A fast and practical online calculation method for moment of inertia

Abstract

The present invention belongs to the technical field of power system analysis, and in particular, relates to a method for rapid and practical online calculation of moment of inertia. The present invention includes a simulation cutting method and a unit accumulation method, and uses the simulation cutting method and the unit accumulation method to calculate the moment of inertia of the system; and also includes: using the simulation cutting method and the unit accumulation method to preliminarily calculate the moment of inertia of different operating modes of the power grid in the same region; using the simulation cutting method and the unit accumulation method to calculate the moment of inertia values ​​of the same power grid, and performing comparative analysis; determining a rapid and practical method for calculating the moment of inertia suitable for the power grid through the functional relationship between the two algorithms. The present invention can quickly calculate the moment of inertia of the system, saving the complex calculation process and a lot of time of simulation calculation. The moment of inertia of a power grid in a certain region can be accurately calculated, and it is highly practical. Different from the previous theoretical algorithms, it is a quantitative analysis, summary, and display of the actual operation mode of the power grid.

Description

Technical Field

[0001] The invention belongs to the technical field of power system analysis, and in particular relates to a fast and practical online calculation method for moment of inertia. Background Art

[0002] my country's economy is shifting from high-speed development to high-quality development. In the field of energy, as the revolution in energy production and consumption continues to advance, clean production and electrification on the consumption side have become important trends and characteristics of my country's current energy system. In 2019, State Grid Corporation of my country proposed a dual 50% goal of 50% clean energy rate and 50% terminal electrification rate by 2050, which will make the dynamic characteristics of the world's largest AC / DC interconnected power grid in my country more complex and increase the risk of safe and stable operation. Objectively, higher requirements are put forward for the state of the power system under the new situation, especially more timely moment of inertia perception methods, more accurate moment of inertia calculation technology and more reliable analysis and evaluation methods.

[0003] There are currently two common rotational inertia algorithms in the world, namely the "simulation cutting method" and the "unit accumulation method". The simulation cutting method calculates the frequency drop rate by artificially setting the power shortage in the simulation program. The simulation process is time-consuming and cumbersome, but the result is highly accurate and is not suitable for fast online calculations. The unit accumulation method simply accumulates the rotational inertia of the grid-connected units. The process is simple and fast, but the error is large, and it is not suitable for accurate offline calculations.

[0004] The following is a brief description of the "simulation cutting method" and the "unit accumulation method":

[0005] The simulation cutting method calculates the system moment of inertia by considering the worst case of a local power grid, cutting off a generator with the largest moment of inertia that has been connected to the grid in the area, and calculating by finding the maximum rate of change of frequency. If the initial frequency of the system is 50Hz, the expression of the system moment of inertia obtained by the simulation cutting method is:

[0006]

[0007] In the formula, H 切机 is the system moment of inertia calculated by the machine cutting method; df / dt is the frequency change rate; △P is the total power loss due to system failure, and H` is the moment of inertia corresponding to a single generator that has been disconnected from the grid.

[0008] The unit accumulation method is a method that uses the accumulated results of the moments of inertia of all grid-connected units as the system moment of inertia, provided that the moment of inertia of a single generator is known, which is usually calculated based on the time constant provided by the manufacturer. The online single generator moment of inertia has a nominal value H1 and an inertia time constant T j1 and the rated capacity of a single generator S N1 The relationship is as follows:

[0009]

[0010] Where ω is the angular velocity of the generator, in rad / s; f is the frequency of the generator, in Hz; 2πf is twice the circumference of a circle, π, multiplied by the frequency f, in Hz.

[0011] If there are N online generators, the total moment of inertia of the system obtained by the accumulation method is H 累加 for

[0012] H 累加 =H1+H2+H3+...+H N (3)

[0013] Among them, H1, H2, H3...H N is the rotational inertia of each of the N online units.

[0014] If the data calculated by the simulation cutting method comes from the offline research state, the result is accurate but cannot reflect the real-time state of the power grid; if the data calculated by the unit accumulation method comes from the online real-time state, the result is highly timely but less accurate. Therefore, no algorithm can meet the requirements of fast and accurate moment of inertia calculation and evaluation.

