Method and system for screening sending-end high-frequency control scenes triggered by multiple types of disturbances

Abstract

The invention discloses a method for screening sending-end high-frequency control scenes caused by multi-type disturbance, and the method comprises the steps: obtaining power grid system data and a power grid structure, selecting a typical operation mode based on the power grid system data and the power grid structure, initializing a fault set corresponding to the typical operation mode, and obtaining a first fault set; defining an R value model, adjusting the boundary of a system operation mode according to constraint factors of the R value model and a typical operation mode, generating an operation mode set, setting first fault set simulation according to the operation mode set, and calculating according to constraint conditions to obtain a system quasi-steady-state frequency deviation maximum value after a fault; defining a high-frequency control action criterion, and comparing and screening out a scene meeting a high-frequency control condition according to the maximum value of the quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion; a xi value model is defined, the most serious high-frequency control scene is screened out for the high-frequency control condition scene according to the xi value calculation result, and the emergency control failure and the third defense line maloperation risk are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automatic control, and in particular to a method and system for screening high-frequency control scenarios of a multi-type disturbance-induced transmitter. Background Art

[0002] my country's Southwest Power Grid will build new Jinshang-Hubei UHV DC, Southeast Tibet-Guangdong-Hong Kong-Macao Greater Bay Area UHV DC and Sichuan-Chongqing UHV AC projects. The projects are located in my country's high-altitude areas. After the new energy is collected through the multi-voltage AC grid and sent through DC, it interacts with the local AC weak grid. After the AC fault or DC commutation failure, lockout, restart and other disturbances, the fault will cause a large number of new energy access low-voltage penetration, short-term disturbances and permanent disturbances are intertwined, and the high-frequency characteristics of the system are complex. When the actual power grid fault occurs and generates high frequency, there are usually emergency control and the third line of defense high-frequency cutting control to solve it. For example, after the continuous commutation failure of the three major UHV DC in the southwest, the emergency control is triggered by the active DC lockout measures to avoid the high-frequency risk of the system; for example, in order to avoid further system frequency deterioration caused by the large number of synchronous machines cut, the Northwest Power Grid has set up a round of low-threshold new energy cutting rounds, expanding the existing frequency defense line of the sending-end power grid. That is, the existing second and third line frequency defense system has made great contributions to ensuring the stability of the system frequency.

[0003] However, with the construction of AC / DC projects, recoverable short-term faults such as multiple DC commutation failures and large-scale low-frequency penetration of new energy have occurred frequently. Once the high-frequency cutting machine is triggered and restored, it will face the risk of high and low frequency chain reaction. Therefore, it is necessary to systematically sort out and screen the permanent frequency disturbances such as high frequency of isolated grid caused by permanent line disconnection, low voltage and high frequency caused by system voltage-frequency coupling, high frequency of system caused by safety control refusal to operate or under-cutting after DC locking, short-term high frequency caused by DC commutation failure, short-term high frequency of system caused by AC faults, etc., to enhance the understanding of the causes of high frequency, and provide control scenarios and control needs for the subsequent frequency emergency control involving flexible resources such as new energy and energy storage, and optimization of the third line of defense constants for high-frequency cutting, to avoid false operation of the third line of defense high-frequency cutting machine caused by short-term disturbances, insufficient control of the second line of defense caused by permanent disturbances, or empty control cutting caused by low-frequency penetration of new energy, etc., to achieve the optimization and improvement of the frequency defense system under the background of new power system. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: the present invention solves the problem of frequent recoverable short-term faults such as multiple DC commutation failures and large-scale low-frequency penetration of new energy in the construction of AC and DC projects. Once the high-frequency shear machine is triggered and recovered, it will face the risk of high and low frequency chain reactions.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for screening high-frequency control scenarios of a multi-type disturbance-induced transmitter, comprising:

[0008] Acquire power grid system data and power grid grid structure, select a typical operation mode based on the power grid system data and power grid grid structure, initialize a fault set corresponding to the typical operation mode, and obtain a first fault set;

[0009] Define the R value model, adjust the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generate an operation mode set, set the first fault set simulation according to the operation mode set, and calculate the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions;

[0010] Define the high-frequency control action criterion, and screen out the scenarios that meet the high-frequency control conditions based on the comparison between the maximum quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion;

[0011] Define the ξ value model, and screen out the maximum value of the ξ value for the high-frequency control condition scenario based on the ξ value calculation results, and take the maximum value as the most serious high-frequency control scenario.

