Distributed new energy frequency support system based on power grid inertia and frequency modulation demand

Abstract

The invention discloses a distributed new energy frequency support system based on power grid inertia and frequency modulation demand, and relates to the technical field of power systems, and the system comprises the steps: analyzing the load state of an AC power distribution network, and obtaining a power distribution network state reference characteristic value; analyzing the inertia of the alternating-current power distribution network to obtain an inertia characteristic value; analyzing the fluctuation state of the alternating-current power distribution network, and obtaining a state characteristic value of the power distribution network in combination with the inertia characteristic value; combining the power distribution network state reference characteristic value and the power distribution network state characteristic value, and performing comprehensive analysis to obtain a frequency support characteristic value; based on the frequency support characteristic value, comparing to obtain a primary frequency modulation control scheme of the AC power distribution network; and analyzing the application state of the primary frequency modulation control scheme of the AC power distribution network, and comparing to obtain a secondary frequency modulation control scheme of the AC power distribution network. According to the distributed new energy frequency support system based on the power grid inertia and the frequency modulation demand, the problems of power grid frequency fluctuation and insufficient inertia can be better solved, and safe operation of a power system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a distributed new energy frequency support system based on power grid inertia and frequency regulation requirements. Background Art

[0002] Globally, the installed capacity of distributed renewable energy such as wind and solar power has increased rapidly. This energy transformation has reduced dependence on fossil fuels and helped to address climate change, but it has also brought new technical challenges. Unlike traditional centralized power generation, distributed energy (such as rooftop photovoltaics and decentralized wind farms) is connected to the grid in more dispersed locations and on a smaller scale, and power generation is intermittent and volatile. 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 access of a high proportion of renewable energy generation, especially photovoltaic and wind power, most of them are connected to the grid through power electronic equipment and 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 the 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 the present invention is that traditional power grid inertia analysis is often based on a static system model, which cannot effectively capture dynamic inertia changes, resulting in insufficient accuracy in frequency response prediction, and traditional distributed new energy frequency support methods are often isolated, which may lead to inaccurate frequency response predictions 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 quickly and effectively, it may cause further frequency deviation and even trigger a chain reaction, increasing the risk of system instability. Isolated support methods may not be able to effectively deal with regional frequency fluctuations, and these regional fluctuations may expand and affect the stability of the entire power grid.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a distributed new energy frequency support system based on grid inertia and frequency regulation requirements, comprising:

[0006] State reference eigenvalue comparison module, inertia eigenvalue acquisition module, state eigenvalue acquisition module, frequency support eigenvalue analysis module, primary frequency modulation control scheme comparison module and secondary frequency modulation control scheme comparison module;

[0007] The state reference characteristic value comparison module analyzes the load state of the AC distribution network and obtains the distribution network state reference characteristic value by comparison;

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

[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 in combination with the inertia characteristic value;

[0010] The frequency support characteristic value analysis module combines the distribution network state reference characteristic value and the distribution network state characteristic value to obtain the frequency support characteristic 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 characteristic 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 obtains the secondary frequency regulation control scheme of the AC distribution network by comparison.

[0013] As a preferred solution of the distributed renewable energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: the analysis of the load state of the AC distribution network and the comparison to obtain the reference characteristic value of the distribution network state include analyzing the load state of the AC distribution network and obtaining the load data set of the AC distribution network;

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

[0015] As an optimal solution of the distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements described in the present invention, the AC distribution network load data set includes the active power of the distribution network, the apparent power of the distribution network, and the operating frequency of the distribution network.

[0016] As a preferred solution of the distributed new energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: the analysis of the inertia of the AC distribution network to obtain the inertia characteristic value includes analyzing the inertia of the AC distribution network to obtain an inertia data set of the AC distribution network, and the inertia data set of the AC distribution network 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 power grid frequency;

[0017] Obtain compensation factors for AC distribution network inertia data sets;

[0018] Obtain the generator speed parameter and the grid frequency parameter change rate;

[0019] Based on the acquired AC distribution network inertia data set, the compensation factor of the AC distribution network inertia data set, the generator speed parameter and the grid frequency parameter change rate, a comprehensive analysis is performed to obtain the inertia eigenvalue, which is used as the analysis basis for obtaining the frequency support eigenvalue through comprehensive analysis.

