A frequency safety assessment method and system taking into account spatial distribution and limiting links

Abstract

The present invention provides a frequency safety assessment method and system taking into account spatial distribution and limiting links, including: initializing equivalent speed regulator model parameters; establishing a vibration dynamics model based on model parameters, network parameters and preset fault information; solving the model to obtain the unit frequency; determining the conditional criterion and error of the primary frequency modulation energy according to the model parameters and frequency; when the error exceeds the error range, iterating and correcting the adjustment coefficient of the model for multiple times until the primary frequency modulation energy meets the conditional criterion; determining the conditional criterion and error of the primary frequency modulation power according to the model parameters and frequency; when the error exceeds the error range, iterating and correcting the equivalent first-order inertia time constant of the model for multiple times until the primary frequency modulation energy and power of the unit meet the condition and power criterion; outputting the frequency modulation energy of the speed regulator, the frequency of each unit and the safety conclusion. It can accurately reflect the response characteristics of the unit speed regulator after entering the limiting link, and the influence of the frequency spatial distribution characteristics on the frequency safety conclusion.

Description

Technical Field

[0001] The present invention relates to the technical field of power system safety assessment, and in particular to a frequency safety assessment method and system taking into account spatial distribution and amplitude limiting links. Background Art

[0002] The current mainstream frequency stability analysis method is mainly a mathematical analytical method for establishing a frequency response model analysis. However, this method ignores the reflection of the frequency space difference characteristics, aggregates the synchronous generator and the new energy unit into a model under a single inertia center, and uses an analytical calculation method to solve it, aiming to obtain the time domain expression of the frequency response curve. In a high-proportion new energy power system, the accuracy of the model will be significantly affected. In addition to the risk of failure of the unified inertia center assumption, with the diversification of frequency regulation resource response methods and the increasingly prominent characteristics of frequency regulation response speed and depth, the accuracy of equivalent aggregation of multiple speed regulators and rotors according to the original method will also decrease. This type of model is mainly suitable for systems with close electrical connections and similar frequency regulation response characteristics of different units, or for scenarios where only a rough analysis of the overall frequency change trend of the system is required and the analysis accuracy is not high.

[0003] The time-domain simulation method based on a detailed model has a relatively high calculation accuracy and almost no limitations on applicability, but it has the disadvantage of insufficient mechanism disclosure and is difficult to apply to online frequency stability analysis. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a frequency safety assessment method and system taking into account spatial distribution and limiting links, the method comprising:

[0005] Obtaining device parameters, network parameters and preset fault information of the system; initializing equivalent speed regulator model parameters by aggregating the device parameters;

[0006] Based on the initialized equivalent governor model parameters, network parameters and preset fault information, a vibration dynamics model is established; according to the modal analysis method, the vibration dynamics model is solved to obtain the common mode component and the oscillation component of the system; according to the common mode component and the oscillation component, the frequency of the unit is determined;

[0007] According to the parameters of the equivalent speed governor model and the frequency of the unit, the sum of each mechanical power change and the power change is calculated; the conditional criterion and error of the primary frequency regulation energy of the unit are determined according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation energy of the unit exceeds the error range, the adjustment coefficient of the equivalent speed governor model is corrected through multiple iterations, and the equivalent speed governor model is solved again until the primary frequency regulation energy of the unit meets the conditional criterion of the primary frequency regulation energy of the unit;

[0008] Determine the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, correct the equivalent first-order inertia time constant of the equivalent speed regulator model through multiple iterations, and re-solve the equivalent speed regulator model until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit;

[0009] Output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

[0010] Furthermore, by aggregating the device parameters, the equivalent speed regulator model parameters are initialized, specifically:

[0011]

[0012] The parameters of the two speed regulators are recorded as follows: S N1 and S N2 , the adjustment coefficients are R 1 and R 2. The work ratios of high pressure cylinders are F H1 and F H2 , the equivalent first-order inertia time constant is T R1 and T R2 , the aggregated equipment and control parameters are: Equipment capacity S N The adjustment coefficient is R , the work ratio of the high pressure cylinder is F H , the equivalent first-order inertia time constant is T R , It is the maximum value of the equivalent first-order inertia time constant of the conventional unit speed governor. All are intermediate variables.

