A power grid static stability dominant mode identification method based on voltage phasor trajectory

Abstract

The application discloses a power grid static stability leading mode identification method based on a voltage phasor trajectory, and comprises the following steps: based on input wide-area measurement data, calculating equivalent parameters of all nodes; based on the equivalent parameters of all nodes, generating an equivalent two-node power grid parameter model; based on the equivalent two-node power grid parameter model, calculating a node voltage phasor trajectory; based on the node voltage phasor trajectory, calculating trajectory sensitivity of the node voltage phasor; based on the trajectory sensitivity of the node voltage phasor, determining a static stability leading mode identification criterion; and determining leading states at different time points in a dynamic evolution process of the power grid and leading state leading points according to the static stability leading mode identification criterion and the node voltage phasor trajectory.

Description

Technical Field

[0001] This invention relates to the field of active security defense for large power grids under wide-area measurement information, and more specifically, to a method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories. Background Technology

[0002] With the continuous expansion of the AC / DC scale of the power grid, the widespread use of power electronic equipment, and the large-scale access of diverse loads, the power grid operation scenarios are becoming more complex, the dynamic characteristics of the system are more variable, and the stability modes are more difficult to distinguish. The safe and stable operation of the power grid faces significant challenges. As an important component of power system safety and stability analysis, static stability analysis will also face significant challenges under the new power grid development trend.

[0003] Static power angle stability and voltage stability are two typical stability modes in AC / DC hybrid power grids. Due to the strong coupling characteristics and complex interaction mechanisms of modern power grids, these two stability modes often intertwine during actual power system operation. Power angle problems are often accompanied by voltage problems, and vice versa. The two problems are intertwined and mutually influential, making it difficult to formulate targeted safety control strategies. Currently, methods for analyzing the dominant stability modes of power grids include: ① analyzing the stability dominant mode through changes in active power margin indicators; ② using wide-area branch response information combined with the spatiotemporal variation of voltage to determine the stability dominant mode using quantitative evaluation indices; ③ using simplified branch transient transmission capacity indices that characterize the power grid stability state to determine the stability dominant mode; and ④ analyzing the distribution characteristics of wide-area reactive power branches to determine the dominant instability mode. The aforementioned theoretical methods have good application effects and guiding significance for the identification of the dominant stability mode of the system and the formulation of auxiliary control strategies when the system model parameters are complete and accurate and the operating scenario is known and controllable. However, the effectiveness of the online identification method for the dominant stability mode of the power grid needs to be further studied when facing new power systems with more complex stability mechanisms, more variable stability scenarios, and model parameters that are difficult to obtain accurately.

[0004] Therefore, based on the above technical background, conducting power system stability analysis using wide-area measurement information can meet the technical requirements for model universality and avoid data dependence on parameters, which has significant research value and engineering significance. Summary of the Invention

[0005] To address at least one of the problems described in the background section, this invention provides a method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories.

[0006] According to one aspect of the present invention, a method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories is provided, comprising:

[0007] Based on the input wide-area measurement data, calculate the equivalent parameters of all nodes in the network;

[0008] Based on the equivalent parameters of all nodes in the network, an equivalent two-node power grid parameter model is generated.

[0009] Based on the equivalent two-node power grid parameter model, the node voltage phasor trajectory is calculated.

[0010] Calculate the trajectory sensitivity of nodal voltage phasors based on nodal voltage phasor traject ...

[0011] Based on the trajectory sensitivity of nodal voltage phasors, a criterion for identifying the dominant static stability mode is determined.

[0012] Based on the static stability dominant mode identification criteria and the node voltage phasor trajectory, the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid are determined.

[0013] Optionally, calculating the equivalent parameters of all network nodes based on the input wide-area measurement data includes:

[0014] The line impedance Z of the entire network is obtained in real time from the wide-area measurement system. i and the voltage U of each node i ∠θ i ;

[0015] Through Y i =1 / Z i The admittance on each line is calculated, and the nodal admittance matrix Y of the line is generated;

[0016] Inverting the nodal admittance matrix Y yields the nodal impedance matrix Z;

[0017] Based on the nodal impedance matrix Z, calculate the equivalent impedance Z of all load nodes. ieq ;

[0018] Based on the equivalent impedance Z ieq Based on the node voltage, calculate the equivalent electromotive force of all load nodes according to the power flow formula.

