Online transient security and stability control strategy matching method and related device

Abstract

The application discloses an online transient security and stability control strategy matching method and related devices, and the online transient security and stability control mode word considering the time and space distribution characteristics of new energy is used to quickly generate a short-time conservative mode most unfavorable to the transient stability of a system, to predict the worst direction of the influence of short-time fluctuation of new energy on control in advance, and to determine the online transient security and stability control strategy according to the emergency control amount of the current mode and the conservative mode, so that the corresponding emergency control strategy can be quickly matched according to the actual operation mode, and the reliability and precision of online transient security and stability control can be improved.

Description

Technical Field

[0001] This invention relates to an online transient safety and stability control strategy matching method and related apparatus, belonging to the field of power system automatic control technology. Background Technology

[0002] With the rapid development of ultra-high voltage direct current and large-scale renewable energy grid-connected power systems, the time-varying characteristics of operating modes have increased, and the uncertainty of injected power has increased, making "online budgeting and real-time matching" more difficult. The time-varying characteristics of control measures may cause decision-making biases. Based on deterministic online safety and stability analysis methods, there is an under-control risk in large-scale renewable energy grid-connected systems.

[0003] Existing research avoids the problem of incompatibility in online control strategies by matching the mode words of online control strategies with the measured mode words of the safety control device at the most recent moment before the fault. Furthermore, in the online control strategy distribution process, an adaptability assessment of the control strategy is immediately performed based on the current cross-sectional data after the online control strategy is generated. However, when the mode changes significantly, mode word matching problems still exist. Therefore, there is an urgent need for a more reliable and accurate online transient safety and stability control strategy matching method. Summary of the Invention

[0004] This invention provides an online transient safety and stability control method and related apparatus, which solves the problems disclosed in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] Online transient safety and stability control strategy matching methods include:

[0007] New energy sources are grouped, and online transient safety and stability control mode words that take into account the spatiotemporal distribution characteristics of new energy sources are generated; wherein, the online transient safety and stability control mode words include the output fluctuation direction of new energy sources in each group at the next moment;

[0008] Based on the direction of power output fluctuation of the new energy source at the next moment, determine the emergency control quantity under the short-term conservative mode of the system; where the short-term conservative mode is the mode when the short-term emergency control quantity is at its maximum.

[0009] Compare the emergency control quantities under the current system mode with those under the short-term conservative mode to determine the online transient safety and stability control strategy.

[0010] Based on the online transient safety and stability control strategy and the online transient safety and stability control method, the online transient safety and stability control strategy is matched after the actual fault occurs.

[0011] The new energy sources can be grouped into the following categories:

[0012] Using the oscillation center of the minimum transient stability margin grouping mode under the current fault as the cut set, the new energy sources in the same cut set as the critical group generators are classified into group S, and the new energy sources in the same cut set as the remaining group generators are classified into group A.

[0013] Traverse group S, classify new energy sources with a first electrical distance less than a first threshold into group S1, and classify the remaining new energy sources into group S2; where the first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center;

[0014] Traverse group A, classify new energy sources with a second electrical distance less than the second threshold into group A1, and classify the remaining new energy sources into group A2; where the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center.

[0015] Based on the direction of power output fluctuation of the new energy source in the next moment, determine the emergency control quantities under the short-term conservative mode of the system, including:

[0016] Based on the direction of the power output fluctuation of the new energy source in the next moment, determine the short-term conservative mode of the system;

[0017] Emergency control quantities are calculated using time-domain simulation under a short-term conservative approach.

[0018] Based on the direction of the power output fluctuation of the new energy source in the next moment, the short-term conservative approach of the system is determined, including:

[0019] If the output of the S1 group of renewable energy fluctuates downward in the next moment, the short-term conservative approach of the system is based on the current approach of the system: the output of the S1 group of renewable energy fluctuates downward, while the output of the S2 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output of the renewable energy due to the downward fluctuation.

[0020] If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source.

[0021] If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0022] If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source.

[0023] If the output of the S1 group of new energy sources does not fluctuate downwards in the next moment, the output of the S2 group of new energy sources does not fluctuate downwards, the output of the A1 group of new energy sources does not fluctuate upwards in the next moment, and the output of the A2 group of new energy sources does not fluctuate upwards, the short-term conservative mode of the system is the current mode of the system.

