Distributed energy storage system

Abstract

The invention discloses a distributed energy storage system, and relates to the technical field of distributed energy. The system comprises a plurality of distributed energy storage units arranged according to a preset sequence, each distributed energy storage unit comprises a plurality of energy storage converters, and synchronous data bus ends of the plurality of energy storage converters in each distributed energy storage unit are mutually connected through a communication bus; in the plurality of distributed energy storage units, according to a preset sequence, in every two adjacent distributed energy storage units, the communication bus of the distributed energy storage unit arranged in the front is connected with the communication bus of the distributed energy storage unit arranged in the rear; the plurality of energy storage converters arranged in the front distributed energy storage unit and the plurality of energy storage converters arranged in the rear distributed energy storage unit can be subjected to data time sequence synchronization. According to the system, the cost for realizing data time sequence synchronization between the energy storage converters in the distributed energy storage system can be remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the field of distributed energy technology, and in particular to a distributed energy storage system. Background Art

[0002] With the development of distributed energy resources and smart grid technology, the traditional power system structure dominated by large central power stations is changing, and distributed energy storage systems are gradually becoming an important part of the power system. Distributed energy storage systems can improve the flexibility of the power system, support the two-way flow of the power system, and meet the customized needs of the user side. In recent years, battery energy storage technology in energy storage technology has made significant progress, including cost reduction, performance improvement, and reliability enhancement. These advances have made distributed energy storage a viable solution and promoted its widespread application in power systems.

[0003] Due to its own characteristics, the distributed energy storage system arranges multiple distributed energy storage units in a square array and controls them through software to synchronize the data of the distributed energy storage units in the entire square array. If a distributed energy storage unit contains multiple energy storage converters, it is necessary to realize the parallel function between the energy storage converters, that is, to set the master and slave machines in multiple energy storage converters so that the master machine can distribute power and coordinate communication with the slave machine when receiving the total power output. Therefore, it is necessary to realize data timing synchronization between energy storage converters.

[0004] At present, multiple energy storage converters inside distributed energy storage units in distributed energy storage systems perform data timing synchronization through a communication bus. However, the above method can only synchronize the data timing of multiple energy storage converters inside the same distributed energy storage unit, and cannot achieve data timing synchronization for all energy storage converters contained in a square array. On this basis, if all energy storage converters contained in the square array are connected to each other by adding a new bus, it will not only cause a waste of cables, but also add ports for realizing the transceiver function, corresponding transceivers and conversion chips and other components to the main control chip of the control board card inside each energy storage converter, and provide corresponding software programs for executing data timing synchronization. This greatly increases the research and development, material and software maintenance costs, resulting in excessively high costs for realizing data timing synchronization between energy storage converters in distributed energy storage systems, resulting in a decline in the market competitiveness of distributed energy storage systems. Summary of the invention

[0005] In view of this, the present application provides a distributed energy storage system, the main purpose of which is to solve the technical problem of high cost of achieving data timing synchronization between energy storage converters in existing distributed energy storage systems.

[0006] According to a first aspect of the present invention, there is provided a distributed energy storage system, the system comprising a plurality of distributed energy storage units arranged in a preset order, each of the distributed energy storage units comprising a plurality of energy storage converters;

[0007] The synchronous data bus terminals of the multiple energy storage converters in each of the distributed energy storage units are connected to each other via a communication bus;

[0008] Among the multiple distributed energy storage units, in accordance with the preset order, in every two adjacent distributed energy storage units, the communication bus of the distributed energy storage unit arranged in front is connected to the communication bus of the distributed energy storage unit arranged in the back, so that the multiple energy storage inverters in the distributed energy storage unit arranged in front can perform data timing synchronization with the multiple energy storage inverters in the distributed energy storage unit arranged in the back.

[0009] Optionally, the communication bus is a controller area network bus, and the controller area network bus includes a low-level signal line and a high-level signal line; the synchronous data bus end includes a low-level synchronous data bus end and a high-level synchronous data bus end; the low-level synchronous data bus ends of the multiple energy storage inverters in each of the distributed energy storage units are interconnected through the low-level signal line; the high-level synchronous data bus ends of the multiple energy storage inverters in each of the distributed energy storage units are connected through the high-level signal line; in the multiple distributed energy storage units, according to the preset order, in each adjacent two distributed energy storage units, the low-level signal line of the distributed energy storage unit arranged in front is connected to the low-level signal line of the distributed energy storage unit arranged in the back, and the high-level signal line of the distributed energy storage unit arranged in front is connected to the high-level signal line of the distributed energy storage unit arranged in the back.

