Power system frequency stability weak point identification method and device, storage medium, program product and computer equipment

Abstract

The invention discloses a power system frequency stability weak point identification method and device, a storage medium, a program product and computer equipment. The method comprises the following steps: acquiring frequency response track information corresponding to a to-be-identified power system; determining a frequency drop deviation (FDD) value based on the frequency response trajectory information, and determining a frequency drop index (FDI) value based on the FDD value; determining a frequency recovery deviation (FRD) value based on the frequency response trajectory information, and determining a frequency recovery index (FRI) value based on the FRD value; and identifying the system frequency stability weak point of the to-be-identified power system by using the FDI value and the FRI value, so that analysis accuracy and physical clarity (with interpretable physical significance) can be considered when the system frequency stability weak point of the to-be-identified power system is identified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, and particularly relates to a power system frequency stability weak point identification method and device, a storage medium, a program product and computer equipment. BACKGROUND

[0002] At present, large-scale renewable energy represented by wind and light is connected to the power grid, and the proportion of new devices such as energy storage, flexible load and power electronic converter is significantly increased. The power system is transforming from the traditional structure dominated by synchronous generators to a new type of power system with high proportion of renewable energy and high proportion of power electronic devices.

[0003] This transformation has brought profound changes to the dynamic characteristics of the system: the decline in the proportion of synchronous units has weakened the inertia response capability of the system, and the uncertainty of wind and light output has intensified the power disturbance intensity. The fast response characteristics of power electronic interface devices make the frequency dynamic process present new features such as multi-time scale coupling, strong nonlinearity and prominent uncertainty. The frequency reflecting the characteristics of the whole network has shown differences and partitioning. The traditional frequency stability evaluation index proposed on the background of consistent whole network frequency can only reflect part of the characteristics of the primary frequency response trajectory, and it is difficult to accurately depict the dynamic interaction mechanism of multi-source heterogeneous devices and the whole process of primary frequency response of each node of the system, and it is difficult to meet the analysis needs of the new type of power system.

[0004] In related technologies, data-driven and artificial intelligence are used to construct evaluation methods to ensure analysis accuracy, but at least the problem of insufficient physical meaning interpretability exists. SUMMARY

[0005] To solve the above technical problems, the embodiments of the present application provide a power system frequency stability weak point identification method, device, storage medium, program product and computer equipment, which can balance analysis accuracy and physical clarity (with interpretable physical meaning) when identifying power system frequency stability weak points.

[0006] In a first aspect, the embodiments of the present application provide a power system frequency stability weak point identification method, comprising:

[0007] Obtaining frequency response trajectory information corresponding to a to-be-identified power system;

[0008] Determining a frequency drop deviation FDD value based on the frequency response trajectory information, and determining a frequency drop index FDI value based on the FDD value;

[0009] Determining a frequency recovery deviation FRD value based on the frequency response trajectory information, and determining a frequency recovery index FRI value based on the FRD value;

[0010] The FDI value and the FRI value are used to identify weak points of system frequency stability of the power system to be identified.

[0011] Optionally, the frequency response trajectory information comprises first primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises:

[0012] obtaining frequency information corresponding to a synchronized phasor measurement device PMU in a wide-area measurement system WAMS, wherein the frequency information comprises real-time frequency information and historical frequency information;

[0013] determining the first primary frequency response trajectory information based on the frequency information.

[0014] Optionally, the frequency response trajectory information comprises second primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises:

[0015] simulating and analyzing the power system to be identified through electromechanical transient time-domain simulation to obtain the second primary frequency response trajectory information.

[0016] Optionally, the frequency response trajectory information comprises frequency values of a plurality of nodes in the power system to be identified in a preset time period;

[0017] the calculation formula of the FDD value comprises:

[0018]

[0019] wherein, FDD i,t represents the FDD value of the i th node at the t th moment, f i,t represents the frequency value of the i th node at the t th moment, f n represents a preset frequency rating value, and the t th moment is included in the preset time period;

[0020] the calculation formula of the FDI value comprises:

[0021]

[0022] wherein, FDI i represents the FDI value of the i th node, t f represents a system fault moment of the power system to be identified, t nad represents a moment when a frequency value trajectory corresponding to the i th node reaches a lowest point.