[0020] As a preferred solution of the distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements described in the present invention, the compensation factor of the AC distribution network inertia data set includes a compensation factor of a set rated capacity of the generator set, a compensation factor of a set inertia constant of the generator set, a compensation factor of a set generator speed, and a compensation factor of a set grid frequency change rate.

[0021] As an optimal solution of the distributed new energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: the analysis of the fluctuation state of the AC distribution network and the acquisition of the distribution network state characteristic value in combination with the inertia characteristic value include analyzing the fluctuation state of the AC distribution network and obtaining the AC distribution network fluctuation state data set. The AC distribution network fluctuation state data set specifically includes the number of frequency fluctuations per unit time, the abnormal load fluctuation frequency, and the total harmonic distortion rate.

[0022] As a preferred solution of the distributed renewable energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: based on the acquired AC distribution network fluctuation state data set, combined with the inertia characteristic value, a comprehensive analysis is performed to obtain the distribution network state characteristic value, and the distribution network state characteristic value is used as the analysis basis for the comprehensive analysis to obtain the frequency support characteristic value.

[0023] As a preferred solution of the distributed renewable energy frequency support system based on grid inertia and frequency regulation demand described in the present invention, wherein: the comprehensive analysis to obtain the frequency support characteristic value includes combining the distribution network state reference characteristic value and the distribution network state characteristic value, and comprehensively analyzing to obtain the frequency support characteristic value, and the frequency support characteristic value is used as an analysis basis for comparing to obtain the primary frequency regulation control scheme of the AC distribution network.

[0024] As a preferred solution of the distributed renewable energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: the comparison based on the frequency support characteristic value to obtain the primary frequency regulation control scheme of the AC distribution network includes comparing the frequency support characteristic value with the primary frequency regulation control scheme of the AC distribution network corresponding to each frequency support characteristic value stored in the database to obtain the primary frequency regulation control scheme of the AC distribution network corresponding to the frequency support characteristic value.

[0025] As a preferred solution of the distributed new energy frequency support system based on power grid inertia and frequency regulation demand described in the present invention, wherein: 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 analyzing the application status of the primary frequency regulation control scheme of the AC distribution network and obtaining a scheme application status data set, wherein the scheme application status data set specifically includes device response time, frequency recovery time, and the absolute value of the difference between the device response power and the reference power;

[0026] Based on the acquired scheme application status data set, a scheme application status evaluation value is obtained through comprehensive analysis, and the scheme application status evaluation value is used as the analysis basis for comparing the secondary frequency regulation control scheme of the AC distribution network;

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

[0028] Beneficial effects of the present invention: The distributed renewable energy frequency support system based on grid inertia and frequency regulation demand provided by the present invention accurately identifies and analyzes the current operating status of the distribution network by providing a distributed renewable energy frequency support system based on grid inertia and frequency regulation demand, which helps to grasp the changing trend and abnormal conditions of the grid load in real time, and provides reliable basic data for subsequent inertia analysis and frequency support. The reference characteristic value of the distribution network state is compared with the characteristic value of the distribution network state, and the frequency support characteristic value is obtained through comprehensive analysis, which provides key data support for the selection and optimization of the frequency regulation control scheme, and can significantly improve the frequency stability of the grid. In the context of a high proportion of 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, and ensure the safe operation of the power system.