[0010] Optionally, the system also includes a first terminal resistor and a second terminal resistor; the first end of the first terminal resistor is connected to the low-level signal line in the first distributed energy storage unit, and the second end of the first terminal resistor is connected to the high-level signal line in the first distributed energy storage unit, wherein the first distributed energy storage unit is the distributed energy storage unit that is arranged in the first position according to the preset order among multiple distributed energy storage units; the first end of the second terminal resistor is connected to the low-level signal line in the last distributed energy storage unit, and the second end of the second terminal resistor is connected to the high-level signal line in the last distributed energy storage unit, wherein the last distributed energy storage unit is the distributed energy storage unit that is arranged in the last position according to the preset order among multiple distributed energy storage units.

[0011] Optionally, the serial communication bus ends of each energy storage converter in the distributed energy storage unit are interconnected via a serial communication bus, so that multiple energy storage converters in the same distributed energy storage unit can perform data exchange based on the serial communication bus.

[0012] Optionally, the serial communication bus is an RS485 bus or a CAN bus.

[0013] Optionally, all the energy storage inverters included in the multiple distributed energy storage units include a pre-selected host energy storage inverter; among all the energy storage inverters included in the multiple distributed energy storage units, the energy storage inverters other than the host energy storage inverter are slave energy storage inverters; the host energy storage inverter is used to send a synchronization signal of the host energy storage inverter to each of the slave energy storage inverters, so that the slave energy storage inverters perform data timing synchronization based on the synchronization signal.

[0014] Optionally, the host energy storage converter has a remote communication port for connecting to a remote host computer.

[0015] Optionally, the host energy storage inverter is configured to perform the following processing: determine whether the synchronization signal of each of the slave energy storage inverters is consistent in timing with the synchronization signal of the host energy storage inverter; when it is determined that the synchronization signal of the slave energy storage inverter is not consistent in timing with the synchronization signal of the host energy storage inverter, send an alarm prompt message to the host computer.

[0016] Optionally, determining whether the synchronization signal of each of the slave energy storage converters is consistent with the synchronization signal of the host energy storage converter in timing, includes: determining the synchronization signal of the slave energy storage converter as a slave synchronization signal, and determining the synchronization signal of the host energy storage converter as a host synchronization signal; determining the host low level duration and the host synchronization signal cycle of the host synchronization signal; determining the slave low level duration and the slave synchronization signal cycle of the slave synchronization signal of each of the slave energy storage converters; determining whether the slave low level duration of each of the slave synchronization signals is the same as the host low level duration, and determining whether the slave synchronization signal cycle of each of the slave synchronization signals is the same as the host synchronization signal cycle; when the slave low level duration is different from the host low level duration, or the slave synchronization signal cycle is different from the host synchronization signal cycle, it is determined that the synchronization signal of the slave energy storage converter is not consistent with the synchronization signal of the host energy storage converter in timing.

[0017] Optionally, when it is determined that the synchronization signal of the slave energy storage inverter is not in timing consistency with the synchronization signal of the host energy storage inverter, sending an alarm prompt message to the host computer includes: determining the slave energy storage inverter that is not in timing consistency with the synchronization signal of the host energy storage inverter; and sending the alarm prompt message containing the identification information of the slave energy storage inverter to the host computer.

[0018] The present invention provides a distributed energy storage system. First, the synchronous data bus terminals of multiple energy storage converters in each distributed energy storage unit in the system are interconnected through a communication bus, so that multiple energy storage converters in the same distributed energy storage unit can perform data timing synchronization through synchronization information; further, the communication bus used to connect multiple energy storage converters in each distributed energy storage unit is connected to the communication bus used to connect multiple energy storage converters in an adjacent distributed energy storage unit, and each distributed energy storage unit in the entire array is connected with the bus in a hand-in-hand manner. Without adding additional communication ports for data timing synchronization to the energy storage converter, the original synchronous data bus terminal can be used for data timing synchronization, so that data timing synchronization can be performed between the energy storage converters in each two adjacent distributed energy storage units without the need for a corresponding software program for executing data timing synchronization, thereby enabling data timing synchronization between all energy storage converters in the distributed energy storage system. At the same time, each distributed energy storage unit in the entire array is connected hand in hand. Compared with the method of adding a new bus to connect all the energy storage converters contained in the array, it can significantly reduce the use of cables and significantly reduce the cost of realizing data timing synchronization between the energy storage converters in the distributed energy storage system.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 One of the structural schematic diagrams of a distributed energy storage system provided by an embodiment of the present invention is shown;

[0022] Figure 2 One of the structural schematic diagrams of an exemplary distributed energy storage system provided by an embodiment of the present invention is shown;