[0023] Optionally, the frequency response trajectory information comprises frequency values of a plurality of nodes in the power system to be identified in a preset time period;

[0024] The calculation formula of the FRD value comprises:

[0025]

[0026] wherein FRD i,t represents the FRD value of the i th node at the t th moment, f lim represents a preset frequency steady-state deviation limit value, f i,t represents the frequency value of the i th node at the t th moment, f n represents a preset frequency rating value, and the t th moment is included in the preset time period;

[0027] The calculation formula of the FRI value comprises:

[0028]

[0029] wherein FRI i represents the FRI value of the i th node, t nad represents the moment when the frequency value trajectory corresponding to the i th node reaches the lowest point, t pun represents a preset penalty period, t cal represents a preset FRI value calculation period, and p is a penalty coefficient and is greater than 1.

[0030] Optionally, the identification of the system frequency stability weak point of the power system to be identified based on the FDI value and the FRI value comprises:

[0031] determining a frequency stability value based on the FDI value and the FRI value;

[0032] identifying the system frequency stability weak point of the power system to be identified based on the frequency stability value.

[0033] In a second aspect, an embodiment of the present application provides a power system frequency stability weak point identification device, comprising:

[0034] a trajectory acquisition module configured to acquire frequency response trajectory information corresponding to a power system to be identified;

[0035] a frequency drop index value determination module configured to determine a frequency drop deviation FDD value based on the frequency response trajectory information, and determine a frequency drop index FDI value based on the FDD value;

[0036] a frequency recovery index value determination module configured to determine a frequency recovery deviation FRD value based on the frequency response trajectory information, and determine a frequency recovery index FRI value based on the FRD value;

[0037] The identification module is used to identify the weak points in the system frequency stability of the power system to be identified by using the FDI value and the FRI value.

[0038] Thirdly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in any of the above-mentioned embodiments.

[0039] Fourthly, embodiments of this application provide a computer program product, including computer instructions that, when executed by a processor, implement the steps of the method described in any of the above-described embodiments.

[0040] Fifthly, embodiments of this application provide a computer device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the steps of the method described in any of the preceding claims.

[0041] In summary, the embodiments of this application have at least the following beneficial effects:

[0042] Using the embodiments of this application, frequency response trajectory information corresponding to the power system to be identified is obtained; based on the frequency response trajectory information, a frequency sag deviation (FDD) value is determined, and a frequency sag index (FDI) value is determined based on the FDD value; a frequency recovery deviation (FRD) value is determined based on the frequency response trajectory information, and a frequency recovery index (FRI) value is determined based on the FRD value; using the FDI value and the FRI value, weak points in the system frequency stability of the power system to be identified are identified, thereby achieving both analytical accuracy and physical clarity (having interpretable physical meaning) when identifying weak points in the frequency stability of the power system. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the method for identifying weak points in power system frequency stability provided in this application embodiment;

[0044] Figure 2 This is a schematic diagram of the FDI provided in the embodiments of this application;

[0045] Figure 3 This is a schematic diagram of the FRI provided in the embodiments of this application;

[0046] Figure 4 This is a schematic diagram of the FRI provided in the embodiments of this application;

[0047] Figure 5 This is a schematic diagram of the FRI provided in the embodiments of this application;

[0048] Figure 6is a structural schematic diagram of a power system frequency stability weak point identification device provided by an embodiment of the present application;

[0049] Figure 7 is a structural schematic diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0051] In the description of the present application, the terms "first", "second", "third", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified. In the description of the present application, the term "comprising" and its variants are open inclusion, i.e. "including but not limited to". The term "based on" is "at least partially based on". The term "according to" is "at least partially according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments".

[0052] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In the description of the present application, it should be noted that, unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as understood by a person skilled in the art. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] In some related technologies, the frequency stability evaluation indexes proposed in the context of full grid frequency consistency, such as frequency change rate, maximum frequency deviation, steady-state frequency recovery value, etc., can only reflect part of the characteristics of the primary frequency response trajectory, and are difficult to accurately depict the dynamic interaction mechanism of multi-source heterogeneous devices and the whole process of the primary frequency response of each node of the system.

[0055] In a first aspect, referring to Figure 1 , a flowchart of a power system frequency stability weak point identification method provided by an embodiment of the present application is shown, which includes S101-S104, and specifically as follows:

[0056] S101, frequency response trajectory information corresponding to the to-be-identified power system is acquired.