[0012] As a preferred solution of the method for screening high-frequency control scenarios of the transmitter caused by multiple types of disturbances described in the present invention, the initialization of the fault set corresponding to the typical operation mode includes:

[0013] The first fault set includes a short-term fault set and a permanent fault set;

[0014] The short-term fault set can be: AC line N-2 / N-1 fault near the sending-end DC, DC commutation failure, and DC restart success;

[0015] Permanent faults may include DC blocking fault at the sending end, DC restart failure, and DC blocking fault.

[0016] As a preferred solution of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter described in the present invention, the R value model includes:

[0017] The startup capacity of renewable energy is divided by the system static load minus the unbalanced power caused by system disturbances, among which, the startup capacity of renewable energy is less than or equal to the maximum capacity of renewable energy acceptable to the power grid system, the system static load is greater than or equal to the minimum load under the historical operation mode data of the system, and the unbalanced power caused by system disturbances is less than or equal to the maximum disturbance power acceptable to the power grid system.

[0018] As a preferred solution of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter described in the present invention, it also includes:

[0019] Adjusting the flow operation boundary includes:

[0020] The load is reduced to the minimum load, the capacity of the synchronous units is reduced, and the capacity of the new energy units remains unchanged;

[0021] The DC transmission power remains unchanged, the capacity of the synchronous units is reduced to the safety start-up capacity, and the capacity of the new energy units is increased;

[0022] The capacity of synchronous units remains unchanged, the DC transmission power increases to the maximum transmission capacity, and the capacity of new energy units increases.

[0023] As a preferred solution of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter described in the present invention, the maximum value of the quasi-steady-state frequency deviation of the system after the fault is calculated according to the constraint conditions, including:

[0024] Select a short-term fault type and a permanent fault type, set fault parameters for the short-term fault type and the permanent fault type, and perform short-term fault simulation and permanent fault simulation;

[0025] The power grid response when short-term faults and permanent faults occur is simulated in the power grid model to obtain the maximum frequency deviation corresponding to each fault;

[0026] Adjust the operation mode, calculate the R value in the system, and compare it with the R value calculated last time. If the last R value is less than or equal to the R value in the system, switch to short-term fault simulation or permanent fault simulation;

[0027] Comparing the frequency results of each operating mode fault set after simulation, according to the high-frequency machine cutting criterion, the high-frequency machine cutting action fault and system operation mode are determined as follows:

[0028] When the system frequency is greater than or equal to the frequency threshold, and the time from the occurrence of the fault to the current time is greater than or equal to the time threshold, the system operation mode executes the system flow operation mode corresponding to the R value that triggers the high-frequency machine cutting action after the system fault. The high-frequency machine cutting action fault is an expected fault that triggers the system flow operation mode when the system quasi-steady-state frequency deviation triggers the system.

[0029] As a preferred solution of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter described in the present invention, the high-frequency control action criterion includes:

[0030] When a system failure occurs, if the highest transient frequency of the system does not exceed the first frequency threshold, the automatic high-frequency cutting device should not operate;

[0031] The frequency starting threshold of the first round of high-frequency cutting action is not lower than the frequency threshold.

