A power scheduling method and related apparatus

Abstract

The application discloses a power scheduling method and related device, and relates to the technical field of power electronics. The method comprises the following steps: acquiring a microgrid voltage under the condition that a microgrid connected with an energy storage system satisfies a weak grid condition; scheduling power of the energy storage system according to the microgrid voltage and an operating state of the energy storage system; under the condition that the operating state of the energy storage system is a discharging state, scheduling power of the energy storage system to make the microgrid voltage not higher than a preset overvoltage threshold voltage; and under the condition that the operating state of the energy storage system is a charging state, scheduling power of the energy storage system to make the microgrid voltage not lower than a preset undervoltage threshold voltage. The method avoids microgrid fluctuation caused by energy storage system operation, thereby avoiding frequent shutdown of the energy storage system caused by microgrid fluctuation, reducing the time of energy storage system failure shutdown, protecting the safe operation of equipment in the microgrid, and prolonging the service life of the equipment in the microgrid.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power dispatching method and related apparatus. Background Technology

[0002] A microgrid is a small-scale power generation and distribution system consisting of distributed power sources, energy storage systems, energy conversion devices, loads, monitoring and protection devices, etc.

[0003] Because microgrids have weak grid characteristics, when energy storage systems are running, they can cause voltage fluctuations in the microgrid, which can lead to frequent overvoltage or undervoltage faults and shutdowns. Summary of the Invention

[0004] In view of the above problems, this application provides a power dispatching method and related apparatus to avoid frequent shutdowns of energy storage systems, reduce the downtime of energy storage system failures, and protect the safe operation of equipment in the microgrid. The specific solution is as follows:

[0005] The first aspect of this application provides a power scheduling method, including:

[0006] Under the condition that the microgrid connected to the energy storage system meets the weak grid conditions, the microgrid voltage is obtained;

[0007] When the energy storage system is in a discharge state, power scheduling is performed on the energy storage system to ensure that the microgrid voltage does not exceed a preset overvoltage threshold voltage.

[0008] When the energy storage system is in a charging state, power scheduling is performed on the energy storage system to ensure that the microgrid voltage is not lower than a preset undervoltage threshold voltage.

[0009] In one possible implementation, the power scheduling method further includes:

[0010] When the energy storage system is restarted after an overvoltage fault shutdown, the change in the microgrid voltage is obtained.

[0011] When the microgrid voltage increases with the discharge power of the energy storage system, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0012] In one possible implementation, the power scheduling method further includes:

[0013] When the energy storage system is in a discharge state, the rate of increase of the discharge power of the energy storage system and the rate of increase of the microgrid voltage are obtained.

[0014] If the rate of increase of the discharge power of the energy storage system reaches a first threshold and the rate of increase of the microgrid voltage reaches a second threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0015] In one possible implementation, when the energy storage system is in a discharge state, the power scheduling of the energy storage system includes:

[0016] When the microgrid voltage is less than the preset overvoltage threshold voltage, the discharge power of the energy storage system is increased to raise the microgrid voltage to the preset overvoltage threshold voltage.

[0017] In one possible implementation, when the energy storage system is in a discharge state, the power scheduling of the energy storage system includes:

[0018] When the microgrid voltage rises to a preset overvoltage threshold voltage, the energy storage system is controlled to maintain the current discharge power for discharge.

[0019] In one possible implementation, the power scheduling method further includes:

[0020] When the energy storage system restarts after an undervoltage fault shutdown, the change in the microgrid voltage is obtained.

[0021] When the microgrid voltage decreases as the charging power of the energy storage system increases, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0022] In one possible implementation, the power scheduling method further includes:

[0023] When the energy storage system is in a charging state, the rate of increase of the charging power of the energy storage system and the rate of decrease of the microgrid voltage are obtained.

[0024] If the rate of increase of the charging power of the energy storage system reaches the third threshold and the rate of decrease of the microgrid voltage reaches the fourth threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0025] In one possible implementation, when the energy storage system is in a charging state, the power scheduling of the energy storage system includes:

[0026] If the microgrid voltage is greater than the preset undervoltage threshold voltage, the charging power of the energy storage system is increased to reduce the microgrid voltage to the preset undervoltage threshold voltage.