[0057] S102, a frequency drop deviation FDD (Frequency Drop Deviation) value is determined based on the frequency response trajectory information, and a frequency drop index FDI (Frequency DropIndex) value is determined based on the FDD value.

[0058] S103, a frequency recovery deviation FRD (Frequency Recovery Deviation) value is determined based on the frequency response trajectory information, and a frequency recovery index FRI (Frequency RecoveryIndex) value is determined based on the FRD value.

[0059] S104, the FDI value and the FRI value are used to identify the system frequency stability weak point of the to-be-identified power system.

[0060] In an optional implementation, the frequency response trajectory information includes first primary frequency response trajectory information, and the acquiring of the frequency response trajectory information corresponding to the to-be-identified power system includes:

[0061] Frequency information corresponding to a phasor measurement unit PMU (Phasor Measurement Unit) in a wide area measurement system WAMS (Wide Area Measurement System) is acquired, wherein the frequency information includes real-time frequency information and historical frequency information;

[0062] The first primary frequency response trajectory information is determined based on the frequency information.

[0063] In some examples, for new power system frequency stability monitoring and other purposes, the frequency trajectory of the to-be-identified node can be extracted through the WAMS. The WAMS is a power grid dynamic monitoring and control system composed of synchronous phasor measurement devices. The WAMS has the characteristics of remote high-precision synchronous phasor measurement, high-speed communication, and rapid reaction, and can extract real-time and historical frequency information of the PMU deployment point (for example, the node where the PMU is deployed), thereby forming a frequency trajectory to form first primary frequency response trajectory information.

[0064] In an optional implementation, the frequency response trajectory information includes second primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the to-be-identified power system comprises:

[0065] The second primary frequency response trajectory information is obtained by simulating and analyzing the to-be-identified power system through electromechanical transient time domain simulation.

[0066] In some examples, for new power system frequency stability evaluation, planning, operation, and other research, the frequency trajectory of the to-be-identified node can be obtained through electromechanical transient time domain simulation. For example, electromechanical transient time domain simulation software (PSS / E, PSASP, etc.) can be used to simulate various faults of the power system and perform dynamic stability analysis, and has a rich library of steady-state and transient models, such as various conventional units, wind turbine generators, photovoltaic power stations, energy storage, DC transmission lines, and complex load models, which are sufficient to cover all components of the new power system. Therefore, a new power system model that needs to be identified for frequency stability weakness can be built in the electromechanical transient time domain simulation software, and various disturbances can be set for simulation and analysis to extract the primary frequency response trajectory of the to-be-identified node of the system to form second primary frequency response trajectory information.

[0067] In an optional implementation, the frequency response trajectory information includes frequency values of a plurality of nodes in the to-be-identified power system respectively in a preset time period;

[0068] The calculation formula of the FDD value comprises:

[0069]

[0070] wherein, FDD i,t represents the FDD value of the i th node at time t, f i,t represents the frequency value of the i th node at time t, f n represents a preset frequency rating value, and the time t is included in the preset time period;

[0071] The calculation formula of the FDI value comprises:

[0072]

[0073] wherein FDI i represents the FDI value of the ith node, t f represents the system fault moment of the power system to be identified, t nad represents the moment when the frequency value trajectory corresponding to the ith node reaches the lowest point.

[0074] It can be understood that, referring to Figure 2 , FDI can be defined as f = f n , t = t nad and the area surrounded by the post-fault frequency trajectory. The above FDI value can be used to represent the cumulative effect of frequency deviation on time, so as to quantify the frequency drop stage of the node to be identified.

[0075] In an optional implementation, the frequency response trajectory information comprises frequency values of a plurality of nodes in the power system to be identified respectively in a preset time period;

[0076] The calculation formula of the FRD value comprises:

[0077]

[0078] wherein FRD i,t represents the FRD value of the ith node at t, f lim represents a preset frequency steady-state deviation limit, f i,t represents the frequency value of the ith node at t, f n represents a preset frequency rated value, and the t moment is included in the preset time period;

[0079] The calculation formula of the FRI value comprises:

[0080]

[0081] wherein FRI i represents the FRI value of the ith node, t nad represents the moment when the frequency value trajectory corresponding to the ith node reaches the lowest point, t pun represents a preset penalty period, t cal represents a preset FRI value calculation period, and p is a penalty coefficient and greater than 1.