[0023] Figure 3 A second structural schematic diagram of a distributed energy storage system provided by an embodiment of the present invention is shown;

[0024] Figure 4 A second schematic diagram of the structure of an exemplary distributed energy storage system provided in an embodiment of the present invention is shown;

[0025] Figure 5 A third structural schematic diagram of a distributed energy storage system provided by an embodiment of the present invention is shown;

[0026] Figure 6 A fourth structural schematic diagram of a distributed energy storage system provided by an embodiment of the present invention is shown;

[0027] Figure 7 A waveform diagram of a synchronization signal provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0029] In one embodiment, Figure 1 As shown, a distributed energy storage system is provided, and the application of the system in energy storage scenarios is used as an example for explanation. The distributed energy storage system includes multiple distributed energy storage units arranged in a preset order, and each of the distributed energy storage units includes multiple energy storage converters (Power Conversion Systems, PCS). Each distributed energy storage unit may include multiple energy storage devices, such as batteries, etc. Each energy storage device is connected to an energy storage converter, which is used to convert external AC power into DC power and charge the energy storage device, and can also convert the DC power output by the energy storage device into AC power to output electrical energy to the outside. Here, for the convenience of description, Figure 1 Each distributed energy storage unit in the distributed energy storage system includes two energy storage converters. In actual situations, the number of energy storage converters in each distributed energy storage unit applicable to the distributed energy storage system is greater than or equal to two.

[0030] Furthermore, the preset order may be the order in which multiple distributed energy storage units are set. The preset order may be independent of the position of each distributed energy storage unit, and the position may be set for each distributed energy storage unit in turn. The specific setting form of the preset order may be determined according to actual conditions and is not limited here.

[0031] Specifically, the synchronous data bus terminals of the multiple energy storage converters in each of the distributed energy storage units are interconnected through a communication bus to achieve data timing synchronization of the multiple energy storage converters in the same distributed energy storage unit. Among them, each energy storage converter has a communication transceiver (not shown in the figure), which can be a microcontroller arranged on a board, used to realize the transmission of the synchronization signal through the bus, and the synchronous data bus terminal is arranged on the bus signal transceiver. The synchronous data bus terminal of the communication transceiver of one energy storage converter can be connected to the synchronous data bus terminal of the communication transceiver of another energy storage converter through the communication bus to realize data communication between several energy storage converters. Here, a synchronous signal interaction terminal can be drawn out on the communication bus, which is used to output the signal on the communication bus to the outside, or to send the external signal to the communication bus.

[0032] Further, in the plurality of distributed energy storage units, according to the preset order, in each adjacent two distributed energy storage units, the communication bus of the distributed energy storage unit arranged in front is connected to the communication bus of the distributed energy storage unit arranged in the back, so that the multiple energy storage converters in the distributed energy storage unit arranged in front can perform data timing synchronization with the multiple energy storage converters in the distributed energy storage unit arranged in the back. Specifically, each adjacent two distributed energy storage units include the distributed energy storage unit arranged in front and the distributed energy storage unit arranged in the back, and the data bus can be connected to the communication bus of the distributed energy storage unit arranged in front, and the data bus can be connected to the communication bus of the distributed energy storage unit arranged in the back, so that all the energy storage converters in the two adjacent distributed energy storage units can synchronize the synchronization signal, thereby realizing that all the energy storage converters in each adjacent two distributed energy storage units can perform data timing synchronization. Here, the process of data timing synchronization can be a process of unifying the synchronization signals of each energy storage converter, and the synchronization signal is a square wave signal with alternating high and low levels. Here, one energy storage inverter can be used as a host energy storage inverter to send a square wave signal, and the square wave signal can be transmitted to each energy storage inverter in the system via a communication bus, so that other energy storage inverters can perform data timing synchronization based on the square wave signal sent by the host energy storage inverter.

[0033] As an example, Figure 2As shown, the distributed energy storage system includes three distributed energy storage units arranged in a preset order, namely a first distributed energy storage unit, a second distributed energy storage unit and a third distributed energy storage unit, and each distributed energy storage unit contains two energy storage converters. The first distributed energy storage unit and the second distributed energy storage unit are two distributed energy storage units adjacent to each other in a preset order, wherein the first distributed energy storage unit is the distributed energy storage unit arranged in front, and the second distributed energy storage unit is the distributed energy storage unit arranged in the back. Further, the second distributed energy storage unit and the third distributed energy storage unit are two distributed energy storage units adjacent to each other in a preset order, wherein the second distributed energy storage unit is the distributed energy storage unit arranged in front, and the third distributed energy storage unit is the distributed energy storage unit arranged in the back.