[0027] In one possible implementation, when the energy storage system is in a charging state, the power scheduling of the energy storage system includes:

[0028] When the microgrid voltage drops to a preset undervoltage threshold voltage, the energy storage system is controlled to maintain the current charging power for charging.

[0029] A second aspect of this application provides a power dispatching device, comprising:

[0030] The voltage acquisition unit is used to acquire the microgrid voltage when the microgrid connected to the energy storage system meets the weak grid conditions.

[0031] The power dispatching unit performs power dispatching on the energy storage system when the energy storage system is in a discharging state, so that the microgrid voltage does not exceed a preset overvoltage threshold voltage; and performs power dispatching on the energy storage system when the energy storage system is in a charging state, so that the microgrid voltage does not fall below a preset undervoltage threshold voltage.

[0032] In one possible implementation, the power dispatching unit is specifically used to increase the discharge power of the energy storage system when the microgrid voltage is less than a preset overvoltage threshold voltage, so that the microgrid voltage rises to the preset overvoltage threshold voltage.

[0033] In one possible implementation, the power scheduling unit is specifically used to increase the charging power of the energy storage system when the microgrid voltage is greater than a preset undervoltage threshold voltage, so that the microgrid voltage drops to the preset undervoltage threshold voltage.

[0034] A third aspect of this application provides an energy storage system, including: a battery module and an energy storage converter;

[0035] The battery module is connected to the DC side of the energy storage converter;

[0036] The AC side of the energy storage converter is connected to the microgrid;

[0037] The energy storage converter is used to execute the power scheduling method of the first aspect or any implementation thereof.

[0038] A fourth aspect of this application provides a computer program product including computer-readable instructions that, when executed on an energy storage system, cause the energy storage system to implement the power scheduling method of the first aspect or any implementation thereof.

[0039] The fifth aspect of this application provides a computer storage medium carrying one or more computer programs, which, when executed by an energy storage system, enable the energy storage system to implement the power scheduling method described in the first aspect or any implementation thereof.

[0040] By employing the above technical solutions, the power dispatching method and related apparatus provided in this application, when the microgrid connected to the energy storage system meets the weak grid conditions, obtain the microgrid voltage, and perform power dispatching on the energy storage system based on the microgrid voltage and the operating status of the energy storage system. When the energy storage system is in a discharging state, power dispatching ensures that the microgrid voltage does not exceed a preset overvoltage threshold voltage. When the energy storage system is in a charging state, power dispatching ensures that the microgrid voltage does not fall below a preset undervoltage threshold voltage. This avoids microgrid fluctuations caused by the operation of the energy storage system, thereby preventing frequent shutdowns of the energy storage system due to microgrid fluctuations, reducing the downtime of energy storage system failures, protecting the safe operation of equipment in the microgrid, and improving the service life of equipment in the microgrid. Attached Figure Description

[0041] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0042] Figure 1 A flowchart illustrating a power scheduling method provided in an embodiment of this application;

[0043] Figure 2 A flowchart illustrating a method for determining weak network conditions provided in an embodiment of this application;

[0044] Figure 3 A flowchart illustrating a method for determining weak network conditions provided in an embodiment of this application;

[0045] Figure 4 A flowchart illustrating a power scheduling method provided in an embodiment of this application;

[0046] Figure 5 This is a schematic diagram of a power scheduling device provided in an embodiment of this application. Detailed Implementation

[0047] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0048] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0049] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0050] Due to the inherent weaknesses of microgrids, there is a significant probability of voltage fluctuations during the operation of energy storage systems. Large voltage fluctuations can cause the energy storage system to report overvoltage or undervoltage faults and shut down. Furthermore, even after the energy storage system recovers from a fault due to these voltage fluctuations, it may still report overvoltage or undervoltage faults and shut down frequently.

[0051] To address the aforementioned technical problems, this application provides a power scheduling method. The power scheduling method of this application embodiment will be described in detail below with reference to the accompanying drawings.

[0052] Reference Figure 1 , Figure 1 This is a flowchart illustrating a power scheduling method provided in an embodiment of this application, as shown below. Figure 1 As shown in the embodiment of this application, a power scheduling method is provided and applied to an energy storage system. The energy storage system includes an energy storage converter, and the energy storage converter performs power scheduling. The power scheduling method may include steps 101 to 104, which are described in detail below.

