Limit calculation method and system based on transient stability quantitative analysis and medium

Abstract

The invention discloses a limit calculation method and system based on transient stability quantitative analysis and a medium, and the limit calculation method based on transient stability quantitative analysis introduces terminal voltage drop safety analysis in the transient stability quantitative analysis. In the multi-swing-angle stability quasi-quantitative credibility analysis and complexity sensitive influence analysis of transient stability quasi-quantitative analysis based on hierarchical fusion of partial numerical integration, a voltage drop quantitative index and the difference degree of a front segment and a rear segment and a front stage and a rear stage are introduced; in order to excavate the influence degree of voltage key features and simulation method simplification and model simplification on the key features, a frequency drop quantitative index and the difference degree of front and back two segments and front and back two stages are introduced, so that the influence degree of frequency key features and simulation method simplification and model simplification on the key features is excavated; and rapid quasi-quantitative limit calculation search meeting power angle, voltage and frequency safety at the same time is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to power systems and their automation technology, in particular to a limit calculation method, system and medium based on transient stability quantitative analysis. BACKGROUND

[0002] With the vigorous development of large-scale renewable energy, leading to large-scale renewable energy grid connection. Due to the temporal and spatial uncertainty of renewable energy output and the introduction of large-scale power electronic controlled devices in hybrid power transmission systems, the transient stability quantitative screening analysis of a large number of examples and fault scenes under strong coupling complex models and the required algorithm accuracy and computational load under load limit calculation in a large number of ways are more and more demanding.

[0003] Traditional load limit or critical fault clearing time calculation is mainly based on complete numerical simulation method using serial or parallel processing mode, checking the maximum search parameter value that meets the transient power angle, voltage and frequency safety under the search parameter (adjustment mode or fault clearing time) space, and the maximum search parameter transmission power of the corresponding transmission section is the transmission section load limit (or the fault clearing time is the critical fault clearing time). Due to the long time-consuming of complete numerical simulation for obtaining the disturbed trajectory after the expected fault is disturbed, the online practicalization process of the limit calculation function is seriously restricted. SUMMARY

[0004] The purpose of the present application is to provide a limit calculation method based on transient stability quantitative analysis which takes into account the rapidity and accuracy; another purpose of the present application is to provide a limit calculation system and medium based on transient stability quantitative analysis which takes into account the rapidity and accuracy.

[0005] Technical scheme: The limit calculation method based on transient stability quantitative analysis provided by the present application comprises the following steps:

[0006] The power increase space required for calculating the load limit of each load limit section is estimated for the load limit estimation of the power system, and the calculation fault clearing time search space is estimated for the critical fault clearing time CCT of the power system;

[0007] Based on the number of examination faults, parallel processing calculation capacity and limit calculation accuracy, the power increase space of each section and the calculation fault clearing time search space are respectively averaged and divided into several sections, the transient evaluation task is determined, the transient evaluation task is subjected to transient stability quantitative analysis in parallel search space, and the critical safe and critical unsafe power search interval and the critical safe and critical unsafe fault clearing time search interval of each section examination fault under the limit calculation accuracy requirement are obtained;

[0008] For the power search intervals and fault clearing time search intervals of critical safety and critical insecurity for each cross-section assessment fault, the calculation tasks are divided according to the limit calculation accuracy requirements. The transient stability quantitative analysis of each calculation task is carried out by adding numerical simulation or integration to determine the transient safety stability.

[0009] Furthermore, the transient stability quasi-quantitative analysis includes the following steps:

[0010] A quasi-quantitative reliability analysis of transient stability is conducted using the Taylor expansion method based on the classical power system model.

[0011] If the stability of the results of the transient stability quasi-quantitative reliability analysis is determined, then proceed to the transient stability quantitative analysis; otherwise, perform the transient stability quasi-quantitative analysis with hierarchical fusion of numerical integrals.

[0012] If the stability of the transient stability quasi-quantitative reliability analysis result is determined after one numerical integration of the hierarchical fusion part, then the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins; otherwise, a second numerical integration of the hierarchical fusion part is performed.

[0013] If the numerical integration of the hierarchical fusion part is performed twice, regardless of whether the stability of the result of the transient stability quasi-quantitative reliability analysis is certain or uncertain, the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins.

[0014] Furthermore, the transient stability quasi-quantitative reliability analysis based on the Taylor expansion method of the classical power system model includes sequentially performing the quasi-quantitative reliability analysis of initial swing angle stability, multi-swing angle stability, complexity-sensitive impact analysis, and generator terminal voltage drop safety analysis. Among these, the generator terminal voltage drop safety analysis involves determining the voltage drop safety quantification index η of the generator terminal voltage based on the generator terminal voltage curve. v .