[0082] It can be understood that, referring to Figures 3-5 , FRI can be defined as f = f lim , t = t nad and the area surrounded by the post-fault frequency trajectory. In order to ensure the effectiveness of FRI, a penalty period t pun is defined. When the frequency trajectory exceeds t pun and does not reach flim part will be punished; FRI value calculation period t cal The period set for calculating FRI, both parameters can be set according to actual needs. Based on the above definition, FRI can be divided into three cases:

[0083] (1) Referring to Figure 3 , f qs ≥ f lim , and the recovery time does not exceed t pun , wherein f qs represents the frequency value (i.e. quasi-steady frequency value) of t nad +t cal .

[0084] (2) Referring to Figure 4 , f qs ≥ f lim , and the recovery time exceeds t pun .

[0085] (3) Referring to Figure 5 , f qs < f lim .

[0086] The above three cases can be integrated to derive the calculation formula of the FRI value. Thus, the FRI value can be used to represent the frequency minimum point and the quasi-steady frequency f qs , so as to quantify the frequency recovery stage of the to-be-identified node.

[0087] In an optional implementation, the FDI value and the FRI value are used to identify the system frequency stability weak point of the to-be-identified power system, which includes:

[0088] Based on the FDI value and the FRI value, a frequency stability value is determined.

[0089] Based on the frequency stability value, the system frequency stability weak point of the to-be-identified power system is identified.

[0090] In some examples, based on the FDI value and the FRI value, the frequency stability value can be determined, which can include: the FDI value and the FRI value are respectively normalized, and the frequency stability value is determined based on the normalized FDI value and the FRI value.

[0091] Following the above example, the mathematical expression of the normalization processing can include:

[0092]

[0093] wherein, denotes the normalized value of index n, which can take FDI or FRI, denotes the index value of index n of the i th node (FDI value or FRI value), denotes the minimum value in the index values of index n of all nodes, denotes the maximum value in the index values of index n of all nodes.

[0094] In some examples, the above frequency stability value can be obtained by adding the square values of the FDI value and the FRI value respectively, and then taking the square root of the added value, which is formulated as follows:

[0095]

[0096] wherein FS i denotes the frequency stability value of the i th node, denotes the normalized FDI value of the i th node, denotes the normalized FRI value of the i th node.

[0097] In the above formula, FS i ranges from 0 to 1. Both FDI and FRI are based on the cumulative effect of frequency deviation on time, so the worse the frequency stability of the system node, the greater the frequency deviation and the longer the recovery time when subjected to disturbance, and the greater the FDI and FRI, i.e. weak frequency stability node.

[0098] In this embodiment, the frequency stability index considering the cumulative effect of frequency deviation on time can reflect the whole process of the frequency response of each node of the new power system after being subjected to serious disturbance, and accurately identify the weak point of the frequency stability of the system.

[0099] In a second aspect, correspondingly, the embodiments of the present application also provide a power system frequency stability weak point identification device, which can realize all processes of the power system frequency stability weak point identification method provided by the above-mentioned embodiments.

[0100] Referring to Figure 6 , a structure schematic diagram of a power system frequency stability weak point identification device provided by the embodiments of the present application is shown, which comprises:

[0101] The trajectory acquisition module 601 is configured to acquire frequency response trajectory information corresponding to the power system to be identified.

[0102] The frequency drop index value determination module 602 is configured to determine a frequency drop deviation FDD value based on the frequency response trajectory information, and determine a frequency drop index FDI value based on the FDD value.

[0103] The frequency recovery index value determination module 603 is configured to determine a frequency recovery deviation (FRD) value based on the frequency response trajectory information, and determine a frequency recovery index (FRI) value based on the FRD value.

[0104] The identification module 604 is configured to identify the weak point of system frequency stability of the power system to be identified by using the FDI value and the FRI value.

[0105] In an optional embodiment, the frequency response trajectory information includes first primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises:

[0106] obtaining frequency information corresponding to a phasor measurement unit (PMU) in a wide area measurement system (WAMS), wherein the frequency information includes real-time frequency information and historical frequency information;

[0107] determining the first primary frequency response trajectory information based on the frequency information.

[0108] In an optional embodiment, the frequency response trajectory information includes second primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises:

[0109] performing simulation analysis on the power system to be identified by electromechanical transient time domain simulation to obtain the second primary frequency response trajectory information.