[0053] 101: Obtain the microgrid voltage when the microgrid connected to the energy storage system meets the weak grid conditions;

[0054] During the operation of the energy storage system, it is necessary to determine in real time whether the microgrid connected to the energy storage system meets the weak network conditions.

[0055] Weak grid conditions characterize the conditions under which power dispatching of the energy storage system is required. If power dispatching of the energy storage system is not performed when the weak grid conditions are met, it will lead to overvoltage failure and shutdown of the energy storage system due to excessively high microgrid voltage, or undervoltage failure and shutdown of the energy storage system due to excessively low microgrid voltage.

[0056] The microgrid voltage is the AC port voltage of the energy storage converter.

[0057] The energy storage converter obtains the microgrid voltage by periodically sampling the microgrid voltage.

[0058] Power scheduling of the energy storage system is performed based on the microgrid voltage and the operating status of the energy storage system.

[0059] The operating states of an energy storage system include: discharge state and charging state.

[0060] 102: When the energy storage system is in the discharge state, power dispatch is performed on the energy storage system to ensure that the microgrid voltage does not exceed the preset overvoltage threshold voltage.

[0061] When the energy storage system is in the discharge state, the microgrid voltage increases as the discharge power of the energy storage system increases. By performing power scheduling on the energy storage system, the microgrid voltage is kept below the preset overvoltage threshold voltage to avoid the energy storage system reporting an overvoltage fault and shutting down due to excessively high microgrid voltage.

[0062] 103: When the energy storage system is in the charging state, power scheduling is performed on the energy storage system to ensure that the microgrid voltage is not lower than the preset undervoltage threshold voltage.

[0063] When the energy storage system is in charging mode, the microgrid voltage decreases as the charging power of the energy storage system increases. By performing power scheduling on the energy storage system, the microgrid voltage is kept above the preset undervoltage threshold voltage, thus preventing the energy storage system from reporting an undervoltage fault and shutting down due to excessively low microgrid voltage.

[0064] As can be seen, the power dispatching method disclosed in this embodiment obtains the microgrid voltage when the microgrid connected to the energy storage system meets the weak grid conditions. Based on the microgrid voltage and the operating status of the energy storage system, power dispatching is performed on the energy storage system. When the energy storage system is in a discharging state, power dispatching is performed to ensure that the microgrid voltage does not exceed a preset overvoltage threshold voltage. When the energy storage system is in a charging state, power dispatching is performed to ensure that the microgrid voltage does not fall below a preset undervoltage threshold voltage. This avoids microgrid fluctuations caused by the operation of the energy storage system, thereby avoiding frequent shutdowns of the energy storage system due to microgrid fluctuations, reducing the downtime of energy storage system failures, preventing user losses, protecting the safe operation of equipment in the microgrid, and improving the service life of equipment in the microgrid.

[0065] This embodiment does not require adding hardware circuits to the energy storage system or microgrid, requires minimal modification to the original microgrid system, and is easy to implement.

[0066] The weak network conditions described in the above embodiments can be implemented in various ways.

[0067] In one possible implementation, please refer to Figure 2 The flowchart shown illustrates the weak grid condition judgment method, which couples the charging and discharging power of the energy storage system with the microgrid voltage to determine whether the microgrid connected to the energy storage system meets the weak grid conditions.

[0068] When the energy storage system is in the discharge state, the rising rate of the discharge power of the energy storage system and the rising rate of the microgrid voltage are obtained. When the rising rate of the discharge power of the energy storage system reaches the first threshold and the rising rate of the microgrid voltage reaches the second threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0069] In this method of implementing weak grid conditions, when the rapid increase in the discharge power of the energy storage system affects the rapid increase in the microgrid voltage, it is determined that the microgrid connected to the energy storage system meets the weak grid conditions. The first threshold and the second threshold are set according to the actual application scenario.