[0034] Furthermore, one end of the first data bus is connected to the communication bus in the first distributed energy storage unit, and the other end of the first data bus is connected to the communication bus in the second distributed energy storage unit; further, one end of the second data bus is connected to the communication bus in the second distributed energy storage unit, and the other end of the second data bus is connected to the communication bus in the third distributed energy storage unit, so that in every two adjacent distributed energy storage units, the multiple energy storage inverters in the front distributed energy storage unit can synchronize data timing with the multiple energy storage inverters in the rear distributed energy storage unit.

[0035] The present invention provides a distributed energy storage system. First, the synchronous data bus terminals of multiple energy storage converters in each distributed energy storage unit in the system are connected through a communication bus to achieve data timing synchronization of multiple energy storage converters in the same distributed energy storage unit. Furthermore, the communication bus used to connect multiple energy storage converters in each distributed energy storage unit is connected to the communication bus used to connect multiple energy storage converters in an adjacent distributed energy storage unit, and each distributed energy storage unit in the entire array is connected with the communication bus in a hand-in-hand manner. Without adding an additional communication port for data timing synchronization to the energy storage converter, the original synchronous data bus terminal can be used for data timing synchronization, so that data timing synchronization can be achieved between the energy storage converters in each two adjacent distributed energy storage units without the need for a corresponding software program for executing data timing synchronization, thereby enabling data timing synchronization between all energy storage converters in the distributed energy storage system. At the same time, each distributed energy storage unit in the entire array is connected hand in hand. Compared with the method of adding a new bus to connect all the energy storage converters contained in the array, it can significantly reduce the use of cables and significantly reduce the cost of realizing data timing synchronization between the energy storage converters in the distributed energy storage system.

[0036] In an optional embodiment, if Figure 3 As shown, the communication bus is a controller area network (CAN), and the above-mentioned data bus can also be a CAN bus; further, the controller area network bus as a communication bus includes a low-level signal line and a high-level signal line. In the CAN bus, the low-level signal line and the high-level signal line are two differential signal lines, which constitute the basic electrical connection of the CAN bus, used to transmit differential signals, and the voltage difference between the low-level signal line and the high-level signal line is used to represent the logic state on the bus. In the CAN bus, the logic "1" (recessive level) corresponds to the situation where the voltage difference between the high-level signal line and the low-level signal line is zero, and the logic "0" (dominant level) corresponds to the situation where the voltage of the high-level signal line is higher than that of the low-level signal line.

[0037] Furthermore, the synchronous data bus terminal of the energy storage inverter includes a low-level synchronous data bus terminal CANL and a high-level synchronous data bus terminal CANH. The low-level synchronous data bus terminals CANL of the multiple energy storage inverters in each of the distributed energy storage units are interconnected through the low-level signal line, and the high-level synchronous data bus terminals CANH of the multiple energy storage inverters in each of the distributed energy storage units are interconnected through the high-level signal line, so as to realize data timing synchronization of the multiple energy storage inverters in the same distributed energy storage unit.

[0038] Furthermore, among the multiple distributed energy storage units, according to the preset order, in every two adjacent distributed energy storage units, the low-level signal line of the distributed energy storage unit arranged in front is connected to the low-level signal line of the distributed energy storage unit arranged in the back, and the high-level signal line of the distributed energy storage unit arranged in front is connected to the high-level signal line of the distributed energy storage unit arranged in the back.

[0039] Specifically, one end of a data bus can be connected to the low-level signal line of the distributed energy storage unit arranged in front, and the other end of the data bus can be connected to the low-level signal line of the distributed energy storage unit arranged in the back; further, one end of another data bus can be connected to the high-level signal line of the distributed energy storage unit arranged in front, and the other end of the data bus can be connected to the high-level signal line of the distributed energy storage unit arranged in the back, so as to realize that all energy storage converters in two adjacent distributed energy storage units can synchronize signals with each other, thereby realizing data timing synchronization between all energy storage converters in two adjacent distributed energy storage units.

[0040] As an example, Figure 4As shown, the distributed energy storage system includes three distributed energy storage units arranged in a preset order, namely a first distributed energy storage unit, a second distributed energy storage unit and a third distributed energy storage unit, and each distributed energy storage unit contains two energy storage converters. The first distributed energy storage unit and the second distributed energy storage unit are two distributed energy storage units adjacent to each other in a preset order, wherein the first distributed energy storage unit is the distributed energy storage unit arranged in front, and the second distributed energy storage unit is the distributed energy storage unit arranged in the back. Further, the second distributed energy storage unit and the third distributed energy storage unit are two distributed energy storage units adjacent to each other in a preset order, wherein the second distributed energy storage unit is the distributed energy storage unit arranged in front, and the third distributed energy storage unit is the distributed energy storage unit arranged in the back.

