Distribution network topology identification method, device and terminal equipment

Abstract

The present invention is applicable to the technical field of distribution network topology identification, and provides a distribution network topology identification method, device and terminal equipment. The method comprises: obtaining the actual value of the voltage phase of each node in the process of distribution network topology change through a micro synchronous phasor measurement device, and determining a first moment according to the actual value of the voltage phase of each node in the process of topology change, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes; modeling multiple candidate topologies to obtain a simulation model of each candidate topology; for each candidate topology, based on the simulation model of the candidate topology and the electrical quantity of each node in the distribution network topology at the first moment, performing flow calculation to obtain an estimated value of the voltage phase of each node in the candidate topology; based on the estimated value of the voltage phase of each node in each candidate topology and the actual value of the voltage phase of each node at the first moment, determining the distribution network topology structure at the first moment from multiple candidate topologies.

Description

Technical Field

[0001] The present application belongs to the technical field of distribution network topology identification, and in particular, relates to a distribution network topology identification method, apparatus and terminal equipment. Background Art

[0002] With the development of new power systems, the structure of distribution networks has become increasingly complex and has changed more frequently. In order to ensure the safety, stability and economic operation of the system, it is necessary to collect a variety of data information from the distribution network system so that the network topology of the distribution network can be understood and updated in a timely manner. In the prior art, data information in the distribution network system is often obtained using a Supervisory Control And Data Acquisition (SCADA) system. The SCADA system not only has a limited number of system data types, but also often has false alarms or non-reports in the acquired telesignaling data. The data lacks an accurate time stamp and has a long refresh cycle, resulting in poor real-time performance of the distribution network system measurement data.

[0003] In recent years, the emergence of micro-synchronous phasor measurement units (PMUs) has made up for the shortcomings of SCADA systems. The μPMU device has a high sampling frequency of up to 9600Hz, which greatly improves the real-time performance of data acquisition. It can also synchronously measure the injected power, voltage phase and other data information of the installed nodes. The phasor data with time stamps provides new possibilities for the real-time problem of distribution network topology identification.

[0004] However, traditional methods for topology identification suitable for SCADA systems, such as graph theory, matrix method, and power flow transfer method, not only have defects in the real-time performance of topology identification, but also are difficult to detect and identify the changed distribution network topology in a timely manner when the distribution network system lines change. In addition, the accuracy of topology identification needs to be improved. Summary of the invention

[0005] In view of this, the embodiments of the present invention provide a distribution network topology identification method, apparatus and terminal device, which improve the real-time performance and accuracy of distribution network topology identification.

[0006] This application is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a distribution network topology identification method, comprising: obtaining the actual value of the voltage phase of each node during the distribution network topology change process through a micro-synchronous phasor measurement device, and determining a first moment according to the actual value of the voltage phase of each node during the topology change process, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes; modeling multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between each node relative to the topology before the distribution network topology changes; for each candidate topology, performing flow calculation based on the simulation model of the candidate topology and the electrical quantities of each node in the distribution network topology at the first moment to obtain an estimated voltage phase of each node in the candidate topology; determining the distribution network topology structure at the first moment from multiple candidate topologies based on the estimated voltage phase of each node in each candidate topology and the actual value of the voltage phase of each node at the first moment.

[0008] Based on the first aspect, in some embodiments, the first moment is determined according to the actual value of the voltage phase of each node during the topology change process, including: selecting a time window w to determine the calculation function Δ(t); calculating the function value of the calculation function Δ(t) in different time windows according to the actual value of the voltage phase of each node during the distribution network topology change process, and determining the moment when the function value increases sharply as the second moment; the increase of the function value at the moment when the function value increases sharply relative to the third moment exceeds a threshold, and the third moment is before the second moment; the first moment is after the second moment, when the difference between the maximum and minimum values ​​of the function Δ(t) within a preset time period is less than a threshold, determining the end moment of the preset time period as the first moment.

[0009] Based on the first aspect, in some embodiments, the calculation function Δ(t) is:

[0010]

[0011] Among them, Δ(t) is a 1-norm function with time t as a variable, θ(t) is a vector composed of the actual values ​​of the node voltage phase at time t, θ(ti) is a vector composed of the actual values ​​of the node voltage phase at time ti, and w is the time window of the function Δ(t).