[0015] There are two common rotational inertia algorithms in the world, namely the "simulation cutting method" and the "unit accumulation method". The simulation cutting method requires simulation calculation of the power grid, and the calculation results can truly reflect the system rotational inertia, but the calculation process is cumbersome and time-consuming, and is not suitable for online rapid and practical calculation of rotational inertia. The unit accumulation method only needs to accumulate the given online unit rotational inertia to quickly obtain the calculation results. The calculation process is simple and fast, but the calculation accuracy is poor and cannot reflect the actual system rotational inertia results. Summary of the invention

[0016] In view of the shortcomings of the above-mentioned prior art, the present invention provides a fast and practical online calculation method for the moment of inertia taking into account multiple factors, which is intended to achieve the invention purpose of fast and accurate calculation and estimation of the moment of inertia of the local power grid.

[0017] The technical solution adopted by the present invention to achieve the above-mentioned purpose is:

[0018] A method for calculating the rotational inertia quickly and practically online includes a simulation cutting method and a unit accumulation method, wherein the rotational inertia of the system is calculated by using the simulation cutting method and the unit accumulation method; and the method also includes the following steps:

[0019] Step 1. Use the simulated machine cutting method and the unit accumulation method to preliminarily calculate the rotation inertia of different operation modes of the same regional power grid;

[0020] Step 2. For the same power grid, the values ​​of the moment of inertia calculated by the simulation cutting method and the unit accumulation method are compared and analyzed;

[0021] Step 3. Determine a fast and practical method for calculating the moment of inertia suitable for the power grid through the functional relationship between the two algorithms.

[0022] Furthermore, the simulation cutting method and the unit accumulation method are used in step 1 to preliminarily calculate the rotational inertia of the power grid in the same region in different operation modes, including: simulating the cutting of a single generator with the largest rotational inertia of the entire network in the simulation program, obtaining the average df / dt value in the interval of 0-3 seconds after simulation, substituting the average df / dt value, △P, and H' into formula (1), and automatically calculating H 切机 value; at the same time, the T j1 , S N1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 .

[0023] Furthermore, the moment of inertia values ​​calculated by the simulation cutting method and the unit accumulation method for the same power grid in step 2 are compared and analyzed; including: 切机 With H 累加 A large number of calculations found that H 切机 With H 累加 The results show a linear relationship, and there are many factors that affect the sublinear relationship. The functional relationship between the two is as follows:

[0024] H 切机 =H 累加 / (K1×A+K2×B+K3) (4)

[0025] Among them, A and B are multiple factors that affect the linear relationship: A is the non-renewable energy power generation in the actual operation mode, B is the proportion of new energy in the actual operation mode, K1 is the coefficient corresponding to A, K2 is the coefficient corresponding to B, and K3 is a constant.

[0026] Furthermore, the method for calculating the moment of inertia of a fast and practical type suitable for the power grid is determined by the functional relationship between the two algorithms in step 3, including: firstly, using the two methods to respectively calculate the moment of inertia of multiple operating modes as a data sample library, and then finding the multivariate linear regression functional relationship between the ratio of the two algorithm results, the non-new energy power generation and the proportion of new energy in the data sample library; using N operating modes to calculate the data to obtain the sample library, and obtaining the multivariate linear regression function equation (4):

[0027] After obtaining the regression function K1, K2, K3 coefficients, first use the accumulation method to quickly calculate the moment of inertia H of a given operating mode.累加 , and then substitute the non-renewable energy power generation A of the actual operation mode and the proportion of renewable energy B of the actual operation mode into the regression function equation (4), and use H 累加 Calculate the reverse H 切机 ; Using the inherent relationship characteristics of the existing regional power grid cutting method and the accumulation method, when K1, K2, and K3 are known, using the H of a given operating mode 累加 , the actual operating mode of non-renewable energy power generation A and the actual operating mode of new energy proportion B, quickly calculate H 切机 result.