[0029] By combining the reference characteristic value of the distribution network state with the characteristic value of the distribution network state, the frequency support characteristic value is obtained through comprehensive analysis, which can accurately identify the real-time operating state of the power grid and more accurately judge the frequency response capability of the power grid under the current load conditions. By analyzing the frequency support characteristic value, the frequency support strategy can be adjusted in real time to ensure that appropriate frequency support is provided under different power grid states. Dynamic adjustment helps to respond to power grid frequency fluctuations in a timely manner, avoid excessive or insufficient support, and maintain frequency stability. Comprehensive analysis of the frequency support characteristic value can realize the automation of frequency regulation decision-making. The system can automatically analyze and judge based on real-time data, automatically select the optimal frequency support plan, 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 of the AC distribution network, comparing it with the secondary frequency regulation control scheme of the AC distribution network, and analyzing the application status of the primary frequency regulation control scheme, the effect of the scheme in actual operation can be accurately identified, which can help determine whether the primary frequency regulation is sufficient or needs further adjustment. According to the actual effect of the primary frequency regulation, the secondary frequency regulation control scheme is designed in a targeted manner to ensure that the frequency regulation strategy is more accurate and can effectively compensate for the insufficient primary frequency regulation, thereby better restoring and maintaining the stability of the power grid frequency, which helps to optimize the utilization of frequency regulation resources and improve the stability and reliability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 An overall structural diagram of a distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements provided for one embodiment of the present invention.

[0033] Figure 2 A flowchart of the steps of comparing and obtaining a secondary frequency regulation control scheme for an AC distribution network in a distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements provided in one embodiment of the present invention.

[0034] Figure 3 A three-dimensional image of the change in inertia characteristic value of a distributed renewable energy frequency support system based on grid inertia and frequency regulation demand as the grid frequency change rate and the compensation factor of the set grid frequency change rate are provided for one embodiment of the present invention.

[0035] Figure 4 An image showing the change of inertia characteristic value of a distributed renewable energy frequency support system based on grid inertia and frequency regulation demand with the rate of change of grid frequency provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0038] Example 1

[0039] Reference Figure 1-Figure 4 , which is an embodiment of the present invention, provides a distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements, including:

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

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

[0042] The specific analysis process includes: analyzing the load state of the AC distribution network to obtain the AC distribution network load data set, which specifically includes the active power of the distribution network, the apparent power of the distribution network, and the operating frequency of the distribution network; storing the active power of the distribution network, the apparent power of the distribution network, and the operating frequency of the distribution network as designated tags, and comparing the designated tags with the distribution network state reference characteristic values ​​corresponding to the designated tags stored in the database to obtain the distribution network state reference characteristic values ​​corresponding to the designated tags.

[0043] It should be noted that the above-mentioned active power is the power actually consumed or converted into useful work in the power system, which is obtained by a power meter. The apparent power is the product of voltage and current, including the combined effect of active power and reactive power, obtained based on the power meter. The operating frequency is the oscillation frequency of the alternating current in the power system, usually 50 Hz (Hz) or 60 Hz (Hz), obtained based on the smart meter. The power factor (PF) is the ratio of active power to apparent power, which indicates the proportion of actual work done in the power system. Frequency fluctuations will affect the operating status of motors and other inductive loads, and thus affect the demand for reactive power 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 the active power demand in the power grid. If power generation cannot be adjusted in time, the frequency will further drop, which may eventually lead to system instability.

[0044] It should be noted that the above-mentioned real-time analysis of load status can timely discover abnormal status of the distribution network. If the ratio of active power to apparent power (power factor) is abnormal, it may mean equipment failure or excessive load, and necessary measures can be taken to improve the stability and safety of the system. Detailed analysis of load status can provide basic data support for load forecasting, active scheduling and demand response, which is of great significance for reducing peak load, balancing load and optimizing resource allocation. Analysis of load status can better meet users' demand for power supply, optimize the distribution network power supply plan and improve user satisfaction.

[0045] The inertia characteristic value acquisition module 200 analyzes the inertia of the AC power distribution network to obtain an inertia characteristic value.

[0046] The specific analysis process is as follows: analyzing the inertia of the AC distribution network to obtain an inertia data set of the AC distribution network, the inertia data set of the AC distribution network specifically including the rated capacity of the generator set, the inertia constant of the generator set, the generator speed, and the grid frequency change rate; obtaining the compensation factor of the inertia data set of the AC distribution network, the compensation factor of the inertia data set of the AC distribution network including the compensation factor of the set rated capacity of the generator set, the compensation factor of the set inertia constant of the generator set, the compensation factor of the set generator speed, and the compensation factor of the set grid frequency change rate; obtaining the generator parameter speed and the grid frequency parameter change rate (the generator parameter speed and the grid frequency parameter change rate are both obtained from the database and used as reference values); based on the obtained inertia data set of the AC distribution network, the compensation factor of the inertia data set of the AC distribution network, and the generator parameter speed and the grid frequency parameter change rate, a comprehensive analysis is performed to obtain an inertia eigenvalue, and the inertia eigenvalue is used as an analysis basis for obtaining a frequency support eigenvalue through comprehensive analysis.

