Communication-free coordinated frequency support method and system for shachanggong new energy base

Abstract

The application discloses a communication-free cooperative frequency support method and system for Shaguo Huang new energy base, and relates to the field of power systems.The method comprises the following steps: obtaining the current voltage value and reference voltage value of a DC bus and the current steady-state operating power of multiple types of resources; calculating the equivalent frequency deviation of the sending-end system according to the current voltage value and the reference voltage value of the DC bus, wherein the equivalent frequency deviation is used to represent frequency disturbance; calculating the available support capacity of the multiple types of resources at the current operating point according to the current steady-state operating power of the multiple types of resources; and according to the equivalent frequency deviation and the available support capacity, obtaining the target control instruction for the multiple types of resources and issuing the target control instruction to a controller, so that the controller responds to the target control instruction to adjust the current steady-state operating power of the multiple types of resources. The method can quickly perceive disturbance at the sending end without relying on long-distance receiving-end frequency communication, thereby reducing the influence of communication delay, packet loss and link abnormality on frequency support.

Description

Technical Field

[0001] This application relates to the field of power systems, and in particular to a communication-free frequency support method and system for the Shagohuang New Energy Base. Background Technology

[0002] In large-scale new energy bases in desert areas, wind turbines, photovoltaic units, energy storage systems, and electrolyzers are typically connected to the sending-end converter station via an AC collection system, and then transmitted to the receiving-end load center via a voltage source type high-voltage direct current transmission system (VSC-HVDC). As the scale of the base expands and the transmission distance increases, the frequency support capability of the sending-end system is affected by multiple factors, including the decreasing proportion of synchronous power sources, frequent switching of operating scenarios, and enhanced source-load fluctuations.

[0003] In existing projects, how the sending-end system can quickly sense frequency disturbances at the receiving end has become a key issue in order to respond rapidly to such disturbances. Common approaches mainly fall into two categories: one is to transmit the receiving-end frequency measurement value to the sending end via fiber optics, GOOSE, or other long-distance communication channels, with the sending-end energy storage or renewable energy units then providing tracking support; the other is to rely solely on the sending-end's local frequency measurement signal for droop control or virtual inertia control. Both approaches have significant limitations. The former relies heavily on long-distance, highly reliable, low-latency communication links, which can easily introduce additional delays and errors when the transmission distance is long or the link status is unstable. The latter, because VSC-HVDC decouples the AC frequencies of the sending and receiving ends, often fails to reflect the receiving-end system disturbances in a timely and accurate manner, resulting in a significant lag in support actions.

[0004] Based on this, it is necessary to propose a frequency support method that does not rely on long-distance frequency communication and can realize disturbance sensing by utilizing the energy transient characteristics of the VSC-HVDC DC link itself. Summary of the Invention

[0005] The purpose of this application is to provide a communication-free frequency support method and system for the Shagohuang New Energy Base, so as to realize a frequency support method that does not rely on long-distance frequency communication and can realize disturbance sensing by utilizing the energy transient characteristics of the VSC-HVDC DC link itself.

[0006] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a method for non-communication-coordinated frequency support in the Shagohuang New Energy Base, including: Obtain the current voltage and reference voltage of the DC bus, as well as the current steady-state operating power of various resource types; The equivalent frequency deviation of the sending-end system is calculated based on the current voltage value and reference voltage value of the DC bus. The equivalent frequency deviation is used to characterize frequency disturbances. Calculate the available support capacity of the various types of resources at the current operating point based on their current steady-state operating power. Based on the equivalent frequency deviation and the available support capability, target control commands are issued to the multi-type resources and sent to the controller, which then responds to the target control commands to adjust the current steady-state operating power of the multi-type resources.

[0007] Secondly, this application provides a method for non-communication-coordinated frequency support in the Shagohuang new energy base, including: The data acquisition module is used to acquire the current voltage value and reference voltage value of the DC bus, as well as the current steady-state operating power of various types of resources; The deviation calculation module is used to calculate the equivalent frequency deviation of the sending-end system based on the current voltage value and the reference voltage value of the DC bus. The equivalent frequency deviation is used to characterize frequency disturbance. The support calculation module is used to calculate the available support capacity of the various types of resources at the current operating point based on the current steady-state operating power of the various types of resources; The instruction generation module is used to generate target control instructions for the multiple types of resources based on the equivalent frequency deviation and the available support capability, and to send the target control instructions to the controller, which responds to the target control instructions to adjust the current steady-state operating power of the multiple types of resources.