[0019] Optionally, the node admittance matrix Y is:

[0020]

[0021] In the formula, matrix element Y ii The self-admittance between each node, matrix element Y ij The mutual admittance between nodes;

[0022] The node impedance matrix Z is:

[0023]

[0024] In the formula, matrix element Z ii The self-impedance between each node, matrix element Z ij The mutual impedance between nodes;

[0025] The equivalent impedance Z of all load nodes is calculated based on the node impedance matrix Z. ieq ,include:

[0026] Using formula For all self-impedance Z ii With load impedance Z i By performing anti-parallel connection, the equivalent impedance Z of all load nodes can be obtained. ieq .

[0027] Optionally, the static stable dominant mode identification criterion D st The expression is:

[0028]

[0029] In the formula, U n U m δ n δ m These are the coordinates of four points on the trajectory sensitivity plane, representing the voltage amplitude and power angle relative to the parametric sensitivity, respectively, where p is the dimension of the characteristic parameter of the Minkowski distance.

[0030] According to another aspect of the present invention, a device for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories is provided, comprising:

[0031] The first calculation module is used to calculate the equivalent parameters of all nodes in the network based on the input wide-area measurement data;

[0032] The generation module is used to generate an equivalent two-node power grid parameter model based on the equivalent parameters of all nodes in the network.

[0033] The second calculation module is used to calculate the node voltage phasor trajectory based on the equivalent two-node power grid parameter model.

[0034] The third calculation module is used to calculate the trajectory sensitivity of the node voltage phasors based on the node voltage phasor trajectory.

[0035] The first determining module is used to determine the static stability dominant mode identification criteria based on the trajectory sensitivity of the node voltage phasor.

[0036] The second determination module is used to determine the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid, based on the static stability dominant mode identification criteria and the node voltage phasor trajectory.

[0037] Optionally, the first calculation module is specifically used for:

[0038] The line impedance Z of the entire network is obtained in real time from the wide-area measurement system. i and the voltage U of each node i ∠θ i ;

[0039] Through Y i =1 / Z i The admittance on each line is calculated, and the nodal admittance matrix Y of the line is generated;

[0040] Inverting the nodal admittance matrix Y yields the nodal impedance matrix Z;

[0041] Based on the nodal impedance matrix Z, calculate the equivalent impedance Z of all load nodes. ieq ;

[0042] Based on the equivalent impedance Z ieq Based on the node voltage, calculate the equivalent electromotive force of all load nodes according to the power flow formula.

[0043] Optionally, the node admittance matrix Y is:

[0044]

[0045] In the formula, matrix element Y ii The self-admittance between each node, matrix element Y ij The mutual admittance between nodes;

[0046] The node impedance matrix Z is:

[0047]

[0048] In the formula, matrix element Z ii The self-impedance between each node, matrix element Z ij The mutual impedance between nodes;

[0049] The equivalent impedance Z of all load nodes is calculated based on the node impedance matrix Z. ieq ,include:

[0050] Using formula For all self-impedance Z ii With load impedance Z i By performing anti-parallel connection, the equivalent impedance Z of all load nodes can be obtained. ieq .

[0051] Optionally, the static stable dominant mode identification criterion D st The expression is:

[0052]

[0053] In the formula, U n Um δ n δ m These are the coordinates of four points on the trajectory sensitivity plane, representing the voltage amplitude and power angle relative to the parametric sensitivity, respectively, where p is the dimension of the characteristic parameter of the Minkowski distance.

[0054] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0055] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0056] Compared with existing technologies, this invention starts with voltage phasor trajectories and constructs an equivalent model of the complex system using the Thevenin equivalent concept. It analyzes the geometric features and trajectory sensitivity characteristics of the voltage phasor trajectories in a two-dimensional Cartesian coordinate system. Based on this, and combining the voltage phasor trajector trajectories and Minkowski distance, a static stability dominance identification criterion for the power grid is constructed. This criterion identifies the static stability dominance boundary point and maps its mode transformation process onto the voltage phasor trajectories, accurately and intuitively reflecting the stability dominance situation during the dynamic evolution of the power grid. This invention can accurately and effectively identify the stability dominance mode of complex power grids, with fast calculations and accurate results. It can meet the timeliness and applicability requirements of new power systems for power grid stability dominance mode analysis, providing scientific theoretical support for the static stability situation assessment and precise control of power systems. Attached Figure Description

[0057] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0058] Figure 1 This is a flowchart illustrating a method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories, provided in an exemplary embodiment of the present invention.