[0032] As a preferred solution of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter of the present invention, the most serious high-frequency control scenario is screened out according to the ξ value calculation result, including:

[0033] The ξ index value model is expressed as:

[0034]

[0035] Among them, t0 is the time when the result frequency value reaches the frequency threshold after setting the fault simulation, t Δ To set the fault simulation result frequency to f Δ Moment, f Δi is the frequency deviation value corresponding to the i-th second after the simulated fault occurs, f Δ is the maximum frequency deviation value after the simulated fault occurs, and g is the system frequency sampling interval value;

[0036] Calculate the ξ value in the scenario results that meet the high-frequency control criteria, and screen out the most serious high-frequency control scenario based on the ξ value.

[0037] In a second aspect, the present invention provides a system for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances, comprising:

[0038] An initialization module is used to obtain power grid system data and power grid grid structure, select a typical operation mode based on the power grid system data and power grid grid structure, initialize a fault set corresponding to the typical operation mode, and obtain a first fault set;

[0039] A calculation module is used to define an R value model, adjust the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generate an operation mode set, set the first fault set simulation according to the operation mode set, and calculate the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions;

[0040] The comparison module is used to define the high-frequency control action criterion, and screen out the scenarios that meet the high-frequency control conditions based on the comparison between the maximum value of the quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion;

[0041] The screening module is used to define the ξ value model, screen out the maximum value of the ξ value according to the ξ value calculation result for the high-frequency control condition scenario, and take the maximum value as the most serious high-frequency control scenario.

[0042] In a third aspect, the present invention provides a computing device, comprising:

[0043] Memory and processor;

[0044] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the method for screening high-frequency control scenarios of the multi-type disturbance-induced transmitter are implemented.

[0045] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the method for screening high-frequency control scenarios of a multi-type disturbance-induced transmitter.

[0046] The beneficial effects of the present invention are as follows: the present invention considers the influence of three factors, namely, the static load of the power grid, the access amount of new energy and the system disturbance, combines the existing stabilization and control cutting measures, estimates the scenario set of high-risk high-frequency control of the power grid system at the sending end, constructs an index for judging the severity of the disturbance of the system frequency, and then quickly calculates the high-frequency control action scenarios caused by the system frequency deviation and delay after short-term and permanent disturbances, realizes the rapid assessment of the high-frequency risks caused by the access of new energy and the increase in the scale of DC transmission, improves the understanding of the causes of high frequency in weak power grids at the sending end, and avoids the risk of emergency control failure and false operation of the third line of defense. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0048] Figure 1 An overall flow chart of a method for screening high-frequency control scenarios of a multi-type disturbance-induced transmitter provided by the present invention;

[0049] Figure 2 An actual power grid geographical wiring diagram of a multi-type disturbance-induced high-frequency control scenario screening method provided by the present invention;

[0050] Figure 3 A system frequency curve diagram of a method for screening high-frequency control scenarios at a transmitting end caused by multiple types of disturbances provided by the present invention. DETAILED DESCRIPTION

[0051] 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.

[0052] 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.

[0053] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0054] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0055] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0056] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] Example 1

[0058] Reference Figure 1 , is an embodiment of the present invention, and provides a method for screening high-frequency control scenarios of a multi-type disturbance-induced transmitter, comprising:

[0059] S100: acquiring power grid system data and a power grid structure, selecting a typical operation mode based on the power grid system data and the power grid structure, initializing a fault set corresponding to the typical operation mode, and obtaining a first fault set;

[0060] In the embodiment of the present application, the first fault set includes a short-term fault set and a permanent fault set;

[0061] The short-term fault set can be: AC line N-2 / N-1 fault near the sending-end DC, DC commutation failure, and DC restart success;

[0062] Permanent faults may include DC blocking fault at the sending end, DC restart failure, and DC blocking fault.

[0063] Specifically, short-term faults can also be instantaneous voltage sags, small equipment failures, instantaneous load fluctuations, etc.

[0064] Permanent failures can also include damage to large equipment, serious line failures, failures caused by natural disasters, etc.

[0065] Among the short-term faults of the present invention, the short-circuit faults give priority to selecting the DC near area with heavier current, including the AC line preset N-1 / N-2 faults, DC commutation failure, and DC restart;

[0066] Permanent faults include all DC single / bipolar lockout faults, commutation failure lockout, and DC restart failure in the sending-end power grid system at the same time or successively. Single-circuit DC lockout considers safety and control measures and safety and control refusal to operate. Multiple-circuit DC lockout considers safety and control measures operation.