[0015] Furthermore, in the reliability analysis of the quasi-quantitative stability of the multi-pendulum work angle and the analysis of the complexity-sensitive impact of the transient stability quasi-quantitative analysis of the numerical integration of the hierarchical fusion part, the voltage drop safety quantitative analysis index η of the generator terminal voltage is introduced. v Difference in the quantitative index of voltage drop between the two stages The difference in indicators obtained by referring to the voltage sag quantification method of the binary meter for the terminal voltage curve. Frequency drop quantification index η s Difference in frequency drop between the two levels The difference in frequency drop quantization index caused by differences in numerical simulation and fused multi-step Taylor model.

[0016] The limit calculation system based on transient stability quantitative analysis comprises

[0017] A search space estimation module is configured to estimate a power increase space required for calculating a load limit of each load limit section of a power system, and estimate a calculation fault clearance time search space of a critical fault clearance time (CCT) of the power system.

[0018] A transient stability quasi-quantitative analysis module is configured to average classify the power increase space of each section and the calculation fault clearance time search space according to the number of test faults, parallel processing calculation capacity and limit calculation accuracy, determine transient evaluation tasks, perform transient stability quasi-quantitative analysis on the transient evaluation tasks in parallel search spaces, and obtain critical safe and critical unsafe power search intervals and critical safe and critical unsafe fault clearance time search intervals of each section test fault under the limit calculation accuracy requirement.

[0019] A transient stability quantitative analysis module is configured to classify the critical safe and critical unsafe power search intervals and the critical safe and critical unsafe fault clearance time search intervals of each section test fault according to the limit calculation accuracy requirement, form calculation tasks, perform transient stability quantitative analysis on the calculation tasks by increasing numerical simulation or integration, and determine transient security stability.

[0020] Further, in the transient stability quasi-quantitative analysis module, the transient stability quasi-quantitative analysis comprises the following steps:

[0021] Perform transient stability quasi-quantitative reliability analysis based on a Taylor expansion method of a classical model of the power system.

[0022] If the stability of the transient stability quasi-quantitative reliability analysis result is determined, enter the transient stability quantitative analysis; otherwise, perform transient stability quasi-quantitative analysis with hierarchical fusion of partial numerical integration.

[0023] If the stability of the transient stability quasi-quantitative reliability analysis result is determined after the hierarchical fusion of partial numerical integration for one time, enter the transient stability quantitative analysis; otherwise, perform the hierarchical fusion of partial numerical integration for the second time.

[0024] If the stability of the transient stability quasi-quantitative reliability analysis result is determined or not determined after the hierarchical fusion of partial numerical integration for two times, enter the transient stability quantitative analysis.

[0025] Further, in the transient stability quasi-quantitative analysis module, the transient stability quasi-quantitative reliability analysis based on the Taylor expansion method of the classical model of the power system comprises in turn the first swing angle stability quasi-quantitative reliability analysis, the multi-swing angle stability quasi-quantitative reliability analysis, the complexity sensitive influence analysis and the machine terminal voltage drop safety analysis; wherein the machine terminal voltage drop safety analysis is to determine the voltage drop safety quantitative analysis index η of the machine terminal voltage according to the machine terminal voltage curve v .

[0026] Further, in the transient stability quasi-quantitative analysis module, in the multi-swing angle stability quasi-quantitative reliability analysis and the complexity sensitive influence analysis of the transient stability quasi-quantitative analysis of the hierarchical fusion part numerical integral, the voltage drop safety quantitative analysis index η of the machine terminal voltage is introduced v , the voltage drop quantitative index difference degree of the two levels before and after the index difference of the machine terminal voltage curve referring to the voltage drop quantitative method of the binary table the frequency drop quantitative index η s , the frequency drop quantitative index difference degree of the two levels before and after and the frequency drop quantitative index difference degree caused by the difference between the numerical simulation and the fusion multi-step Taylor model

[0027] The computer device of the present application comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the processor executes the computer program to realize the steps of the above method.

[0028] The computer readable storage medium of the present application has a computer program stored thereon, and the computer program is executed by the processor to realize the steps of the above method.