[0041] Furthermore, one end of the third data bus is connected to the high-level signal line in the first distributed energy storage unit, and the other end of the third data bus is connected to the high-level signal line in the second distributed energy storage unit; further, one end of the fourth data bus is connected to the low-level signal line in the first distributed energy storage unit, and the other end of the fourth data bus is connected to the low-level signal line in the second distributed energy storage unit.

[0042] Further, one end of the fifth data bus is connected to the high level signal line in the second distributed energy storage unit, and the other end of the fifth data bus is connected to the high level signal line in the third distributed energy storage unit; further, one end of the sixth data bus is connected to the low level signal line in the second distributed energy storage unit, and the other end of the sixth data bus is connected to the low level signal line in the third distributed energy storage unit. Through the above connection method, in each of two adjacent distributed energy storage units, the multiple energy storage converters in the front distributed energy storage unit can perform data timing synchronization with the multiple energy storage converters in the rear distributed energy storage unit based on synchronization information.

[0043] The embodiments provided in the present application can transmit differential signals between the energy storage converters in the distributed energy storage system based on the CAN bus, so that the energy storage converters in the distributed energy storage system can perform data timing synchronization, thereby improving the stability of data timing synchronization of the distributed energy storage system.

[0044] In an optional embodiment, if Figure 5As shown, the system also includes a first terminal resistor R1 and a second terminal resistor R2. Among them, on the board of the communication transceiver of the existing energy storage converter, a chip resistor is connected between the high-level synchronous data bus terminal CANH and the low-level synchronous data bus terminal CANL to solve the problems of integrity and impedance matching of the synchronization signal, so that the synchronization signal changes from a dominant state to a recessive state more quickly. In the energy storage converter provided in the embodiment of the present application, a chip resistor may not be set on the board of the communication transceiver of each energy storage converter, but the integrity and impedance matching problems of the synchronization signal are solved by setting the first terminal resistor R1 and the second terminal resistor R2 in the distributed energy storage system. Here, the resistance values ​​of the first terminal resistor R1 and the second terminal resistor R2 can be 120 ohms respectively.

[0045] Specifically, the first end of the first terminal resistor R1 is connected to the low-level signal line in the first distributed energy storage unit, and the second end of the first terminal resistor R1 is connected to the high-level signal line in the first distributed energy storage unit, wherein the first distributed energy storage unit is the distributed energy storage unit that is arranged in the first place according to the preset order among all the distributed energy storage units in the distributed energy storage system.

[0046] Furthermore, the access point on the high-level signal line in the first distributed energy storage unit that is connected to the data bus can be determined as the first high-level signal line access point, and the access point on the low-level signal line in the first distributed energy storage unit that is connected to the data bus can be determined as the first low-level signal line access point; further, among the multiple energy storage inverters in the first distributed energy storage unit, the energy storage inverter farthest from the first high-level signal line access point and the first low-level signal line access point is determined as the first target energy storage inverter, and the first end of the first terminal resistor R1 is connected to the low-level synchronous data bus terminal CANL of the first target energy storage inverter, and the second end of the first terminal resistor R1 is connected to the high-level synchronous data bus terminal CANH of the first target energy storage inverter.

[0047] Furthermore, the first end of the second terminal resistor R2 is connected to the low-level signal line in the last distributed energy storage unit, and the second end of the second terminal resistor R2 is connected to the high-level signal line in the last distributed energy storage unit, wherein the last distributed energy storage unit is the distributed energy storage unit arranged at the last position in the preset order among all the distributed energy storage units in the distributed energy storage system.

[0048] Furthermore, the access point of the high-level signal line in the last distributed energy storage unit that is connected to the data bus can be determined as the second high-level signal line access point, and the access point of the low-level signal line in the last distributed energy storage unit that is connected to the data bus can be determined as the second low-level signal line access point; further, among the multiple energy storage inverters in the last distributed energy storage unit, the energy storage inverter farthest from the second high-level signal line access point and the second low-level signal line access point is determined as the second target energy storage inverter, and the first end of the second terminal resistor R2 is connected to the low-level synchronous data bus terminal CANL of the second target energy storage inverter, and the second end of the second terminal resistor R2 is connected to the high-level synchronous data bus terminal CANH of the second target energy storage inverter.