[0059] Figure 2 This is a schematic diagram of an equivalent two-node power grid parameter model provided by an exemplary embodiment of the present invention;

[0060] Figure 3 This is a schematic diagram of the node voltage phasor trajectory provided in an exemplary embodiment of the present invention;

[0061] Figure 4a This is a schematic diagram of a static stable dominant mode recognition criterion provided in an exemplary embodiment of the present invention;

[0062] Figure 4bThis is a schematic diagram of a static stable dominant pattern recognition criterion provided in an exemplary embodiment of the present invention;

[0063] Figure 5a This is a schematic diagram of the dominant criterion for static stability of two nodes provided in an exemplary embodiment of the present invention;

[0064] Figure 5b This is a pattern recognition analysis diagram of the two-node static stability dominant criterion provided in an exemplary embodiment of the present invention;

[0065] Figure 6 This is a diagram of an IEEE 10-machine 39-node system provided in an exemplary embodiment of the present invention;

[0066] Figure 7a This is a schematic diagram of the dominant static stability criterion for an IEEE 10-machine 39-node system provided in an exemplary embodiment of the present invention;

[0067] Figure 7b This is a pattern recognition analysis diagram of the dominant static stability criterion for an IEEE 10-machine 39-node system provided in an exemplary embodiment of the present invention;

[0068] Figure 8 This is a schematic diagram of the structure of a power grid static stability dominant mode identification device based on voltage phasor trajectory provided in an exemplary embodiment of the present invention;

[0069] Figure 9 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0070] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0071] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0072] Figure 1 A flowchart illustrating the power grid static stability dominant mode identification method based on voltage phasor trajectories provided by this invention is shown. Figure 1As shown, the method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories includes: calculating the equivalent parameters of all nodes in the network based on the input wide-area measurement data; generating an equivalent two-node power grid parameter model based on the equivalent parameters of all nodes in the network; calculating the node voltage phasor trajector trajectories based on the equivalent two-node power grid parameter model; calculating the trajectory sensitivity of the node voltage phasors based on the node voltage phasors; determining the static stability dominant mode identification criterion based on the trajectory sensitivity of the node voltage phasors; and determining the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid based on the static stability dominant mode identification criterion and the node voltage phasor trajectories.

[0073] In this invention, the efficient and accurate static dominant stability pattern identification method is of great significance for ensuring the safe and stable operation of new power systems. The static stability dominant identification technology based on voltage phasor trajectories and the response-based power system analysis model have the characteristics of strong model applicability and weak parameter dependence, while also possessing timeliness and accuracy, making them important means to solve the problem of identifying the dominant stability patterns of complex power systems. Currently, analysis methods based on voltage phasor trajectories generally adopt the form of total parametric differentiation or indeterminate integrals. This method requires high data accuracy and has clear requirements for the differentiability and differentiability of the trajectory, making it unable to fully adapt to special cases.

[0074] Therefore, this invention proposes a method for identifying the dominant static stability mode of a power grid. This method simplifies complex systems and extracts voltage phasor trajectory information, then uses proposed indicators to determine the dominant static stability mode of the power grid. It exhibits good robustness and strong applicability. The specific steps are as follows:

[0075] Step (1): Calculate the equivalent parameters of the entire network and obtain the line impedance Z of the entire network in real time from the wide area measurement system. i and the voltage U of each node i ∠θ i Through Y i =1 / Z i The admittances on each line are calculated, and the nodal admittance matrix Y of the line is generated:

[0076]

[0077] Inverse the matrix to obtain the nodal impedance matrix Z:

[0078]

[0079] Wherein, matrix element Y ii and Y ij These represent the self-admittance and mutual admittance between each node, Z. ii and Z ijThese are the self-impedance and mutual impedance between each node. Using formula (3), the self-impedance and load impedance Z are... i By performing anti-parallel connection, the equivalent impedance Z of all load nodes can be obtained. ieq .

