Distributed renewable energy frequency support system based on inertia and frequency regulation requirements of power grid

Abstract

The present invention relates to the technical field of power systems. Disclosed is a distributed renewable energy frequency support system based on the inertia and frequency regulation requirements of a power grid. The system involves: analyzing the load state of an alternating-current power distribution network, so as to obtain a power distribution network state reference characteristic value; analyzing the inertia of the alternating-current power distribution network, so as to obtain an inertia characteristic value; analyzing the fluctuation state of the alternating-current power distribution network, and in view of the inertia characteristic value, obtaining a power distribution network state characteristic value; in view of the power distribution network state reference characteristic value and the power distribution network state characteristic value, performing comprehensive analysis to obtain a frequency support characteristic value; on the basis of the frequency support characteristic value, performing comparison to obtain a primary frequency regulation control scheme for the alternating-current power distribution network; and analyzing the application state of the primary frequency regulation control scheme for the alternating-current power distribution network, and performing comparison to obtain a secondary frequency regulation control scheme for the alternating-current power distribution network. The distributed renewable energy frequency support system based on the inertia and frequency regulation requirements of a power grid as provided in the present invention can better cope with the problems of frequency fluctuations and insufficient inertia of a power grid, thereby ensuring the safe operation of a power system.

Description

Distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements Technical Field

[0001] This invention relates to the field of power system technology, specifically to a distributed new energy frequency support system based on grid inertia and frequency regulation requirements. Background Technology

[0002] Globally, the installed capacity of distributed renewable energy sources such as wind and solar power is rapidly increasing. This energy transition reduces dependence on fossil fuels and helps address climate change, but it also brings new technological challenges. Unlike traditional centralized power generation, distributed energy sources (such as rooftop photovoltaics and decentralized wind farms) are connected to the grid in more dispersed locations, are smaller in scale, and their power generation is intermittent and fluctuating. The inertia of traditional power grids is mainly provided by synchronous generators, which store kinetic energy through rotating mass and can provide instantaneous support when the grid frequency fluctuates. With the high proportion of renewable energy generation connected, especially photovoltaics and wind power, most of them are connected to the grid through power electronic devices, which lack physical inertia, resulting in a decrease in the overall inertia of the grid. The reduction in grid inertia makes the grid frequency more prone to rapid changes when load or power generation fluctuates, increasing the difficulty of maintaining frequency stability. Summary of the Invention

[0003] In view of the above-mentioned problems, the present invention is proposed.

[0004] Therefore, the technical problem solved by this invention is that traditional power grid inertia analysis is often based on static system models, which cannot effectively capture dynamic inertia changes, resulting in insufficient accuracy of frequency response prediction. In addition, traditional distributed renewable energy frequency support methods are often isolated, which may lead to inaccurate frequency response prediction of the power grid when frequency fluctuations occur, and the scheduling and control strategies cannot be adjusted in time, ultimately affecting the frequency stability of the power grid. If the power grid cannot respond effectively in a fast time, it may lead to further frequency deviation, or even trigger a chain reaction, increasing the risk of system instability. Isolated support methods may not be able to effectively deal with regional frequency fluctuation problems, and these regional fluctuations may expand and affect the stability of the entire power grid.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a distributed new energy frequency support system based on grid inertia and frequency regulation requirements, comprising:

[0006] The module includes a state reference feature value comparison module, an inertia feature value acquisition module, a state feature value acquisition module, a frequency support feature value analysis module, a primary frequency modulation control scheme comparison module, and a secondary frequency modulation control scheme comparison module.

[0007] The state reference feature value comparison module analyzes the load status of the AC distribution network and compares the load status to obtain the distribution network state reference feature value.

[0008] The inertia characteristic value acquisition module analyzes the inertia of the AC distribution network to obtain inertia characteristic values;

[0009] The state characteristic value acquisition module analyzes the fluctuation state of the AC distribution network and obtains the state characteristic value of the distribution network by combining the inertia characteristic value.

[0010] The frequency support feature value analysis module combines the distribution network state reference feature value and the distribution network state feature value to obtain the frequency support feature value through comprehensive analysis;

[0011] The primary frequency regulation control scheme comparison module compares and obtains the primary frequency regulation control scheme of the AC distribution network based on the frequency support feature value.

[0012] The secondary frequency regulation control scheme comparison module analyzes the application status of the primary frequency regulation control scheme of the AC distribution network and compares them to obtain the secondary frequency regulation control scheme of the AC distribution network.

[0013] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the step of analyzing the AC distribution network load status and comparing to obtain the distribution network status reference feature value includes analyzing the AC distribution network load status and obtaining the AC distribution network load dataset.