[0024] By comparing the emergency control quantities under the current system mode with those under the short-term conservative mode, the online transient safety and stability control strategy is determined, including:

[0025] Compare the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode;

[0026] If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode;

[0027] If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode; where the difference is the difference between the emergency control quantity under the current mode and the emergency control quantity under the short-term conservative mode.

[0028] Online transient safety and stability control methods also include unit inertia ratio, new energy fluctuation, and cross-sectional power at the oscillation center;

[0029] Based on the online transient security and stability control strategy and the online transient security and stability control method, the online transient security and stability control strategy is matched after an actual fault occurs, including:

[0030] If the actual online mode after the actual fault occurs meets the preset conditions, it will be matched to the strategy corresponding to the emergency control quantity under the short-term conservative mode; otherwise, it will be matched to the strategy corresponding to the emergency control quantity under the current mode. The preset conditions are: the ratio of the unit inertia of the critical group to the remaining group after the system transient instability is greater than the third threshold, the fluctuation of new energy is greater than the critical fluctuation, and the cross-sectional power of the oscillation center is increased or unchanged compared with the current mode.

[0031] An online transient safety and stability control strategy matching device includes:

[0032] The mode word generation module groups the new energy sources and generates online transient safety and stability control mode words that take into account the spatiotemporal distribution characteristics of the new energy sources; among them, the online transient safety and stability control mode words include the output fluctuation direction of the new energy sources in each group at the next moment;

[0033] The emergency control quantity determination module determines the emergency control quantity of the system under the short-term conservative mode based on the direction of the power output fluctuation of the new energy source in the next moment; where the short-term conservative mode is the mode when the short-term emergency control quantity is at its maximum.

[0034] The strategy determination module compares the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode to determine the online transient safety and stability control strategy.

[0035] The stability control module matches the online transient safety and stability control strategy after an actual fault occurs, based on the online transient safety and stability control strategy and the online transient safety and stability control method.

[0036] In the method character generation module, the grouping of new energy sources includes:

[0037] Using the oscillation center of the minimum transient stability margin grouping mode under the current fault as the cut set, the new energy sources in the same cut set as the critical group generators are classified into group S, and the new energy sources in the same cut set as the remaining group generators are classified into group A.

[0038] Traverse group S, classify new energy sources with a first electrical distance less than a first threshold into group S1, and classify the remaining new energy sources into group S2; where the first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center;

[0039] Traverse group A, classify new energy sources with a second electrical distance less than the second threshold into group A1, and classify the remaining new energy sources into group A2; where the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center.

[0040] The emergency control quantity determination module is used to determine the short-term conservative mode of the system based on the direction of the power output fluctuation of the new energy source at the next moment, and to calculate the emergency control quantity under the short-term conservative mode.

[0041] In the emergency control quantity determination module, the short-term conservative mode of the system is determined based on the direction of the power output fluctuation of the new energy source in the next moment, including:

[0042] If the output of the S1 group's renewable energy fluctuates downward in the next moment, the system's short-term conservative approach is as follows: based on the current system approach, the output of the S1 group's renewable energy fluctuates downward, while the output of the S2 group's synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0043] If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source.

[0044] If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0045] If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source.

[0046] If the output of the S1 group of new energy sources does not fluctuate downwards in the next moment, the output of the S2 group of new energy sources does not fluctuate downwards, the output of the A1 group of new energy sources does not fluctuate upwards in the next moment, and the output of the A2 group of new energy sources does not fluctuate upwards, the short-term conservative mode of the system is the current mode of the system.

[0047] The strategy determination module compares the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode. If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode. If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode. The difference is the difference between the emergency control quantity under the current system mode and the emergency control quantity under the short-term conservative mode.

[0048] A computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform an online transient security and stability control strategy matching method.

[0049] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing an online transient safety and stability control strategy matching method.

[0050] The beneficial effects achieved by this invention are as follows: By considering the spatiotemporal distribution characteristics of new energy sources in the online transient safety and stability control mode word, this invention can quickly generate the short-term conservative mode that is most unfavorable to the transient stability of the system, predict in advance the worst direction of the impact of short-term fluctuations of new energy sources on control, and determine the online transient safety and stability control strategy based on the emergency control quantities of the current mode and the conservative mode. It can quickly match the corresponding emergency control strategy according to the actual operation mode word, thereby improving the reliability and accuracy of online transient safety and stability control. Attached Figure Description

[0051] Figure 1 This is a flowchart of the method of the present invention;

[0052] Figure 2 This is a schematic diagram of the Northwest power system. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0054] like Figure 1 As shown, the online transient safety and stability control strategy matching method includes:

[0055] Step 1: Group the new energy sources and generate an online transient safety and stability control mode word that takes into account the spatiotemporal distribution characteristics of the new energy sources; wherein, the online transient safety and stability control mode word includes the output fluctuation direction of the new energy sources in each group at the next moment;

[0056] Step 2: Determine the emergency control quantity under the short-term conservative mode of the system based on the direction of the power output fluctuation of the new energy source at the next moment; where the short-term conservative mode is the mode when the short-term emergency control quantity is at its maximum.