[0013] Furthermore, based on the initialized equivalent speed regulator model parameters, network parameters and preset fault information, a vibration dynamics model is established, including:

[0014] Based on the initialized equivalent governor model parameters, network parameters and preset fault information, the frequency-dynamic vibration model of the multi-machine system under the original coordinates is specifically:

[0015]

[0016] in, is the column vector composed of the internal potential phase angles, They represent the diagonal matrices composed of the inertia time constant and damping coefficient of each unit, B K is the stiffness matrix representing the interaction between the rotors of each unit, B F is the distribution coefficient matrix of the system disturbance power distributed to the rotors of each unit, is a column vector composed of the mechanical power changes of the unit under the original coordinates, is the diagonal matrix composed of the primary frequency modulation transfer functions of each speed regulator of the synchronous unit under the original coordinates, is a column vector consisting of the disturbance power of each node in the system.

[0017] Furthermore, the vibration dynamics model is solved according to the modal analysis method to obtain the common mode component and oscillation component of the system, including:

[0018] By solving Get the natural oscillation frequency ,in, ; Solve for each The eigenvector of ,by is a matrix composed of column vectors It is called the vibration matrix, from which the vibration dynamics model in modal coordinates is obtained as follows:

[0019]

[0020] in, is the quantity to be solved in modal coordinates, M p is the mass matrix in modal coordinates, D p is the damping matrix in modal coordinates, K p is the elastic matrix in modal coordinates, F p is the excitation vector in modal coordinates, Represents the column vector composed of the mechanical power variation of the unit under modal coordinates;

[0021] Solving the above equation, we can get the mode 1 frequency The time domain expression of is:

[0022]

[0023] in

[0024]

[0025] In the above formula, All are intermediate variables;

[0026] The frequency of the ith mode whose modal order is greater than 1 The time domain expression of is:

[0027]

[0028] Further, determining the frequency of the unit according to the common mode component and the oscillation component includes:

[0029] Transform the modal coordinates back to the original coordinates to obtain the frequency of the i-th unit The time domain expression is:

[0030]

[0031] Further, according to the equivalent governor model parameters and the frequency of the unit, the sum of each mechanical power change and the power change is calculated, including:

[0032] Calculate the sum of the mechanical power changes of each unit :

[0033]

[0034] in, It is the change in mechanical power of each unit after the limiting link. is the upper limit of mechanical power of the i-th unit,

[0035]

[0036] The mechanical power variation of each unit before limiting is obtained by the following convolution calculation:

[0037]

[0038] Further, the condition criterion and error of the primary frequency regulation energy of the unit are determined according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation energy of the unit exceeds the error range, the adjustment coefficient of the equivalent speed regulator model is corrected through multiple iterations, and the equivalent speed regulator model is solved again until the primary frequency regulation energy of the unit meets the condition criterion of the primary frequency regulation energy of the unit, including:

[0039] The parameters are corrected according to the primary frequency regulation energy of the unit, and the energy condition criteria are defined as follows:

[0040]

[0041] in, is the power variation of the equivalent speed regulator model;

[0042]

[0043] In the above formula, is the maximum time deviation, is an intermediate variable;

[0044] The error of the primary frequency regulation energy of the unit is recorded as E err :

[0045]

[0046] When the error E err When the error range is exceeded, the adjustment coefficient of the equivalent speed regulator model is corrected. R，

[0047]

[0048] in, is the R value at the i+1th iteration, K K The intensity coefficient for correcting the parameter R is used. The corrected parameter R is used to re-solve the equivalent speed regulator model in an iterative manner until the primary frequency regulation energy of the unit meets the conditional criterion of the primary frequency regulation energy of the unit, and the iteration ends.