[0014] The active power, apparent power, and operating frequency of the distribution network are stored as designated tags. The designated tags are compared with the distribution network state reference feature values ​​corresponding to each designated tag stored in the database to obtain the distribution network state reference feature value corresponding to the designated tag.

[0015] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the AC distribution network load dataset includes the distribution network active power, the distribution network apparent power, and the distribution network operating frequency.

[0016] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the step of analyzing the inertia of the AC distribution network to obtain inertia characteristic values ​​includes analyzing the inertia of the AC distribution network and obtaining an AC distribution network inertia dataset. The AC distribution network inertia dataset specifically includes the rated capacity of the generator set, the inertia constant of the generator set, the generator speed, and the grid frequency change rate.

[0017] Obtain the compensation factor for the AC distribution network inertia dataset;

[0018] Obtain the generator's reference speed and the grid frequency's reference rate of change;

[0019] Based on the acquired AC distribution network inertia dataset, the compensation factor of the AC distribution network inertia dataset, and the rate of change of the generator reference speed and the grid frequency reference speed, the inertia characteristic value is obtained through comprehensive analysis. The inertia characteristic value is used as the basis for the comprehensive analysis to obtain the frequency support characteristic value.

[0020] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the compensation factors of the AC distribution network inertia dataset include a set compensation factor for the rated capacity of the generator set, a set compensation factor for the inertia constant of the generator set, a set compensation factor for the generator speed, and a set compensation factor for the grid frequency change rate.

[0021] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the step of analyzing the fluctuation state of the AC distribution network and obtaining the distribution network state characteristic value by combining the inertia characteristic value includes analyzing the fluctuation state of the AC distribution network and obtaining an AC distribution network fluctuation state dataset. The AC distribution network fluctuation state dataset specifically includes the number of frequency fluctuations per unit time, the frequency of abnormal load fluctuations, and the total harmonic distortion rate.

[0022] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the distribution network state characteristic value is obtained by comprehensively analyzing the acquired AC distribution network fluctuation state dataset and inertia characteristic value, and the distribution network state characteristic value is used as the analytical basis for obtaining the frequency support characteristic value through comprehensive analysis.

[0023] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the frequency support characteristic value obtained by comprehensive analysis includes combining the distribution network state reference characteristic value and the distribution network state characteristic value to obtain the frequency support characteristic value. The frequency support characteristic value serves as the basis for analysis to compare and obtain the primary frequency regulation control scheme of the AC distribution network.

[0024] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the step of obtaining the AC distribution network primary frequency regulation control scheme based on the frequency support feature value includes comparing the frequency support feature value with the AC distribution network primary frequency regulation control schemes corresponding to each frequency support feature value stored in the database to obtain the AC distribution network primary frequency regulation control scheme corresponding to the frequency support feature value.

[0025] As a preferred embodiment of the distributed new energy frequency support system based on grid inertia and frequency regulation requirements described in this invention, the step of analyzing the application status of the primary frequency regulation control scheme of the AC distribution network and comparing it to obtain the secondary frequency regulation control scheme of the AC distribution network includes analyzing the application status of the primary frequency regulation control scheme of the AC distribution network and obtaining a scheme application status dataset. The scheme application status dataset specifically includes equipment response time, frequency recovery time, and the absolute value of the difference between equipment response power and reference power.

[0026] Based on the acquired application status dataset, a comprehensive analysis is conducted to obtain the application status evaluation value of the scheme. The application status evaluation value of the scheme serves as the basis for comparison and analysis of the secondary frequency regulation control scheme of the AC distribution network.

[0027] The application status evaluation value of the scheme is compared with the AC distribution network secondary frequency regulation control scheme corresponding to the application status evaluation value of each scheme stored in the database to obtain the AC distribution network secondary frequency regulation control scheme corresponding to the application status evaluation value of the scheme.

[0028] The beneficial effects of this invention are as follows: The distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements provided by this invention accurately identifies and analyzes the current operating status of the distribution network, which helps to grasp the changing trends and abnormal situations of the grid load in real time. It provides reliable basic data for subsequent inertia analysis and frequency support. By comparing the distribution network status reference characteristic value with the distribution network status characteristic value, a comprehensive analysis is conducted to obtain the frequency support characteristic value, providing key data support for the selection and optimization of frequency regulation control schemes. This can significantly improve the frequency stability of the grid. In the context of high-proportion renewable energy access, this multi-level, multi-module analysis and control system can better cope with the problems of grid frequency fluctuations and insufficient inertia, ensuring the safe operation of the power system.

