shortened or lengthened.

[0069] Specific operation process: At system startup or when the cable length is initially set, the master reads and stores the cable length information (the first cable distance), calculates the signal transmission delay (the first delay time) based on the cable length, and sends this delay time to the slave. The slave adjusts its clock synchronization based on the received delay time. After the system has been running for a period of time, the master periodically (for example, every 24 hours or less) rechecks the cable length (the current cable distance). If the difference between the current cable distance and the stored first cable distance is less than or equal to a preset difference (for example, the preset difference may be 3 meters, indicating that the effect of cable length changes on signal delay is negligible), the system determines that resynchronization is not necessary because the change in cable length will not significantly affect signal transmission delay. If the difference between the current cable distance and the first cable distance exceeds the preset difference, the master recalculates the signal transmission delay time (the current delay time) and sends it to the slave. The slave adjusts its own clock signal based on the received current delay time to ensure synchronization with the master's clock.

[0070] Ignoring the effects of cable length in a specific usage scenario offers a beneficial effect: Dynamically monitoring cable length changes and automatically adjusting clock synchronization allows the system to adapt to various layout requirements and operating environment changes, improving the system's overall adaptability and flexibility. In the event of minor changes in cable length, there's no need to re-perform complex clock synchronization adjustments, reducing maintenance and debugging workload and lowering system maintenance costs. Through regular monitoring and immediate adjustments when necessary, the system ensures that carrier signal synchronization remains within an acceptable error range despite changes in cable length, ensuring the real-time and stable operation of the system. When the system needs to expand, new devices can be quickly added and synchronization adjusted without the need to manually reconfigure the synchronization parameters of all devices, improving the efficiency and convenience of system expansion. Compared to using optical fiber or other high-cost, low-latency transmission media, the dynamic cable length compensation mechanism allows the use of lower-cost cables while maintaining the synchronization accuracy required by the system, achieving an optimal balance between cost and performance.

[0071] In some embodiments, the energy storage converter further includes: a fifth processing unit, configured to obtain a first time mapping relationship before sending the first delay time to the second controller within a preset time period, wherein the first time mapping relationship is a mapping relationship between the preset time period and the first cable; and a sixth processing unit, configured to determine the corresponding preset time period based on the first time mapping relationship and the first cable distance.

[0072] Specifically, there is a direct relationship between cable length and signal transmission delay. By establishing a mapping relationship, the system can accurately calculate signal transmission delay based on different cable lengths, allowing for more precise adjustment of the preset time period and ensuring high-precision clock synchronization between devices. This is crucial for power electronics equipment that require precise control of signal phase and frequency. When cables in the system change due to equipment additions, layout adjustments, or maintenance needs, the mapping relationship allows for rapid adjustment of the preset time period, ensuring that the system maintains stable synchronization even with cable length changes. This dynamic adjustment capability enables the system to adapt to changing operating environments, improving overall flexibility and adaptability. During the system design phase, establishing a mapping relationship allows for pre-calculation of the required preset time period for different cable lengths, reducing the complexity of the system synchronization circuitry. This approach simplifies system design, reduces R&D costs and design cycles, and also reduces the demand for real-time computing resources during system operation. Small changes in cable length can result in significant differences in signal delay, which in turn affects system synchronization performance. By promptly adjusting the preset time period through the mapping relationship, synchronization errors caused by cable length changes can be effectively avoided, reducing system failure rates and improving overall operational reliability. When determining the preset time period, the system can rationally allocate signal processing and data transmission resources based on the mapping between actual cable length and time delay, avoiding resource waste while ensuring efficient execution of critical synchronization operations. This mapping allows the system to automatically adapt to changes in cable length, reducing the maintenance and debugging workload associated with these changes. This not only saves maintenance time and costs, but also improves system maintainability and long-term economic benefits.

[0073] In some embodiments, the acquisition unit also includes: an acquisition module for acquiring a second time mapping relationship, where the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; a first determination module for determining the corresponding first delay time based on the second time mapping relationship and the first cable distance.