[0070] Because the rapid increase in the discharge power of the energy storage system in this implementation leads to rapid changes in the microgrid voltage, the response time for the energy storage system is short. Therefore, once the energy storage system detects that the microgrid voltage has risen to a preset overvoltage threshold, it controls the energy storage system to maintain its current discharge power to stabilize the microgrid voltage at the preset overvoltage threshold, preventing the microgrid voltage from continuing to rise and causing the energy storage system to report an overvoltage fault and shut down. In one possible implementation, if the microgrid voltage is lower than the preset overvoltage threshold, the discharge power of the energy storage system is increased to raise the microgrid voltage to the preset overvoltage threshold. This maximizes the discharge power of the energy storage system while ensuring that the microgrid voltage does not become excessively high, thus meeting the discharge requirements. The preset overvoltage threshold is set according to the actual application scenario, and it is lower than the overvoltage protection voltage of the energy storage system, ensuring stable and safe operation of all devices in the microgrid under the preset overvoltage threshold.

[0071] When the energy storage system is in the charging state, the rising rate of change of the charging power of the energy storage system and the falling rate of change of the microgrid voltage are obtained. When the rising rate of change of the charging power of the energy storage system reaches the third threshold and the falling rate of change of the microgrid voltage reaches the fourth threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

[0072] In this method of implementing weak grid conditions, when the charging power of the energy storage system rises rapidly and causes the microgrid voltage to drop rapidly, it is determined that the microgrid connected to the energy storage system meets the weak grid conditions. The third and fourth thresholds are set according to the actual application scenario.

[0073] It should be noted that the first threshold and the third threshold can be the same or different, and the second threshold and the fourth threshold can be the same or different.

[0074] Because the rapid increase in charging power of the energy storage system in this weak grid condition implementation causes a rapid drop in microgrid voltage, leaving a short response time for the energy storage system, once the energy storage system detects that the microgrid voltage has dropped to a preset undervoltage threshold, it controls the energy storage system to maintain the current charging power to stabilize the microgrid voltage at the preset undervoltage threshold, preventing the energy storage system from reporting an undervoltage fault and shutting down due to further voltage drops. In one possible implementation, if the microgrid voltage is higher than the preset undervoltage threshold, the charging power of the energy storage system is increased to bring the microgrid voltage down to the preset undervoltage threshold. This ensures that the microgrid voltage does not drop too low while maximizing the charging power of the energy storage system to meet charging requirements. The preset undervoltage threshold is set according to the actual application scenario, and it must be higher than the undervoltage protection voltage of the energy storage system, ensuring stable and safe operation of all devices in the microgrid under the preset undervoltage threshold.

[0075] In another implementation, please refer to Figure 3 The flowchart shown illustrates the method for judging weak network conditions. The weak network conditions are judged after the energy storage system reports a fault and shuts down, and then restarts.

[0076] If the energy storage system is operating normally, and its operating state is discharge mode, and the microgrid voltage becomes too high after the energy storage system operates at full power, the energy storage system will report an overvoltage fault and shut down. After the fault shutdown, the microgrid voltage will momentarily return to normal. After the energy storage system recovers and restarts automatically, it is determined whether the microgrid connected to the energy storage system meets the weak grid conditions. Specifically, the changes in the energy storage system's discharge power and the microgrid voltage are obtained. If the microgrid voltage increases as the energy storage system's discharge power increases, then the microgrid connected to the energy storage system is determined to meet the weak grid conditions.

[0077] Similarly, if the energy storage system is in charging mode, and the microgrid voltage is too low after the energy storage system operates at full power, the energy storage system will report an undervoltage fault and shut down. After the fault shutdown, the microgrid voltage will momentarily return to normal. After the energy storage system recovers and restarts automatically, it is determined whether the microgrid connected to the energy storage system meets the weak grid conditions. Specifically, the changes in the energy storage system's charging power and the microgrid voltage are obtained. If the microgrid voltage decreases as the energy storage system's charging power increases, then it is determined that the microgrid connected to the energy storage system meets the weak grid conditions.

[0078] It should be noted that the energy storage system can automatically restart after an overvoltage fault or an undervoltage fault, based on the control logic of the fault recovery self-starting mechanism. This embodiment does not make specific limitations on this.

[0079] In this implementation method under weak grid conditions, when the energy storage system shuts down due to an overvoltage fault or an undervoltage fault and then restarts, it is easy to determine whether the microgrid connected to the energy storage system meets the weak grid conditions based on the changes in the energy storage system's operating power and the microgrid voltage. Since the energy storage system's operating power changes from full capacity to a gradual increase, sufficient response time is provided, allowing for more refined power scheduling of the energy storage system.