[0029] Beneficial effects: compared with the prior art, the method has the following advantages: 1, the method estimates the power increase space of each section and the search space of each calculation fault clearing time according to the load limit and critical fault clearing time of the power system, determines transient evaluation tasks and performs transient stability quasi-quantitative analysis, obtains the critical safe and critical unsafe power search interval and the critical safe and critical unsafe fault clearing time search interval of each section under the condition of meeting the limit calculation accuracy requirement, and compresses the search space, ensures the voltage and frequency safety and stability, and improves the rapidity and accuracy of subsequent calculation; and then the transient stability quantitative analysis of each calculation task is performed through numerical simulation or integration to determine the transient safety and stability; 2, in the quasi-quantitative reliability analysis and complexity sensitive influence analysis of multi-swing power angle stability, the voltage drop quantitative index and the difference degree of the front and rear two sections and the front and rear two stages, the frequency drop quantitative index and the difference degree of the front and rear two sections and the front and rear two stages are introduced, so that the limit calculation search considers the transient power angle, voltage and frequency safety at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a curve diagram of the bus voltage at the machine end;

[0031] Figure 2 is a curve diagram of the frequency at the machine end bus. DETAILED DESCRIPTION

[0032] The limit calculation method based on transient stability quantitative analysis according to the present application is as follows:

[0033] For the load limit and critical fault clearing time CCT of the offline and online power system, the power increase space of each section and the fault clearing time search space are estimated respectively, the tasks are divided into several grades according to the number of tasks, the transient evaluation tasks are determined, and the transient evaluation tasks are evaluated in the parallel search space.

[0034] In order to accurately realize the transient evaluation considering the transient power angle, voltage and frequency safety while considering the rapidity, the transient evaluation of the first round of parallel tasks adopts transient stability quasi-quantitative analysis, the calculation tasks with smaller power increase and transient very stable, and the calculation tasks with larger power increase and transient very unstable are analyzed by quasi-quantitative reliability analysis through the disturbed trajectory obtained by Taylor expansion of the classical model, or the disturbed trajectory after 1-2 times of hierarchical fusion of partial numerical integration, and the stability (transient stability or transient instability) can be determined. For the calculation tasks with slightly larger power increase and transient stability close to critical stability or critical instability, the stability cannot be determined by quasi-quantitative analysis after 1-2 times of hierarchical fusion of partial numerical integration, and the stability is uncertain.

[0035] After determining the critical safe and critical unsafe points by analyzing the transient evaluation results, since the critical safe point is the minimum power adjustment range under which the transient stability quantitative analysis is safe and stable for each section, and the critical unsafe point is the maximum power adjustment range under which the transient stability quantitative analysis is unsafe or uncertain for each section, the calculation task of transient stability quantitative analysis which cannot determine stability is included in the subsequent search space, and the transient stability quantitative analysis determines the safety and stability after detailed numerical simulation, thereby reducing the time-consuming of detailed simulation of part of the calculation task (realizing fast compression of the limit search space), and ensuring the accuracy of quantitative evaluation in the limit search.

[0036] For the load limit of the offline and online power system, the number of sections k is designed, the number of expected faults N i of the i-th section is designed, and the search space of the i-th section is [P 1i , P 2i ]. The power increase space of each section or the search space of each calculation fault clearing time is estimated. For the load limit, the same adjustment is checked for each section fault mode, and the upper limit of the adjustable space refers to the smaller one of the sending end power increase (including starting) and the receiving end load increase space under the given adjustment mode of the examination section. That is, the adjustable space P sgi of the specified load reduction node and region, and the adjustable space P ldi of the receiving end load increase to the specified amount and the specified unit power reduction to replace the load increase. The maximum adjustment multiple n i of the specified section is specified. The power increase space of the i-th section is estimated as [P 1i , P 2i ], wherein P 1i is equal to 0, and P 2i is equal to n i *min(P sgi , P ldi ).

[0037] For the critical fault clearing time CCT of the offline and online power system, the number of faults k is designed, the search space of the i-th fault is [T 1i , T 2i ], such as T 1i 0s and T 2i 1s. For CCT, the upper limit of the adjustable space refers to the maximum time delay of the fault clearing time under the calculation time sequence of the examination fault, which is generally 1s. For the critical fault clearing time CCT of the offline and online power system, the search space of each calculation fault clearing time is estimated. In general cases, the search space of cct is 0.1s-1s.

[0038] The first round of transient stability fast and accurate quantitative analysis based on search space is critical safety and critical unsafe point search. There are generally two search methods to achieve critical safety and critical unsafe point search. One is serial search method, and the other is parallel search method. The former is mainly used for offline single machine search, and the latter is mainly used for online multi-machine cluster search.