[0028] Furthermore, the step 1 adopts the simulation cutting method and the unit accumulation method to preliminarily calculate the rotational inertia of different operation modes of the power grid in the same region, including: using the simulation cutting method and the unit accumulation method to preliminarily calculate the rotational inertia of 11 different operation modes respectively; simulating the removal of a single generator with a maximum rotational inertia of 1000MW, importing the system frequency change curve data obtained by simulating the power system analysis and comprehensive program PSASP into the Matlab program, and obtaining the df / dt average value in the 0-3 second interval after simulation, substituting the df / dt average value, △P, and H` into formula (1), and automatically calculating H 切机 value; at the same time, the T j1 , S N1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 .

[0029] Furthermore, the step 2 is to use the simulation cutting method and the unit accumulation method to calculate the moment of inertia values ​​of the same power grid, and then compare and analyze them; including: 切机 , H 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of new energy proportion B constitute the data sample library, the preliminary calculation of 11 different operating modes results show: 累加 and H 切机 are two nearly parallel curves; the ratio of the two is relatively flat and does not fluctuate much; the fluctuation of the two is greatly affected by the proportion of renewable energy in the grid-connected power source B, and less affected by the non-renewable energy power generation A in the grid-connected power source; through the existing results, it can be preliminarily inferred that the mathematical relationship between the results of the two algorithms is relatively linear and is affected by the non-renewable energy power generation A in the actual operation mode and the proportion of renewable energy in the actual operation mode B. After linear fitting, the Northeast Power Grid H 切机 With H 累加 Linear relationship function between results:

[0030] H 切机 =H 累加 / (0.0000069428034×A-0.16386522×B+0.88763558) (5).

[0031] Further, in step 3, a fast and practical method for calculating the moment of inertia applicable to the power grid is determined by the functional relationship between the two algorithms; including: converting the measured H 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of new energy proportion B data into formula (5), get H 切机 The values ​​prove the accuracy and practicality of regression equations (4) and (5). Therefore, equations (4) and (5) can be used to perform rapid and practical online evaluation of the power grid moment of inertia.

[0032] Furthermore, the formulas (4) and (5) can be used to perform a rapid and practical online evaluation of the moment of inertia of the power grid, specifically including: converting the measured H in the event of a single large generator tripping at the 1000MW level into 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of new energy proportion B data into formula (5), get H 切机 It is 325092.8MW.s; the accuracy and practicality of regression equations (4) and (5) are proved. Therefore, equations (4) and (5) can be used for rapid and practical online evaluation of power grid rotation inertia.

[0033] A computer storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for rapidly and practically calculating the moment of inertia in an online manner taking multiple factors into consideration.

[0034] The present invention has the following beneficial effects and advantages:

[0035] The present invention combines and improves the "simulation cutting method" and the "unit accumulation method" to find the functional relationship between the results of the two methods. Under the premise of considering multiple factors affecting the function, a new type of rapid and practical online calculation method for the moment of inertia considering multiple factors is proposed.

[0036] Compared with the prior art, the present invention has a fast calculation speed. After the moment of inertia value is calculated by a simple unit accumulation method, the system moment of inertia can be quickly calculated by using the existing functional relationship between the calculation results of the unit accumulation method and the simulation cutting method for a certain area of ​​the power grid, thereby eliminating the complex calculation process of the simulation calculation and saving a lot of time.

[0037] Compared with the prior art, the present invention has high calculation accuracy. The proposed algorithm draws on and gives full play to the advantages of two existing algorithms, and can accurately calculate the rotational inertia of a regional power grid.

[0038] Compared with the prior art, the present invention is highly practical. Different from the previous theoretical algorithms, the proposed algorithm calculates the moment of inertia based on the actual grid operation parameters, which is a quantitative analysis, summary and display of the actual grid operation mode, and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 It is a variation trend curve of the moment of inertia obtained by the theoretical algorithm of the present invention and the corresponding data. DETAILED DESCRIPTION

[0041] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0043] Refer to the following Figure 1 The technical solutions of some embodiments of the present invention are described.

[0044] Example 1

[0045] The invention discloses a fast and practical online calculation method for the moment of inertia, which comprises classical algorithms for the moment of inertia: a simulation cutting method and a unit accumulation method. The simulation cutting method and the unit accumulation method are used to calculate the moment of inertia of the system.