[0008] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method for non-communication cooperative frequency support at the Shagohuang New Energy Base.

[0009] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method for non-communication cooperative frequency support at the Shagohuang New Energy Base.

[0010] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method for supporting non-communication cooperative frequencies at the Shagohuang New Energy Base.

[0011] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a communication-free frequency support method and system for the Shagohuang New Energy Base. It utilizes the characteristics of power imbalance at the receiving end, which is primarily manifested as transient DC link energy and DC bus voltage deviation. Based on the current voltage value and reference voltage value of the DC bus, the equivalent frequency deviation of the sending-end system is calculated, and subsequent support calculations are performed based on this equivalent frequency deviation. This method can quickly detect disturbances at the sending end without relying on long-distance receiving-end frequency communication, thereby reducing the impact of communication delay, packet loss, and link anomalies on frequency support. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart illustrating the non-communication cooperative frequency support method for the Shagohuang New Energy Base in one embodiment of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] The communication-free frequency support method for the Shagohuang New Energy Base in this application embodiment is executed by a computer device, which is typically a local computer device within the Shagohuang New Energy Base.

[0017] In one embodiment, the non-communication coordination frequency support method for the Shagohuang New Energy Base provided in this application specifically includes: Step S110: Obtain the current voltage value and reference voltage value of the DC bus, as well as the current steady-state operating power of various resource types.

[0018] Specifically, this method periodically acquires some basic data information to support subsequent calculations.

[0019] In this embodiment, the various resource types include energy storage systems, electrolyzers, wind turbines, and photovoltaic units. Correspondingly, the current steady-state operating power of these resources includes the steady-state operating power of the energy storage system, electrolyzer, wind turbine, and photovoltaic unit at the current time t. In addition, other data used for subsequent supporting calculations can also be obtained in this step; please refer to the subsequent explanation of supporting calculations for details.

[0020] Step S120: Calculate the equivalent frequency deviation of the sending-end system based on the current voltage value of the DC bus and the reference voltage value. The equivalent frequency deviation is used to characterize frequency disturbances.

[0021] Specifically, the calculation of the equivalent frequency deviation of the sending-end system based on the current voltage value and reference voltage value of the DC bus includes: calculating the difference between the current voltage value and the reference voltage value of the DC bus to obtain the voltage deviation of the DC bus; and mapping the voltage deviation of the DC bus to the equivalent frequency deviation of the sending-end system through a pre-calibrated voltage-frequency droop mapping coefficient.

[0022] The design principle of this step is as follows: Because the sending-end and receiving-end systems are far apart, their frequencies are decoupled via a VSC-HVDC link, preventing the controllable unit of the sending-end system from directly measuring the receiving-end system frequency. Therefore, a communication-free frequency mapping mechanism based on DC link capacitor energy buffering is designed. Specifically, when the receiving-end system frequency deviates, the VSC-HVDC autonomously adjusts its active power exchange at the converter station closer to the receiving-end system to support its frequency. Specifically, the VSC-HVDC achieves the receiving-end system's frequency response by employing a droop control strategy with overcurrent limiting, as follows: ; ; in, This indicates an active power adjustment command output from the VSC-HVDC receiving-end converter station; Indicates the capacity of the VSC-HVDC transmission channel; Indicates the frequency change at the sending end; Indicates the frequency-power droop factor; Refers to the overcurrent coefficient of VSC-HVDC; This refers to the initial value of the output active power of the VSC-HVDC receiving-end converter station; This refers to the active power command value output by the VSC-HVDC receiving-end converter station.