[0049] Further, the condition criterion and error of the primary frequency regulation power of the unit are determined according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected through multiple iterations, and the equivalent speed regulator model is solved again until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit, including:

[0050] The condition criteria for defining the primary frequency regulation power of the unit are:

[0051]

[0052] The error of the primary frequency regulation power of the unit is recorded as P err :

[0053]

[0054] Among them, when the error P err When the error range is exceeded, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected. T R ,

[0055]

[0056] in K T For the parameters T R The corrected strength coefficient is used to calculate the equivalent first-order inertia time constant. T R , the equivalent speed regulator model is solved again in an iterative manner until the primary frequency regulation energy and power of the unit meet the conditions and power criteria of the primary frequency regulation energy of the unit, and the iteration ends.

[0057] Furthermore, the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion are output, among which,

[0058] According to the maximum frequency deviation of the system output The safety decision to determine the system frequency, the maximum frequency deviation is:

[0059]

[0060] The frequency safety conclusion of the system is determined based on the maximum frequency deviation.

[0061] The present invention also provides a frequency safety assessment system taking into account spatial distribution and amplitude limiting links, including:

[0062] A model parameter initialization module is used to obtain the device parameters, network parameters and preset fault information of the system; and initialize the equivalent governor model parameters by aggregating the device parameters;

[0063] A model building module is used to establish a vibration dynamics model based on the initialized equivalent governor model parameters, network parameters and preset fault information; solve the vibration dynamics model according to the modal analysis method to obtain the common mode component and oscillation component of the system; determine the frequency of the unit according to the common mode component and the oscillation component;

[0064] A modulation coefficient correction module is used to calculate the sum of each mechanical power change and the power change according to the equivalent speed governor model parameters and the frequency of the unit; determine the conditional criterion and error of the unit's primary frequency regulation energy according to the sum of the mechanical power change and the power change; when the error of the unit's primary frequency regulation energy exceeds the error range, correct the modulation coefficient of the equivalent speed governor model through multiple iterations, and re-solve the equivalent speed governor model until the unit's primary frequency regulation energy meets the conditional criterion of the unit's primary frequency regulation energy;

[0065] A time constant correction module, used for determining the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, correcting the equivalent first-order inertia time constant of the equivalent speed regulator model through multiple iterations, and re-solving the equivalent speed regulator model until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit;

[0066] The conclusion output module is used to output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

[0067] The present invention provides a frequency safety assessment method and system taking into account the spatial distribution and the amplitude limiting link. The calculated common mode component frequency curve is consistent with the simulation result. The calculation error of the maximum frequency deviation and the maximum frequency deviation moment is less than 1%. The present invention can accurately reflect the response characteristics of the speed governor of the unit with frequency distribution characteristics after entering the amplitude limiting link. The existing analysis models are mostly single inertia center models, which cannot characterize the dynamics of multiple machines and cannot effectively analyze the frequency distribution characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a flow chart of a frequency safety assessment method taking into account spatial distribution and amplitude limiting links provided by an embodiment of the present invention;

[0069] Figure 2 is a flowchart of an algorithm solution involved in an embodiment of the present invention;

[0070] Figure 3 It is the IEEE 2-zone 4-machine system topology structure involved in the embodiment of the present invention;

[0071] Figure 4 It is a process demonstration of the decoupling-iterative approximation algorithm involved in the embodiment of the present invention;

[0072] Figure 5 It is a structural schematic diagram of a frequency safety assessment system taking into account spatial distribution and limiting links provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0073] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0074] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0075] Example 1

[0076] See also Figure 1-2 As shown, the present invention provides a frequency safety assessment method taking into account spatial distribution and limiting links, and the specific process is as follows:

[0077] Step S101, obtaining device parameters, network parameters and preset fault information of the system; initializing equivalent speed regulator model parameters by aggregating the device parameters.