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

[0048] The larger the inertia constant, the larger the rotational mass of the generator set, which can provide more inertia support when the frequency changes, alleviating the rapid fluctuation of the frequency. The change in the generator speed directly leads to the change in the grid frequency. A decrease in speed usually means a decrease in the rate of change of the grid frequency, while an increase in speed means an increase in the rate of change of the grid frequency. The higher the inertia constant of the generator set, the lower the rate of change of the grid frequency, which is beneficial to the frequency stability of the grid. The more large-capacity and high-inertia generator sets there are in the grid, the larger the overall inertia of the grid, the smaller the frequency fluctuation, and the better the stability.

[0049] It should be noted that the above analysis of data such as the rated capacity of the generator set, inertia constant, generator speed and grid frequency change rate can accurately calculate the inertia characteristic value of the grid, which reflects the response capability of the grid when facing frequency fluctuations, so that the frequency support strategy can more accurately match the actual needs of the grid. Through the comprehensive analysis of the inertia characteristic value obtained, the grid can quickly determine the frequency support demand under different load changes or fault conditions. The timely response capability ensures that when the frequency deviates from the rated value, the system can quickly make adjustments to avoid excessive frequency fluctuations and improve the stability of the grid. The inertia characteristic value can reveal the inertia distribution in the grid area and provide a scientific basis for the planning and development of the grid.

[0050] Furthermore, the specific analysis process of the inertia eigenvalue is as follows:

[0051]

[0052] In the formula, α is the inertia characteristic value, 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 grid frequency change rate, μ 1 is the compensation factor of the set ed, μ 2 is the compensation factor of the set gl, μ 3 is the compensation factor of the set zs, μ 4 is the compensation factor of the set bp, czs is the parameterized speed of the generator, and cbp is the parameterized change rate of the grid frequency.

[0053] It needs to be explained that Figure 3 A three-dimensional graph showing the change of the inertia characteristic value with the grid frequency change rate and the compensation factor of the set grid frequency change rate. Figure 4As shown in the graph of the change of inertia eigenvalue with the rate of change of grid frequency, the greater the rate of change of grid frequency, the smaller the inertia eigenvalue. As the rate of change of grid frequency increases, the influence of the rate of change of grid frequency on the inertia eigenvalue decreases. The above inertia eigenvalue is calculated by the rated capacity of the generator set, the inertia constant of the generator set, the generator speed, and the rate of change of grid frequency. Ed, gl, zs, and bp are normalized. The inertia eigenvalue combines the physical parameters of the generator set (such as rated capacity and inertia constant) and dynamic operating parameters (such as speed and frequency change rate), which can accurately characterize the inertia response capability of the grid under frequency fluctuations and reflect the grid's ability to cope with frequency changes. The buffering capacity provides an accurate basis for the frequency regulation strategy. By calculating the inertia characteristic value in real time, the stability of the power grid can be dynamically evaluated, especially when the load changes or emergencies occur. The larger the inertia characteristic value, the smaller the fluctuation of the power grid frequency and the more stable the system. The calculated inertia characteristic value can identify the inertia level of the power grid under different conditions, so as to formulate more targeted frequency regulation measures. A high-inertia power grid may require fewer frequency regulation resources, while a low-inertia power grid requires faster and stronger frequency support, which helps the dispatch center understand the response characteristics of the generator set, thereby more effectively dispatching power generation resources, improving the response efficiency of frequency support, and reducing the amplitude and recovery time of frequency fluctuations.

[0054] It needs to be explained that the compensation factors of ed, gl, zs, and bp set above are obtained from the database. According to the historical data, a mapping set of the historically measured rated capacity of the generator set, the inertia constant of the generator set, the generator speed, the grid frequency change rate and the compensation factors of ed, gl, zs, and bp is established to obtain the compensation factors of ed, gl, zs, and bp corresponding to the current ed, gl, zs, and bp.