[0046] like Figure 1 As shown, Figure 1 It is the change trend curve of the moment of inertia and the corresponding data obtained by the theoretical algorithm of the present invention. The present invention also includes the following steps:

[0047] Step 1. Use the simulated machine cutting method and the unit accumulation method to preliminarily calculate the rotational inertia of different operating modes of the same regional power grid.

[0048] In the simulation program, a single generator with the largest moment of inertia in the entire grid is simulated and removed. After simulation, the average df / dt value in the interval of 0-3 seconds is obtained. The average df / dt value, △P, and H` are substituted into formula (1) to automatically calculate H 切机 value.

[0049] At the same time, the T j1 , SN1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 .

[0050] Step 2. For the same power grid, use the simulated machine cutting method and the unit accumulation method to calculate the moment of inertia values, and perform a comparative analysis.

[0051] Generally speaking, after studying different operation modes of a certain area power grid, 切机 With H 累加 A large number of calculations can be found that H 切机 With H 累加 The results show a linear relationship, and there are many factors that affect the sublinear relationship. The functional relationship between the two is as follows:

[0052] H 切机 =H 累加 / (K1×A+K2×B+K3) (4)

[0053] Among them, A and B are multiple factors that affect the linear relationship: A is the non-renewable energy power generation in the actual operation mode, B is the proportion of new energy in the actual operation mode, K1 is the coefficient corresponding to A, K2 is the coefficient corresponding to B, and K3 is a constant.

[0054] Step 3. Determine a fast and practical method for calculating the moment of inertia that is suitable for a certain power grid through the functional relationship between the two algorithms.

[0055] Based on the above inference, we can first use two methods to calculate the moment of inertia of multiple operating modes as a data sample library, and then find the multivariate linear regression function relationship between the ratio of the two algorithm results, the non-renewable energy power generation and the proportion of new energy in the data sample library. Using N operating modes to calculate the data sample library, we can get the multivariate linear regression function equation (4):

[0056] After obtaining the regression function K1, K2, K3 coefficients, first use the accumulation method to quickly calculate the moment of inertia H of a given operating mode. 累加 Then, the non-renewable energy power generation A of the actual operation mode and the proportion of renewable energy B of the actual operation mode are substituted into the regression function equation (4) and H 累加 Calculate the reverse H 切机 This is done by using the inherent relationship between the existing regional power grid cutting method and the accumulation method. When K1, K2, and K3 are known, the H 累加 , the actual operating mode of non-renewable energy power generation A and the actual operating mode of new energy proportion B, quickly calculate H 切机 result.

[0057] In the actual operation of the power grid, this method can quickly and accurately perform online calculation and evaluation of the moment of inertia, eliminating the tedious steps of simulation calculation while ensuring accuracy.

[0058] Example 2

[0059] The present invention further provides an embodiment, which is a fast and practical online calculation method for the moment of inertia, and is verified by the calculation method for the moment of inertia in the actual power grid.

[0060] The invention discloses a rapid and practical online calculation method for the moment of inertia, which is improved on the basis of a simulated machine cutting method and a unit accumulation method through a moment of inertia algorithm.

[0061] Grid rotational inertia: The moment of inertia is the measure of the inertia of a rigid body when it rotates around an axis. The grid rotational inertia is the sum of the rotational inertia of all online generators and loads in the power system under a specific operating mode.

[0062] In specific implementation, the present invention comprises the following steps:

[0063] Step 1. Calculate the moment of inertia of the same power grid using the simulated machine cutting method and the unit accumulation method respectively.

[0064] Taking the Northeast Power Grid as an example, the rotational inertia of 11 different operating modes was preliminarily calculated using the simulated machine cutting method and the unit accumulation method. The simulation was performed to cut off a single generator with the maximum rotational inertia of 1000MW. The system frequency change curve data obtained by simulating the power system analysis comprehensive program PSASP (Power System Analysis Software Package) was imported into the Matlab program. After the simulation, the df / dt average value in the 0-3 second interval was obtained. The df / dt average value, △P, and H` were substituted into formula (1) to automatically calculate H 切机 At the same time, the T j1 , S N1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 .

[0065] Step 2. For the same power grid, use the simulated machine cutting method and the unit accumulation method to calculate the moment of inertia values, and perform a comparative analysis.