[0074] Specifically, the second time mapping relationship accounts for multiple variables that affect signal transmission, making delay calculation more detailed and closer to actual values. For example, for the same cable length, the impact of different temperature conditions on signal transmission speed can be taken into account, resulting in a more accurate delay time. By considering multiple factors, including environmental factors and cable characteristics, the system can better withstand the impact of fluctuating external conditions and ensure stability under different operating conditions. This is particularly important in scenarios with significant climate change or harsh operating environments. The second time mapping relationship allows the system to automatically adjust the delay time based on real-time cable characteristics and environmental conditions without manual intervention. This automated adaptability greatly improves the operational convenience and efficiency of power electronics systems that require long-term stable operation. During the initial system design phase, designers can use the second time mapping relationship to perform more precise timing planning and circuit design, ensuring the coordinated operation of all devices under different operating conditions and avoiding design defects caused by inaccurate signal delay estimates. Delay adjustment based on the second time mapping relationship reduces uncertainty during the commissioning process, allowing the system to reach a stable operating state more quickly after deployment. Furthermore, because the system can automatically adapt to environmental changes, maintenance workload and time are reduced.

[0075] In some embodiments, the acquisition unit also includes: a second determination module for determining the above-mentioned first delay time according to t=L / v, wherein t is the above-mentioned first delay time, v is the propagation speed of the signal of the above-mentioned first controller in the above-mentioned cable, and L is the above-mentioned first cable distance.

[0076] According to some embodiments of the present application, another aspect of the embodiments of the present application provides a clock synchronization method for an energy storage system, which is applied to a second controller in the energy storage system, wherein a first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and the second controller electrically connected to the first controller is connected in series with the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, the digital signal processor and the field editable gate array can communicate bidirectionally, the field editable gate array of the first controller and the field editable gate array of the first controller are electrically connected using the cable, the first controller is used to centrally control the second controllers, and the second controller is used to adjust the power of the energy storage system, such as Figure 3 As shown, the method includes:

[0077] Step S301: receiving a first delay time sent by the first controller, and adding the first delay time to the clock of the second controller, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller;

[0078] Step S302: Obtain a cable length between the second controller and the next second controller to obtain a second cable distance, and determine a second delay time based at least on the second cable distance, where the second delay time is a phase difference between a clock of the second controller and a clock of the next second controller, wherein the second controller and the next second controller are electrically connected via a cable.

[0079] Step S303: Send the first delay time to the second controller within a preset time period, so that the next second controller adds the clock of the next second controller to the second delay time, thereby achieving clock synchronization between the second controller and the next second controller.

[0080] The principle of the second delay time is the same as that of the first delay time, so it will not be described again here.

[0081] In the above steps, the signal transmission speed in the cable is far lower than the speed of light, and the specific value depends on the cable material and structure. By determining the first delay time based on at least the first cable distance, an estimated first delay time for the signal to be transmitted from the first controller to the second controller can be calculated. By using a delay compensation mechanism during the delay calculation, the required first delay time can be automatically calculated and applied based on the cable length. When the signal reaches the second controller, due to the compensation sent in advance, the second controller can receive the signal on time and achieve synchronization. In a parallel architecture with multiple second controllers, the signal travels from the first controller to the first second controller, then from the first second controller to the second second controller, and so on, achieving precise clock synchronization for all devices. Although using cables instead of optical fibers increases signal transmission delay, this problem can be overcome by introducing a delay compensation mechanism. Compared to optical fibers, cables are significantly less expensive, thus solving the problem of the high cost of optical fiber electrical connection for clock synchronization between the first and second controllers in existing energy storage systems.

[0082] In some embodiments, after sending the first delay time to the second controller within a preset time period, the method further includes: receiving a shutdown instruction sent by the first controller, and switching the state of the second controller to a shutdown state, wherein, when there is at least one faulty device among all the second controllers, and the faulty device is the second controller closest to the first controller, the first controller sends a shutdown instruction to the second controllers other than the second controller electrically connected to the first controller, so as to control the shutdown of the second controllers other than the second controller electrically connected to the first controller; when there is at least one faulty device among all the second controllers, and the faulty device is not the second controller closest to the first controller, the first controller sends the shutdown instruction to the target controller to control the shutdown of the target controller, and the target controller is the second controller other than the faulty device and all the second controllers between the faulty device and the first controller.