[0029] By combining the distribution network status reference characteristic value and the distribution network status characteristic value, a comprehensive analysis is conducted to obtain the frequency support characteristic value. This allows for accurate identification of the real-time operating status of the power grid and a more accurate assessment of the grid's frequency response capability under current load conditions. Analyzing the frequency support characteristic value enables real-time adjustment of the frequency support strategy, ensuring appropriate frequency support is provided under different power grid conditions. Dynamic adjustment helps to respond promptly to power grid frequency fluctuations, avoiding excessive or insufficient support and maintaining frequency stability. Comprehensive analysis of the frequency support characteristic value can automate frequency regulation decisions. The system can automatically analyze and judge based on real-time data, automatically select the optimal frequency support scheme, reduce manual intervention, and improve the intelligence level of frequency regulation control.

[0030] By analyzing the application status of the primary frequency regulation control scheme in the AC distribution network and comparing it with the secondary frequency regulation control scheme, the application status of the primary frequency regulation control scheme can be accurately identified. This can help determine whether the primary frequency regulation is sufficient or needs further adjustment. Based on the actual effect of the primary frequency regulation, a targeted secondary frequency regulation control scheme can be designed to ensure that the frequency regulation strategy is more accurate and can effectively compensate for the deficiencies of the primary frequency regulation, thereby better restoring and maintaining the stability of the power grid frequency. This helps to optimize the utilization of frequency regulation resources and improve the stability and reliability of the power grid. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 is an overall structural diagram of a distributed new energy frequency support system based on grid inertia and frequency regulation requirements provided by an embodiment of the present invention.

[0033] Figure 2 is a flowchart of the steps to obtain the secondary frequency regulation control scheme of AC distribution network by comparison in a distributed new energy frequency support system based on grid inertia and frequency regulation requirements according to an embodiment of the present invention.

[0034] Figure 3 is a three-dimensional image showing the change of the inertia characteristic value of a distributed new energy frequency support system based on grid inertia and frequency regulation requirements as a result of the compensation factor for the grid frequency change rate and the set grid frequency change rate, according to an embodiment of the present invention.

[0035] Figure 4 is an image showing the change in inertia characteristic value of a distributed new energy frequency support system based on grid inertia and frequency regulation requirements as a function of the grid frequency, according to an embodiment of the present invention. Detailed Implementation

[0036] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0037] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0038] Example 1

[0039] Referring to Figures 1-4, an embodiment of the present invention provides a distributed new energy frequency support system based on grid inertia and frequency regulation requirements, comprising:

[0040] The system includes a state reference feature value comparison module 100, an inertia feature value acquisition module 200, a state feature value acquisition module 300, a frequency support feature value analysis module 400, a primary frequency modulation control scheme comparison module 500, and a secondary frequency modulation control scheme comparison module 600.

[0041] The state reference feature value comparison module 100 analyzes the load status of the AC distribution network and obtains the state reference feature value of the distribution network.

[0042] The specific analysis process includes: analyzing the load status of the AC distribution network to obtain an AC distribution network load dataset, which specifically includes the active power, apparent power, and operating frequency of the distribution network; storing the active power, apparent power, and operating frequency of the distribution network as specified tags; comparing the specified tags with the corresponding distribution network status reference feature values ​​stored in the database to obtain the distribution network status reference feature value corresponding to the specified tag.

[0043] It should be noted that the active power mentioned above refers to the power actually consumed or converted into useful work in the power system, obtained from power meters. Apparent power is the product of voltage and current, encompassing the combined effect of active and reactive power, and is also obtained from power meters. The operating frequency is the oscillation frequency of AC power in the power system, typically 50 Hz or 60 Hz, obtained from smart meters. The power factor (PF) is the ratio of active power to apparent power, representing the proportion of work actually done in the power system. Frequency fluctuations affect the operating status of motors and other inductive loads, thereby affecting reactive power demand and the power factor. If the frequency drops, it usually means an increase in load or insufficient power generation, which may lead to an increase in active power demand in the grid. If power generation cannot be adjusted in time, the frequency will drop further, eventually leading to system instability.

[0044] It should be noted that the above-mentioned real-time analysis of load status can promptly detect abnormal states in the distribution network. If the ratio of active power to apparent power (power factor) is abnormal, it may indicate equipment failure or excessive load. Necessary measures can then be taken to improve the stability and security of the system. Detailed analysis of load status can provide basic data support for load forecasting, proactive scheduling, and demand response. It is of great significance for reducing peak load, balancing load, and optimizing resource allocation. Analyzing load status can better meet users' power supply needs, optimize distribution network power supply schemes, and improve user satisfaction.

[0045] The inertia characteristic value acquisition module 200 analyzes the inertia of the AC distribution network and obtains the inertia characteristic value.