[0039] In the first embodiment, the serial search mainly used for offline single machine search, the offline search first determines whether the examination fault is transient safe under the Xs corresponding mode. If Xs is safe, limit search is performed (otherwise, the current mode is unsafe and limit search is not performed, and reverse limit search, i.e. strategy search, is performed). Then, between Xu (initially equal to the maximum adjustable space) and Xs (initially equal to 0), the transient safety of the examination fault under the Xu corresponding mode and the transient safety of the examination fault under the Xs corresponding mode are determined in turn based on transient stability fast and accurate quantitative analysis. If the Xu corresponding mode is safe, the section transmission power corresponding to the Xu corresponding mode is the section limit power or the fault clearing time corresponding to the Xu corresponding mode is the CCT. Otherwise, the search space is bisected by bisection method, and whether the search midpoint of (Xu+Xs) / 2 is safe is evaluated. If it is safe, Xs is updated to (Xu+Xs) / 2 (if it is not safe, Xu is updated to (Xu+Xs) / 2), and the process is continued until the limit convergence precision between Xu and Xs is met, the section transmission power corresponding to the Xs corresponding mode is the section limit power, or the fault clearing time corresponding to the Xs corresponding mode is the CCT. The search process stops.

[0040] In another embodiment, the parallel search mainly used for online multi-machine cluster search, the parallel search is to search for critical safe and critical unsafe positions by searching for critical safe and critical unsafe positions based on detailed numerical simulation transient evaluation results of search space slices in parallel. The number of examination faults, parallel processing computing capacity and limit computing precision requirement are used as the basis.

[0041] For the load limit of the power system, the search space of the i-th section is [P 1i ,P 2i ], the number of computing CPUs is n, the limit computing precision is 5MW, the search space slices are equally divided, i.e. ∑N i *(P 2i -P 1i ) / 5, the time consumption is estimated according to the allocation of m computing tasks to each CPU, and m is selected to meet the requirement of n / m≤d. The approximate CPU core multiple transient evaluation task ΣN i *(P 2i -P 1i ) / n / m is generated, and the parallel computing platform is submitted for transient stability quantitative analysis. When the parallel computing task of the computing platform is scheduled, the N iAll anticipated faults are scheduled on a single CPU to minimize the number of adjustments made using the same approach.

[0042] For the critical fault clearing time (CCT) of a power system, the design calculates the number of faults k, and the search space for the i-th fault is [T]. 1i ,T 2i (e.g., T) 1i For 0s, T 2i Given a time limit of 1 second, with n CPUs, the maximum computational precision is 0.005 seconds. The search space is sliced ​​using equal-order slices, i.e., ∑(T) 2i -T 1i ) / 0.005, allocate m computing tasks to each CPU to estimate the time consumption, select the task that requires m to satisfy n / m≤d, and generate a transient evaluation task ∑(T) based on the approximate multiple of the number of CPU cores. 2i -T 1i ) / n / m, and submit them to the parallel computing platform for fast transient stable quasi-quantitative analysis.

[0043] Once the parallel computing tasks are determined, they are submitted to the parallel computing platform for transient evaluation, which assesses the transient security and stability of each computing task.

[0044] The first round employs transient stability quasi-quantitative analysis, which uses Taylor expansion based on the classic power system model to obtain the disturbed trajectory or hierarchical fusion of partial numerical integration during the fault period to obtain the disturbed trajectory. Quasi-quantitative analysis determines the transient stability of each computational task and rapidly compresses the search space to reduce time consumption.

[0045] The transient stability quasi-quantitative analysis employs a two-layer fast transient stability quasi-quantitative analysis method. The first layer performs a transient stability quasi-quantitative reliability analysis based on the Taylor expansion method of the classical power system model. If the stability of the results of the first-layer transient stability quasi-quantitative analysis is uncertain, the second layer, a graded fusion of numerical integration, is initiated. This further graded cyclic fusion of numerical integration takes into account the influence of complexity factors, progressively improving the accuracy of the disturbed trajectory. To balance speed and robustness of the computational task's effective quantitative analysis, the first round performs a maximum of 1-2 levels of fusion of numerical integration. If the 1-2 levels of fusion of numerical integration fail, regardless of whether the stability of the transient stability quasi-quantitative reliability analysis results is determined, the transient assessment of the computational task is terminated.