[0057] Step 3: Compare the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode to determine the online transient safety and stability control strategy;

[0058] Step 4: Based on the online transient safety and stability control strategy and the online transient safety and stability control method, perform online transient safety and stability control strategy matching after the actual fault occurs.

[0059] The above method, by considering the spatiotemporal distribution characteristics of new energy sources, quickly generates the short-term conservative mode that is most unfavorable to the transient stability of the system, predicts in advance the worst direction of the impact of short-term fluctuations of new energy sources on control, and determines the online transient safety and stability control strategy based on the emergency control quantities of the current mode and the conservative mode. It can quickly match the corresponding emergency control strategy according to the actual operation mode, and improve the reliability and accuracy of online transient safety and stability control.

[0060] In step 1, the new energy sources are mainly divided into four groups, defined as S1, S2, A1, and A2. Specifically, the grid is divided into two parts using the oscillation center of the minimum transient stability margin grouping mode under the current anticipated fault as the cut set. New energy sources in the same cut set as the critical group generators are assigned to group S, and new energy sources in the same cut set as the remaining group generators are assigned to group A. Then, group S is further traversed, and new energy sources with a first electrical distance less than a first threshold are assigned to group S1, and the remaining new energy sources are assigned to group S2. Group A is traversed, and new energy sources with a second electrical distance less than a second threshold are assigned to group A1, and the remaining new energy sources are assigned to group A2. The first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center, and the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center. The setting of the first threshold and the second threshold is related to the actual grid structure of the grid in the group, that is, related to the equivalent impedance.

[0061] Based on clustering, an online transient safety and stability control mode word is generated that considers the spatiotemporal distribution characteristics of new energy sources. The online transient safety and stability control mode word includes the current system startup mode, unit inertia ratio, load, key equipment startup and shutdown status, active power, reactive power, current output of new energy sources in each cluster, output fluctuation direction of new energy sources in each cluster at the next moment, new energy fluctuation amount, and cross-sectional power of the oscillation center. Among them, the current system startup mode, unit inertia ratio, load, key equipment startup and shutdown status, active power, reactive power, current output of new energy sources in each cluster, new energy fluctuation amount, and cross-sectional power of the oscillation center can all be obtained directly by statistics. The output fluctuation direction of new energy sources at the next moment is a predicted value, which can be predicted based on historical information. The fluctuation direction includes upward, downward, and basically unchanged. Upward indicates an increase in output, and downward indicates a decrease in output.

[0062] Based on the direction of the power output fluctuation of the new energy source in the next moment, the short-term conservative mode of the system can be further determined, as follows:

[0063] If the output of the S1 group's renewable energy source fluctuates downwards in the next moment, the system's short-term conservative approach is as follows: based on the current system mode, the output of the S1 group's renewable energy source fluctuates downwards, while the output of the S2 group's synchronous generators increases; wherein, the increased output of the synchronous generators is equal to the decreased output of the renewable energy source due to the downward fluctuation, and the maximum fluctuation range of the renewable energy source is generally taken as 5% of the maximum output of the day.

[0064] If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source.

[0065] If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0066] If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source.

[0067] If the output of the S1 group of new energy sources does not fluctuate downwards in the next moment, the output of the S2 group of new energy sources does not fluctuate downwards, the output of the A1 group of new energy sources does not fluctuate upwards in the next moment, and the output of the A2 group of new energy sources does not fluctuate upwards, the short-term conservative mode of the system is the current mode of the system.

[0068] The emergency control strategy under the anticipated fault is calculated using a conservative approach to obtain the system's stable emergency control quantity, which is the emergency control quantity calculated under a short-term conservative approach.

[0069] Compare the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode. Specifically, compare the difference between the two. If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode. If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode.