[0012] Based on the first aspect, in some embodiments, multiple candidate topologies are modeled to obtain a simulation model of each candidate topology, wherein the branch connection status between nodes of the candidate topology is different from the topology before the distribution network topology changes, and also includes: based on the branch setting in the first topology of the distribution network, the connection status of a branch in the first topology of the distribution network is changed in turn to obtain multiple different candidate topologies, wherein the first topology is the distribution network topology at the third moment.

[0013] Based on the first aspect, in some embodiments, for each candidate topology, a power flow calculation is performed based on a simulation model of the candidate topology and the electrical quantities of each node in the distribution network topology at a first moment to obtain an estimated voltage phase of each node in the candidate topology, including: obtaining the electrical quantities of each node in the distribution network topology at a first moment through a micro-synchronous phasor measurement device, the electrical quantities including node voltage amplitude and node power; for each candidate topology, a power flow calculation is performed based on a simulation model of the candidate topology and the electrical quantities of each node in the distribution network topology at a first moment to obtain a power flow calculation result of the candidate topology; candidate topologies with converged power flow are screened according to the power flow calculation results, and the estimated voltage phase of each node in the power flow calculation results of the candidate topologies with converged power flow are saved.

[0014] Based on the first aspect, in some embodiments, based on the estimated voltage phase of each node in each candidate topology and the actual voltage phase value of each node at the first moment, a distribution network topology structure at the first moment is determined from multiple candidate topologies, including: calculating the difference D between each candidate topology and the distribution network topology structure at the first moment in turn according to the estimated voltage phase of each node in the candidate topology and the actual voltage phase value of each node at the first moment; and determining the candidate topology whose difference D is closest to 0 as the distribution network topology structure at the first moment.

[0015] Based on the first aspect, in some embodiments, the difference D is:

[0016]

[0017] Among them, D is the difference value, M is the number of nodes, θ l represents the estimated node voltage phase at node l, θ lm Represents the actual value of the node voltage phase at node 1.

[0018] In a second aspect, an embodiment of the present application provides a DC distribution network fault locating device, comprising: a data acquisition module, used to obtain the actual value of the voltage phase of each node during the distribution network topology change process through a micro-synchronous phasor measurement device, and determine the first moment according to the actual value of the voltage phase of each node during the topology change process, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes; a topology modeling module, used to model multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between each node relative to the topology before the distribution network topology changes; a flow calculation module, used to perform flow calculation for each candidate topology based on the simulation model of the candidate topology and the electrical quantities of each node in the distribution network topology at the first moment, to obtain an estimated voltage phase of each node in the candidate topology; a topology identification module, used to determine the distribution network topology structure at the first moment from the multiple candidate topologies based on the estimated voltage phase of each node in each candidate topology and the actual value of the voltage phase of each node at the first moment.

[0019] In a third aspect, an embodiment of the present application provides a terminal device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and wherein the processor implements the steps of the distribution network topology identification method as described in any one of the first aspects above when executing the computer program.

[0020] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, characterized in that when the computer program is executed by a processor, the steps of the distribution network topology identification method as described in any one of the above-mentioned first aspects are implemented.

[0021] In the embodiment of the present application, the real-time voltage phase value of each node of the distribution network obtained by the micro synchronous vector measurement device can timely detect the change of the distribution network topology, thereby improving the real-time performance of the distribution network topology identification. The stable moment after the distribution network completes the topology change is determined by the change of the voltage phase value at multiple moments, which is used to identify the distribution network topology. By using the difference between the voltage phase estimate and the actual voltage phase value of the candidate topology, the candidate topologies with different connection states are exhaustively enumerated, and the actual topology after the distribution network topology change is determined, thereby improving the accuracy of the distribution network topology identification.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a flow chart of a distribution network topology identification method provided in an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the topological structure of the distribution network before the change provided by the embodiment of the present application;

[0026] Figure 3 It is a schematic diagram of the actual topological structure after the distribution network changes provided in the embodiment of the present application;