[0078] Calculate the equivalent governor model parameters based on the device parameters, and consider the parameter correction when the governor parameters have a high difference. Take the aggregation process of two governors as an example:

[0079]

[0080] The parameters of the two speed regulators are recorded as follows: The equipment capacities are S N1 and S N2 , the adjustment coefficients are R 1 and R 2. The work ratios of high pressure cylinders are F H1 and F H2 , the equivalent first-order inertia time constant is T R1 and T R2 , the aggregated equipment and control parameters are: Equipment capacity S N The adjustment coefficient is R , the work ratio of the high pressure cylinder is F H , the equivalent first-order inertia time constant is T R , It is the maximum value of the equivalent first-order inertia time constant of the conventional unit speed governor. All are intermediate variables.

[0081] Step S102, based on the initialized equivalent governor model parameters, network parameters and preset fault information, establish a vibration dynamics model; solve the vibration dynamics model according to the modal analysis method to obtain the common mode component and oscillation component of the system; determine the frequency of the unit according to the common mode component and the oscillation component.

[0082] Based on the initialized equivalent governor model parameters, network parameters and preset fault information, the frequency-dynamic vibration model of the multi-machine system under the original coordinates is specifically:

[0083]

[0084] in, is the column vector composed of the internal potential phase angles, They represent the diagonal matrices composed of the inertia time constant and damping coefficient of each unit, B K is the stiffness matrix representing the interaction between the rotors of each unit, B F is the distribution coefficient matrix of the system disturbance power distributed to the rotors of each unit, is a column vector composed of the mechanical power changes of the unit under the original coordinates, is the diagonal matrix composed of the primary frequency modulation transfer functions of each speed regulator of the synchronous unit under the original coordinates, is a column vector consisting of the disturbance power of each node in the system.

[0085] By solving Get the natural oscillation frequency ,in, ; Solve for each The eigenvector of ,by is a matrix composed of column vectors It is called the vibration matrix, from which the vibration dynamics model in modal coordinates is obtained as follows:

[0086]

[0087] in, is the quantity to be solved in modal coordinates, M p is the mass matrix in modal coordinates, D p is the damping matrix in modal coordinates, K p is the elastic matrix in modal coordinates, F p is the excitation vector in modal coordinates, Represents the column vector composed of the mechanical power variation of the unit under modal coordinates;

[0088] Solving the above equation, we can get the mode 1 frequency The time domain expression of is:

[0089]

[0090] in,

[0091]

[0092] In the above formula, All are intermediate variables;

[0093] The frequency of the ith mode whose modal order is greater than 1 The time domain expression of is:

[0094]

[0095] Transform the modal coordinates back to the original coordinates to obtain the frequency of the i-th unit The time domain expression is:

[0096]

[0097] Step S103, according to the equivalent speed governor model parameters and the frequency of the unit, calculate the sum of each mechanical power change and the power change; determine the conditional criterion and error of the unit's primary frequency regulation energy according to the sum of the mechanical power change and the power change; when the error of the unit's primary frequency regulation energy exceeds the error range, correct the adjustment coefficient of the equivalent speed governor model through multiple iterations, and re-solve the equivalent speed governor model until the unit's primary frequency regulation energy meets the conditional criterion of the unit's primary frequency regulation energy.

[0098] The decoupling-iterative approximation solution framework is used to solve the aggregation model parameters and the system frequency safety level, as follows:

[0099] Calculate the sum of the mechanical power changes of each unit :

[0100]

[0101] in, It is the change in mechanical power of each unit after the limiting link. is the upper limit of mechanical power of the i-th unit,

[0102]

[0103] The mechanical power variation of each unit before limiting is obtained by the following convolution calculation:

[0104]

[0105] The common mode component frequency calculation and the mechanical power change calculation under the action of the speed regulator are performed alternately until convergence. Specifically, the parameters are corrected according to the primary frequency regulation energy of the unit, and the conditional criterion for defining the energy is:

[0106]

[0107] in, is the power variation of the equivalent speed regulator model;

[0108]

[0109] In the above formula, is the maximum time deviation, is an intermediate variable;

[0110] The error of the primary frequency regulation energy of the unit is recorded as E err :

[0111]

[0112] When the error E err When the error range is exceeded, the adjustment coefficient of the equivalent speed regulator model is corrected. R，

[0113]

[0114] in, is the R value at the i+1th iteration, K K The intensity coefficient for correcting the parameter R is used. The corrected parameter R is used to re-solve the equivalent speed regulator model in an iterative manner until the primary frequency regulation energy of the unit meets the conditional criterion of the primary frequency regulation energy of the unit, and the iteration ends.