[0055] It should be noted that the ε 1 , ε 2 , ε 3 , τ 1 , τ 2 , τ 3 They are also obtained through a mapping set of historical data and compensation factors established in a database, that is, the corresponding compensation factors are obtained according to the current data.

[0056] 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 in combination with the inertia characteristic value.

[0057] The specific analysis process is as follows: analyze the fluctuation state of the AC distribution network to obtain the fluctuation state data set of the AC distribution network. The fluctuation state data set of the AC distribution network specifically includes the number of frequency fluctuations per unit time, the abnormal load fluctuation frequency, and the total harmonic distortion rate; based on the obtained fluctuation state data set of the AC distribution network, combined with the inertia eigenvalue, a comprehensive analysis is performed to obtain the distribution network state eigenvalue, and the distribution network state eigenvalue is used as the analysis basis for the frequency support eigenvalue obtained by comprehensive analysis.

[0058] It should be noted that the number of frequency fluctuations per unit time mentioned above refers to the number of times the grid frequency deviates from the rated value within a certain period of time, which is obtained through frequency meters and grid monitoring systems. The abnormal load fluctuation frequency refers to the frequency of abnormal and large fluctuations in grid load, which is obtained through load monitoring equipment and power management systems. The total harmonic distortion (THD) refers to the degree of distortion of the voltage or current waveform relative to the ideal sine wave, which is obtained through harmonic analyzers, smart meters and power quality monitoring systems. The abnormal load fluctuation frequency directly affects the number of frequency fluctuations per unit time, because load fluctuations directly lead to power imbalance and cause frequency fluctuations. The abnormal load fluctuation frequency may indirectly increase the total harmonic distortion rate, because the violent fluctuations of nonlinear loads will increase the generation of harmonics. The increase in the total harmonic distortion rate will affect the frequency regulation efficiency of the grid and may lead to an increase in the number of frequency fluctuations. Frequency fluctuations may in turn affect the harmonic level of the grid, forming a feedback effect.

[0059] It should be noted that the above-mentioned distribution network state characteristic values ​​integrate multi-dimensional data such as frequency fluctuation, load fluctuation, harmonic distortion, etc. Through the comprehensive analysis of these data, we can have a more comprehensive understanding of the operating status of the distribution network. Multi-dimensional analysis is helpful to formulate more accurate frequency support strategies to ensure that frequency support can adapt to the actual power grid conditions. Different fluctuation states may require different support strategies. High-frequency fluctuations may require fast-response support, while abnormal load fluctuations may require support that focuses on local areas. Comprehensive analysis of the distribution network state characteristic values ​​can formulate more targeted support strategies and improve the support effect. The analysis of the number of frequency fluctuations, abnormal load fluctuation frequency and total harmonic distortion rate can reveal the dynamic change characteristics of the power grid. Combined with the inertia characteristic value, it can better evaluate the frequency support needs of the power grid under different states, so as to take timely measures to alleviate frequency fluctuations and maintain the stability of the power grid.

[0060] Furthermore, the specific analysis process of the distribution network state characteristic value is as follows:

[0061]

[0062] 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 abnormal load fluctuation frequency, jb is the total harmonic distortion rate, ε 1is the compensation factor of the set bd, ε 2 is the compensation factor of the set yc, ε 3 is the compensation factor of the set jb.

[0063] It needs to be explained that the above-mentioned 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. BD, YC and JB are normalized, and the number of frequency fluctuations, the frequency of abnormal load fluctuations, the total harmonic distortion rate and the inertia characteristic value are combined. The distribution network state characteristic values ​​can comprehensively reflect the key dimensions of power grid operation. This multi-dimensional comprehensive analysis can more accurately evaluate the current state of the power grid and identify potential stability problems. The state characteristic values ​​calculated in combination with these parameters can accurately characterize the operation risks of the power grid, especially when the load fluctuates violently or the harmonic distortion is large. The introduction of the inertia characteristic value can more comprehensively evaluate the response capability of the power grid and timely identify potential risks. The state characteristic value combines 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, thereby making the frequency support strategy more targeted. This dynamic adjustment can more effectively smooth out frequency fluctuations and maintain the stability of the power grid.