[0027] Figure 4 It is a schematic diagram of the function value of the topological moment identification parameter provided in the embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the distribution network topology node information and node connection status provided by an embodiment of the present application;

[0029] Figure 6 It is a schematic diagram of the power flow calculation principle provided by the embodiment of the present application;

[0030] Figure 7 It is a schematic diagram of the structure of a distribution network topology identification device provided in an embodiment of the present application;

[0031] Figure 8 It is a schematic diagram of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0033] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0034] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0035] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0036] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0037] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0038] In order to solve the problems of real-time and accuracy of network topology identification in distribution network, the present invention provides a distribution network topology identification method. Figure 1 As shown, the distribution network topology identification method may include steps 101 to 104.

[0039] Step 101: Obtain the actual voltage phase value of each node during the distribution network topology change process through a micro-synchronous phasor measurement device, and determine the first moment according to the actual voltage phase value of each node during the topology change process, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes.

[0040] During the operation of the distribution network, if the topology changes at a certain moment, the power flow distribution in the system will also change, and the voltage phasors of each node will change at the same time. Compared with the changes in the voltage amplitude of each node, the changes in the node voltage phase are more obvious. The μPMU device can measure the actual value of the node voltage phase at each time point during the topology change process, and determine the time when the topology change occurs by identifying the parameters at the time of the topology change.

[0041] Using the change in voltage phase before and after the topology change, the identification parameters of the topology change moment are defined:

[0042]

[0043] Among them, Δ(t) is a 1-norm function with time t as a variable, θ(t) is a vector composed of the actual values ​​of the node voltage phase at time t, θ(ti) is a vector composed of the actual values ​​of the node voltage phase at time ti, and w is the time window of the function Δ(t).

[0044] When the distribution network topology changes at time t, the Δ(t) value will have a step change compared to the Δ(ti) value, and the larger the w value, the larger the difference between the Δ(t) value and the Δ(ti) value. After selecting the time window w and determining the calculation function Δ(t), the function value of the calculation function Δ(t) in different time windows is calculated according to the actual value of the voltage phase of each node during the distribution network topology change process, and the moment when the function value increases sharply is determined to be the second moment. The increase of the function value at the moment when the function value increases sharply relative to the third moment exceeds the threshold, and the third moment is before the second moment.

[0045] In some embodiments, the distribution network topology changes from Figure 2 becomes Figure 3 , the branch between node 2 and node 3 is disconnected, and the time window w of the identification parameter at the time of topology change takes four different values ​​of 1, 2, 4 and 6 respectively. The Δ(t) function value at each moment in the 0-50s time range is as follows Figure 4 As shown, at t=20s, the Δ(t) function value of the vertical axis increases sharply, and t=20s is determined to be the second moment.

[0046] At the same time, when different time windows are selected, as the time window w increases, the amplitude of the change in the Δ(t) function value also increases, and the recognizability is higher. When the Δ(t) function curves of multiple selected time windows increase sharply at the same time, the function graphs of multiple time windows can confirm each other.

[0047] In some embodiments, when the function value at a certain moment increases to more than five times that of the previous moment, it is judged that the increase at this moment relative to the previous moment exceeds the threshold, and the function value increases sharply, and this moment is determined to be the second moment and the previous moment is the third moment.

[0048] After the second moment, when the difference between the maximum and minimum values ​​of the function Δ(t) in the preset time period is less than a threshold value, the end moment of the preset time period is determined to be the first moment. For example, the preset time period is 5 seconds, and when the difference between the maximum and minimum values ​​of the function values ​​at each moment in 5 seconds is less than ten times the minimum value of the function in 5 seconds, it is determined that the difference between the maximum and minimum values ​​in the 5 seconds period is less than the threshold value, and the end moment of the 5 seconds period is determined to be the first moment.

[0049] The node voltage phase value measured by the μPMU device at the first moment is the actual value of the node voltage phase of the new topology after the distribution network topology changes.

[0050] Step 102: Modeling multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between nodes relative to the topology before the distribution network topology is changed.