[0046] The first layer, based on the Taylor expansion method of the classical power system model, performs transient stability quasi-quantitative reliability analysis, including sequential analysis of the stability of the first swing angle, the stability of multiple swing angles, the analysis of complex sensitivity effects, and the safety analysis of generator terminal voltage dips. The significance and extraction methods of key characteristic indicators in the analysis of the stability of the first swing angle, the stability of multiple swing angles, and the analysis of complex sensitivity effects can be found in patent application number 2023103357931. Based on this, transient voltage and frequency dip quantitative safety analysis is added for generator terminal voltage and frequency. Specifically, the generator terminal voltage curve is derived from the generator's power angle, angular velocity, and acceleration using the Taylor expansion of the classical model, as shown in the following equation:

[0047]

[0048] Let the work angle, angular velocity, and acceleration at time t0 be respectively... Terminal voltage, x′ fed by the classical model potential source d Effective and ineffective are respectively and And assume the extrapolated potential If the admittance matrix is ​​constant and time-varying, then:

[0049]

[0050] Therefore, we can deduce that x′ d Reactive power of the injection machine terminal bus for

[0051] Therefore, the terminal voltage is:

[0052] The terminal voltage sag safety analysis is based on the calculated terminal voltage curve V. it The characteristic index of the voltage drop at the excavator end is used to compensate for the shortcomings of the index reflecting the difference in fault location that relies on engineering experience in the analysis of complex and sensitive impacts, thereby improving the resolution of the algorithm.

[0053] Considering that the transient process of the network is ignored in the electromechanical transient simulation, the frequency of the generator terminal bus is approximated as the angular frequency of the unit. That is, the frequency of the generator terminal bus is obtained by approximating the angular frequency of the unit.

[0054] For the terminal voltage and frequency curves of different simplification methods and different grade segments, key transient voltage and frequency characteristics were obtained using the voltage sag quantization method of a binary table. The curves and meanings corresponding to the key voltage characteristics are shown in Table 1.

[0055] Table 1

[0056]

[0057] Considering the screening rules for the quantitative safety analysis of voltage and frequency drops at the generator terminals, and based on the set threshold values, practical rules are adopted or combined with key characteristic indicators based on the requirements of key characteristic indicators. The key characteristic indicators of transient voltage are shown in Table 2.

[0058] Table 2

[0059]

[0060] The key characteristic indicators of transient frequency are shown in Table 3.

[0061] Table 3

[0062]

[0063] In the quantitative reliability analysis of transient stability, if transient voltage safety is required, then η must be... v Greater than a certain set positive value, Less than a certain set positive value, and / or Less than a certain set positive value.

[0064] In another implementation, if transient voltage unsafety is required, then η is required. v Less than a certain negative value Less than a certain set positive value Less than a certain set positive value.

[0065] In the quantitative reliability analysis of transient stability quasi-quantitative methods, if Greater than a certain set positive value and / or If the voltage exceeds a certain set positive value, the safety of the transient voltage is uncertain.

[0066] The second-level hierarchical fusion numerical simulation transient stability rapid quasi-quantitative analysis retains the same process at each level, including: rapid determination of the disturbed trajectory, automatic switching between partial numerical integration and multi-step Taylor expansion, acceleration of partial numerical integration and multi-step Taylor expansion, and rule-based quasi-quantitative analysis. However, in the sensitivity analysis of the impact of multi-pendulum stability credibility and complexity, the analysis is mainly limited to the difference index of the characteristic work angle stability mechanism between the two energy groups (such as the stability margin difference). Minimum potential kinetic energy reduces area difference (etc.), and also introduced the voltage drop safety quantitative analysis index η of the terminal voltage. v and the degree of difference between the two levels This reflects voltage sag and the difference in voltage sag between the preceding and following stages. The index difference is obtained based on the terminal voltage curves from partial numerical simulations and the terminal voltage curves derived from multi-step Taylor expansion, referencing the voltage sag quantification method using a binary table. This reflects the extent to which the model affects the voltage.

[0067] Quantitative analysis index η of voltage drop safety at the terminal voltage v The voltage sag quantization method of the binary table was directly obtained from the terminal voltage curve of a portion of the numerical simulation segment. The difference in voltage drop between the two stages is quantified by the degree of difference. To measure the difference in voltage sag quantification caused by variations in the fully detailed numerical simulation and the multi-step Taylor factor model, this reflects the degree of influence of the complex model on voltage sag. In the curve of the generator bus voltage, the segment [0~t0] corresponds to the first-level fully detailed numerical simulation segment. The voltage sag quantification index obtained from this bus segment is... The [t0~T0] segment corresponds to the first-level fusion multi-step Taylor expansion segment, and the voltage drop index obtained from the bus in this segment is as follows: This reflects the difference in voltage parameters between the [0~t0] segment and the [t0~T0] segment. The difference in voltage parameters between the [0~t0] segment and the [0~t1] segment obtained through complete and detailed numerical simulation is... The former compares the differences between detailed numerical simulation and multi-step Taylor expansion within the same level. The latter compares the impact of increasing the number of detailed numerical segments between different levels.