[0067] It should be noted that in power system planning and operation, fault simulation and analysis can help understand the system performance under different fault conditions and ensure rapid response when a fault occurs.

[0068] S200: defining an R value model, adjusting the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generating an operation mode set, setting a first fault set simulation according to the operation mode set, and calculating the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions;

[0069] In an embodiment of the present application, the R value model includes the startup capacity of the new energy divided by the system static load minus the unbalanced power caused by the system disturbance, wherein the startup capacity of the new energy is less than or equal to the maximum capacity of the new energy acceptable to the power grid system, the system static load is greater than or equal to the minimum load under the historical operating mode data of the system, and the unbalanced power caused by the system disturbance is less than or equal to the maximum disturbance power acceptable to the power grid system.

[0070] Specifically, for power systems with high penetration of renewable energy, it is necessary to introduce variables that characterize the penetration rate into the power grid system, determine the increase in the proportion of renewable energy power generation, and define an index R value model based on renewable energy power generation to evaluate the frequency anti-disturbance capability of the system, which is expressed as:

[0071]

[0072] Among them, Se is the startup capacity of renewable energy, Se≤the maximum capacity of renewable energy that the power grid system can accept, L is the static load of the system, L≥the minimum load under the historical operation mode data of the system, ΔP is the unbalanced power generated by the system disturbance, ΔP≤the maximum disturbance power that the power grid system can accept, at time t=0, ΔP| t＝0+ Get the maximum value under the selected method, and R(t) gets the maximum value.

[0073] In the embodiment of the present application, adjusting the flow operation boundary includes:

[0074] The load is reduced to the minimum load, the capacity of the synchronous units is reduced, and the capacity of the new energy units remains unchanged;

[0075] The DC transmission power remains unchanged, the capacity of the synchronous units is reduced to the safety start-up capacity, and the capacity of the new energy units is increased;

[0076] The capacity of synchronous units remains unchanged, the DC transmission power increases to the maximum transmission capacity, and the capacity of new energy units increases.

[0077] Specifically, the boundary adjustments of the power flow operation are marked as follows: a. the load is reduced to the minimum load, the capacity of the synchronous unit is reduced, and the capacity of the new energy unit remains unchanged; b. the DC transmission power remains unchanged, the capacity of the synchronous unit is reduced to the safety start-up capacity, and the capacity of the new energy unit is increased; c. the capacity of the synchronous unit remains unchanged, the DC transmission power is increased to the maximum transmission capacity, and the capacity of the new energy unit is increased. The above a, b, and c all increase the proportion of the new energy unit capacity a, and each iteration increases b. The b value is an artificially defined value, and a+b≤the maximum proportion of new energy that the system can connect to.

[0078] It should be noted that by optimizing the operating mode, increasing the proportion of new energy in the power system, reducing dependence on traditional energy, and adjusting the operating boundaries, we can better manage the unbalanced power of the power system, reduce frequency deviations caused by disturbances, reasonably allocate the capacity of synchronous units and new energy units, and improve the operating efficiency and economy of the power system.

[0079] In the embodiment of the present application, a short-term fault type and a permanent fault type are selected, fault parameters are set for the short-term fault type and the permanent fault type, and short-term fault simulation and permanent fault simulation are performed;

[0080] The power grid response when short-term faults and permanent faults occur is simulated in the power grid model to obtain the maximum frequency deviation corresponding to each fault;

[0081] Adjust the operation mode, calculate the R value in the system, and compare it with the R value calculated last time. If the last R value is less than or equal to the R value in the system, switch to short-term fault simulation or permanent fault simulation;

[0082] Comparing the frequency results of each operating mode fault set after simulation, according to the high-frequency machine cutting criterion, the high-frequency machine cutting action fault and system operation mode are determined as follows:

[0083] When the system frequency is greater than or equal to the frequency threshold, and the time from the occurrence of the fault to the current time is greater than or equal to the time threshold, the system operation mode executes the system flow operation mode corresponding to the R value that triggers the high-frequency machine cutting action after the system fault. The high-frequency machine cutting action fault is an expected fault that triggers the system flow operation mode when the system quasi-steady-state frequency deviation triggers the system.