[0070] Based on the online transient safety and stability control strategy and the online transient safety and stability control mode, the online transient safety and stability control strategy is matched after an actual fault occurs. When matching the online emergency control strategy after an actual fault occurs, it is necessary to match the strategy corresponding to the emergency control quantity under the current mode or the strategy corresponding to the emergency control quantity under the short-term conservative mode according to the actual online mode. The specific process can be as follows:

[0071] If the actual online mode after the actual fault occurs meets the preset conditions, it will be matched to the strategy corresponding to the emergency control quantity under the short-term conservative mode; otherwise, it will be matched to the strategy corresponding to the emergency control quantity under the current mode. The preset conditions are: the ratio of the unit inertia of the critical group to the remaining group after the system transient instability is greater than the third threshold, the fluctuation of new energy is greater than the critical fluctuation, and the cross-sectional power of the oscillation center is increased or unchanged compared with the current mode.

[0072] The above calculation process for the critical fluctuation of new energy includes: Since the emergency control quantity issued under the current method is generally greater than the control quantity when the system is critically stable under the current method, that is, a certain control margin is left. When the left control margin is P0, the proportion of new energy fluctuation under the perturbation conservative method is simulated by sensitivity. When the new energy fluctuation is exactly at the critical fluctuation quantity, the system is critically stable when the emergency control quantity issued under the current method is adopted after the expected fault.

[0073] The above method is only applicable to scenarios where two groups are relatively unstable. For scenarios where local units are relatively unstable compared to the system, short-term fluctuations in new energy sources have little impact on emergency control quantities. Furthermore, during new energy fluctuations, the on / off status of synchronous units should remain unchanged.

[0074] by Figure 2 Taking the Northwest Power Grid under a typical large-scale operation in the summer of 2019 as an example, the online emergency control strategy calculation refresh time is 5 minutes. At 2 PM on a certain day, the Gansu renewable energy 7000MW experienced a fault at Quanhe N-2. The fault disappeared in 0.1 seconds, and the line was disconnected. The system became transiently unstable, and generator tripping control was implemented in 0.3 seconds. Based on the electrical distance from the oscillation center at the Quanyu section, the renewable energy in Gansu located in the critical group was classified as S1, the renewable energy in Xinjiang as S2, the renewable energy in Gansu located in the remaining groups and the renewable energy in Qinghai as A1, and the renewable energy in Ningxia and Shaanxi as A2. The maximum fluctuation of renewable energy was 5%, or 350MW. According to historical fluctuation information, the most likely direction of the renewable energy fluctuation in Gansu from 2 PM to 2 PM on that day was downward, and the most likely direction of the renewable energy fluctuation in Qinghai was upward. Therefore, the conservative approach based on the 2 PM method was to reduce the output of renewable energy in group S1 by 350MW, increase the output of renewable energy in group A1 by 350MW, increase the output of the Xinjiang synchronous generator by 350MW, and decrease the output of the Shaanxi synchronous generator by 350MW. The control quantities under the current mode and conservative mode at 14:00 are shown in Table 1. Since the difference in control quantities exceeds 150MW, which is more than 100MW for a single switchable unit, the information on the current mode and conservative mode, as well as the emergency control quantity, are updated to the safety and stability control device at 14:05 to address the transient instability problem caused by the anticipated fault due to uncertain fluctuations in renewable energy between 14:05 and 14:10. When the actual online mode at 14:08 shows a 5% fluctuation in renewable energy and the Quanhe N-2 fault occurs, a conservative control quantity of 1300MW is issued online after mode matching.

[0075] Table 1 Control Quantity Table

[0076]

[0077]

[0078] Based on the same technical solution, the present invention also discloses a software device for the above method, an online transient safety and stability control strategy matching device, comprising:

[0079] The mode word generation module groups the new energy sources and generates online transient safety and stability control mode words that take into account the spatiotemporal distribution characteristics of the new energy sources; among them, the online transient safety and stability control mode words include the output fluctuation direction of the new energy sources in each group at the next moment.

[0080] In the method character generation module, the grouping of new energy sources includes:

[0081] Using the oscillation center of the minimum transient stability margin grouping mode under the current fault as the cut set, the new energy sources in the same cut set as the critical group generators are classified into group S, and the new energy sources in the same cut set as the remaining group generators are classified into group A.

[0082] Traverse group S, classify new energy sources with a first electrical distance less than a first threshold into group S1, and classify the remaining new energy sources into group S2; where the first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center;

[0083] Traverse group A, classify new energy sources with a second electrical distance less than the second threshold into group A1, and classify the remaining new energy sources into group A2; where the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center.