[0080]

[0081] The equivalent potential can be obtained from the equivalent impedance and node voltage using the power flow formula.

[0082] Step (2): Generate the equivalent two-node power grid parameter model according to step (1). The schematic diagram of the equivalent two-node power grid parameter model is shown below. Figure 2 As shown. Z s ∠α s =R s +jX s For the equivalent resistance and reactance of the network, U is the phasor of the line-transmitted current. L ∠δ L Z represents the node voltage and phase angle on the load side. L ∠α L =R L +jX L For the external load impedance, S L ∠Φ L =P L +jQ L This represents the receiving-end power and its power factor angle corresponding to the load.

[0083] The system can be derived as follows:

[0084]

[0085] The power absorbed on the load side is:

[0086]

[0087] Step (3): By rearranging formulas (6) and (7), the voltage phasor trajectory is obtained. The schematic diagram of the nodal voltage phasor trajectory is shown below. Figure 3 As shown, its expression formula is formula (8):

[0088]

[0089]

[0090] Considering system R s Much smaller than X s Ignore its impact on line parameters:

[0091]

[0092] Step (4): The voltage phasor trajectory sensitivity is calculated by applying formulas (9), (10), and (11).

[0093]

[0094]

[0095] When a small disturbance occurs in the system, a higher-order infinitesimal ρ is generated, which is approximately 0. Therefore, based on the overall changes in the power grid, the voltage phasor trajectory sensitivity under small disturbance conditions can be obtained as shown in formula (8).

[0096]

[0097] Where ΔU and Δδ represent the voltage and power angle increment changes under small disturbance conditions, respectively.

[0098] Step (5): Obtain the voltage amplitude U according to formulas (12) and (13). L and work angle δ L Regarding parameter Z respectively L Sensitivity ΔU L and Δδ L :

[0099]

[0100]

[0101] Step (6): Combining formula (13) and calculating according to formula (14), the static stable dominant mode recognition criterion is obtained:

[0102]

[0103] Among them, U n U m δ n δ m These are the coordinates of four points on the trajectory sensitivity plane, representing the voltage amplitude and power angle relative to the parametric sensitivity, respectively, where p is the dimension of the characteristic parameter of the Minkowski distance.

[0104] in, Figure 4a A schematic diagram of the static stable dominant pattern recognition criterion is shown. Figure 4b A schematic diagram of a pattern recognition criterion for statically stable dominant patterns is shown.

[0105] In this embodiment of the invention, the Thevenin equivalent parameter model is adopted to perform equivalent processing on the network parameters under wide-area measurement, resulting in an equivalent two-node AC line parameter model. This model can then be used to evaluate the static stability dominant characteristics of nodes at any given time. Specifically, this can be interpreted as follows:

[0106] 1)0 <D st When the value is less than 1, the system is in a state dominated by static power angle stability. The closer the value is to 0, the greater the influence of power angle stability on the system.

[0107] 2)D st When = 1, the system is in a critical state of static voltage stability and power angle stability, and the two have the same degree of influence on system stability.

[0108] 3)D st When the value is greater than 1, the system is in a state dominated by static voltage stability. The further away from 1 the value is from 1, the greater the influence of voltage stability on the system.

[0109] Step (7): Based on the dominant stable mode identification criterion obtained in step (6), map it to the voltage phasor trajectory to obtain the dominant state and its dominant boundary point at different times during the dynamic evolution of the power grid.

[0110] To more clearly illustrate the optimal effect of implementing the present invention, the technical solution of the present invention will be further described in detail below with examples of a two-node system and an IEEE-39 node system.

[0111] (1) System Model Description

[0112] The two-node system adopts a constant power factor angle model. The head-end potential E = 1.05pu remains constant, and the network equivalent impedance R... s =0.02pu, X s =0.2pu, load impedance R L =2pu,X L =0.2pu, and gradually decrease to 0 at a constant ratio. Figure 6 The IEEE-39 node system diagram is shown, as follows: Figure 6 As shown, the IEEE-39 node system includes 10 generators, 46 lines and 19 loads. The loads are in a constant power model. Under the initial load mode, the power factor of the load at node 15 is kept constant, and its active and reactive power are increased separately. The increased output is shared by the 10 generators, and the parameter changes under the continuous power flow section are tracked.