[0064] The frequency support characteristic value analysis module 400 combines the distribution network state reference characteristic value and the distribution network state characteristic value to obtain the frequency support characteristic value through comprehensive analysis.

[0065] The specific analysis process is: combining the distribution network state reference characteristic value and the distribution network state characteristic value, a comprehensive analysis is performed to obtain the frequency support characteristic value, and the frequency support characteristic value is used as the analysis basis for comparing the primary frequency regulation control scheme of the AC distribution network.

[0066] It should be noted that the above combination of distribution network state reference characteristic value and frequency support characteristic value provides an accurate assessment of the current state of the power grid, so that frequency regulation resources can be reasonably allocated, avoiding excessive or insufficient frequency regulation, and reducing resource waste. Through accurate frequency support characteristic value analysis, appropriate frequency regulation measures can be taken in time to avoid excessive frequency fluctuations, thereby effectively improving the frequency stability state characteristic value of the power grid, which can accurately reflect the actual operating conditions 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 plan more targeted and avoiding the deviations that may be caused by formulating frequency regulation plans 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 loads and operating conditions, thereby formulating more accurate frequency regulation strategies to ensure frequency stability.

[0067] It should be noted that the specific analysis process of the above frequency support characteristic value is as follows:

[0068]

[0069] Where δ is the frequency support eigenvalue, γ is the distribution network state eigenvalue, β is the distribution network state reference eigenvalue, and e is a natural constant.

[0070] It should be noted that the above-mentioned frequency support characteristic value is calculated by combining the distribution network state reference characteristic value and the distribution network state characteristic value. The combination of the distribution network state reference characteristic value (preset or historical ideal state value) and the real-time distribution network state characteristic value can accurately reflect the actual operation of the current power grid. Through this dynamic matching, the frequency support characteristic value can be calculated more accurately, so as to formulate a frequency support strategy that is more in line with the current power grid needs. 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 configuration of frequency regulation resources, avoiding waste of resources, preventing the shortage of frequency regulation resources, and ensuring the efficient implementation of frequency regulation measures. The calculated frequency support characteristic value can be used as an important basis for automated frequency regulation decision-making, reducing manual intervention, and improving the automation level of the frequency regulation process. It is especially important for large-scale and complex power grids, and can improve the response speed to frequency fluctuations.

[0071] The primary frequency regulation control scheme comparison module 500 compares and obtains the primary frequency regulation control scheme of the AC distribution network based on the frequency support characteristic value.

[0072] The specific analysis process is: compare the frequency support characteristic value with the primary frequency regulation control scheme of the AC distribution network corresponding to each frequency support characteristic value stored in the database to obtain the primary frequency regulation control scheme of the AC distribution network corresponding to the frequency support characteristic value.

[0073] In a specific embodiment, by comparing the current frequency support characteristic value with the historical data in the database, the frequency regulation control scheme closest to the current power grid state can be quickly found, which can ensure that the selected frequency regulation scheme has been verified under similar conditions and has good results, thereby improving the accuracy and effectiveness of frequency regulation control. By comparing the database, the most suitable frequency regulation scheme can be determined in a short time, avoiding the lag and uncertainty of manual selection of schemes, responding to power grid frequency fluctuations more quickly, and improving the frequency regulation reaction speed. Selecting a verified frequency regulation scheme can reduce the risk of frequency regulation failure or poor effect, help maintain frequency stability under different power grid conditions, and reduce the risk of frequency fluctuations or system instability due to improper frequency regulation schemes.

[0074] 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 by comparison.

[0075] like Figure 2 As shown, the specific analysis process is: analyze the application status of the primary frequency regulation control scheme of the AC distribution network to obtain the scheme application status data set, which specifically includes the device response time, frequency recovery time, and the absolute value of the difference between the device response power and the reference power; based on the obtained scheme application status data set, comprehensively analyze to obtain the scheme application status evaluation value, and the scheme application status evaluation value is used as the analysis basis for comparing the secondary frequency regulation control scheme of the AC distribution network; compare the scheme application status evaluation value with the secondary frequency regulation control scheme of the AC distribution network corresponding to each scheme application status evaluation value stored in the database, and obtain the secondary frequency regulation control scheme of the AC distribution network corresponding to the scheme application status evaluation value.