[0068] In addition to introducing voltage drop quantification indicators and the difference between the two segments and the two stages to explore key voltage characteristics and the impact of simulation method simplification and model simplification on key characteristics, frequency drop quantification indicators and the difference between the two segments and the two stages are also introduced to explore key frequency characteristics and the impact of simulation method simplification and model simplification on key characteristics.

[0069] Frequency drop quantification index η s The frequency drop quantization method was directly obtained from the terminal frequency curve of a partial numerical simulation segment, referencing a binary table. To quantify the difference in frequency sag between the preceding and following stages, the frequency sag quantification index was obtained using a binary table-based frequency sag quantification method, based on the unit frequency curves from partial numerical simulations and the generator terminal frequency curves derived from multi-step Taylor expansion. because The difference in frequency drop quantification index caused by differences in multi-step Taylor series models is used to fully detailed numerical simulations and reflect the degree of influence of complex models on frequency drop.

[0070] Considering that the transient process of the network is ignored in the electromechanical transient simulation, the frequency of the generator terminal bus is approximated as the angular frequency of the unit. That is, the frequency of the generator terminal bus is obtained by approximating the angular frequency of the unit.

[0071] In the frequency curve of the generator bus, the segment [0~t0] corresponds to the first-level fully detailed numerical simulation segment. The frequency drop index obtained from this bus segment is: The segment [t0~T0] corresponds to the first-level fusion multi-step Taylor expansion segment, and the frequency drop index is obtained from the bus of this segment. This reflects the difference in frequency parameters between the [0~t0] segment and the [t0~T0] segment. The difference in frequency parameters between the [0~t0] segment and the [0~t1] segment obtained through complete and detailed numerical simulation is... The former compares the differences between detailed numerical simulation and multi-step Taylor expansion within the same level. The latter compares the impact of increasing the number of detailed numerical segments between different levels. Figure 2 ω i f is the angular frequency of the generator set. e This is the rated frequency.

[0072] Table 4 shows the key characteristic indicators analyzed during the quasi-quantitative reliability analysis of the stability of the first pendulum's power angle, the quasi-quantitative reliability analysis of the stability of multiple pendulums' power angles, and the analysis of the sensitivity to complexity. Regardless of whether the transient power angle is safe or not, if the safety of the transient voltage is uncertain, or if the transient power angle is safe but the transient voltage is unsafe, or if the transient voltage is safe but the transient power angle is unsafe, then its stability is uncertain. That is, only when all three are simultaneously stable or safe, is the transient analysis safe; only when all three are simultaneously unstable or unsafe, is the transient analysis unsafe.

[0073] Table 4

[0074] Transient power angle Transient voltage Transient frequency Transient analysis Safe Safe Safe Safe Safe Uncertain or unsafe Uncertain or unsafe Uncertain Unsafe Uncertain or safe Uncertain or safe Uncertain Unsafe Unsafe Unsafe Unsafe

[0075] The results of the first round of transient stability rapid quasi-quantitative analysis returned by the parallel computing platform are analyzed to determine the critical safety and critical insecurity power space search intervals for each section of the load limit, or the critical safety and critical insecurity fault clearing time search intervals for each computational fault (CCT). The critical safety point is the minimum power adjustment level that is safe and stable under the transient stability quasi-quantitative analysis for each section under the test fault. The critical insecurity point corresponds to the maximum power adjustment level that is unstable / insecure or uncertain under the transient stability quasi-quantitative analysis for each section under the test fault.

[0076] If the difference between the critical unsafe and critical safe points determined in the first round does not meet the limit calculation accuracy requirements, the search space is further refined, and transient stability quantitative analysis is used to search for critical unsafe and critical safe points that meet the limit calculation accuracy requirements for each cross section (if one round of search does not meet the limit calculation accuracy, the search space can be refined in multiple rounds until the search meets the accuracy requirements).

[0077] In one implementation, when the increment of the cross section is 1000MW, the search range of the cross section is 0-1000MW.

[0078] The limit calculation system based on transient stability quantitative analysis described in this invention includes:

[0079] The search space estimation module is used to estimate the power increase space required when calculating the load limit of each load limit section for the load limit of the power system, and to estimate the search space for each calculated fault clearing time for the critical fault clearing time (CCT) of the power system.

[0080] The transient stability quasi-quantitative analysis module is used to average the power increase space and the fault clearing time search space of each section based on the number of assessment faults, parallel processing computing capabilities, and limit calculation accuracy, to determine the transient assessment task. In the parallel search space, transient stability quasi-quantitative analysis is performed to obtain the power search intervals and fault clearing time search intervals of each section's assessment faults that meet the limit calculation accuracy requirements.