[0066] H 切机 , H 累加 The data sample library consisting of the non-renewable energy power generation A in actual operation mode and the proportion of new energy in actual operation mode B is shown in Table 1 and Figure 1 shown.

[0067] Table 111 Sample library of operation mode data

[0068]

[0069]

[0070] From Table 1 and Figure 1 It can be seen that the preliminary calculation results of 11 different operation modes show that: 累加 (yellow curve ③) and H 切机 (Gray curve ②) are two nearly parallel curves; the ratio of the two (dark blue curve ⑤) is relatively straight and does not fluctuate much; the fluctuations of the two (such as the 5th, 6th, and 7th modes corresponding to the horizontal axis) are greatly affected by the proportion of renewable energy in the grid-connected power source B (red curve ④) and less affected by the non-renewable energy power generation A in the grid-connected power source (light blue curve ①). Other factors affecting the volatility of the two are unknown and need to be further explored in subsequent research. Although the sample size is small, it can be preliminarily inferred from the existing results that the mathematical relationship between the results of the two algorithms is relatively linear and is also affected by factors such as the non-renewable energy power generation A in the actual operation mode and the proportion of renewable energy B in the actual operation mode. After linear fitting, the Northeast Power Grid H is obtained. 切机 With H 累加 Linear relationship function between results:

[0071] H 切机 =H 累加 / (0.0000069428034×A-0.16386522×B+0.88763558) (5).

[0072] Step 3. The measured H 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of renewable energy proportion B and other data into formula (5), and get H 切机 The values ​​prove the accuracy and practicality of regression equations (4) and (5). Therefore, equations (4) and (5) can be used to conduct rapid and practical online evaluation of the moment of inertia of the Northeast Power Grid.

[0073] Specifically, the measured H in a 1000MW large single generator tripping event in the Northeast Power Grid in 2019 was 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of renewable energy proportion B and other data into formula (5), and get H 切机 It is 325092.8MW.s. The accuracy and practicality of regression equations (4) and (5) are proved, so equations (4) and (5) can be used for rapid and practical online evaluation of the moment of inertia of the Northeast Power Grid.

[0074] Among them, the tripping event of a 1000MW large single generator in the Northeast Power Grid in 2019 is as follows:

[0075] On a certain day in November 2019, a 1000MW large single generator in the Northeast Power Grid tripped, causing the frequency of the Liaoning Power Grid to drop from 50.05Hz to 49.90Hz, a drop of 0.15Hz. The fault occurred during the early peak period of the Liaoning Power Grid. The total power generation capacity of the Northeast Power Grid was 62.21 million kilowatts, and the unified load was 48.32 million kilowatts. At the time of the fault, the total thermal power generation of the Northeast Power Grid was 44.17 million kilowatts, accounting for 69%, the new energy power generation was 13.6 million kilowatts, accounting for 21%, and the nuclear power generation was 4.44 million kilowatts, accounting for 9.2%.

[0076] Example 3

[0077] Based on the same inventive concept, an embodiment of the present invention further provides a computer storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of a method for quickly and practically calculating the moment of inertia online described in Embodiments 1 and 2 are implemented.