[0076] It should be noted that the above-mentioned device response time refers to the time taken from receiving the frequency modulation instruction to the device actually adjusting the output power, which is usually obtained through the timestamp record or event recorder in the control system. The frequency recovery time refers to the time required for the frequency deviation to recover to a value close to the rated value, which is usually obtained through a frequency meter or a power grid monitoring system (SCADA). The absolute value of the difference between the device response power and the reference power refers to the absolute value of the difference between the actual output power of the device and the expected power, reflecting the accuracy of the device response, which is usually obtained through a power meter or control system data record. The device response time determines the speed at which the frequency modulation starts and affects the starting time of the frequency recovery. A shorter response time usually helps to shorten the frequency recovery time. The absolute value of the difference between the device 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.

[0077] It should be noted that the above analysis of the application status of the primary frequency regulation control scheme can accurately evaluate the effectiveness of the current frequency regulation measures. The scheme application status evaluation value obtained by comprehensive analysis can accurately reflect the actual performance of the primary frequency regulation, so as to select the most matching secondary frequency regulation control scheme in the comparison process to ensure that the frequency regulation strategy is more accurate. After comparing the database, the system can quickly identify the secondary frequency regulation scheme that is most suitable for the current power grid state, ensure that the frequency is quickly restored to the rated value and maintain stability. The rapid adjustment capability 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 shortcomings of the primary frequency regulation control and make targeted supplements and optimizations in the secondary frequency regulation, so as to better restore the power grid frequency and enhance the overall stability of the power grid. By comparing the scheme application status evaluation value with the historical data in the database, the system can automatically select the secondary frequency regulation scheme that is most suitable for the current power grid state, reduce human intervention, and improve the automation level of frequency regulation control.

[0078] Furthermore, the scheme application status evaluation value, the specific analysis process is:

[0079]

[0080] Where ω is the evaluation value of the solution application status, xy is the device response time, hf is the frequency recovery time, cz is the absolute value of the difference between the device response power and the reference power, and cz 1 is the device response power, cz 2 is the device response reference power, τ 1 is the compensation factor of the set xy, τ 2 is the compensation factor of the set hf, ε 3 is the compensation factor of the set CZ, and e is a natural constant.

[0081] It needs to be explained that the above-mentioned scheme application status evaluation value is calculated through the absolute value of the difference between the equipment response time, frequency recovery time, and the equipment response power and the reference power, and xy, hf, and cz are normalized. The scheme application status evaluation value combines the three key indicators of equipment response time, frequency recovery time, and power response accuracy, which can comprehensively reflect the actual application effect of the frequency modulation control scheme. The multi-dimensional comprehensive evaluation can more accurately judge the effectiveness of the frequency modulation scheme. Through the comprehensive calculation of these indicators, the evaluation value can reflect the performance of the frequency modulation scheme in different dimensions, such as response speed, recovery efficiency, and output accuracy, so as to more accurately evaluate the overall frequency modulation efficiency. The scheme application status evaluation value is based on the actual response of the frequency modulation equipment, so that the power grid dispatcher can optimize the frequency modulation strategy based on actual performance rather than theoretical predictions, which can ensure that the frequency modulation scheme achieves the best effect in actual application, and then make targeted improvements and continuously optimize the frequency modulation strategy.