[0081] The transient stability quantitative analysis module is used to search for the power range and fault clearing time range of critical safety and critical insecurity for each cross-section of the test fault. It is divided into categories according to the limit calculation accuracy requirements to form calculation tasks. By adding numerical simulation or integration, transient stability quantitative analysis is performed on each calculation task to determine the transient safety and stability.

[0082] Furthermore, in the transient stability quasi-quantitative analysis module, the transient stability quasi-quantitative analysis includes the following steps:

[0083] A quasi-quantitative reliability analysis of transient stability is conducted using the Taylor expansion method based on the classical power system model.

[0084] If the stability of the results of the transient stability quasi-quantitative reliability analysis is determined, then proceed to the transient stability quantitative analysis; otherwise, proceed to the transient stability quasi-quantitative analysis with numerical integration of the hierarchical fusion part. If the stability of the results of the transient stability quasi-quantitative reliability analysis is still uncertain after two numerical integrations of the hierarchical fusion part, then proceed to the transient stability quantitative analysis.

[0085] Furthermore, in the transient stability quasi-quantitative analysis module, the transient stability quasi-quantitative reliability analysis based on the Taylor expansion method of the classical power system model includes sequentially performing the first swing angle stability quasi-quantitative reliability analysis, multi-swing angle stability quasi-quantitative reliability analysis, complexity sensitivity impact analysis, and generator terminal voltage drop safety analysis. Among these, the generator terminal voltage drop safety analysis involves determining the voltage drop safety quantification index η of the generator terminal voltage based on the generator terminal voltage curve. v .

[0086] Furthermore, in the transient stability quasi-quantitative analysis module, in the reliability analysis of the multi-pendulum work angle stability quasi-quantitative analysis and the complexity-sensitive impact analysis of the transient stability quasi-quantitative analysis of the numerical integration of the hierarchical fusion part, the voltage drop safety quantification analysis index η of the terminal voltage is introduced. vDifference in the quantitative index of voltage drop between the two stages The difference in indicators obtained by referring to the voltage sag quantification method of the binary meter for the terminal voltage curve. Frequency drop quantification index η s Difference in frequency drop between the two levels The difference in frequency drop quantization index caused by differences in numerical simulation and fused multi-step Taylor model.

[0087] The computer device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above method.

[0088] The computer-readable storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the above-described method.

[0089] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0090] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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... Figure One One or more processes and / or boxes Figure One A device that provides the functions specified in one or more boxes.

[0091] 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 OneOne or more processes and / or boxes Figure One The function specified in one or more boxes.

[0092] 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 One One or more processes and / or boxes Figure One The steps of the function specified in one or more boxes.

Claims

1. A limit calculation method based on transient stability quantitative analysis, characterized in that, Includes the following steps: The required power increase space for calculating the load limit of each section is estimated for the load limit of the power system, and the search space for each calculated fault clearing time is estimated for the critical fault clearing time (CCT) of the power system. Based on the number of assessment faults, parallel processing computing capabilities, and ultimate computing accuracy, the power increase space and fault clearing time search space for each section are averaged to determine the transient assessment task. In the parallel search space, transient stability quasi-quantitative analysis is performed on the transient assessment task to obtain the power search intervals for critical safety and critical insecurity of each section's assessment faults and the fault clearing time search intervals for critical safety and critical insecurity under the ultimate computing accuracy requirements. For the power search intervals and fault clearing time search intervals of critical safety and critical insecurity for each cross-section assessment fault, the calculation tasks are divided according to the limit calculation accuracy requirements. The transient stability quantitative analysis of each calculation task is carried out by adding numerical simulation or integration to determine the transient safety stability.

2. The limit calculation method based on transient stability quantitative analysis according to claim 1, characterized in that, Transient stable quasi-quantitative analysis includes the following steps: A quasi-quantitative reliability analysis of transient stability is conducted using the Taylor expansion method based on the classical power system model. If the stability of the results of the transient stability quasi-quantitative reliability analysis is determined, then proceed to the transient stability quantitative analysis; otherwise, perform the transient stability quasi-quantitative analysis with hierarchical fusion of numerical integrals. If the stability of the transient stability quasi-quantitative reliability analysis result is determined after one numerical integration of the hierarchical fusion part, then the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins; otherwise, a second numerical integration of the hierarchical fusion part is performed. If the numerical integration of the hierarchical fusion part is performed twice, regardless of whether the stability of the result of the transient stability quasi-quantitative reliability analysis is certain or uncertain, the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins.