[0113] (2) Validation of indicator effectiveness

[0114] Stability dominance identification criterion D for two nodes st The construction, and the corresponding changes in the static stability dominant criterion, are as follows: Figure 5a As shown. When the load impedance reaches Z... L When = 0.09 + j0.009pu, the stable dominant identification criterion D st=1 This point is the dominant static stability boundary point in the dynamic evolution of the system. Based on the dominant boundary point and its stable transition mode, mapped to the voltage phasor trajectory, the dynamic transition process of the mode can be obtained as follows: Figure 5b As shown.

[0115] Depend on Figure 7a It can be seen that in the IEEE 39-node continuous power flow scenario, as the load changes, the system is in the process of transitioning from voltage stability to power angle stability. Furthermore, as the load increases until a critical point, the system gradually tends towards a power angle-dominated stable mode, and the degree of this transition gradually deepens. There is a stable dominant dividing point in this transition process. According to... Figure 7b The changes in the dominance of power angle stability and voltage stability are clearly visible.

[0116] Therefore, the static stability dominant mode identification method proposed in this invention can effectively identify the static stability dominant state of the power grid, and has good application effect and guiding significance for the identification of the system stability dominant mode and the formulation of auxiliary control strategies.

[0117] This invention starts with voltage phasor trajectories and, through the Thevenin equivalent concept, constructs an equivalent model of the complex system. It analyzes the geometric characteristics and trajectory sensitivity of the voltage phasor trajectories in a two-dimensional Cartesian coordinate system. Based on this, and combining the voltage phasor trajector trajectories and Minkowski distance, it constructs a criterion for identifying the dominant static stability mode of the power grid, identifies the dominant static stability boundary point, and maps its mode transformation process onto the voltage phasor trajectories. This accurately and intuitively reflects the dominant stability situation during the dynamic evolution of the power grid. This invention can accurately and effectively identify the dominant stability mode of complex power grids, with fast calculations and precise results. It can meet the timeliness and applicability requirements of new power systems for analyzing the dominant stability mode of the power grid, providing scientific theoretical support for the assessment and precise control of the static stability situation of power systems.

[0118] Compared with existing technologies, the present invention provides a method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories, which has the following advantages:

[0119] (1) For the whole network parameter model, an equivalent two-node AC circuit model is built. The trajectory mathematical model is obtained by combining the voltage phasor trajectory and energy conversion relationship. The voltage change law is deduced from the perspective of sensitivity, and the trajectory sensitivity model is obtained. Its physical characteristics are obvious and it has strong physical properties.

[0120] (2) Using Minkowski distance as the parameter evaluation basis, a power grid static stability dominant mode identification criterion based on voltage phasor trajectory is constructed, and this criterion is mapped onto the voltage phasor trajectory to intuitively display its dominant mode.

[0121] (3) The method was analyzed and verified by a single-machine two-node system and an IEEE 10-machine 39-node system, demonstrating the effectiveness and applicability of the method.

[0122] The method provided by this invention is mainly applied to the field of online safety analysis of large power grids. It can be based entirely on real-time online measurement data of the power grid. Through the static stability dominant mode identification method proposed in this patent, it can achieve rapid evaluation of the static stability dominant mode of the power grid. The calculation is fast and the results are accurate, meeting the applicability requirements of static stability analysis of power grids.

[0123] The method provided by this invention, which involves the analysis of voltage phasor trajector trajector trajector sensitivity and Minkowski distance, can effectively avoid the model anomaly problems caused by missing or erroneous measured data, and provides a simple, efficient and reliable trajectory analysis method.

[0124] The method provided in this invention is essentially a response-based analysis approach, characterized by strong model applicability and weak parameter dependence, making it a crucial tool for identifying dominant stability modes in complex power systems. Voltage phasor trajectories contain rich stability characteristics of the power grid and represent the simplest and most direct way to depict its spatiotemporal dynamics. In-depth analysis of the temporal and geometric characteristics of voltage phasor trajectories reveals the underlying stability mechanisms, providing an effective path for identifying dominant static stability modes in the power grid. The combination of these two approaches offers both speed and interpretability, effectively supporting the construction of future online security defense systems for the power grid.