[0051] The power flow distribution of the distribution network is different under different topological conditions. For a known distribution network, the node information it contains is fixed, but the connection status between nodes will change. For each node connection status, the estimated voltage phase of each node under the node connection status can be obtained through power flow calculation.

[0052] In some embodiments, based on the branch settings in the first topology of the distribution network, the connection state of a branch in the first topology of the distribution network is changed in sequence to obtain multiple different candidate topologies, wherein the first topology is the distribution network topology at the third moment.

[0053] Step 103: for each candidate topology, a power flow calculation is performed based on the simulation model of the candidate topology and the electrical quantity of each node of the distribution network topology at the first moment to obtain an estimated voltage phase value of each node in the candidate topology.

[0054] In some embodiments, the implementation process of step 103 may include steps 1031 to 1033 .

[0055] Step 1031: Obtain the electrical quantities of each node in the distribution network topology at the first moment through a micro-synchronous phasor measurement device, where the electrical quantities include node voltage amplitude and node power.

[0056] like Figure 5 There are 10 nodes in the distribution network topology shown. Figure 5 All possible connection relationships between the 10 nodes are shown in FIG. 1 . For a known distribution network topology, the admittance between each two nodes is a fixed value. In this embodiment, μPMU devices are arranged on the 10 nodes, and the node injection current and node voltage can be measured by the μPMU devices.

[0057] Step 1032: For each candidate topology, a power flow calculation is performed based on the simulation model of the candidate topology and the electrical quantities of each node of the distribution network topology at the first moment to obtain a power flow calculation result of the candidate topology.

[0058] like Figure 6 As shown, according to the node voltage equation, the injected current I of node m m Satisfies the following formula:

[0059]

[0060] Where V n is the voltage at node n, Y mn Satisfies the following equation:

[0061]

[0062] In the formula, y mn is the branch admittance between nodes m and n; k∈m represents the set of nodes connected to m.

[0063] The injected power and injected current I at node m m and the voltage V at node m m The relationship is as follows:

[0064]

[0065] Where P m +jQ m represents the injected power of node m, P m is the injected active power of node m, Q m is the injected reactive power of node m, V m is the voltage at node m, is the conjugate of the injected current.

[0066] The injected current I is derived from equations (2) and (4): m expression:

[0067]

[0068] In the formula Indicates V m The conjugation of.

[0069] From equation (2) and equation (5), we can deduce:

[0070]

[0071] Conjugate the admittance in the above formula Expressed algebraically, voltage Expressed in polar coordinate form, the real and imaginary parts in formula (6) are expressed as:

[0072]

[0073] in,

[0074]

[0075] In the formula and Represent the active power and reactive power of the load at node m, respectively. and They represent the active power and reactive power generated by the generator at node m respectively.

[0076] Based on the Newton-Raphson method, using equation (7) and the known branch admittance y mn , node voltage V m And power data P m The node voltage phase estimation value θ under different topological conditions can be calculated.

[0077] Step 1033: selecting candidate topologies with converged power flow according to the power flow calculation results, and saving estimated voltage phase values ​​of each node in the power flow calculation results of the candidate topologies with converged power flow.

[0078] In some embodiments, a convergence judgment flag success is set: when success=1, convergence; when success=0, no convergence. Topologies with non-convergent power flows are topologies with line errors and are discarded, while topologies with convergent power flows are retained as candidate topologies. The estimated voltage phase of each node of each candidate topology is calculated for topology identification.

[0079] Step 104: determining a distribution network topology structure at a first moment from a plurality of candidate topologies based on the estimated voltage phase of each node in each candidate topology and the actual voltage phase of each node at a first moment.

[0080] According to the estimated voltage phase of each node in the candidate topology and the actual voltage phase of each node at the first moment, the difference D between each candidate topology and the distribution network topology at the first moment is calculated in turn.

[0081] The phase difference D is calculated by the estimated voltage phase of each node and the actual voltage phase of each node at the first moment, and the calculation formula is:

[0082]

[0083] Where D is the difference value, M is the number of nodes with μPMU devices installed, θ l represents the voltage phase estimate of node l under a certain topology, θ lm Represents the actual value of the node voltage phase at node l.