[0049] In the embodiment provided by the present application, no chip resistor is set on the bus signal transceiver in the energy storage converter, but two terminal resistors are set on the first distributed energy storage unit and the last distributed energy storage unit in the distributed energy storage system. At the same time, it is ensured that in the communication bus connection of the entire array, the first distributed energy storage unit and the last distributed energy storage unit are at the two farthest ends, that is, the cable distance between the two is the longest between all distributed energy storage units, so as to solve the problems of integrity and impedance matching of synchronization signals. In the above manner, the number of resistors required by the system can be greatly reduced, thereby greatly reducing the hardware cost of the system.

[0050] In an optional embodiment, if Figure 6 As shown, the serial communication bus terminals of the multiple energy storage converters in the distributed energy storage unit are connected to each other through a serial communication bus, so that the multiple energy storage converters in the same distributed energy storage unit can exchange data based on the serial communication bus. Here, the energy storage converter in the same distributed energy storage unit can be connected to the serial communication bus terminals RS of other energy storage converters in the distributed energy storage unit through the serial communication bus terminal RS, so as to parallel the multiple energy storage converters in the same distributed energy storage unit and realize the parallel communication function between multiple energy storage converters. Here, the serial communication bus is an RS485 bus or a CAN bus. The embodiment provided by the present application can enable multiple energy storage converters in the same distributed energy storage unit to communicate in parallel. When multiple energy storage converters are running in parallel, they exchange information through the serial communication bus terminal, which is very important to realize the coordinated control and optimized management of the energy storage system, including coordinated control, state monitoring, fault management, load distribution, parameter synchronization, remote monitoring, and energy management, etc., which improves the coordinated control and optimized management capabilities of the distributed energy storage system.

[0051] In an optional embodiment, all the energy storage converters included in the multiple distributed energy storage units include a pre-selected host energy storage converter; here, one energy storage converter can be pre-determined as the host energy storage converter among all the energy storage converters in the distributed energy storage system. Furthermore, among all the energy storage converters included in the multiple distributed energy storage units, the energy storage converters other than the host energy storage converter are pre-determined as slave energy storage converters.

[0052] Furthermore, the host energy storage converter is used to send the synchronization signal of the host energy storage converter to each of the slave energy storage converters, so that the slave energy storage converters perform data timing synchronization based on the synchronization signal. The embodiment provided by the present application enables the host energy storage converter to send a synchronization signal to each slave energy storage converter, so that each slave energy storage converter performs data timing synchronization on itself based on the synchronization signal of the host energy storage converter, thereby ensuring the consistency of data timing between each energy storage converter in the distributed energy storage system.

[0053] In an optional embodiment, the host energy storage converter has a remote communication port for connecting to a remote host computer, where the host computer can be a remote monitoring device for monitoring the operation of the distributed energy storage system, such as a monitoring computer, a monitoring server, etc. Further, the host energy storage converter is configured to perform the following processing: first, determine whether the synchronization signal of each of the slave energy storage converters is in time sequence with the synchronization signal of the host energy storage converter; specifically, the host energy storage converter can obtain the synchronization signal used by the slave energy storage converter during operation from each slave energy storage converter, and compare the synchronization signal used by each slave energy storage converter during operation with the synchronization signal of the host energy storage converter to determine whether the synchronization signal of each slave energy storage converter is synchronized with the synchronization signal of the host energy storage converter.

[0054] Furthermore, when it is determined that the synchronization signal of the slave energy storage inverter does not keep the timing consistent with the synchronization signal of the host energy storage inverter, an alarm prompt message is sent to the host computer. Specifically, when it is determined that there is a slave energy storage inverter in the distributed energy storage system that is not synchronized with the synchronization signal of the host energy storage inverter, an alarm prompt message can be sent to the host computer so that relevant staff can be informed in time that there is an energy storage inverter with an inconsistent synchronization signal in the distributed energy storage system. The embodiment provided by the present application can monitor the synchronization signal of each energy storage inverter in the system, determine whether there is an energy storage inverter with inconsistent synchronization signal, and when an energy storage inverter with inconsistent synchronization signal is found, an alarm prompt message is issued in time, so that relevant staff can monitor the abnormal situation, thereby improving the operating stability of the distributed energy storage system.

[0055] In an optional embodiment, the method of determining whether the synchronization signal of each slave energy storage converter is in time sequence with the synchronization signal of the master energy storage converter includes: first, determining the synchronization signal of each slave energy storage converter as a slave synchronization signal, and determining the synchronization signal of the master energy storage converter as a master synchronization signal. Figure 7 As shown, the synchronization signal exists in the form of a square wave signal. The square wave signal has two stable voltage levels, usually represented as logic "0" and logic "1", corresponding to low level and high level respectively. Furthermore, the square wave signal is periodically repeated, and it has a fixed period. The ratio of the high level part of the square wave signal to the period is called the duty cycle. Figure 7 In the synchronization signal shown, the period of the synchronization signal is 6 milliseconds, and the duration of the low level in the period is 3 microseconds. In the period, except for the duration of the low level, the synchronization signal is kept at a high level.