[0023] This strategy allows the VSC-HVDC to provide power support to suppress frequency fluctuations in the receiving-end system during periods of frequency volatility. At this time, a power mismatch exists between the active power output of the VSC-HVDC receiving-end converter station and the input power of the sending-end converter station. This instantaneous power mismatch is absorbed by the DC link capacitor, which releases or absorbs energy, thus causing a DC voltage deviation. The dynamic changes in the DC link voltage are shown below: ; In the formula, Indicates the DC capacitor capacitance of VSC-HVDC; Indicates the DC bus voltage of VSC-HVDC; This indicates the input active power of the VSC-HVDC sending-end converter station.

[0024] This voltage deviation propagates along the DC link and is observable at the transmitting end system. At this point, the current voltage value of the DC bus is filtered and compared with a reference value to obtain the DC bus voltage deviation: ; in, This indicates the voltage deviation of the DC bus at the current time t; This represents the voltage value of the DC bus at the current time t; This indicates the reference voltage value of the DC bus.

[0025] Based on the drooping strategy, construct the equivalent frequency deviation of the sending-end system: ; ; in, This indicates the equivalent frequency deviation of the sending system at the current time t. This represents the voltage-frequency droop mapping coefficient. This represents the reference frequency of the sending system at the current time t. This is the rated frequency of the sending-end system.

[0026] In this embodiment, preferably, when the equivalent frequency deviation is calculated, it is determined whether the equivalent frequency deviation is less than the preset dead zone. If it is, the execution of subsequent steps is paused; otherwise, the execution of subsequent steps continues, so as to avoid frequent actions caused by slight fluctuations.

[0027] Step S130: Calculate the available support capacity of the various types of resources at the current operating point based on their current steady-state operating power.

[0028] Specifically, the formula for calculating the available support capacity of the energy storage system at the current time t is: ; ; ; in, and These represent the available upward and downward support capabilities of the energy storage system at the current time t. For the power capacity of the energy storage system, Let t be the steady-state discharge power of the energy storage system at the current time t. The steady-state charging power of the energy storage system at the current time t. This represents the remaining energy of the energy storage system at the current time t. For the discharge efficiency of the energy storage system, To improve the charging efficiency of energy storage systems. For the energy capacity of the energy storage system, and These represent the minimum and maximum states of charge of the energy storage system, respectively. This represents the steady-state operating power of the energy storage system at the current time t.

[0029] The formula for calculating the available support capacity of the electrolytic cell at the current time t is: ; ; in, and These represent the available upward and downward adjustment capabilities of the electrolytic cell at the current time t, respectively. This refers to the operating status index of the electrolytic cell at the current time t. A value of 0 corresponds to the shutdown state, and a value of 1 corresponds to the startup state. This represents the minimum stable load factor for the electrolytic cell. This represents the ramp-up coefficient of the electrolytic cell. This represents the steady-state operating power of the electrolyzer at the current time t. This refers to the installed capacity of the electrolytic cell.

[0030] The formula for calculating the available support capacity of wind turbines and photovoltaic units at the current time t is: ; ; in, and These represent the available upward and downward adjustment capabilities of the photovoltaic unit at the current time t. and These represent the available upward and downward support capabilities of the wind turbine at the current time t. and These represent the maximum output power of the photovoltaic unit and the wind turbine at the current time t, respectively. and These represent the steady-state operating power of the photovoltaic unit and the wind turbine at the current time t, respectively.

[0031] The above-mentioned available support capacity calculation results form a resource capacity vector: , ; Resource capability vectors are used as input for subsequent steps.

[0032] Step S140: Based on the equivalent frequency deviation and available support capacity (specifically the resource capacity vector mentioned above), target control commands are issued for multiple types of resources and sent to the controller. The controller responds to the target control commands to adjust the current steady-state operating power of the multiple types of resources.

[0033] Specifically, in the target control commands for various resource types based on equivalent frequency deviation and available support capacity, the target control commands for electrolyzers, wind turbines, and photovoltaic units are generated using a droop control strategy, while the target control commands for energy storage systems are generated using a virtual management control strategy based on a droop control strategy. Furthermore, the target control commands for various resource types include: the setpoint changes in the steady-state operating power of energy storage systems, electrolyzers, wind turbines, and photovoltaic units.