[0084] The emergency control quantity determination module determines the short-term conservative mode of the system based on the direction of the power output fluctuation of the new energy source at the next moment, and calculates the emergency control quantity under the short-term conservative mode.

[0085] In the emergency control quantity determination module, the short-term conservative mode of the system is determined based on the direction of the power output fluctuation of the new energy source in the next moment, including:

[0086] If the output of the S1 group's renewable energy fluctuates downward in the next moment, the system's short-term conservative approach is as follows: based on the current system approach, the output of the S1 group's renewable energy fluctuates downward, while the output of the S2 group's synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0087] If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source.

[0088] If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy.

[0089] If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source.

[0090] If the output of the S1 group of new energy sources does not fluctuate downwards in the next moment, the output of the S2 group of new energy sources does not fluctuate downwards, the output of the A1 group of new energy sources does not fluctuate upwards in the next moment, and the output of the A2 group of new energy sources does not fluctuate upwards, the short-term conservative mode of the system is the current mode of the system.

[0091] The strategy determination module compares the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode. If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode. If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode. The difference is the difference between the emergency control quantity under the current system mode and the emergency control quantity under the short-term conservative mode.

[0092] The stability control module matches the online transient safety and stability control strategy after an actual fault occurs, based on the online transient safety and stability control strategy and the online transient safety and stability control method.

[0093] Based on the same technical solution, the present invention also discloses a computer-readable storage medium for storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform an online transient security and stability control strategy matching method.

[0094] Based on the same technical solution, the present invention also discloses a computing device, including one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for executing an online transient safety and stability control strategy matching method.

[0095] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.

[0096] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0097] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0099] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. An online transient safety and stability control strategy matching method, characterized in that, include: New energy sources are grouped, and online transient safety and stability control mode words that take into account the spatiotemporal distribution characteristics of new energy sources are generated; wherein, the online transient safety and stability control mode words include the output fluctuation direction of new energy sources in each group at the next moment; Based on the direction of power output fluctuation of the new energy source in the next moment, the short-term conservative mode of the system is determined, and the emergency control quantity is calculated by time-domain simulation under the short-term conservative mode; where the short-term conservative mode is the mode when the short-term emergency control quantity is at its maximum. Compare the emergency control quantities under the current system mode with those under the short-term conservative mode to determine the online transient safety and stability control strategy. Based on the online transient safety and stability control strategy and the online transient safety and stability control method, the online transient safety and stability control strategy is matched after the actual fault occurs; The above-mentioned grouping of new energy sources includes: using the oscillation center of the grouping mode with the minimum transient stability margin under the current anticipated fault as the cut set, grouping new energy sources in the same cut set as the critical group generators into group S, and grouping new energy sources in the same cut set as the remaining group generators into group A; traversing group S, grouping new energy sources with a first electrical distance less than a first threshold into group S1, and grouping the remaining new energy sources into group S2; wherein, the first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center; traversing group A, grouping new energy sources with a second electrical distance less than a second threshold into group A1, and grouping the remaining new energy sources into group A2; wherein, the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center; The above-mentioned short-term conservative approach to determining the system based on the direction of power output fluctuation of the new energy source at the next moment includes: If the output of the S1 group's renewable energy fluctuates downward in the next moment, the system's short-term conservative approach is as follows: based on the current system approach, the output of the S1 group's renewable energy fluctuates downward, while the output of the S2 group's synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy. If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source. If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy. If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source. If the output of the S1 group of new energy sources does not fluctuate downwards in the next moment, the output of the S2 group of new energy sources does not fluctuate downwards, the output of the A1 group of new energy sources does not fluctuate upwards in the next moment, and the output of the A2 group of new energy sources does not fluctuate upwards, the short-term conservative mode of the system is the current mode of the system.

2. The online transient safety and stability control strategy matching method according to claim 1, characterized in that, By comparing the emergency control quantities under the current system mode with those under the short-term conservative mode, the online transient safety and stability control strategy is determined, including: Compare the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode; If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode; If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode; where the difference is the difference between the emergency control quantity under the current mode and the emergency control quantity under the short-term conservative mode.