[0078] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0079] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0080] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0081] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0082] Finally, 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A fast and practical online calculation method for the moment of inertia, including a simulated machine cutting method and a unit accumulation method, which calculates the moment of inertia of the system by using the simulated machine cutting method and the unit accumulation method; its characteristics are: The following steps are also included: Step 1. Use the simulated generator cutting method and the unit accumulation method to preliminarily calculate the moment of inertia of the power grid in the same area in different operating modes, including: simulate the cutting of a single generator with the largest moment of inertia in the entire network in the simulation program, obtain the average value of df / dt in the range of 0-3 seconds after simulation, substitute the average value of df / dt, △P, and H` into formula (1), and automatically calculate H 切机 value: In the formula, H 切机 is the system moment of inertia calculated by the machine-cutting method; df / dt is the frequency change rate; △P is the total power loss of the system failure, and H` is the moment of inertia corresponding to the single generator that has been disconnected from the grid; at the same time, the T j1 , S N1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 : Among them, H1 is the nominal value of the moment of inertia of a single online generator, T j1 is the inertia time constant, S N1 is the rated capacity of a single generator, ω is the angular velocity of the generator, in rad / s; f is the frequency of the generator, in Hz; 2πf is twice the circumference of pi π multiplied by the frequency f, in Hz; H 累加 =H1+H2+H3+...+H N (3) Among them, H1, H2, H3...H N is the moment of inertia of each of the N online units; Step 2: Compare and analyze the values ​​of the moment of inertia calculated by the simulation cutting method and the unit accumulation method for the same power grid, including: 切机 With H 累加 A large number of calculations found that H 切机 With H 累加 The results show a linear relationship, and the functional relationship between the two is as follows: H 切机 =H 累加 / (K1×A+K2×B+K3)(4) A is the non-renewable energy power generation in the actual operation mode, B is the proportion of renewable energy in the actual operation mode, K1 is the coefficient corresponding to A, K2 is the coefficient corresponding to B, and K3 is a constant; Step 3. Determine a fast and practical method for calculating the moment of inertia applicable to the power grid through the functional relationship between the two algorithms, including: first, using the two methods to calculate the moment of inertia of multiple operating modes as a data sample library, and then finding the multivariate linear regression function relationship between the ratio of the two algorithm results, the non-renewable energy power generation and the proportion of new energy in the data sample library; using N operating modes to calculate the data to obtain the sample library, and obtain formula (4): After obtaining the regression function coefficients K1, K2, and K3, first use the accumulation method to quickly calculate the moment of inertia H of a given operating mode 累加 , and then substitute the non-renewable energy power generation A of the actual operation mode and the proportion of renewable energy B of the actual operation mode into formula (4), and use H 累加 Calculate the reverse H 切机 .

2. The method for rapid and practical online calculation of moment of inertia according to claim 1 is characterized by: The step 1 uses the simulated machine cutting method and the unit accumulation method to preliminarily calculate the rotational inertia of different operation modes of the power grid in the same area, including: using the simulated machine cutting method and the unit accumulation method to preliminarily calculate the rotational inertia of 11 different operation modes; simulating the removal of a single generator with a maximum rotational inertia of 1000MW, importing the system frequency change curve data obtained by simulating the power system analysis and comprehensive program PSASP into the Matlab program, and obtaining the df / dt average value in the 0-3 second interval after simulation, substituting the df / dt average value, △P, and H` into formula (1), and automatically calculating H 切机 value; at the same time, the T j1 , S N1 Substitute the value into formula (2) to calculate the moment of inertia of a single generator, and use the unit accumulation method (3) to calculate the sum of the moments of inertia of all grid-connected generators H 累加 .

3. The method for rapid and practical online calculation of moment of inertia according to claim 2 is characterized by: Step 2: The rotation inertia values ​​calculated by the simulation cutting method and the unit accumulation method for the same power grid are compared and analyzed; including: 切机 , H 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of new energy proportion B constitute the data sample library, the preliminary calculation of 11 different operating modes results show: 累加 and H 切机 are two nearly parallel curves; the ratio of the two is relatively flat and does not fluctuate much; the fluctuation of the two is greatly affected by the proportion of renewable energy in the grid-connected power source B, and less affected by the non-renewable energy power generation A in the grid-connected power source; through the existing results, it can be preliminarily inferred that the mathematical relationship between the results of the two algorithms is relatively linear and is affected by the non-renewable energy power generation A in the actual operation mode and the proportion of renewable energy in the actual operation mode B. After linear fitting, the grid H is obtained. 切机 With H 累加 Linear relationship function between results: H 切机 =H 累加 / (0.0000069428034×A-0.16386522×B+0.88763558) (5); Step 3 is to determine a fast and practical method for calculating the moment of inertia of the power grid through the functional relationship between the two algorithms; including: 累加 , the actual operating mode of non-renewable energy power generation A, the actual operating mode of new energy proportion B data into formula (5), get H 切机 The values ​​prove the accuracy and practicality of regression equations (4) and (5). Therefore, equations (4) and (5) can be used to perform rapid and practical online evaluation of the power grid moment of inertia.

4. A computer storage medium, characterized in that: The computer storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the method for rapid and practical online calculation of moment of inertia described in any one of claims 1 to 3 are implemented.

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