[0110] In an optional embodiment, the frequency response trajectory information includes frequency values of a plurality of nodes in the power system to be identified in a preset time period;

[0111] The FDD value is calculated according to the following formula:

[0112]

[0113] wherein, FDD i,t represents the FDD value of the i th node at the t th moment, f i,t represents the frequency value of the i th node at the t th moment, f n represents a preset frequency rating value, and the t th moment is included in the preset time period.

[0114] The FDI value is calculated according to the following formula:

[0115]

[0116] wherein, FDI i represents the FDI value of the i th node, t f represents the system fault moment of the power system to be identified, t nadThis represents the moment when the frequency value trajectory corresponding to the i-th node reaches its lowest point.

[0117] In one optional implementation, the frequency response trajectory information includes the frequency values ​​of multiple nodes in the power system to be identified within a preset time period.

[0118] The formula for calculating the FRD value includes:

[0119]

[0120] Among them, FRD i,t f represents the FRD value of the i-th node at time t. lim This represents the preset steady-state frequency deviation limit, f. i,t f represents the frequency value of the i-th node at time t. n This represents a preset frequency rating, and time t is included in the preset time period;

[0121] The formula for calculating the FRI value includes:

[0122]

[0123] Among them, FRI i t represents the FRI value of the i-th node. nad Let t represent the time when the frequency trajectory corresponding to the i-th node reaches its lowest point. pun t represents the preset penalty period. cal This indicates the preset FRI value calculation period, where p is the penalty coefficient and is greater than 1.

[0124] In one optional implementation, the step of identifying system frequency stability weaknesses in the power system to be identified using the FDI value and the FRI value includes:

[0125] Based on the FDI value and the FRI value, a frequency stability value is determined;

[0126] Based on the frequency stability value, the weak points in the system frequency stability of the power system to be identified are determined.

[0127] Thirdly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in any of the above-mentioned embodiments.

[0128] Fourthly, embodiments of this application provide a computer program product, including computer instructions that, when executed by a processor, implement the steps of the method described in any of the above-described embodiments.

[0129] In a fifth aspect, an embodiment of the present application provides a computer device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the steps of the method according to any one of the preceding aspects when executing the computer program.

[0130] Referring to Figure 7 The computer device of the embodiment comprises a processor 701, a memory 702, and a computer program stored in the memory 702 and executable on the processor 701, such as a power system frequency stability weakness point identification program. The processor 701 implements the steps in each of the power system frequency stability weakness point identification method embodiments described above when executing the computer program, such as Figure 1 The steps S101-S104 shown.

[0131] For example, the computer program can be divided into one or more modules / units, which are stored in the memory 702 and executed by the processor 701 to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the computer device.

[0132] The computer device can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The computer device can include, but is not limited to, the processor 701 and the memory 702. Those skilled in the art can understand that the schematic diagram is only an example of the computer device, and does not limit the computer device, which can include more or fewer components than the diagram, or combine certain components, or different components, for example, the computer device can also include an input / output device, a network access device, a bus, and the like.

[0133] The processor 701 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, and the like. The general-purpose processor can be a microprocessor or the processor 701 can also be any conventional processor and the like, which is the control center of the computer device, and connects each part of the computer device through various interfaces and lines.

[0134] The memory 702 can be used to store the computer program and / or modules, and the processor 701 realizes various functions of the computer device by running or executing the computer program and / or modules stored in the memory 702, and calling the data stored in the memory 702. The memory 702 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application program required by a function (such as a sound playing function, an image playing function, etc.), and the like; and the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), and the like. In addition, the memory 702 can include a high-speed random access memory, and can also include a nonvolatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory devices.

[0135] The modules / units integrated in the computer device, if realized in the form of software function units and sold or used as independent products, can be stored in a computer readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. When the processor 701 executes the computer program, the steps of the above-mentioned various method embodiments can be realized. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0136] In summary, the embodiments of the present application have at least the following beneficial effects:

[0137] By means of the embodiments of the present application, the frequency response trajectory information corresponding to the to-be-identified power system is acquired; the frequency drop deviation FDD value is determined based on the frequency response trajectory information, and the frequency drop index FDI value is determined based on the FDD value; the frequency recovery deviation FRD value is determined based on the frequency response trajectory information, and the frequency recovery index FRI value is determined based on the FRD value; the FDI value and the FRI value are used to identify the weak point of the system frequency stability of the to-be-identified power system, so that the analysis accuracy and the physical clarity (possessing an interpretable physical meaning) can be taken into account when the weak point of the power system frequency stability is identified.