[0084] For example, a typical transmission-end power grid operation mode is selected to set short-term and permanent fault sets. Among short-term faults, AC short-circuit faults are preferred to DC near-zone selection, and permanent faults are selected from all DC simultaneous or successive single / double-pole blocking faults. All faults are numbered G i ,i=1,2,3…;

[0085] The startup capacity of new energy sources, the static load of the system, and the maximum unbalanced power generated by system disturbances in the statistical power flow data are calculated, and a certain time for the fault to occur is set in the basic power flow data;

[0086] For short-term fault simulation:

[0087] Scan the AC faults in short-term faults, record the DC sending end constant current control failure, power flow blocking, short-circuit faults, local low voltage and high frequency of the load, and filter out the maximum frequency deviation W j_max ;

[0088] Scan all single-circuit DC circuits in the system for k (k = 1, 2, 3...) commutation failures, and ensure that the system does not lose stability until W l-k ≤W l-k-1 , according to the maximum system frequency deviation W l-kmax Sorting;

[0089] According to W l-k Calculate n (n=1,2,3…) DC simultaneous commutation failure x (x=1,2,3…,x≤12) times in descending order, and select the maximum value of system frequency deviation W according to the system instability criterion. n_max ;

[0090] Scan all single-circuit DC in the system for p (p = 1, 2, 3...) times and restart to ensure that the system does not lose stability until W p ≤W P-1 , according to the maximum system frequency deviation W p_max Sorting;

[0091] According to W l-kCalculate z (z=1,2,3…) DC simultaneous commutation failures and q (q=1,2,3…) faults in descending order from large to small, and select the maximum value of system frequency deviation W according to the system instability criterion. z_qmax ;

[0092] For permanent fault simulation:

[0093] Scan all single-circuit DC circuits in the system with permanent faults and restart them u (u=1,2,3…) times respectively. Failure to ensure that the system does not lose stability until W u ≤W u-1 , according to the maximum system frequency deviation W u_max Sorting;

[0094] According to W l-k Calculate h (h=1,2,3…) DC simultaneous commutation failures d (d=1,2,3…) times in descending order, and select the maximum value of system frequency deviation W according to the system instability criterion. h_dmax ;

[0095] Scan all single-circuit DC bipolar blocking faults. For single DC blocking, consider safety control measures and safety control refusal to operate; ensure that the system does not lose stability until W l_c ≤W l_c-1 , according to the maximum system frequency deviation W l_cmax Perform DC fault sequencing;

[0096] According to W l_c Calculate y (y=1,2,3…,y≤maximum number of DC loops) DC single / double blocking faults simultaneously in descending order, consider safety control measures for multiple DC blocking, and select the maximum value of system frequency deviation W according to the system instability criterion. c_max .

[0097] Adjust the operation mode, number D j ,Comparing the frequency results of each operating mode fault set after simulation, according to the high-frequency machine cutting criterion, the high-frequency machine cutting action fault and system operation mode are determined as follows:

[0098]

[0099] Among them, D i-w The high-frequency cutting action is triggered after the system fails. R=R j The system power flow operation mode, G i-w is the expected fault of the system quasi-steady-state frequency deviation triggering the system power flow operation mode, W is the recorded fault set simulation result frequency value, f * is the frequency threshold, and τ is the delay threshold.

[0100] S300: define high-frequency control action criteria, and select scenarios that meet high-frequency control conditions based on the comparison between the maximum value of the quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criteria;

[0101] In the embodiment of the present application, when a system failure occurs, if the highest transient frequency of the system does not exceed the first frequency threshold, the automatic high-frequency cutting device should not operate;

[0102] The frequency starting threshold of the first round of high-frequency cutting action is not lower than the frequency threshold.