[0034] Specifically, for resources such as photovoltaics, wind turbines, and electrolytic cells, a droop control strategy is set up. Taking upward support as an example, the specific calculation is as follows: ; ; ; in, This refers to the installed capacity of photovoltaic units. Refers to the installed capacity of wind turbine units. , , These refer to the power adjustment commands for photovoltaic units, wind turbine components, and electrolytic cells, respectively. , , These refer to the frequency-active power droop coefficient of photovoltaic units, wind turbine components, and electrolytic cells, respectively.

[0035] For energy storage systems, a droop control strategy and a virtual management control strategy are set up, and the specific calculations are as follows: ; in, This refers to the power adjustment command of the energy storage system. Refers to the virtual inertia time constant. This refers to the frequency-active power droop factor of an energy storage system.

[0036] After receiving power adjustment commands (changes in the setpoint of steady-state operating power) from the energy storage system, electrolyzer, wind turbine, and photovoltaic unit, the commands are sent to the corresponding device controllers.

[0037] Specifically: Update the setpoint of the steady-state operating power of the energy storage system to... Update the setpoints for the steady-state operating power of the wind turbine and photovoltaic units to... , Update the setpoint of the steady-state operating power of the electrolytic cell to... .

[0038] After execution of control, the system continuously collects DC bus voltage and status data of each device. When the preset dead zone is exceeded and the set duration is reached, the controller gradually releases additional support commands and can restore the energy storage system to the target state of charge through energy storage recovery logic, thereby avoiding secondary frequency fluctuations.

[0039] In summary, the present invention has the following technical effects: 1. Reduce reliance on long-distance frequency communication channels and improve the timeliness of disturbance detection. This invention utilizes the characteristics of receiving-end power imbalance, which is initially manifested as transient DC link energy and DC bus voltage deviation. Based on the current and reference DC bus voltage values, the equivalent frequency deviation of the sending-end system is calculated, and subsequent support calculations are performed based on this equivalent frequency deviation. Disturbances can be quickly detected at the sending end without relying on long-distance receiving-end frequency communication, thereby reducing the impact of communication delays, packet loss, and link anomalies on frequency support.

[0040] 2. Improve the response speed and sustainability of frequency support. Energy storage systems prioritize rapid support to suppress the rate of frequency change, while electrolyzers provide slow but continuous load reduction support while meeting process constraints. Wind and solar power participate as needed when available margins exist. Therefore, it is possible to balance rapid compensation in the initial stage and continuous compensation in the subsequent stage.

[0041] This application also provides a non-communication-coordinated frequency support system for the Shagohuang New Energy Base, including: The data acquisition module is used to acquire the current voltage value and reference voltage value of the DC bus, as well as the current steady-state operating power of various types of resources; The deviation calculation module is used to calculate the equivalent frequency deviation of the sending-end system based on the current voltage value and reference voltage value of the DC bus. The equivalent frequency deviation is used to characterize frequency disturbances. The support calculation module is used to calculate the available support capacity of various types of resources at the current operating point based on their current steady-state operating power. The instruction generation module is used to generate target control instructions for multiple types of resources based on equivalent frequency deviation and available support capabilities, and to send the target control instructions to the controller. The controller responds to the target control instructions to adjust the current steady-state operating power of the multiple types of resources.

[0042] It should be noted that this non-communication cooperative frequency support system is the physical carrier of the aforementioned non-communication cooperative frequency support method, and its various modules are used to implement the steps in the non-communication cooperative frequency support method. Therefore, for detailed functional descriptions of each module, please refer to the detailed description of the non-communication cooperative frequency support method in this application. It will not be repeated here. It is understood that this non-communication cooperative frequency support system has the same technical effect as the aforementioned non-communication cooperative frequency support method, and solves the same technical problem.

[0043] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0044] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0045] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0046] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0047] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0048] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for non-communication-coordinated frequency support in a desert new energy base, characterized in that, include: Obtain the current voltage and reference voltage of the DC bus, as well as the current steady-state operating power of various resource types; The equivalent frequency deviation of the sending-end system is calculated based on the current voltage value and reference voltage value of the DC bus. The equivalent frequency deviation is used to characterize frequency disturbances. Calculate the available support capacity of the various types of resources at the current operating point based on their current steady-state operating power. Based on the equivalent frequency deviation and the available support capability, target control commands are issued to the multi-type resources and sent to the controller, which then responds to the target control commands to adjust the current steady-state operating power of the multi-type resources.

2. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 1, characterized in that, The various types of resources include energy storage systems, electrolyzers, wind turbines, and photovoltaic units.

3. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 1, characterized in that, The equivalent frequency deviation of the sending-end system is calculated based on the current voltage value and reference voltage value of the DC bus, specifically including: Calculate the difference between the current voltage value and the reference voltage value of the DC bus to obtain the voltage deviation of the DC bus; The voltage deviation of the DC bus is mapped to the equivalent frequency deviation of the sending-end system using a pre-calibrated voltage-frequency droop mapping coefficient.

4. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 2, characterized in that, The formula for calculating the available support capacity of the energy storage system at the current time t is: ； ； ； in, and These represent the available upward and downward adjustment capabilities of the energy storage system at the current time t, respectively. For the power capacity of the energy storage system, Let t be the steady-state discharge power of the energy storage system at the current time t. The steady-state charging power of the energy storage system at the current time t. This represents the remaining energy of the energy storage system at the current time t. For the discharge efficiency of the energy storage system To improve the charging efficiency of energy storage systems. For the energy capacity of the energy storage system, and These represent the minimum and maximum states of charge of the energy storage system, respectively. This represents the steady-state operating power of the energy storage system at the current time t.

5. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 2, characterized in that, The formula for calculating the available support capacity of the electrolytic cell at the current time t is: ； ； in, and These represent the available upward and downward adjustment capabilities of the electrolytic cell at the current time t, respectively. This refers to the operating status index of the electrolytic cell at the current time t. A value of 0 corresponds to the shutdown state, and a value of 1 corresponds to the startup state. This represents the minimum stable load factor for the electrolytic cell. This represents the ramp-up coefficient of the electrolytic cell. This represents the steady-state operating power of the electrolyzer at the current time t. This refers to the installed capacity of the electrolytic cell.

6. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 2, characterized in that, The formula for calculating the available support capacity of the wind turbine and the photovoltaic unit at the current time t is: ； ； in, and These represent the available upward and downward adjustment capabilities of the photovoltaic unit at the current time t. and These represent the available upward and downward support capabilities of the wind turbine at the current time t. and These represent the maximum output power of the photovoltaic unit and the wind turbine at the current time t, respectively. and These represent the steady-state operating power of the photovoltaic unit and the wind turbine at the current time t, respectively.

7. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 2, characterized in that, In the target control instructions for the various types of resources based on the equivalent frequency deviation and the available support capacity, the target control instructions for the electrolyzer, the wind turbine, and the photovoltaic unit are generated using a droop control strategy, and the target control instructions for the energy storage system are generated using the droop control strategy virtual management control strategy.

8. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 2, characterized in that, The target control instructions for the aforementioned multiple types of resources include: The change in the set value of the steady-state operating power of the energy storage system, the electrolytic cell, the wind turbine, and the photovoltaic unit.

9. The method for non-communication coordination frequency support in the Shagohuang new energy base according to claim 1, characterized in that, When calculating the equivalent frequency deviation, it is determined whether the equivalent frequency deviation is less than the preset dead zone. If so, the execution of subsequent steps is paused.

10. A non-communication-coordinated frequency support system for a new energy base in the desert, characterized in that, include: The data acquisition module is used to acquire the current voltage value and reference voltage value of the DC bus, as well as the current steady-state operating power of various types of resources; The deviation calculation module is used to calculate the equivalent frequency deviation of the sending-end system based on the current voltage value and the reference voltage value of the DC bus. The equivalent frequency deviation is used to characterize frequency disturbance. The support calculation module is used to calculate the available support capacity of the various types of resources at the current operating point based on the current steady-state operating power of the various types of resources; The instruction generation module is used to generate target control instructions for the multiple types of resources based on the equivalent frequency deviation and the available support capability, and to send the target control instructions to the controller, which responds to the target control instructions to adjust the current steady-state operating power of the multiple types of resources.

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