[0080] like Figure 4 The flowchart of the power scheduling method shown illustrates that during the power scheduling process of the energy storage system, the voltage judgment logic is entered. The operating power of the energy storage system slowly increases to determine whether the energy storage system is in a discharging or charging state, and corresponding power scheduling is performed for different operating states.

[0081] If the energy storage system is in discharge mode, the power dispatch command issued by the energy storage converter to the energy storage system is mutually constrained by the microgrid voltage and the preset overvoltage threshold voltage. If the microgrid voltage is lower than the preset overvoltage threshold voltage, the discharge power of the energy storage system is increased to raise the microgrid voltage to the preset overvoltage threshold voltage. This ensures that the microgrid voltage is not too high while maximizing the discharge power of the energy storage system to meet the discharge demand. For example, if the discharge power of the energy storage system increases by 20kW, the microgrid voltage will increase by 10V. If the difference between the preset overvoltage threshold voltage and the current microgrid voltage is 30V, then the discharge power can only be increased by 60kW to raise the microgrid voltage by 30V. During normal stable discharge, the discharge power of the energy storage system is relatively stable with small fluctuations. At this time, the microgrid voltage is affected by changes in the external load or changes within the microgrid itself. When changes in the load or the microgrid itself cause a drop in the microgrid voltage, the discharge power of the energy storage system needs to be dispatched. For example, if the microgrid voltage drops by 10V, the energy storage converter can send a power dispatch command to the energy storage system to increase the discharge output by 20kW. If the microgrid voltage rises to a preset overvoltage threshold voltage, the energy storage system is controlled to maintain its current discharge power, meaning the discharge power of the energy storage system remains stable. The preset overvoltage threshold voltage is set according to the actual application scenario, and it is lower than the overvoltage protection voltage of the energy storage system. Furthermore, all devices in the microgrid operate stably and safely under the preset overvoltage threshold voltage.

[0082] If the energy storage system is in charging mode, the power dispatch command issued by the energy storage converter to the energy storage system is mutually constrained by the microgrid voltage and the preset undervoltage threshold voltage. If the microgrid voltage is greater than the preset undervoltage threshold voltage, the charging power of the energy storage system is increased to reduce the microgrid voltage to the preset undervoltage threshold voltage. This ensures that the microgrid voltage does not drop too low while maximizing the charging power of the energy storage system to meet charging demand. For example, if the charging power of the energy storage system increases by 20kW, the microgrid voltage drops by 10V. If the difference between the current microgrid voltage and the preset undervoltage threshold voltage is 30V, then the charging power can only be increased by 60kW to reduce the microgrid voltage by 30V. During normal and stable charging, the charging power of the energy storage system is relatively stable with minimal fluctuations. At this time, the microgrid voltage is affected by changes in the external load or the microgrid itself. When changes in the load or the microgrid itself cause the microgrid voltage to rise, the charging power of the energy storage system needs to be dispatched. For example, if the microgrid voltage rises by 10V, the energy storage converter can send a power dispatch command to the energy storage system to increase the charging output by 20kW. If the microgrid voltage drops to a preset undervoltage threshold voltage, the energy storage system is controlled to maintain the current charging power, meaning the charging power of the energy storage system remains stable. The preset undervoltage threshold voltage is set according to the actual application scenario, and it is greater than the undervoltage protection voltage of the energy storage system. Furthermore, all devices in the microgrid operate stably and safely under the preset undervoltage threshold voltage.

[0083] The above describes a power scheduling method provided by an embodiment of this application. The following describes an apparatus for performing the above power scheduling method.

[0084] This application provides a power scheduling device, please refer to [link to relevant documentation]. Figure 5 The schematic diagram shown illustrates the structure of a power dispatching device, which includes:

[0085] The voltage acquisition unit 501 is used to acquire the microgrid voltage when the microgrid connected to the energy storage system meets the weak grid conditions.

[0086] The power scheduling unit 502 is used to perform power scheduling on the energy storage system when the energy storage system is in a discharging state, so that the microgrid voltage is not higher than a preset overvoltage threshold voltage; and to perform power scheduling on the energy storage system when the energy storage system is in a charging state, so that the microgrid voltage is not lower than a preset undervoltage threshold voltage.