[0138] Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software and the necessary hardware platform, and of course, it can also be implemented entirely by hardware. Based on such understanding, all or part of the technical solutions of the present application which make contributions to the background art can be embodied in the form of a software product. The computer software product can be stored in a storage medium, such as a ROM (Read-Only Memory), a RAM (Random Access Memory), a magnetic disk, an optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the method described in each embodiment or some part of the embodiments of the present application.

[0139] The above is the preferred embodiment of the present application, and it should be pointed out that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered to be within the protection scope of the present application.

Claims

1. A method for identifying a frequency stability weakness in a power system, the method comprising: The method comprises the following steps: obtaining frequency response trajectory information corresponding to the power system to be identified; determining a frequency drop deviation (FDD) value based on the frequency response trajectory information, and determining a frequency drop index (FDI) value based on the FDD value; determining a frequency recovery deviation (FRD) value based on the frequency response trajectory information, and determining a frequency recovery index (FRI) value based on the FRD value; identifying weak points of system frequency stability of the power system to be identified by using the FDI value and the FRI value.

2. The method of claim 1, wherein, The frequency response trajectory information comprises first primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises the following steps: obtaining frequency information corresponding to a phasor measurement unit (PMU) in a wide-area measurement system (WAMS), wherein the frequency information comprises real-time frequency information and historical frequency information; determining the first primary frequency response trajectory information based on the frequency information.

3. The method of claim 1, wherein, The frequency response trajectory information comprises second primary frequency response trajectory information, and the obtaining of the frequency response trajectory information corresponding to the power system to be identified comprises the following steps: performing simulation analysis on the power system to be identified by electromechanical transient time-domain simulation to obtain the second primary frequency response trajectory information.

4. The method of claim 1, wherein, The frequency response trajectory information comprises frequency values of a plurality of nodes in the power system to be identified within a preset time period; The calculation formula of the FDD value comprises: Wherein, FDD i,t represents the FDD value of the i th node at t time, f i,t represents the frequency value of the i th node at t time, f n represents a preset frequency rating value, and the t time is contained in the preset time period; The calculation formula of the FDI value comprises: wherein FDI i represents the FDI value of the ith node, t f represents the system fault moment of the power system to be identified, t nad represents the moment when the frequency value trajectory corresponding to the ith node reaches the lowest point.

5. The method of claim 1, wherein, The frequency response trajectory information comprises frequency values of a plurality of nodes in the power system to be identified within a preset time period; The calculation formula of the FRD value comprises: wherein FRD i,t represents the FRD value of the i-th node at time t, f lim represents a preset frequency steady-state deviation limit value, f i,t represents the frequency value of the i-th node at time t, f n represents a preset frequency rating value, and the time t is contained in the preset time period. The calculation formula of the FRI value comprises: Wherein, FRI i represents the FRI value of the i th node, t nad represents the time when the trajectory of the frequency value corresponding to the i th node reaches the lowest point, t pun represents the preset penalty period, t cal represents the preset FRI value calculation period, p is a penalty coefficient and is greater than 1.

6. The method of claim 1, wherein, The identification of weak points of system frequency stability of the power system to be identified by using the FDI value and the FRI value comprises the following steps: determining a frequency stability value based on the FDI value and the FRI value; identifying weak points of system frequency stability of the power system to be identified based on the frequency stability value.

7. A device for identifying weak points in the frequency stability of a power system, characterized in that, The method comprises the following steps: a trajectory obtaining module configured to obtain frequency response trajectory information corresponding to the power system to be identified; a frequency drop index value determining module configured to determine a frequency drop deviation (FDD) value based on the frequency response trajectory information, and determine a frequency drop index (FDI) value based on the FDD value; a frequency recovery index value determining module configured to determine a frequency recovery deviation (FRD) value based on the frequency response trajectory information, and determine a frequency recovery index (FRI) value based on the FRD value; an identification module configured to identify weak points of system frequency stability of the power system to be identified by using the FDI value and the FRI value.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to implement the method of any one of claims 1-6.

9. A computer program product comprising computer instructions, characterized in that, The computer program is executed by the processor to implement the method of any one of claims 1-6.

10. A computer device, comprising: The device comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the method of any one of claims 1-6 when executing the computer program.

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