[0082] Embodiment 2, an embodiment of the present invention, which is different from the previous embodiment in that:

[0083] If the functions are implemented in the form of 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 the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0084] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0085] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0086] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in 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: A state reference characteristic value comparison module (100), an inertia characteristic value acquisition module (200), a state characteristic value acquisition module (300), a frequency support characteristic 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 characteristic value comparison module (100) analyzes the load state of the AC distribution network and obtains the distribution network state reference characteristic value by comparison; The inertia characteristic value acquisition module (200) analyzes the inertia of the AC power distribution network to obtain an inertia characteristic value; The state characteristic value acquisition module (300) analyzes the fluctuation state of the AC distribution network and obtains the distribution network state characteristic value in combination with the inertia characteristic value; The frequency support characteristic value analysis module (400) combines the distribution network state reference characteristic value and the distribution network state characteristic value to obtain the frequency support characteristic value through comprehensive analysis; The primary frequency regulation control scheme comparison module (500) compares and obtains the primary frequency regulation control scheme of the AC power distribution network based on the frequency support characteristic 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 obtains the secondary frequency regulation control scheme of the AC distribution network by comparison.

2. The distributed renewable energy frequency support system based on grid inertia and frequency modulation requirements as claimed in claim 1, characterized in that: The analyzing the load state of the AC distribution network and obtaining the reference characteristic value of the distribution network state by comparison includes analyzing the load state of the AC distribution network and obtaining an AC distribution network load data set; The active power, apparent power and operating frequency of the distribution network are stored as designated tags, and the designated tags are compared with the distribution network state reference characteristic values ​​corresponding to the designated tags stored in the database to obtain the distribution network state reference characteristic values ​​corresponding to the designated tags.

3. The distributed renewable energy frequency support system based on grid inertia and frequency modulation requirements as claimed in claim 2, characterized in that: The AC distribution network load data set includes the active power of the distribution network, the apparent power of the distribution network, and the operating frequency of the distribution network.

4. The distributed renewable energy frequency support system based on grid inertia and frequency modulation requirements as claimed in claim 3, characterized in that: Analyzing the inertia of the AC distribution network to obtain the inertia characteristic value includes analyzing the inertia of the AC distribution network to obtain an inertia data set of the AC distribution network, wherein the inertia data set of the AC distribution network 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; Obtain compensation factors for AC distribution network inertia data sets; Obtain the generator speed parameter and the grid frequency parameter change rate; Based on the acquired AC distribution network inertia data set, the compensation factor of the AC distribution network inertia data set, the generator speed parameter and the grid frequency parameter change rate, a comprehensive analysis is performed to obtain the inertia eigenvalue, which is used as the analysis basis for obtaining the frequency support eigenvalue through comprehensive analysis.

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

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

7. The distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements as claimed in claim 6, characterized in that: Based on the acquired AC distribution network fluctuation state data set and combined with the inertia eigenvalue, a comprehensive analysis is performed to obtain the distribution network state eigenvalue, which is used as the analysis basis for the frequency support eigenvalue obtained through comprehensive analysis.

8. The distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements as claimed in claim 7, characterized in that: The comprehensive analysis to obtain the frequency support characteristic value includes combining the distribution network state reference characteristic value and the distribution network state characteristic value, and comprehensively analyzing to obtain the frequency support characteristic value, and the frequency support characteristic value is used as an analysis basis for comparing and obtaining the primary frequency regulation control scheme of the AC distribution network.

9. The distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements as claimed in claim 8, characterized in that: The comparing and obtaining the primary frequency regulation control scheme of the AC distribution network based on the frequency support characteristic value includes comparing the frequency support characteristic value with the primary frequency regulation control schemes of the AC distribution network corresponding to each frequency support characteristic value stored in a database to obtain the primary frequency regulation control scheme of the AC distribution network corresponding to the frequency support characteristic value.

10. The distributed renewable energy frequency support system based on grid inertia and frequency regulation requirements as claimed in claim 9, characterized in that: The analyzing the application status of the primary frequency regulation control scheme of the AC distribution network and comparing 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 data set, wherein the scheme application status data set specifically includes a device response time, a frequency recovery time, and an absolute value of a difference between a device response power and a reference power; Based on the acquired scheme application status data set, a scheme application status evaluation value is obtained through comprehensive analysis, and the scheme application status evaluation value is used as the analysis basis for comparing the secondary frequency regulation control scheme of the AC distribution network; The scheme application state evaluation value is compared with the AC distribution network secondary frequency regulation control scheme corresponding to each scheme application state evaluation value stored in the database to obtain the AC distribution network secondary frequency regulation control scheme corresponding to the scheme application state evaluation value.

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