[0046] The specific analysis process is as follows: The inertia of the AC distribution network is analyzed to obtain an AC distribution network inertia dataset. This dataset specifically includes the rated capacity of the generator sets, the generator set inertia constant, the generator speed, and the grid frequency change rate. Compensation factors for the AC distribution network inertia dataset are obtained, including compensation factors for the set rated capacity of the generator sets, the set inertia constant of the generator sets, the set compensation factors for the set generator speed, and the set compensation factors for the set grid frequency change rate. The reference speed of the generators and the reference change rate of the grid frequency are obtained (both are obtained from the database and used as reference values). Based on the obtained AC distribution network inertia dataset, the compensation factors, and the reference speed and frequency change rate of the generators, inertia characteristic values ​​are obtained through comprehensive analysis. These inertia characteristic values ​​serve as the basis for the comprehensive analysis to obtain the frequency support characteristic values.

[0047] It should be noted that the rated capacity of the generator set mentioned above refers to the maximum output power of the generator set under design conditions, obtained through the generator set control system or power dispatching system. The generator set inertia constant is a parameter that measures the energy storage capacity of the generator set, reflecting the rotating mass of the generator set. It represents the ratio of the kinetic energy stored by the generator to its rated capacity at the rated speed, obtained through the generator's design parameters or advanced monitoring system. The generator speed is the rotational speed of the generator rotor, which is directly related to the grid frequency and obtained through the speed sensor and generator set control system. The grid frequency change rate is the rate of change of the grid frequency over time, reflecting the stability of the grid, obtained through the frequency meter and grid monitoring system.

[0048] A larger inertia constant indicates a larger rotating mass of the generator set, which provides more inertial support during frequency changes and mitigates rapid frequency fluctuations. Changes in generator speed directly lead to changes in grid frequency. A decrease in speed usually means a decrease in the rate of change of grid frequency, while an increase in speed means an increase in the rate of change of grid frequency. The higher the inertia constant of the generator set, the lower the rate of change of grid frequency, which is beneficial to the frequency stability of the grid. The more large-capacity, high-inertia generator sets in the grid, the greater the overall inertia of the grid, the smaller the frequency fluctuations, and the better the stability.

[0049] It should be noted that the above analysis of data such as generator rated capacity, inertia constant, generator speed, and grid frequency change rate can accurately calculate the grid's inertia characteristic value, reflecting the grid's response capability in the face of frequency fluctuations. This allows frequency support strategies to more accurately match the actual needs of the grid. Through the comprehensive analysis of the obtained inertia characteristic value, the grid can quickly determine the frequency support requirements under different load changes or fault conditions. The timely response capability ensures that the system can quickly adjust when the frequency deviates from the rated value, avoiding excessive frequency fluctuations and improving grid stability. The inertia characteristic value can reveal the inertia distribution of the grid area, providing a scientific basis for grid planning and development.

[0050] Furthermore, the specific analysis process for the inertia eigenvalues ​​is as follows:

[0051] In the formula, α is the characteristic value of inertia, ed is the rated capacity of the generator set, gl is the inertia constant of the generator set, zs is the generator speed, bp is the rate of change of the grid frequency, μ1 is the set compensation factor of ed, μ2 is the set compensation factor of gl, μ3 is the set compensation factor of zs, μ4 is the set compensation factor of bp, czs is the reference speed of the generator, and cbp is the reference rate of change of the grid frequency.

[0052] It should be explained that, as shown in Figure 3 (a three-dimensional image of the inertia characteristic value changing with the grid frequency change rate and the compensation factor of the set grid frequency change rate), and Figure 4 (an image of the inertia characteristic value changing with the grid frequency change rate), the larger the grid frequency change rate, the smaller the inertia characteristic value. As the grid frequency change rate increases, the influence of the grid frequency change rate on the inertia characteristic value decreases. The aforementioned inertia characteristic value is calculated using the generator set's rated capacity, generator set inertia constant, generator speed, and grid frequency change rate. Normalization is applied to ed, gl, zs, and bp. The inertia characteristic value integrates the generator set's physical parameters (such as rated capacity and inertia constant) and dynamic operating parameters (such as speed and frequency change rate), accurately characterizing the grid frequency change rate. The inertia response capability under frequency fluctuation conditions reflects the power grid's buffering capacity to cope with frequency changes, providing an accurate basis for frequency regulation strategies. By calculating the inertia characteristic value in real time, the stability of the power grid can be dynamically assessed. Especially when load changes or sudden events occur, the larger the inertia characteristic value, the smaller the frequency fluctuation of the power grid, and the more stable the system. The calculated inertia characteristic value can identify the inertia level of the power grid under different conditions, thereby formulating more targeted frequency regulation measures. High-inertia power grids may require less frequency regulation resources, while low-inertia power grids require faster and stronger frequency support. This helps the dispatch center understand the response characteristics of generator units, thereby more effectively dispatching power generation resources, improving the response efficiency of frequency support, and reducing the amplitude and recovery time of frequency fluctuations.