[0083] Specifically, by quickly isolating faulty equipment and shutting down affected equipment, the propagation of fault signals can be effectively prevented, avoiding system-wide instability or safety incidents. This is particularly important for large-scale power facilities such as photovoltaic power plants, where even minor faults can have serious consequences. While isolating the faulty equipment, the system can maintain the normal operation of most other equipment, reducing unnecessary energy loss and avoiding the economic losses caused by a complete system shutdown. For equipment not directly affected by the faulty equipment, continued operation ensures power supply continuity and economic benefits. Shutting down only the affected equipment clearly defines the fault area, making it easier for maintenance personnel to quickly locate and repair the fault. This approach simplifies the fault recovery process, shortens the time it takes to restore normal operation, and improves maintenance efficiency. In the event of partial equipment downtime, the system can automatically adjust the load distribution of the remaining equipment to ensure that the overall output power remains as close to the target as possible, optimizing resource utilization efficiency. This dynamic scheduling capability is particularly important in emergency situations. During system expansion or equipment layout changes, this hierarchical fault management mechanism allows for local adjustments or repairs without affecting the majority of equipment, enhancing the system's adaptability and flexibility in dynamic environments.

[0084] In some embodiments, after sending the first delay time to the next second controller, the method further includes: receiving the current delay time sent by the first controller, adding the clock of the second controller to the current delay time, wherein the first controller obtains the cable length between the first controller and the second controller closest to the first controller after a preset period of time to obtain the current cable distance; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines that there is no need to synchronize the second controller again, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines the phase difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance to obtain the current delay time, and sends the current delay time to the second controller within the preset time period.

[0085] Specifically, dynamic monitoring of cable length changes and automatic clock synchronization adjustments enable the system to adapt to various layout requirements and operating environment changes, improving the system's overall adaptability and flexibility. In the event of minor changes in cable length, there is no need to re-perform complex clock synchronization adjustments, reducing maintenance and debugging workload and lowering system maintenance costs. Through regular monitoring and immediate adjustments when necessary, the system can ensure that the synchronization of the carrier signal remains within an acceptable error range despite changes in cable length, ensuring the real-time and stability of system operation. When the system needs to be expanded, new devices can be quickly connected and synchronized, eliminating the need to manually reconfigure the synchronization parameters of all devices, improving the efficiency and convenience of system expansion. Compared to the use of optical fiber or other high-cost, low-latency transmission media, the dynamic cable length compensation mechanism allows the use of lower-cost cables while maintaining the synchronization accuracy required by the system, achieving an optimal balance between cost and performance.

[0086] In some embodiments, receiving the first delay time sent by the first controller includes: receiving the first delay time sent by the first controller within the preset time period; wherein the first controller obtains a first time mapping relationship, the first time mapping relationship is a mapping relationship between the preset time period and the range of the first cable distance, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; the first controller determines the corresponding preset time period based on the first time mapping relationship and the first cable distance; the first controller determines the first delay time based on t=L / v, or the first controller obtains a second time mapping relationship, the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; the first controller determines the corresponding first delay time based on the second time mapping relationship and the first cable distance, wherein t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

[0087] Specifically, there is a direct relationship between cable length and signal transmission delay. By establishing a mapping relationship, the system can accurately calculate the signal transmission delay based on different cable lengths, thereby more precisely adjusting the preset time period and ensuring high-precision clock synchronization between devices. The second time mapping relationship covers multiple variables that affect signal transmission, which makes the calculation of delay time more detailed and closer to the actual value. For example, under the same cable length, the impact of different temperature conditions on signal transmission speed can be taken into account, resulting in a more accurate delay time. The formula t=L / v is based on the theory of electromagnetic wave propagation in media. The application of this formula ensures the scientific and accurate calculation of signal transmission delay. The propagation speed v of electromagnetic waves is not only related to the physical properties of the medium, such as the dielectric constant and magnetic permeability of the cable, but is also affected by environmental factors such as temperature and humidity. Understanding and applying these theories can help to more accurately estimate signal delay.