[0125] Exemplary device

[0126] Figure 8 This is a schematic diagram of the structure of a power grid static stability dominant mode identification device 800 based on voltage phasor trajectories provided in an exemplary embodiment of the present invention. Figure 8 As shown, the device 800 includes:

[0127] The first calculation module is used to calculate the equivalent parameters of all nodes in the network based on the input wide-area measurement data;

[0128] The generation module is used to generate an equivalent two-node power grid parameter model based on the equivalent parameters of all nodes in the network.

[0129] The second calculation module is used to calculate the node voltage phasor trajectory based on the equivalent two-node power grid parameter model.

[0130] The third calculation module is used to calculate the trajectory sensitivity of the node voltage phasors based on the node voltage phasor trajectory.

[0131] The first determining module is used to determine the static stability dominant mode identification criteria based on the trajectory sensitivity of the node voltage phasor.

[0132] The second determination module is used to determine the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid, based on the static stability dominant mode identification criteria and the node voltage phasor trajectory.

[0133] Optionally, the first calculation module is specifically used for:

[0134] The line impedance Z of the entire network is obtained in real time from the wide-area measurement system. i and the voltage U of each node i ∠θ i ;

[0135] Through Y i =1 / Z i The admittance on each line is calculated, and the nodal admittance matrix Y of the line is generated;

[0136] Inverting the nodal admittance matrix Y yields the nodal impedance matrix Z;

[0137] Based on the nodal impedance matrix Z, calculate the equivalent impedance Z of all load nodes. ieq ;

[0138] Based on the equivalent impedance Z ieq Based on the node voltage, calculate the equivalent electromotive force of all load nodes according to the power flow formula.

[0139] Optionally, the node admittance matrix Y is:

[0140]

[0141] In the formula, matrix element Y ii The self-admittance between each node, matrix element Y ij The mutual admittance between nodes;

[0142] The node impedance matrix Z is:

[0143]

[0144] In the formula, matrix element Z ii The self-impedance between each node, matrix element Z ij The mutual impedance between nodes;

[0145] The equivalent impedance Z of all load nodes is calculated based on the node impedance matrix Z. ieq ,include:

[0146] Using formula For all self-impedance Z ii With load impedance Z i By performing anti-parallel connection, the equivalent impedance Z of all load nodes can be obtained. ieq .

[0147] Optionally, the static stable dominant mode identification criterion D st The expression is:

[0148]

[0149] In the formula, U n U m δ n δ m These are the coordinates of four points on the trajectory sensitivity plane, representing the voltage amplitude and power angle relative to the parametric sensitivity, respectively, where p is the dimension of the characteristic parameter of the Minkowski distance.

[0150] The power grid static stability dominant mode identification device based on voltage phasor trajectory in this embodiment corresponds to the power grid static stability dominant mode identification method based on voltage phasor trajectory in another embodiment of this invention, and will not be described again here.

[0151] Exemplary electronic devices

[0152] Figure 9 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 9 As shown, the electronic device 90 includes one or more processors 91 and memory 92.

[0153] The processor 91 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0154] The memory 92 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 91 may execute the program instructions to implement the methods for information mining of historical change records and / or other desired functions of the software programs of the various embodiments of the present invention described above. In one example, the electronic device may also include an input device 93 and an output device 94, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0155] In addition, the input device 93 may also include, for example, a keyboard, a mouse, etc.

[0156] The output device 94 can output various information to the outside. The output device 94 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0157] Of course, for the sake of simplicity, Figure 9 Only some of the components of the electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0158] Exemplary computer program products and computer-readable storage media

[0159] In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0160] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0161] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods for information mining of historical change records according to various embodiments of the present invention as described in the "Exemplary Methods" section above.