[0115] Step S104, determining the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, correcting the equivalent first-order inertia time constant of the equivalent speed regulator model through multiple iterations, and re-solving the equivalent speed regulator model until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit.

[0116] When the conditional criterion of the primary frequency regulation energy of the unit is met, the parameters are further corrected according to the power error. Specifically, the conditional criterion of the primary frequency regulation power of the unit is defined as:

[0117]

[0118] The error of the primary frequency regulation power of the unit is recorded as P err :

[0119]

[0120] Among them, when the error P err When the error range is exceeded, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected. T R ,

[0121]

[0122] in K T For the parameters T R The corrected strength coefficient is used to calculate the equivalent first-order inertia time constant. T R , the equivalent speed regulator model is solved again in an iterative manner until the primary frequency regulation energy and power of the unit meet the conditions and power criteria of the primary frequency regulation energy of the unit, and the iteration ends.

[0123] Step S105, outputting the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

[0124] Among them, the safety decision of the system frequency is determined according to the maximum frequency deviation of the system output, and the maximum frequency deviation is:

[0125]

[0126] The frequency safety conclusion of the system is determined based on the maximum frequency deviation.

[0127] Example 2

[0128] In order to verify the accuracy and effectiveness of this scheme, based on Figure 3 The IEEE 2-zone 4-machine example shown in Figure 1 compares the approximate solution calculation results based on this scheme with the time domain simulation results based on Simulink. The main parameters of the generator set and its speed regulator are shown in Table 1.

[0129] Table 1 Main parameters of the generator set and its speed regulator

[0130]

[0131] A single-pole blocking fault is set to occur in the DC at bus 7, causing the system to generate a power shortage of 200MW.

[0132] The calculation effect and iteration of the present invention are shown in FIG4 .

[0133] The common mode component frequency curve calculated by the present invention is consistent with the simulink simulation result, and the calculation errors of the maximum frequency deviation and the maximum frequency deviation moment are less than 1%. The present invention can accurately reflect the response characteristics of the unit speed governor with frequency distribution characteristics after entering the limiting link.

[0134] Example 3

[0135] Based on the same inventive concept, the present invention also provides a frequency safety assessment system taking into account spatial distribution and limiting links, such as Figure 5 As shown, including:

[0136] The model parameter initialization module 510 is used to obtain the device parameters, network parameters and preset fault information of the system; and initialize the equivalent governor model parameters by aggregating the device parameters;

[0137] The model building module 520 is used to establish a vibration dynamics model based on the initialized equivalent governor model parameters, network parameters and preset fault information; solve the vibration dynamics model according to the modal analysis method to obtain the common mode component and oscillation component of the system; determine the frequency of the unit according to the common mode component and the oscillation component;

[0138] The adjustment coefficient correction module 530 is used to calculate the sum of each mechanical power change and the power change according to the equivalent speed governor model parameters and the frequency of the unit; determine the condition criterion and error of the unit's primary frequency regulation energy according to the sum of the mechanical power change and the power change; when the error of the unit's primary frequency regulation energy exceeds the error range, correct the adjustment coefficient of the equivalent speed governor model through multiple iterations, and re-solve the equivalent speed governor model until the unit's primary frequency regulation energy meets the condition criterion of the unit's primary frequency regulation energy;

[0139] The time constant correction module 540 is used to determine the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected through multiple iterations, and the equivalent speed regulator model is re-solved until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit;

[0140] The conclusion output module 550 is used to output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

[0141] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 produce 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.