[0088] According to some embodiments of the present application, the embodiments of the present application further provide an energy storage system, such as Figure 4As shown, it includes: a first controller and multiple second controllers (i.e., second controller 1 to second controller n), the first controller is electrically connected to one of all the second controllers in the energy storage system using a cable, the second controller electrically connected to the first controller is serially connected to the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor, a field programmable gate array, and the digital signal processor (DSP) and the field programmable gate array (FPGA) communicate bidirectionally, the field programmable gate array of the first controller is electrically connected to the field programmable gate array of the first controller using the cable, the first controller is used to centrally control the second controllers, the second controller is used to adjust the power of the energy storage system, the first controller is used to execute any one of the above methods, and each of the second controllers is used to execute any one of the above methods.

[0089] In the energy storage system described above, the signal transmission speed in the cable is far slower than the speed of light, with the specific value depending on the cable's material and structure. By determining at least a first delay time based on the first cable distance, an estimated first delay time for the signal to be transmitted from the first controller to the second controller can be calculated. A delay compensation mechanism, when calculating the delay, automatically calculates and applies the required first delay time based on the cable length. When the signal reaches the second controller, thanks to the compensation sent in advance, the second controller receives the signal on time, achieving synchronization. In a parallel architecture with multiple second controllers, the signal travels from the first controller to the first second controller, then from the first second controller to the second second controller, and so on, achieving precise clock synchronization across all devices. While using cables instead of optical fibers increases signal transmission delay, this issue can be overcome by introducing a delay compensation mechanism. Compared to optical fibers, cables are significantly less expensive, thus resolving the high cost of optical fiber electrical connections for clock synchronization between the first and second controllers in prior energy storage systems.

[0090] like Figure 5 The figure shows the working principle of the energy storage system: the energy storage system includes a host and multiple slaves (slave 1, slave 2, ..., slave n). The host and slaves all include ARM, DSP and FPGA. There is bidirectional communication between ARM and FPGA, and bidirectional communication between FPGA and DSP. There is no direct communication between ARM and DSP. Data transmission between ARM and DSP needs to be realized through FPGA. This application adopts a step-by-step transmission method to realize signal transmission. Figure 5The dotted line in the figure indicates that the master FPGA transmits the synchronization signal to the first slave FPGA, which then transmits the synchronization signal to the second slave FPGA, and so on. Each FPGA then synchronizes the received synchronization signal to its own DSP.

[0091] DSPs (digital signal processors) use FPGAs (field-programmable gate arrays) for clock-synchronized signal transmission. In high-speed signal transmission scenarios, such as FPGA clock synchronization, the FPGA's high-speed data processing capabilities ensure that signals are transmitted without delay accumulation or distortion. ARMs are used to provide various cable distances.

[0092] ARM (Advanced RISC Machine): A processor architecture widely used in mobile phones, tablets, embedded systems, and other devices. It is based on a reduced instruction set computing design and offers efficient energy consumption and good performance.

[0093] DSP (Digital Signal Processor): A processor specifically designed for processing digital signals. It is commonly used in fields requiring fast digital signal processing, such as audio, video, and communications. Compared to general-purpose processors, DSPs offer higher processing speed and efficiency, making them suitable for real-time processing tasks.

[0094] FPGA (Field-Programmable Gate Array): A highly programmable chip that can be configured with different logic functions using a hardware description language such as VHDL or Verilog. The flexibility of FPGAs makes them suitable for prototyping, complex computing tasks, and applications requiring highly parallel processing.

[0095] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present application, and that in actual applications, various changes in form and detail may be made thereto without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A clock synchronization method for an energy storage system, applied to a first controller in the energy storage system, wherein the first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and the second controller electrically connected to the first controller is serially connected to the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, the digital signal processor and the field editable gate array can communicate bidirectionally, the field editable gate array of the first controller is electrically connected to the field editable gate array of the first controller using the cable, the first controller is used to centrally control the second controllers, and the second controller is used to adjust the power of the energy storage system, characterized in that include: Obtaining a cable length between the first controller and a second controller closest to the first controller to obtain a first cable distance, and determining a first delay time based at least on the first cable distance, where the first delay time is a phase difference between a clock of the second controller closest to the first controller and a clock of the first controller; The first delay time is sent to the second controller within a preset time period, so that the second controller adds the clock of the second controller to the first delay time, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller.