[0162] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0163] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0164] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0165] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0166] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0167] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0168] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for identifying the dominant static stability mode of a power grid based on voltage phasor trajectories, characterized in that, include: Based on the input wide-area measurement data, calculate the equivalent parameters of all nodes in the network; Based on the equivalent parameters of all nodes in the network, an equivalent two-node power grid parameter model is generated. Based on the equivalent two-node power grid parameter model, the node voltage phasor trajectory is calculated. Calculate the trajectory sensitivity of nodal voltage phasors based on nodal voltage phasor traject ... Based on the trajectory sensitivity of nodal voltage phasors, a criterion for identifying the statically stable dominant mode is determined, wherein the statically stable dominant mode identification criterion... The expression is: In the formula, U n , U m , δ n , δ m These represent the coordinates of four points on the trajectory sensitivity plane relative to the parametric sensitivity, showing the voltage amplitude and power angle. p The dimensions of the characteristic parameter of the Minkowski distance; Based on the static stability dominant mode identification criteria and the node voltage phasor trajectory, the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid are determined.

2. The method according to claim 1, characterized in that, The calculation of equivalent parameters for all network nodes based on the input wide-area measurement data includes: Real-time acquisition of the entire network's line impedance from a wide-area measurement system. and the voltage of each node ; pass The admittance on each line is calculated, and the nodal admittance matrix Y of the line is generated; Inverting the nodal admittance matrix Y yields the nodal impedance matrix Z; Based on the nodal impedance matrix Z, calculate the equivalent impedance of all load nodes. ; Based on equivalent impedance Based on the node voltage, calculate the equivalent electromotive force of all load nodes according to the power flow formula.

3. The method according to claim 2, characterized in that, The node admittance matrix Y is: ； In the formula, matrix elements For the self-admittance between nodes, matrix elements The mutual admittance between nodes; The node impedance matrix Z is: ； In the formula, matrix elements The self-impedance between each node, matrix elements The mutual impedance between nodes; The equivalent impedance of all load nodes is calculated based on the node impedance matrix Z. ,include: Using formula For all self-impedances With load impedance By performing anti-parallel connection, the equivalent impedance of all load nodes can be obtained. .

4. A power grid static stability dominant mode identification device based on voltage phasor trajectory, characterized in that, include: The first calculation module is used to calculate the equivalent parameters of all nodes in the network based on the input wide-area measurement data; The generation module is used to generate an equivalent two-node power grid parameter model based on the equivalent parameters of all nodes in the network. The second calculation module is used to calculate the node voltage phasor trajectory based on the equivalent two-node power grid parameter model. The third calculation module is used to calculate the trajectory sensitivity of the node voltage phasors based on the node voltage phasor trajectory. The first determining module is used to determine the static stability dominant mode identification criterion based on the trajectory sensitivity of the node voltage phasor, wherein the static stability dominant mode identification criterion... The expression is: In the formula, U n , U m , δ n , δ m These represent the coordinates of four points on the trajectory sensitivity plane relative to the parametric sensitivity, showing the voltage amplitude and power angle. p The dimensions of the characteristic parameter of the Minkowski distance; The second determination module is used to determine the dominant state and the dominant boundary point of the dominant state at different times during the dynamic evolution of the power grid, based on the static stability dominant mode identification criteria and the node voltage phasor trajectory.

5. The apparatus according to claim 4, characterized in that, The first calculation module is specifically used for: Real-time acquisition of the entire network's line impedance from a wide-area measurement system. and the voltage of each node ; pass The admittance on each line is calculated, and the nodal admittance matrix Y of the line is generated; Inverting the nodal admittance matrix Y yields the nodal impedance matrix Z; Based on the nodal impedance matrix Z, calculate the equivalent impedance of all load nodes. ; Based on equivalent impedance Based on the node voltage, calculate the equivalent electromotive force of all load nodes according to the power flow formula.

6. The apparatus according to claim 5, characterized in that, The node admittance matrix Y is: ； In the formula, matrix elements For the self-admittance between nodes, matrix elements The mutual admittance between nodes; The node impedance matrix Z is: ； In the formula, matrix elements The self-impedance between each node, matrix elements The mutual impedance between nodes; The equivalent impedance of all load nodes is calculated based on the node impedance matrix Z. ,include: Using formula For all self-impedances With load impedance By performing anti-parallel connection, the equivalent impedance of all load nodes can be obtained. .

7. A computer-readable storage medium, characterized in that, The storage medium stores a computer program for performing the method described in any one of claims 1-3.

8. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1-3.

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