3. The limit calculation method based on transient stability quantitative analysis according to claim 2, characterized in that, The transient stability quasi-quantitative reliability analysis based on the Taylor expansion method of the classical power system model includes sequentially performing quasi-quantitative reliability analysis of initial swing angle stability, multi-swing angle stability, complexity-sensitive impact analysis, and generator terminal voltage dip safety analysis. Among these, the generator terminal voltage dip safety analysis involves determining the voltage dip safety quantification index η based on the generator terminal voltage curve. v .

4. The limit calculation method based on transient stability quantitative analysis according to claim 3, characterized in that, In the transient stability quasi-quantitative analysis of the multi-pendulum work angle stability and the complexity-sensitive impact analysis of the numerical integration of the hierarchical fusion part, the voltage drop safety quantification index η of the generator terminal voltage is introduced. v The differences in voltage sag quantification indices between the preceding and following stages, the differences in indices obtained by referring to the voltage sag quantification method of the terminal voltage curve using a binary table, and the frequency sag quantification index η. s The difference in frequency drop quantization index between the two stages and the difference in frequency drop quantization index caused by differences in numerical simulation and fused multi-step Taylor model.

5. A limit calculation system based on quantitative analysis of transient stability, characterized in that, include The search space estimation module is used to estimate the power increase space required when calculating the load limit of each load limit section for the load limit of the power system, and to estimate the search space for each calculated fault clearing time for the critical fault clearing time (CCT) of the power system. The transient stability quasi-quantitative analysis module is used to average the power increase space and the fault clearing time search space of each section based on the number of assessment faults, parallel processing computing capabilities, and limit calculation accuracy, to determine the transient assessment task. In the parallel search space, the transient stability quasi-quantitative analysis is performed on the transient assessment task to obtain the power search intervals and fault clearing time search intervals of each section's assessment faults that meet the limit calculation accuracy requirements. The transient stability quantitative analysis module is used to search for the power range and fault clearing time range of critical safety and critical insecurity for each cross-section of the test fault. It is divided into categories according to the limit calculation accuracy requirements to form calculation tasks. By adding numerical simulation or integration, transient stability quantitative analysis is performed on each calculation task to determine the transient safety and stability.

6. The limit calculation system based on transient stability quantitative analysis according to claim 5, characterized in that, In the transient stability quasi-quantitative analysis module, transient stability quasi-quantitative analysis includes the following steps: A quasi-quantitative reliability analysis of transient stability is conducted using the Taylor expansion method based on the classical power system model. If the stability of the results of the transient stability quasi-quantitative reliability analysis is determined, then proceed to the transient stability quantitative analysis; otherwise, perform the transient stability quasi-quantitative analysis with hierarchical fusion of numerical integrals. If the stability of the transient stability quasi-quantitative reliability analysis result is determined after one numerical integration of the hierarchical fusion part, then the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins; otherwise, a second numerical integration of the hierarchical fusion part is performed. If the numerical integration of the hierarchical fusion part is performed twice, regardless of whether the stability of the result of the transient stability quasi-quantitative reliability analysis is certain or uncertain, the transient stability quasi-quantitative analysis ends and the transient stability quantitative analysis begins.

7. The limit calculation system based on transient stability quantitative analysis according to claim 6, characterized in that, In the transient stability quasi-quantitative analysis module, the reliability analysis of transient stability quasi-quantitative metrics based on the Taylor expansion method of the classical power system model includes sequentially performing the reliability analysis of the initial swing angle stability quasi-quantitative metrics, the reliability analysis of the multi-swing angle stability quasi-quantitative metrics, the complexity-sensitive impact analysis, and the generator terminal voltage dip safety analysis. Among these, the generator terminal voltage dip safety analysis involves determining the voltage dip safety quantification index η of the generator terminal voltage based on the generator terminal voltage curve. v .

8. The limit calculation system based on transient stability quantitative analysis according to claim 7, characterized in that, In the transient stability quasi-quantitative analysis module, in the reliability analysis of the multi-pendulum work angle stability quasi-quantitative analysis and the complexity-sensitive impact analysis of the transient stability quasi-quantitative analysis of numerical integration in the hierarchical fusion part, the voltage drop safety quantification analysis index η of the terminal voltage is introduced. v The differences in voltage sag quantification indices between the preceding and following stages, the differences in indices obtained by referring to the voltage sag quantification method of the terminal voltage curve using a binary table, and the frequency sag quantification index η. s The difference in frequency drop quantization index between the two stages and the difference in frequency drop quantization index caused by differences in numerical simulation and fused multi-step Taylor model.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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