2. The clock synchronization method of the energy storage system according to claim 1, characterized in that: After sending the first delay time to the second controller within a preset time period, the method further includes: When there is at least one faulty device among all the second controllers, and the faulty device is the second controller closest to the first controller, issuing a shutdown instruction to the other second controllers except the second controller electrically connected to the first controller, so as to control the other second controllers except the second controller electrically connected to the first controller to shut down; When there is at least one faulty device among all the second controllers and the faulty device is not the second controller closest to the first controller, the shutdown instruction is sent to the target controller to control the target controller to shut down. The target controller is the other second controllers except the faulty device and all the second controllers between the faulty device and the first controller.

3. The clock synchronization method of the energy storage system according to claim 1, characterized in that: After sending the first delay time to the second controller within a preset time period, the method further includes: After a preset time period, the cable length between the first controller and the second controller closest to the first controller is obtained to obtain a current cable distance; If the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to a preset difference, determining that the second controller does not need to be synchronized again; When the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the difference between the clock of the second controller closest to the first controller and the clock of the first controller is determined at least based on the current cable distance to obtain the current delay time, and the current delay time is sent to the second controller within the preset time period so that the second controller adds the clock of the second controller to the current delay time.

4. The clock synchronization method of the energy storage system according to claim 1, characterized in that: Before sending the first delay time to the second controller within a preset time period, the method further includes: Acquire a first time mapping relationship, where the first time mapping relationship is a mapping relationship between the preset time period and the range of the first cable distance; The corresponding preset time period is determined according to the first time mapping relationship and the first cable distance.

5. The clock synchronization method of the energy storage system according to claim 1, characterized in that: Determining a first delay time based on at least the first cable distance includes: Acquire a second time mapping relationship, where the second time mapping relationship is a mapping relationship between the first delay time and the range of the first cable distance; The corresponding first delay time is determined according to the second time mapping relationship and the first cable distance.

6. The clock synchronization method of the energy storage system according to claim 1, characterized in that: Determining a first delay time based on at least the first cable distance includes: The first delay time is determined according to t=L / v, wherein t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

7. A clock synchronization method for an energy storage system, applied to a second controller in the energy storage system, wherein a first controller is electrically connected to one of all second controllers in the energy storage system using a cable, and a second controller electrically connected to the first controller is serially connected to the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor and a field editable gate array, the digital signal processor and the field editable gate array can communicate bidirectionally, the field editable gate array of the first controller and the field editable gate array of the first controller are electrically connected using the cable, the first controller is used to centrally control the second controllers, and the second controller is used to adjust the power of the energy storage system, characterized in that include: receiving a first delay time sent by the first controller, and adding the first delay time to the clock of the second controller, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller; Obtaining a cable length between the second controller and the next second controller to obtain a second cable distance, and determining a second delay time based at least on the second cable distance, where the second delay time is a phase difference between a clock of the second controller and a clock of the next second controller, wherein the second controller and the next second controller are electrically connected by a cable; The first delay time is sent to the second controller within a preset time period, so that the next second controller adds the clock of the next second controller to the second delay time, thereby achieving clock synchronization between the second controller and the next second controller.

8. The clock synchronization method of the energy storage system according to claim 7, characterized in that: After sending the first delay time to the second controller within a preset time period, the method further includes: Receive a shutdown instruction sent by the first controller and switch the state of the second controller to a shutdown state, wherein, when there is at least one faulty device among all the second controllers and the faulty device is the second controller closest to the first controller, the first controller sends a shutdown instruction to the second controllers other than the second controller electrically connected to the first controller to control the shutdown of the second controllers other than the second controller electrically connected to the first controller; when there is at least one faulty device among all the second controllers and the faulty device is not the second controller closest to the first controller, the first controller sends the shutdown instruction to the target controller to control the shutdown of the target controller, which is the second controller other than the faulty device and all the second controllers between the faulty device and the first controller.