[0053] It should be explained that the compensation factors of ed, gl, zs, and bp set above are obtained from the database. A mapping set of historically measured generator rated capacity, generator inertia constant, generator speed, grid frequency change rate and compensation factors of ed, gl, zs, and bp is established based on historical data to obtain the compensation factors of ed, gl, zs, and bp corresponding to the current ed, gl, zs, and bp.

[0054] It should be noted that ε1, ε2, ε3, τ1, τ2, and τ3 in the following text are all obtained through the mapping set of historical data and compensation factors established in the database, that is, the corresponding compensation factors are obtained based on the current data.

[0055] The state characteristic value acquisition module 300 analyzes the fluctuation state of the AC distribution network and obtains the state characteristic value of the distribution network by combining the inertia characteristic value.

[0056] The specific analysis process is as follows: Analyze the fluctuation state of the AC distribution network to obtain an AC distribution network fluctuation state dataset. The AC distribution network fluctuation state dataset specifically includes the number of frequency fluctuations per unit time, the frequency of abnormal load fluctuations, and the total harmonic distortion rate. Based on the obtained AC distribution network fluctuation state dataset, combined with the inertia characteristic value, a comprehensive analysis is conducted to obtain the distribution network state characteristic value. The distribution network state characteristic value serves as the basis for the comprehensive analysis to obtain the frequency support characteristic value.

[0057] It should be noted that the frequency fluctuation count per unit time refers to the number of times the power grid frequency deviates from the rated value within a certain period of time, obtained through frequency meters and power grid monitoring systems. Abnormal load fluctuation frequency refers to the frequency of abnormal and large fluctuations in power grid load, obtained through load monitoring equipment and power management systems. Total harmonic distortion (THD) refers to the degree of distortion of voltage or current waveforms relative to an ideal sine wave, obtained through harmonic analyzers, smart meters, and power quality monitoring systems. Abnormal load fluctuation frequency directly affects the frequency fluctuation count per unit time because load fluctuations directly lead to power imbalance, causing frequency fluctuations. Abnormal load fluctuation frequency may indirectly increase the total harmonic distortion because severe fluctuations in nonlinear loads increase the generation of harmonics. An increase in total harmonic distortion will affect the frequency regulation efficiency of the power grid, which may lead to an increase in the frequency fluctuation count. In turn, frequency fluctuations may affect the harmonic level of the power grid, forming a feedback effect.

[0058] It should be noted that the above-mentioned distribution network status characteristics integrate multi-dimensional data such as frequency fluctuations, load fluctuations, and harmonic distortion. Through comprehensive analysis of these data, a more complete understanding of the distribution network's operating status can be achieved. Multi-dimensional analysis helps to formulate more precise frequency support strategies, ensuring that frequency support can adapt to the actual power grid conditions. Different fluctuation states may require different support strategies. High-frequency fluctuations may require rapid response support, while abnormal load fluctuations may require focused support for local areas. Comprehensive analysis of distribution network status characteristics can lead to the formulation of more targeted support strategies and improve support effectiveness. Analysis of the number of frequency fluctuations, the frequency of abnormal load fluctuations, and the total harmonic distortion rate can reveal the dynamic characteristics of the power grid. Combined with inertia characteristics, it is possible to better assess the frequency support requirements of the power grid under different states, thereby taking timely measures to mitigate frequency fluctuations and maintain power grid stability.

[0059] Furthermore, the specific analysis process for the distribution network state characteristic values ​​is as follows:

[0060] In the formula, γ is the characteristic value of the distribution network state, α is the characteristic value of inertia, bd is the number of frequency fluctuations per unit time, yc is the frequency of abnormal load fluctuations, jb is the total harmonic distortion rate, ε1 is the set compensation factor of bd, ε2 is the set compensation factor of yc, and ε3 is the set compensation factor of jb.

[0061] It should be explained that the aforementioned distribution network state characteristic values ​​are calculated by combining the number of frequency fluctuations per unit time, the frequency of abnormal load fluctuations, the total harmonic distortion rate, and the inertia characteristic value. Normalization is applied to bd, yc, and jb. By combining the number of frequency fluctuations, the frequency of abnormal load fluctuations, the total harmonic distortion rate, and the inertia characteristic value, the distribution network state characteristic values ​​can comprehensively reflect various key dimensions of power grid operation. This multi-dimensional comprehensive analysis can more accurately assess the current state of the power grid and identify potential stability problems. The state characteristic values ​​calculated using these parameters can accurately characterize the operational risks of the power grid. Especially when load fluctuations are severe or harmonic distortion is large, the introduction of the inertia characteristic value can more comprehensively assess the power grid's response capability and identify potential risks in a timely manner. The state characteristic values ​​combine multiple key factors such as power grid frequency fluctuations, load fluctuations, and harmonic distortion, and can reflect the dynamic state of the power grid in real time, thus making frequency support strategies more targeted. This dynamic adjustment can more effectively smooth out frequency fluctuations and maintain power grid stability.