[0143] 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 including 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.

[0144] 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.

[0145] 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, and any modifications or equivalents that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A frequency safety assessment method taking into account spatial distribution and limiting links, characterized in that: include: Obtaining device parameters, network parameters and preset fault information of the system; initializing equivalent speed regulator model parameters by aggregating the device parameters; Based on the initialized equivalent speed regulator model parameters, network parameters and preset fault information, a vibration dynamics model is established; and according to the modal analysis method, the vibration dynamics model is solved to obtain the common mode component and the oscillation component of the system; Determining the frequency of the unit according to the common mode component and the oscillation component; According to the parameters of the equivalent speed governor model and the frequency of the unit, the sum of each mechanical power change and the power change is calculated; the conditional criterion and error of the primary frequency regulation energy of the unit are determined according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation energy of the unit exceeds the error range, the adjustment coefficient of the equivalent speed governor model is corrected through multiple iterations, and the equivalent speed governor model is solved again until the primary frequency regulation energy of the unit meets the conditional criterion of the primary frequency regulation energy of the unit; Determine the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, correct the equivalent first-order inertia time constant of the equivalent speed regulator model through multiple iterations, and re-solve the equivalent speed regulator model until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit; Output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

2. The method according to claim 1, characterized in that By aggregating the device parameters, the equivalent speed regulator model parameters are initialized, specifically: The parameters of the two speed regulators are recorded as follows: S N1 and S N2 , the adjustment coefficients are R 1 and R 2. The work ratios of high pressure cylinders are F H1 and F H2 , the equivalent first-order inertia time constant is T R1 and T R2 , the aggregated equipment and control parameters are: Equipment capacity S N The adjustment coefficient is R , the work ratio of the high pressure cylinder is F H , the equivalent first-order inertia time constant is T R , It is the maximum value of the equivalent first-order inertia time constant of the conventional unit speed governor. All are intermediate variables.

3. The method according to claim 1, characterized in that: Based on the initialized equivalent speed regulator model parameters, network parameters and preset fault information, a vibration dynamics model is established, including: Based on the initialized equivalent governor model parameters, network parameters and preset fault information, the frequency-dynamic vibration model of the multi-machine system under the original coordinates is specifically: in, is the column vector composed of the internal potential phase angles, They represent the diagonal matrices composed of the inertia time constant and damping coefficient of each unit, B K is the stiffness matrix representing the interaction between the rotors of each unit, B F is the distribution coefficient matrix of the system disturbance power distributed to the rotors of each unit, is a column vector composed of the mechanical power changes of the unit under the original coordinates, is the diagonal matrix composed of the primary frequency modulation transfer functions of each speed regulator of the synchronous unit under the original coordinates, is a column vector consisting of the disturbance power of each node in the system.

4. The method according to claim 1, characterized in that The common mode components and oscillation components of the system are obtained by solving the vibration dynamics model according to the modal analysis method, including: By solving Get the natural oscillation frequency ,in, ; Solve for each The eigenvector of ,by The matrix composed of column vectors is called the mode matrix , thus the vibration dynamics model in modal coordinates is: in, is the quantity to be solved in modal coordinates, M p is the mass matrix in modal coordinates, D p is the damping matrix in modal coordinates, K p is the elastic matrix in modal coordinates, F p is the excitation vector in modal coordinates, Represents the column vector composed of the mechanical power variation of the unit under modal coordinates; Solving the above equation, we can get the mode 1 frequency The time domain expression of is: in In the above formula, All are intermediate variables; The frequency of the ith mode whose modal order is greater than 1 The time domain expression of is:

5. The method according to claim 1, characterized in that Determining the frequency of the unit according to the common mode component and the oscillation component includes: Transform the modal coordinates back to the original coordinates to obtain the frequency of the i-th unit The time domain expression is:

6. The method according to claim 1, characterized in that According to the equivalent governor model parameters and the frequency of the unit, the sum of each mechanical power change and the power change is calculated, including: Calculate the sum of the mechanical power changes of each unit : in, It is the change in mechanical power of each unit after the limiting link. is the upper limit of mechanical power of the i-th unit, The mechanical power variation of each unit before limiting The following convolution calculation is obtained 7. The method according to claim 1, characterized in that The condition criterion and error of the primary frequency regulation energy of the unit are determined according to the sum of the mechanical power variation and the power variation; when the error of the primary frequency regulation energy of the unit exceeds the error range, the adjustment coefficient of the equivalent speed regulator model is corrected through multiple iterations, and the equivalent speed regulator model is re-solved until the primary frequency regulation energy of the unit meets the condition criterion of the primary frequency regulation energy of the unit, including: The parameters are corrected according to the primary frequency regulation energy of the unit, and the energy condition criteria are defined as follows: in, is the power variation of the equivalent speed regulator model; In the above formula, is the maximum time deviation, is an intermediate variable; The error of the primary frequency regulation energy of the unit is recorded as E err : When the error E err When the error range is exceeded, the adjustment coefficient of the equivalent speed regulator model is corrected. R， in, is the R value at the i+1th iteration, K K The intensity coefficient for correcting the parameter R is used. The corrected parameter R is used to re-solve the equivalent speed regulator model in an iterative manner until the primary frequency regulation energy of the unit meets the conditional criterion of the primary frequency regulation energy of the unit, and the iteration ends.

8. The method according to claim 1, characterized in that The condition criterion and error of the primary frequency regulation power of the unit are determined according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected through multiple iterations, and the equivalent speed regulator model is re-solved until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit, including: The condition criteria for defining the primary frequency regulation power of the unit are: The error of the primary frequency regulation power of the unit is recorded as P err : Among them, when the error P err When the error range is exceeded, the equivalent first-order inertia time constant of the equivalent speed regulator model is corrected. T R , in K T For the parameters T R The corrected strength coefficient is used to calculate the equivalent first-order inertia time constant. T R , the equivalent speed regulator model is solved again in an iterative manner until the primary frequency regulation energy and power of the unit meet the conditions and power criteria of the primary frequency regulation energy of the unit, and the iteration ends.

9. The method according to claim 1, characterized in that: Output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion, among which, According to the maximum frequency deviation of the system output The safety decision to determine the system frequency, the maximum frequency deviation is: The frequency safety conclusion of the system is determined based on the maximum frequency deviation.

10. A frequency safety assessment system taking into account spatial distribution and limiting links, characterized in that: include: A model parameter initialization module is used to obtain the device parameters, network parameters and preset fault information of the system; and initialize the equivalent governor model parameters by aggregating the device parameters; A model building module, used to build a vibration dynamics model based on the initialized equivalent speed regulator model parameters, network parameters and preset fault information; solve the vibration dynamics model according to the modal analysis method to obtain the common mode component and oscillation component of the system; Determining the frequency of the unit according to the common mode component and the oscillation component; A modulation coefficient correction module is used to calculate the sum of each mechanical power change and the power change according to the equivalent speed governor model parameters and the frequency of the unit; determine the conditional criterion and error of the unit's primary frequency regulation energy according to the sum of the mechanical power change and the power change; when the error of the unit's primary frequency regulation energy exceeds the error range, correct the modulation coefficient of the equivalent speed governor model through multiple iterations, and re-solve the equivalent speed governor model until the unit's primary frequency regulation energy meets the conditional criterion of the unit's primary frequency regulation energy; A time constant correction module, used for determining the condition criterion and error of the primary frequency regulation power of the unit according to the sum of the mechanical power change and the power change; when the error of the primary frequency regulation power of the unit exceeds the error range, correcting the equivalent first-order inertia time constant of the equivalent speed regulator model through multiple iterations, and re-solving the equivalent speed regulator model until the primary frequency regulation energy and power of the unit meet the condition and power criterion of the primary frequency regulation energy of the unit; The conclusion output module is used to output the frequency regulation energy of the speed regulator, the frequency of each unit and the safety conclusion.

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