9. The clock synchronization method of the energy storage system according to claim 7, characterized in that: After sending the first delay time to the next second controller, the method further includes: Receive the current delay time sent by the first controller, and add the clock of the second controller to the current delay time, wherein the first controller obtains the cable length between the first controller and the second controller closest to the first controller after a preset period of time to obtain the current cable distance; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines that there is no need to synchronize the second controller again, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to the preset difference, the first controller determines the phase difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance to obtain the current delay time, and sends the current delay time to the second controller within the preset time period.

10. The clock synchronization method of the energy storage system according to claim 7, characterized in that: Receiving a first delay time sent by the first controller includes: receiving the first delay time sent by the first controller within the preset time period; Among them, the first controller obtains a first time mapping relationship, which is a mapping relationship between the preset time period and the range of the first cable distance, and the first cable distance is the cable length between the first controller and the second controller closest to the first controller; the first controller determines the corresponding preset time period based on the first time mapping relationship and the first cable distance; the first controller determines the first delay time based on t=L / v, or the first controller obtains a second time mapping relationship, which is a mapping relationship between the first delay time and the range of the first cable distance; the first controller determines the corresponding first delay time based on the second time mapping relationship and the first cable distance, wherein t is the first delay time, v is the propagation speed of the signal of the first controller in the cable, and L is the first cable distance.

11. An energy storage converter, characterized in that: include: an acquiring unit, configured to acquire a cable length between a first controller and a second controller closest to the first controller to obtain a first cable distance, and determine a first delay time based at least on the first cable distance, where the first delay time is a phase difference between a clock of the second controller closest to the first controller and a clock of the first controller; The first processing unit is used to send the first delay time to the second controller within a preset time period, so that the second controller adds the clock of the second controller to the first delay time, thereby achieving clock synchronization between the first controller and the second controller closest to the first controller.

12. The energy storage converter according to claim 11, characterized in that: The energy storage converter further includes: a second processing unit, configured to, after sending the first delay time to the second controller within a preset time period, if at least one faulty device exists in all the second controllers and the faulty device is the second controller closest to the first controller, issue a shutdown instruction to the other second controllers except the second controller electrically connected to the first controller, so as to control the other second controllers except the second controller electrically connected to the first controller to shut down; The third processing unit is used to send the shutdown instruction to the target controller to control the target controller to shut down when there is at least one faulty device in all the second controllers and the faulty device is not the second controller closest to the first controller. The target controller is the other second controllers except the faulty device and all the second controllers between the faulty device and the first controller.

13. The energy storage converter according to claim 11, characterized in that: The energy storage converter further includes: a fourth processing unit, configured to, after sending the first delay time to the second controller within a preset time period, obtain a cable length between the first controller and a second controller closest to the first controller after a preset time period, to obtain a current cable distance; a first determining unit, configured to determine that it is not necessary to synchronize the second controller again if an absolute value of a difference between the current cable distance and the first cable distance is less than or equal to a preset difference; A second determination unit is used to determine the difference between the clock of the second controller closest to the first controller and the clock of the first controller at least based on the current cable distance when the absolute value of the difference between the current cable distance and the first cable distance is less than or equal to a preset difference, obtain the current delay time, and send the current delay time to the second controller within the preset time period, so that the second controller adds the clock of the second controller to the current delay time.

14. The energy storage converter according to claim 11, characterized in that: The energy storage converter further includes: a fifth processing unit, configured to obtain a first time mapping relationship before sending the first delay time to the second controller within a preset time period, where the first time mapping relationship is a mapping relationship between the preset time period and the first cable; A sixth processing unit is configured to determine the corresponding preset time period according to the first time mapping relationship and the first cable distance.

15. An energy storage system, characterized in that: include: A first controller and multiple second controllers, the first controller is electrically connected to one of all the second controllers in the energy storage system using a cable, the second controller electrically connected to the first controller is serially connected to the other second controllers using the cable, the first controller and the second controller have the same structure, the first controller includes a digital signal processor, a field editable gate array, and bidirectional communication between the digital signal processor and the field editable gate array, the field editable gate array of the first controller is electrically connected to the field editable gate array of the first controller using the cable, the first controller is used to centrally control the second controllers, the second controller is used to adjust the power of the energy storage system, the first controller is used to execute the method described in any one of claims 1 to 6, and each second controller is used to execute the method described in any one of claims 7 to 10.

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