[0062] The frequency support characteristic value analysis module 400 combines the distribution network status reference characteristic value and the distribution network status characteristic value to obtain the frequency support characteristic value through comprehensive analysis.

[0063] The specific analysis process is as follows: combining the distribution network state reference characteristic value and the distribution network state characteristic value, a comprehensive analysis is conducted to obtain the frequency support characteristic value, which serves as the basis for comparison to obtain the analysis of the AC distribution network primary frequency regulation control scheme.

[0064] It should be noted that the above-mentioned combination of distribution network status reference characteristic values ​​and frequency support characteristic values ​​provides an accurate assessment of the current state of the power grid, enabling the rational allocation of frequency regulation resources, avoiding excessive or insufficient frequency regulation, and reducing resource waste. Through precise frequency support characteristic value analysis, appropriate frequency regulation measures can be taken in a timely manner to avoid excessive frequency fluctuations, thereby effectively improving the frequency stability of the power grid. The frequency support characteristic value can accurately reflect the actual operating status of the current power grid. The frequency support characteristic value can better characterize the frequency stability requirements of the power grid, making the primary frequency regulation control scheme more targeted and avoiding the deviations that may be caused by formulating frequency regulation schemes based on static or insufficient data. The frequency support characteristic value comprehensively considers the dynamic characteristics of the power grid and can accurately identify the frequency regulation requirements of the power grid under different load and operating conditions, thereby formulating more precise frequency regulation strategies and ensuring frequency stability.

[0065] It should be noted that the above frequencies support eigenvalues, and the specific analysis process is as follows:

[0066] In the formula, δ is the frequency support characteristic value, γ is the distribution network state characteristic value, β is the distribution network state reference characteristic value, and e is the natural constant.

[0067] It should be noted that the aforementioned frequency support characteristic value is calculated by combining the distribution network state reference characteristic value and the distribution network state characteristic value. By combining the distribution network state reference characteristic value (preset or historical ideal state value) with the real-time distribution network state characteristic value, the actual operating status of the current power grid can be accurately reflected. Through this dynamic matching, the frequency support characteristic value can be calculated more accurately, thereby formulating a frequency support strategy that better meets the current needs of the power grid. By combining the reference characteristic value and the real-time state characteristic value, the frequency support characteristic value can accurately identify the support strength and range required by the current power grid, thereby optimizing the allocation of frequency regulation resources, avoiding resource waste, preventing insufficient frequency regulation resources, and ensuring the efficient implementation of frequency regulation measures. The calculated frequency support characteristic value can serve as an important basis for automated frequency regulation decision-making, reducing manual intervention and improving the automation level of the frequency regulation process. This is especially important for large-scale complex power grids, as it can improve the response speed to frequency fluctuations.

[0068] The primary frequency regulation control scheme comparison module 500 compares and obtains the primary frequency regulation control scheme of AC distribution network based on frequency support characteristic values.

[0069] The specific analysis process is as follows: the frequency support characteristic value is compared with the AC distribution network primary frequency regulation control scheme corresponding to each frequency support characteristic value stored in the database to obtain the AC distribution network primary frequency regulation control scheme corresponding to the frequency support characteristic value.

[0070] In one specific embodiment, by comparing the current frequency support characteristic value with historical data in the database, the frequency regulation control scheme that is closest to the current power grid state can be quickly found. This ensures that the selected frequency regulation scheme has been verified under similar conditions and has good performance, thereby improving the accuracy and effectiveness of frequency regulation control. The database comparison can determine the most suitable frequency regulation scheme in a short time, avoiding the lag and uncertainty of manual scheme selection. It can respond to power grid frequency fluctuations more quickly, improve the frequency regulation response speed, and select a verified frequency regulation scheme to reduce the risk of frequency regulation failure or poor performance. This helps to maintain frequency stability under different power grid conditions and reduce the risk of frequency fluctuations or system instability caused by inappropriate frequency regulation schemes.

[0071] The secondary frequency regulation control scheme comparison module 600 analyzes the application status of the primary frequency regulation control scheme of the AC distribution network and obtains the secondary frequency regulation control scheme of the AC distribution network through comparison.