[0087] In one possible implementation, the power scheduling device further includes:

[0088] The first condition determination unit is used to obtain the change in the microgrid voltage when the energy storage system restarts after an overvoltage fault shutdown; and to determine that the microgrid connected to the energy storage system meets the weak grid condition when the microgrid voltage increases with the discharge power of the energy storage system.

[0089] In one possible implementation, the power scheduling device further includes:

[0090] The second condition determination unit is used to obtain the rate of increase of the discharge power of the energy storage system and the rate of increase of the microgrid voltage when the operating state of the energy storage system is in the discharge state; and to determine that the microgrid connected to the energy storage system meets the weak grid condition when the rate of increase of the discharge power of the energy storage system reaches a first threshold and the rate of increase of the microgrid voltage reaches a second threshold.

[0091] In one possible implementation, the power dispatching unit is specifically used to increase the discharge power of the energy storage system when the microgrid voltage is less than a preset overvoltage threshold voltage, so that the microgrid voltage rises to the preset overvoltage threshold voltage.

[0092] In one possible implementation, the power scheduling unit is specifically used to control the energy storage system to maintain the current discharge power when the microgrid voltage rises to a preset overvoltage threshold voltage.

[0093] In one possible implementation, the power scheduling device further includes:

[0094] The third condition determination unit is used to obtain the change in the microgrid voltage when the energy storage system restarts after an undervoltage fault shutdown; and to determine that the microgrid connected to the energy storage system meets the weak grid condition when the microgrid voltage decreases as the charging power of the energy storage system increases.

[0095] In one possible implementation, the power scheduling device further includes:

[0096] The fourth condition determination unit is used to obtain the rate of increase of the charging power of the energy storage system and the rate of decrease of the microgrid voltage when the operating state of the energy storage system is charging; and to determine that the microgrid connected to the energy storage system meets the weak grid condition when the rate of increase of the charging power of the energy storage system reaches a third threshold and the rate of decrease of the microgrid voltage reaches a fourth threshold.

[0097] In one possible implementation, the power scheduling unit is specifically used to increase the charging power of the energy storage system when the microgrid voltage is greater than a preset undervoltage threshold voltage, so that the microgrid voltage drops to the preset undervoltage threshold voltage.

[0098] In one possible implementation, the power scheduling unit is specifically used to control the energy storage system to maintain the current charging power for charging when the microgrid voltage drops to a preset undervoltage threshold voltage.

[0099] This embodiment discloses a power dispatching device that, when the microgrid connected to the energy storage system meets the weak grid conditions, obtains the microgrid voltage and performs power dispatching on the energy storage system based on the microgrid voltage and the operating status of the energy storage system. When the energy storage system is in a discharging state, power dispatching ensures that the microgrid voltage does not exceed a preset overvoltage threshold voltage. When the energy storage system is in a charging state, power dispatching ensures that the microgrid voltage does not fall below a preset undervoltage threshold voltage. This avoids microgrid fluctuations caused by the operation of the energy storage system, thereby preventing frequent shutdowns of the energy storage system due to microgrid fluctuations, reducing the downtime of energy storage system failures, preventing user losses, protecting the safe operation of equipment in the microgrid, and improving the service life of equipment in the microgrid.

[0100] This embodiment does not require adding hardware circuits to the energy storage system or microgrid, requires minimal modification to the original microgrid system, and is easy to implement.

[0101] This application embodiment also provides an energy storage system, including: a battery module and an energy storage converter;

[0102] The battery module is connected to the DC side of the energy storage converter;

[0103] The AC side of the energy storage converter is connected to the microgrid;

[0104] The energy storage converter is used to execute any of the power scheduling methods provided in the embodiments of this application.

[0105] This application also provides a computer program product including computer-readable instructions, which, when executed on an energy storage system, cause the energy storage system to implement any of the power scheduling methods provided in this application.

[0106] This application also provides a computer-readable storage medium carrying one or more computer programs. When the one or more computer programs are executed by the energy storage system, the energy storage system can implement any of the power scheduling methods provided in this application.

[0107] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0109] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0110] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

Claims

1. A power scheduling method, characterized in that, include: Under the condition that the microgrid connected to the energy storage system meets the weak grid conditions, the microgrid voltage is obtained; When the energy storage system is in a discharge state, power scheduling is performed on the energy storage system to ensure that the microgrid voltage does not exceed a preset overvoltage threshold voltage. When the energy storage system is in a charging state, power scheduling is performed on the energy storage system to ensure that the microgrid voltage is not lower than a preset undervoltage threshold voltage.