[0103] Specifically, if the highest transient frequency of the system does not exceed the first frequency threshold fHz, the automatic high-frequency cutting device should not operate; the first round of frequency starting threshold of the high-frequency cutting machine is generally not lower than the frequency threshold f * ; The frequency threshold difference and delay τ between each round of high-frequency cutting machine should be selected as 0.3s≤τ≤0.5s. The setting should avoid false operation or overshoot. The frequency threshold difference should be selected as 0.1Hz-0.3Hz.

[0104] It should be noted that by precisely controlling the triggering conditions of high-frequency machine cutting, the system instability caused by frequency deviation can be reduced, thereby improving the stability of the entire power system. Reasonable setting of thresholds and delays can more effectively manage loads and avoid unnecessary load cutting. At the same time, it can ensure timely response when it is really needed, improve the efficiency of high-frequency machine cutting response, and ensure that the system frequency can be restored quickly and effectively at critical moments.

[0105] S400: defining a ξ value model, and screening out the most serious high-frequency control scenario according to the ξ value calculation result for the high-frequency control condition scenario;

[0106] In the embodiment of the present application, the ξ index value model is expressed as:

[0107]

[0108] Among them, t0 is the time when the result frequency value reaches the frequency threshold after setting the fault simulation, t Δ To set the fault simulation result frequency to f Δ Moment, f Δi is the frequency deviation value corresponding to the i-th second after the simulated fault occurs, f Δ is the maximum frequency deviation value after the simulated fault occurs, and g is the system frequency sampling interval value;

[0109] Calculate the ξ value in the scenario results that meet the high-frequency control criteria, and screen out the most serious high-frequency control scenario based on the ξ value.

[0110] Specifically, g is the system frequency sampling interval value, which can be taken as 0.01s in general calculation;

[0111] It should be noted that the control quantity rapid calculation method of high-frequency machine cutting control risk is only applicable to screening faults and scenarios that meet the high-frequency machine cutting criteria. The calculation method is only applicable to the power system without considering the frequency regulation characteristics of new energy and energy storage; considering the disconnection of new energy from the grid, the frequency regulation characteristics of synchronous units and hydropower units, the proportion of new energy increases, and the b value is manually set.

[0112] The above is a schematic scheme of a method for screening high-frequency control scenarios of a multi-type disturbance-induced sender in this embodiment. It should be noted that the technical scheme of the device for screening high-frequency control scenarios of a multi-type disturbance-induced sender is the same as the technical scheme of the method for screening high-frequency control scenarios of a multi-type disturbance-induced sender in the above embodiment. For details not described in detail in the technical scheme of the device for screening high-frequency control scenarios of a multi-type disturbance-induced sender in this embodiment, please refer to the description of the technical scheme of the method for screening high-frequency control scenarios of a multi-type disturbance-induced sender in the above embodiment.

[0113] Example 2

[0114] In this embodiment, the device for screening high-frequency control scenarios of a transmitter caused by multiple types of disturbances includes:

[0115] an initialization module, configured to obtain power grid system data and a power grid grid structure, select a typical operation mode based on the power grid system data and the power grid grid structure, initialize a fault set corresponding to the typical operation mode, and obtain a first fault set;

[0116] A calculation module is used to define an R value model, adjust the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generate an operation mode set, set a first fault set simulation according to the operation mode set, and calculate the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions;

[0117] A comparison module is used to define a high-frequency control action criterion, and screen out scenes that meet the high-frequency control conditions according to the comparison between the maximum value of the quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion;

[0118] The screening module is used to define a ξ value model and screen out the most serious high-frequency control scenario according to the ξ value calculation result for the high-frequency control condition scenario.

[0119] Example 3

[0120] This embodiment also provides a computing device suitable for screening scenarios of high-frequency control of a transmitter caused by multiple types of disturbances, including:

[0121] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method for screening high-frequency control scenarios of multiple types of disturbance-induced transmitters as proposed in the above embodiment.