[0056] Then, determine the duration of the host low level of the host synchronization signal and the host synchronization signal cycle, and determine the duration of the slave low level of the slave synchronization signal of each of the slave energy storage converters and the slave synchronization signal cycle. Specifically, when the host synchronization signal drops from a high level to a low level, a host synchronization signal cycle of the host synchronization signal begins. Further, determine the duration for which the host synchronization signal remains at a low level, and determine the duration as the duration of the host low level. Further, determine the time length between two adjacent conversions of the host synchronization signal from a high level to a low level, and determine the time length as the host synchronization signal cycle.

[0057] Furthermore, the method for determining the slave low level duration of the slave synchronization signal and the slave synchronization signal period is the same as the method for determining the host low level duration of the host synchronization signal and the host synchronization signal period, which will not be repeated here.

[0058] Then, determine whether the duration of the slave low level of each slave synchronization signal is the same as the duration of the master low level, and determine whether the slave synchronization signal cycle of each slave synchronization signal is the same as the master synchronization signal cycle. Specifically, compare the duration of the slave low level of each slave synchronization signal with the duration of the master low level to determine whether each slave low level duration is the same as the duration of the master low level, and compare the slave synchronization signal cycle of each slave synchronization signal with the master synchronization signal cycle to determine whether the slave synchronization signal cycle of each slave synchronization signal is the same as the master synchronization signal cycle.

[0059] Finally, when the duration of the low level of the slave is different from that of the low level of the host, or the period of the slave synchronization signal is different from that of the host synchronization signal, it is determined that the synchronization signal of the slave energy storage converter does not maintain timing consistency with the synchronization signal of the host energy storage converter.

[0060] In contrast, when the duration of the low level of all the slaves is the same as the duration of the low level of the host, and the period of the synchronization signal of all the slaves is the same as the period of the synchronization signal of the host, it is determined that the synchronization signal of each of the slave energy storage converters is in time sequence with the synchronization signal of the host energy storage converter. The embodiment provided by the present application can quickly determine whether the synchronization signal of each slave energy storage converter is in time sequence with the synchronization signal of the host energy storage converter, thereby improving the abnormality monitoring capability of the system.

[0061] In an optional embodiment, when it is determined that the synchronization signal of the slave energy storage converter does not keep the timing consistent with the synchronization signal of the host energy storage converter, the method of sending an alarm prompt information to the host computer includes: first, determining the slave energy storage converter that does not keep the timing consistent with the synchronization signal of the host energy storage converter; specifically, if the synchronization signal of the slave energy storage converter does not keep the timing consistent with the synchronization signal of the host energy storage converter, then determining the slave energy storage converter as the target slave energy storage converter, and determining the identification information of the target slave energy storage converter. Among them, each energy storage converter in the system can have pre-set identification information, such as the energy storage converter number, etc.

[0062] Furthermore, an alarm prompt message containing the identification information of the slave energy storage converter is sent to the host computer, so that when the relevant staff receives the alarm prompt message, they can determine which energy storage converter has not achieved data timing synchronization and make further processing. The embodiment provided by the present application enables the relevant staff to immediately determine the energy storage converter that has not achieved timing consistency when the system has a timing inconsistency problem, thereby improving the ability to respond to system abnormalities.

[0063] A distributed energy storage system provided by the present invention utilizes the original ports of the energy storage inverter to enable the host energy storage inverter to perform data timing synchronization on other energy storage inverters in the system without requiring major adjustments to the structures of the existing distributed energy storage system and energy storage inverter, and monitors the results of the data timing synchronization. When there are energy storage inverters that fail to achieve data timing consistency, warning information is issued in a timely manner, thereby improving the data timing synchronization capability and effect of the system at a relatively low cost.

[0064] The above serial numbers of this application are only for description and do not represent the advantages and disadvantages of the implementation scenarios. The above disclosure is only a few specific implementation scenarios of this application, but this application is not limited to them, and any changes that can be thought of by technicians in this field should fall within the scope of protection of this application.