2. The power scheduling method according to claim 1, characterized in that, The power scheduling method further includes: When the energy storage system is restarted after an overvoltage fault shutdown, the change in the microgrid voltage is obtained. When the microgrid voltage increases with the discharge power of the energy storage system, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

3. The power scheduling method according to claim 1, characterized in that, The power scheduling method further includes: When the energy storage system is in a discharge state, the rate of increase of the discharge power of the energy storage system and the rate of increase of the microgrid voltage are obtained. If the rate of increase of the discharge power of the energy storage system reaches a first threshold and the rate of increase of the microgrid voltage reaches a second threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

4. The power scheduling method according to any one of claims 1-3, characterized in that, When the energy storage system is in a discharge state, the power scheduling of the energy storage system includes: When the microgrid voltage is less than the preset overvoltage threshold voltage, the discharge power of the energy storage system is increased to raise the microgrid voltage to the preset overvoltage threshold voltage.

5. The power scheduling method according to claim 4, characterized in that, When the energy storage system is in a discharge state, the power scheduling of the energy storage system includes: When the microgrid voltage rises to a preset overvoltage threshold voltage, the energy storage system is controlled to maintain the current discharge power for discharge.

6. The power scheduling method according to claim 1, characterized in that, The power scheduling method further includes: When the energy storage system restarts after an undervoltage fault shutdown, the change in the microgrid voltage is obtained. When the microgrid voltage decreases as the charging power of the energy storage system increases, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

7. The power scheduling method according to claim 1, characterized in that, The power scheduling method further includes: When the energy storage system is in a charging state, the rate of increase of the charging power of the energy storage system and the rate of decrease of the microgrid voltage are obtained. If the rate of increase of the charging power of the energy storage system reaches the third threshold and the rate of decrease of the microgrid voltage reaches the fourth threshold, it is determined that the microgrid connected to the energy storage system meets the weak grid condition.

8. The power scheduling method according to any one of claims 1, 6, and 7, characterized in that, When the energy storage system is in a charging state, the power scheduling of the energy storage system includes: If the microgrid voltage is greater than the preset undervoltage threshold voltage, the charging power of the energy storage system is increased to reduce the microgrid voltage to the preset undervoltage threshold voltage.

9. The power scheduling method according to claim 8, characterized in that, When the energy storage system is in a charging state, the power scheduling of the energy storage system includes: When the microgrid voltage drops to a preset undervoltage threshold voltage, the energy storage system is controlled to maintain the current charging power for charging.

10. A power dispatching device, characterized in that, include: The voltage acquisition unit is used to acquire the microgrid voltage when the microgrid connected to the energy storage system meets the weak grid conditions. The power dispatching unit performs power dispatching on the energy storage system when the energy storage system is in a discharging state, so that the microgrid voltage does not exceed a preset overvoltage threshold voltage; and performs power dispatching on the energy storage system when the energy storage system is in a charging state, so that the microgrid voltage does not fall below a preset undervoltage threshold voltage.

11. The power dispatching device according to claim 10, characterized in that, The power dispatching unit is specifically used to increase the discharge power of the energy storage system when the microgrid voltage is less than a preset overvoltage threshold voltage, so that the microgrid voltage rises to the preset overvoltage threshold voltage.

12. The power dispatching device according to claim 10, characterized in that, The power scheduling unit is specifically used to increase the charging power of the energy storage system when the microgrid voltage is greater than the preset undervoltage threshold voltage, so that the microgrid voltage drops to the preset undervoltage threshold voltage.

13. An energy storage system, characterized in that, include: Battery modules and energy storage converters; The battery module is connected to the DC side of the energy storage converter; The AC side of the energy storage converter is connected to the microgrid; The energy storage converter is used to execute the power dispatching method according to any one of claims 1 to 9.

14. A computer program product, characterized in that, It includes computer-readable instructions that, when executed on the energy storage system, cause the energy storage system to implement the power scheduling method as described in any one of claims 1 to 9.

15. A computer storage medium, characterized in that, The storage medium carries one or more computer programs, which, when executed by the energy storage system, enable the energy storage system to implement the power scheduling method as described in any one of claims 1 to 9.

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