[0122] Example 4

[0123] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for screening high-frequency control scenarios of multiple types of disturbance-induced transmitters as proposed in the above embodiment is implemented.

[0124] The storage medium proposed in this embodiment and the method for implementing multi-type disturbance-induced high-frequency control scenario screening at the transmitter proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0125] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0126] Example 5

[0127] Refer to Table 1-3, Figure 2-3 This embodiment is different from the first embodiment in that it provides a verification test of a method for screening high-frequency control scenarios at the transmitter induced by multiple types of disturbances, in order to verify and illustrate the technical effects used in this method.

[0128] Take the actual high-frequency control scenario of power grid A as an example. Figure 2 For the actual power grid, the screening methods include:

[0129] Mode 1 power flow: A power grid starts 280 million kilowatts, load 161 million kilowatts, 15 DC transmissions, and the total DC transmission power is about 72.6 million kilowatts. According to the actual A sending end power grid system data and power grid structure, the typical operation mode 1 is selected, and the power flow data R value is adjusted as shown in Table 1;

[0130] Table 1 Adjustment of the R value of the flow data

[0131]

[0132] The short-term fault set and permanent fault set are preset for simulation calculation, and the results are shown in Table 2;

[0133] Table 2 Simulation results

[0134]

[0135]

[0136]

[0137] The method of satisfying the high-frequency cutting machine control criterion satisfies the calculated ξ value shown in Table 3;

[0138] Table 3 ξ value calculation results

[0139]

[0140] According to the ξ value, the scenario with the highest risk of high-frequency cutting control is screened out as the scenario based on the DC mode ①, ②, and ⑤. After 7 phase failures, the highest frequency is 50.77 Hz. The frequency curve is as follows: Figure 3 As shown;

[0141] Depend on Figure 3 It can be seen that the system frequency at 0 seconds is about 49.2Hz. Starting from 0 seconds, the system frequency rises rapidly and reaches a peak of 50.8Hz in a very short time. After reaching the peak, the frequency begins to fluctuate, but generally remains above 50Hz. In the later period (approximately between 7 seconds and 10 seconds), the system frequency drops slightly, but still remains above 49.4Hz. This shows that through the screening and simulation of high-frequency control scenarios, the response of the system to different disturbances can be accurately controlled to ensure that the system frequency is within a safe range and the most serious high-frequency control scenarios are screened out, which is helpful for risk assessment of the power grid, formulation of response measures in advance, and reduction of potential economic losses and power outages.

[0142] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. 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 method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances, characterized in that: include: Acquire power grid system data and power grid grid structure, select a typical operation mode based on the power grid system data and power grid grid structure, initialize a fault set corresponding to the typical operation mode, and obtain a first fault set; Define the R value model, adjust the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generate an operation mode set, set the first fault set simulation according to the operation mode set, and calculate the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions; Define the high-frequency control action criterion, and screen out the scenarios that meet the high-frequency control conditions based on the comparison between the maximum quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion; Define the ξ value model, and screen out the maximum value of the ξ value for the high-frequency control condition scenario based on the ξ value calculation results, and take the maximum value as the most serious high-frequency control scenario.

2. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as claimed in claim 1, characterized in that: The fault set corresponding to the typical operation mode of initialization includes: The first fault set includes a short-term fault set and a permanent fault set; The short-term fault set can be: AC line N-2 / N-1 fault near the sending-end DC, DC commutation failure, and DC restart success; Permanent faults may include DC blocking fault at the sending end, DC restart failure, and DC blocking fault.

3. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as claimed in claim 2, characterized in that: R-Value Models include: The startup capacity of renewable energy is divided by the system static load minus the unbalanced power caused by system disturbances, among which, the startup capacity of renewable energy is less than or equal to the maximum capacity of renewable energy acceptable to the power grid system, the system static load is greater than or equal to the minimum load under the historical operation mode data of the system, and the unbalanced power caused by system disturbances is less than or equal to the maximum disturbance power acceptable to the power grid system.

4. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as described in claim 2 or 3, characterized in that: Also includes: Adjusting the flow operation boundary includes: The load is reduced to the minimum load, the capacity of the synchronous units is reduced, and the capacity of the new energy units remains unchanged; The DC transmission power remains unchanged, the capacity of the synchronous units is reduced to the safety start-up capacity, and the capacity of the new energy units is increased; The capacity of synchronous units remains unchanged, the DC transmission power increases to the maximum transmission capacity, and the capacity of new energy units increases.

5. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as claimed in claim 4, characterized in that: The maximum value of the quasi-steady-state frequency deviation of the system after the fault is calculated based on the constraint conditions, including: Select a short-term fault type and a permanent fault type, set fault parameters for the short-term fault type and the permanent fault type, and perform short-term fault simulation and permanent fault simulation; The power grid response when short-term faults and permanent faults occur is simulated in the power grid model to obtain the maximum frequency deviation corresponding to each fault; Adjust the operation mode, calculate the R value in the system, and compare it with the R value calculated last time. If the last R value is less than or equal to the R value in the system, switch to short-term fault simulation or permanent fault simulation; Comparing the frequency results of each operating mode fault set after simulation, according to the high-frequency machine cutting criterion, the high-frequency machine cutting action fault and system operation mode are determined as follows: When the system frequency is greater than or equal to the frequency threshold, and the time from the occurrence of the fault to the current time is greater than or equal to the time threshold, the system operation mode executes the system flow operation mode corresponding to the R value that triggers the high-frequency machine cutting action after the system fault. The high-frequency machine cutting action fault is an expected fault that triggers the system flow operation mode when the system quasi-steady-state frequency deviation triggers the system.

6. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as claimed in claim 5, characterized in that: High-frequency control action criteria include: When a system failure occurs, if the highest transient frequency of the system does not exceed the first frequency threshold, the automatic high-frequency cutting device should not operate; The frequency starting threshold of the first round of high-frequency cutting action is not lower than the frequency threshold.

7. The method for screening high-frequency control scenarios of a transmitter induced by multiple types of disturbances as claimed in claim 6, characterized in that: The most serious high-frequency control scenarios are selected based on the ξ value calculation results, including: The ξ index value model is expressed as: Among them, t0 is the time when the result frequency value reaches the frequency threshold after setting the fault simulation, t Δ To set the fault simulation result frequency to f Δ Moment, f Δi is the frequency deviation value corresponding to the i-th second after the simulated fault occurs, f Δ is the maximum frequency deviation value after the simulated fault occurs, and g is the system frequency sampling interval value; Calculate the ξ value in the scenario results that meet the high-frequency control criteria, and screen out the most serious high-frequency control scenario based on the ξ value.

8. A system for screening high-frequency control scenarios of multiple types of disturbances, characterized in that: include: An initialization module is used to obtain power grid system data and power grid grid structure, select a typical operation mode based on the power grid system data and power grid grid structure, initialize a fault set corresponding to the typical operation mode, and obtain a first fault set; A calculation module is used to define an R value model, adjust the boundary of the system operation mode according to the constraint factors of the R value model and the typical operation mode, generate an operation mode set, set the first fault set simulation according to the operation mode set, and calculate the maximum value of the quasi-steady-state frequency deviation of the system after the fault according to the constraint conditions; The comparison module is used to define the high-frequency control action criterion, and screen out the scenarios that meet the high-frequency control conditions based on the comparison between the maximum value of the quasi-steady-state frequency deviation of the system after the fault and the high-frequency control action criterion; The screening module is used to define the ξ value model, screen out the maximum value of the ξ value according to the ξ value calculation result for the high-frequency control condition scenario, and take the maximum value as the most serious high-frequency control scenario.

9. An electronic device, characterized in that: The device comprises: processor; a memory for storing processor-executable instructions; The processor is configured to call the instructions stored in the memory to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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