Claims

1. A distributed energy storage system, characterized in that: The system comprises a plurality of distributed energy storage units arranged in a preset order, each of the distributed energy storage units comprising a plurality of energy storage converters; The synchronous data bus terminals of the multiple energy storage converters in each of the distributed energy storage units are connected to each other via a communication bus; Among the multiple distributed energy storage units, in accordance with the preset order, in every two adjacent distributed energy storage units, the communication bus of the distributed energy storage unit arranged in front is connected to the communication bus of the distributed energy storage unit arranged in the back, so that the multiple energy storage inverters in the distributed energy storage unit arranged in front can perform data timing synchronization with the multiple energy storage inverters in the distributed energy storage unit arranged in the back.

2. The system according to claim 1, characterized in that The communication bus is a controller area network bus, and the controller area network bus includes a low-level signal line and a high-level signal line; the synchronous data bus end includes a low-level synchronous data bus end and a high-level synchronous data bus end; The low-level synchronous data bus terminals of the multiple energy storage converters in each of the distributed energy storage units are connected to each other via the low-level signal lines; The high-level synchronous data bus terminals of the multiple energy storage converters in each of the distributed energy storage units are connected via the high-level signal line; Among the multiple distributed energy storage units, according to the preset order, in every two adjacent distributed energy storage units, the low-level signal line of the distributed energy storage unit arranged in front is connected to the low-level signal line of the distributed energy storage unit arranged in the back, and the high-level signal line of the distributed energy storage unit arranged in front is connected to the high-level signal line of the distributed energy storage unit arranged in the back.

3. The system according to claim 2, characterized in that The system also includes a first terminal resistor and a second terminal resistor; The first end of the first terminal resistor is connected to the low-level signal line in the first distributed energy storage unit, and the second end of the first terminal resistor is connected to the high-level signal line in the first distributed energy storage unit, wherein the first distributed energy storage unit is the distributed energy storage unit that is arranged in the first position according to the preset order among the multiple distributed energy storage units; The first end of the second terminal resistor is connected to the low-level signal line in the last distributed energy storage unit, and the second end of the second terminal resistor is connected to the high-level signal line in the last distributed energy storage unit, wherein the last distributed energy storage unit is the distributed energy storage unit arranged at the last position in the preset order among the multiple distributed energy storage units.

4. The system according to claim 1, characterized in that The serial communication bus ends of each energy storage converter in the distributed energy storage unit are connected to each other via a serial communication bus, so that multiple energy storage converters in the same distributed energy storage unit can perform data exchange based on the serial communication bus.

5. The system according to claim 4, characterized in that The serial communication bus is an RS485 bus or a CAN bus.

6. The system according to claim 1, characterized in that Among all the energy storage converters included in the multiple distributed energy storage units, a pre-selected host energy storage converter is included; among all the energy storage converters included in the multiple distributed energy storage units, the energy storage converters other than the host energy storage converter are slave energy storage converters; The master energy storage converter is used to send a synchronization signal of the master energy storage converter to each of the slave energy storage converters, so that the slave energy storage converters perform data timing synchronization based on the synchronization signal.

7. The system according to claim 6, characterized in that The host energy storage converter has a remote communication port for connecting to a remote host computer.

8. The system according to claim 7, characterized in that The host energy storage converter is configured to perform the following processing: Determine whether the synchronization signal of each slave energy storage converter maintains timing consistency with the synchronization signal of the master energy storage converter; When it is determined that the synchronization signal of the slave energy storage converter does not keep timing consistency with the synchronization signal of the master energy storage converter, an alarm prompt message is sent to the host computer.

9. The system according to claim 8, characterized in that The step of determining whether the synchronization signal of each slave energy storage converter is in time sequence consistent with the synchronization signal of the master energy storage converter comprises: Determine the synchronization signal of the slave energy storage converter as the slave synchronization signal, and determine the synchronization signal of the host energy storage converter as the host synchronization signal; Determine the host low level duration of the host synchronization signal and the host synchronization signal period; Determine the slave low level duration of the slave synchronization signal of each of the slave energy storage converters and the slave synchronization signal cycle; Determine whether the duration of the slave low level of each of the slave synchronization signals is the same as the duration of the master low level, and determine whether the slave synchronization signal period of each of the slave synchronization signals is the same as the master synchronization signal period; When the duration of the low level of the slave is different from that of the host, or the period of the slave synchronization signal is different from that of the host synchronization signal, it is determined that the synchronization signal of the slave energy storage converter does not maintain timing consistency with the synchronization signal of the host energy storage converter.

10. The system according to claim 8, characterized in that When it is determined that the synchronization signal of the slave energy storage converter does not keep the timing consistent with the synchronization signal of the host energy storage converter, sending an alarm prompt information to the host computer includes: Determine the slave energy storage converter that does not keep timing consistent with the synchronization signal of the master energy storage converter; Sending the alarm prompt information including the identification information of the slave energy storage converter to the host computer.

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