3. The online transient safety and stability control strategy matching method according to claim 2, characterized in that, Online transient safety and stability control methods also include unit inertia ratio, new energy fluctuation, and cross-sectional power at the oscillation center; Based on the online transient security and stability control strategy and the online transient security and stability control method, the online transient security and stability control strategy is matched after an actual fault occurs, including: If the actual online mode after the actual fault occurs meets the preset conditions, it will be matched to the strategy corresponding to the emergency control quantity under the short-term conservative mode; otherwise, it will be matched to the strategy corresponding to the emergency control quantity under the current mode. The preset conditions are: the ratio of the unit inertia of the critical group to the remaining group after the system transient instability is greater than the third threshold, the fluctuation of new energy is greater than the critical fluctuation, and the cross-sectional power of the oscillation center is increased or unchanged compared with the current mode.

4. An online transient safety and stability control strategy matching device, characterized in that, include: The mode word generation module groups the new energy sources and generates online transient safety and stability control mode words that take into account the spatiotemporal distribution characteristics of the new energy sources; among them, the online transient safety and stability control mode words include the output fluctuation direction of the new energy sources in each group at the next moment; The process of grouping new energy sources includes: using the oscillation center of the least transient stability margin grouping mode under the current anticipated fault as the cut set, grouping new energy sources in the same cut set as the critical group generators into group S, and grouping new energy sources in the same cut set as the remaining group generators into group A; traversing group S, grouping new energy sources with a first electrical distance less than a first threshold into group S1, and grouping the remaining new energy sources into group S2; wherein, the first electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group S and the oscillation center; traversing group A, grouping new energy sources with a second electrical distance less than a second threshold into group A1, and grouping the remaining new energy sources into group A2; wherein, the second electrical distance is the electrical distance between the grid-connected bus of all new energy sources in group A and the oscillation center; The emergency control quantity determination module determines the short-term conservative mode of the system based on the output fluctuation direction of the new energy source at the next moment. Under the short-term conservative mode, the emergency control quantity is calculated by time-domain simulation. The short-term conservative mode is the mode when the short-term emergency control quantity is at its maximum. Based on the direction of the power output fluctuation of the new energy source in the next moment, the short-term conservative approach of the system is determined, including: If the output of the S1 group's renewable energy fluctuates downward in the next moment, the system's short-term conservative approach is as follows: based on the current system approach, the output of the S1 group's renewable energy fluctuates downward, while the output of the S2 group's synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy. If the output of the renewable energy source in group A1 fluctuates upward in the next moment, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A1 fluctuates upward, while the synchronous generators in group A2 reduce their output; whereby the reduced output of the synchronous generators is equal to the increased output due to the upward fluctuation of the renewable energy source. If the output of the S1 group of renewable energy does not fluctuate downward in the next moment, while the output of the S2 group of renewable energy fluctuates downward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the S2 group of renewable energy fluctuates downward, and at the same time, the output of the S1 group of synchronous generators increases; whereby the increased output of the synchronous generators is equal to the reduced output due to the downward fluctuation of the renewable energy. If the output of the renewable energy source in group A1 does not fluctuate upward in the next moment, while the output of the renewable energy source in group A2 fluctuates upward, the short-term conservative approach of the system is as follows: based on the current approach of the system, the output of the renewable energy source in group A2 fluctuates upward, while the output of the synchronous generators in group A1 decreases; wherein, the output reduction of the synchronous generators is equal to the output increase due to the upward fluctuation of the renewable energy source. If the output of the S1 group of new energy sources does not fluctuate downward in the next moment, the output of the S2 group of new energy sources does not fluctuate downward, the output of the A1 group of new energy sources does not fluctuate upward in the next moment, and the output of the A2 group of new energy sources does not fluctuate upward, the short-term conservative mode of the system is the current mode of the system; The strategy determination module compares the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode to determine the online transient safety and stability control strategy. The stability control module matches the online transient safety and stability control strategy after an actual fault occurs, based on the online transient safety and stability control strategy and the online transient safety and stability control method.

5. The online transient safety and stability control strategy matching device according to claim 4, characterized in that, The strategy determination module compares the emergency control quantity under the current system mode with the emergency control quantity under the short-term conservative mode. If the difference is less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode. If the difference is not less than the single generator capacity / single site load in the control strategy table, the online transient safety and stability control strategy is the strategy corresponding to the emergency control quantity under the current mode and the strategy corresponding to the emergency control quantity under the short-term conservative mode. The difference is the difference between the emergency control quantity under the current system mode and the emergency control quantity under the short-term conservative mode.

6. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 3.

7. A computing device, characterized in that, include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1 to 3.

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