[0072] As shown in Figure 2, the specific analysis process is as follows: The application status of the primary frequency regulation control scheme of the AC distribution network is analyzed to obtain a scheme application status dataset. This dataset specifically includes equipment response time, frequency recovery time, and the absolute value of the difference between the equipment response power and the reference power. Based on the obtained application status dataset, a comprehensive analysis is performed to obtain the scheme application status evaluation value. This evaluation value serves as the basis for comparing and obtaining the secondary frequency regulation control scheme of the AC distribution network. The scheme application status evaluation value is then compared with the AC distribution network secondary frequency regulation control schemes corresponding to the application status evaluation values ​​of each scheme stored in the database to obtain the AC distribution network secondary frequency regulation control scheme corresponding to the application status evaluation value of that scheme.

[0073] It should be noted that the above-mentioned equipment response time refers to the time from receiving the frequency modulation command to the actual adjustment of the equipment's output power. It is usually obtained through timestamp recording or event logger in the control system. The frequency recovery time refers to the time required from frequency deviation to recovery to near the rated value. It is usually obtained through frequency meter or SCADA system. The absolute value of the difference between the equipment response power and the reference power refers to the absolute value of the difference between the actual output power of the equipment and the expected power, reflecting the accuracy of the equipment response. It is usually obtained through power meter or control system data recording. The equipment response time determines the speed at which frequency modulation starts and affects the start time of frequency recovery. A shorter response time usually helps to shorten the frequency recovery time. The absolute value of the difference between the equipment response power and the reference power reflects the accuracy of the frequency modulation response. A smaller difference helps to shorten the frequency recovery time because the frequency can stabilize near the rated value more quickly.

[0074] It should be noted that the above analysis of the application status of the primary frequency regulation control scheme can accurately assess the effectiveness of the current frequency regulation measures. The comprehensive analysis of the scheme application status evaluation value can accurately reflect the actual performance of primary frequency regulation, thereby selecting the most suitable secondary frequency regulation control scheme during the comparison process, ensuring that the frequency regulation strategy is more accurate. After comparing with the database, the system can quickly identify the secondary frequency regulation scheme most suitable for the current power grid state, ensuring that the frequency quickly recovers to the rated value and maintains stability. The ability to adjust quickly is particularly critical when dealing with complex and dynamic power grid conditions. Through the comprehensive analysis of the scheme application status evaluation value, the system can identify the deficiencies of primary frequency regulation control and make targeted supplements and optimizations in secondary frequency regulation, thereby better restoring the power grid frequency and enhancing the overall stability of the power grid. By comparing the scheme application status evaluation value with historical data in the database, the system can automatically select the secondary frequency regulation scheme most suitable for the current power grid state, reducing human intervention and improving the automation level of frequency regulation control.

[0075] Furthermore, the application status assessment values ​​of the solution are analyzed in the following specific steps:

[0076] In the formula, ω is the application status evaluation value of the scheme, xy is the equipment response time, hf is the frequency recovery time, cz is the absolute value of the difference between the equipment response power and the reference power, cz1 is the equipment response power, cz2 is the equipment response reference power, τ1 is the set compensation factor of xy, τ2 is the set compensation factor of hf, τ3 is the set compensation factor of cz, and e is the natural constant.

[0077] It should be explained that the above-mentioned application status evaluation value is calculated using the absolute value of the equipment response time, frequency recovery time, and the difference between the equipment response power and the reference power. The xy, hf, and cz values ​​are normalized. The application status evaluation value combines three key indicators: equipment response time, frequency recovery time, and the accuracy of power response. This comprehensive evaluation can fully reflect the actual application effect of the frequency regulation control scheme. This multi-dimensional comprehensive evaluation can more accurately determine the effectiveness of the frequency regulation scheme. Through the comprehensive calculation of these indicators, the evaluation value can reflect the performance of the frequency regulation scheme in different dimensions, such as response speed, recovery efficiency, and output accuracy, thereby more accurately evaluating the overall frequency regulation efficiency. The application status evaluation value is based on the actual response of the frequency regulation equipment, allowing the power grid dispatching system to optimize the frequency regulation strategy based on actual performance rather than theoretical predictions. This ensures that the frequency regulation scheme achieves the best results in practical applications, enabling targeted improvements and continuous optimization of the frequency regulation strategy.

[0078] Example 2, an embodiment of the present invention, differs from the previous embodiment in that:

[0079] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0080] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0081] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0082] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0083] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements, characterized in that, include: The module includes a state reference feature value comparison module (100), an inertia feature value acquisition module (200), a state feature value acquisition module (300), a frequency support feature value analysis module (400), a primary frequency modulation control scheme comparison module (500), and a secondary frequency modulation control scheme comparison module (600). The state reference feature value comparison module (100) analyzes the load status of the AC distribution network and compares the state reference feature values ​​of the distribution network. The inertia characteristic value acquisition module (200) analyzes the inertia of the AC distribution network and obtains the inertia characteristic value; The state characteristic value acquisition module (300) analyzes the fluctuation state of the AC distribution network and obtains the state characteristic value of the distribution network by combining the inertia characteristic value. The frequency support feature value analysis module (400) combines the power distribution network status reference feature value and the power distribution network status feature value to comprehensively analyze and obtain the frequency support feature value; The primary frequency regulation control scheme comparison module (500) compares and obtains the primary frequency regulation control scheme of AC distribution network based on the frequency support feature value. The secondary frequency regulation control scheme comparison module (600) analyzes the application status of the primary frequency regulation control scheme of the AC distribution network and compares them to obtain the secondary frequency regulation control scheme of the AC distribution network.

2. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 1, characterized in that: The analysis of the AC distribution network load status and the comparison to obtain the distribution network status reference feature value include analyzing the AC distribution network load status and obtaining the AC distribution network load dataset. The active power, apparent power, and operating frequency of the distribution network are stored as designated tags. The designated tags are compared with the distribution network state reference feature values ​​corresponding to each designated tag stored in the database to obtain the distribution network state reference feature value corresponding to the designated tag.

3. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 2, characterized in that: The AC distribution network load dataset includes the distribution network active power, the distribution network apparent power, and the distribution network operating frequency.

4. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 3, characterized in that: The analysis of the inertia of the AC distribution network to obtain inertia characteristic values ​​includes analyzing the inertia of the AC distribution network and obtaining an AC distribution network inertia dataset. The AC distribution network inertia dataset specifically includes the rated capacity of the generator set, the inertia constant of the generator set, the generator speed, and the rate of change of the grid frequency. Obtain the compensation factor for the AC distribution network inertia dataset; Obtain the generator's reference speed and the grid frequency's reference rate of change; Based on the acquired AC distribution network inertia dataset, the compensation factor of the AC distribution network inertia dataset, and the rate of change of the generator reference speed and the grid frequency reference speed, the inertia characteristic value is obtained through comprehensive analysis. The inertia characteristic value is used as the basis for the comprehensive analysis to obtain the frequency support characteristic value.

5. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 4, characterized in that: The compensation factors for the AC distribution network inertia dataset include a compensation factor for the rated capacity of the generator set, a compensation factor for the inertia constant of the generator set, a compensation factor for the generator speed, and a compensation factor for the rate of change of the power grid frequency.

6. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 5, characterized in that: The analysis of the AC distribution network fluctuation state, combined with the inertia characteristic value, to obtain the distribution network state characteristic value includes analyzing the AC distribution network fluctuation state and obtaining the AC distribution network fluctuation state dataset. The AC distribution network fluctuation state dataset specifically includes the number of frequency fluctuations per unit time, the frequency of abnormal load fluctuations, and the total harmonic distortion rate.

7. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 6, characterized in that: Based on the acquired AC distribution network fluctuation state dataset, combined with inertia characteristic values, the distribution network state characteristic values ​​are obtained through comprehensive analysis. These distribution network state characteristic values ​​serve as the analytical basis for obtaining frequency support characteristic values ​​through comprehensive analysis.

8. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 7, characterized in that: The frequency support characteristic value obtained by the comprehensive analysis includes combining the distribution network state reference characteristic value and the distribution network state characteristic value. The frequency support characteristic value is used as the basis for analysis to compare and obtain the primary frequency regulation control scheme of AC distribution network.

9. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 8, characterized in that: The process of obtaining a primary frequency regulation control scheme for the AC distribution network based on frequency support feature values ​​involves comparing the frequency support feature values ​​with the AC distribution network primary frequency regulation control schemes corresponding to each frequency support feature value stored in the database to obtain the AC distribution network primary frequency regulation control scheme corresponding to that frequency support feature value.

10. The distributed new energy frequency support system based on grid inertia and frequency regulation requirements as described in claim 9, characterized in that: The analysis of the application status of the primary frequency regulation control scheme of the AC distribution network and the comparison to obtain the secondary frequency regulation control scheme of the AC distribution network include the analysis of the application status of the primary frequency regulation control scheme of the AC distribution network and the acquisition of the scheme application status dataset. The scheme application status dataset specifically includes equipment response time, frequency recovery time, and the absolute value of the difference between equipment response power and reference power. Based on the acquired application status dataset, a comprehensive analysis is conducted to obtain the application status evaluation value of the scheme. The application status evaluation value of the scheme serves as the basis for comparison and analysis of the secondary frequency regulation control scheme of the AC distribution network. The application status evaluation value of the scheme is compared with the AC distribution network secondary frequency regulation control scheme corresponding to the application status evaluation value of each scheme stored in the database to obtain the AC distribution network secondary frequency regulation control scheme corresponding to the application status evaluation value of the scheme.

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