[0084] The candidate topology whose difference D is closest to 0 is determined as the distribution network topology at the first moment.

[0085] Example 1, the actual topology of this example changes from Figure 2 Changes to Figure 3 ,The μPMU device is used to obtain the actual value of the voltage phase of each node during the change process.

[0086] The first, second and third moments are determined by identifying the parameters at the time of topology change, and the actual values ​​of the voltage phases of each node at the first moment are recorded. Figure 2 The connection status of one of the branches in the topology is obtained to obtain multiple candidate topologies. Each candidate topology is modeled and power flow calculation is performed. The candidate topologies with unconvergent power flow calculation results are discarded, and the candidate topologies with convergent power flow calculation results are retained.

[0087] The difference D of each candidate topology of power flow convergence is calculated and compared. The candidate topology with the smallest difference D value is the actual distribution network topology at the first moment. The node connectivity status of the candidate topology is shown in Table 1, where "1" indicates connectivity and "0" indicates disconnection.

[0088] Table 1 Node connection status

[0089]

[0090] The difference D of the candidate topology is 6.6381e-04, which is close to 0.

[0091] Comparative analysis Table 1 and Figure 3 From the structure, we can see that the connection relationship and status between the nodes in the recognition result correspond one-to-one with the structure in the graph, indicating that the recognition result is correct.

[0092] In order to test the recognition effect of the topology recognition method, different errors were added to the measured values, and multiple topology recognitions were performed according to the above steps. The recognition results are shown in Table 2.

[0093] Table 2 Recognition effect

[0094]

[0095] Under different error settings, the recognition accuracy rate reached more than 95%. This shows that when μPMU devices are installed on all nodes, the topology recognition algorithm based on μPMU devices can realize the correct recognition of the distribution network topology.

[0096] See also Figure 7 An embodiment of the present invention provides a distribution network topology identification device 70, including a data acquisition module 710, a topology modeling module 720, a power flow calculation module 730 and a topology identification module 740.

[0097] The data acquisition module 710 is used to obtain the actual value of the voltage phase of each node during the distribution network topology change process through a micro-synchronous phasor measurement device, and determine the first moment according to the actual value of the voltage phase of each node during the topology change process, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes.

[0098] The topology modeling module 720 is used to model multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the branch connection state between nodes of the candidate topology is different from the topology before the distribution network topology changes.

[0099] The power flow calculation module 730 is used to perform power flow calculation for each candidate topology based on the simulation model of the candidate topology and the electrical quantity of each node of the distribution network topology at the first moment, so as to obtain an estimated voltage phase value of each node in the candidate topology.

[0100] The topology identification module 740 is used to determine the distribution network topology structure at the first moment from multiple candidate topologies based on the estimated voltage phase of each node in each candidate topology and the actual voltage phase of each node at the first moment.

[0101] Figure 8 Schematic diagram of a terminal device provided by an embodiment of the present invention. Figure 8 As shown, the terminal device 8 of this embodiment includes: a processor 80, a memory 81, and a computer program 82 stored in the memory 81 and executable on the processor 80, such as a distribution network topology identification program. When the processor 80 executes the computer program 82, the steps in the above-mentioned distribution network topology identification method embodiment are implemented, such as Figure 1 Alternatively, when the processor 80 executes the computer program 82, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 7 Functions of modules 710 to 740 are shown.

[0102] Exemplarily, the computer program 82 may be divided into one or more modules / units, which are stored in the memory 81 and executed by the processor 80 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 82 in the terminal device 8. For example, the computer program 82 may be divided into a data acquisition module 710, a topology modeling module 720, a power flow calculation module 730, and a topology identification module 740.

[0103] The terminal device 8 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal device may include, but is not limited to, a processor 80 and a memory 81. Those skilled in the art will appreciate that Figure 8 It is only an example of the terminal device 8 and does not constitute a limitation of the terminal device 8. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.

[0104] The processor 80 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0105] The memory 81 may be an internal storage unit of the terminal device 8, such as a hard disk or memory of the terminal device 8. The memory 81 may also be an external storage device of the terminal device 8, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device 8. Further, the memory 81 may also include both an internal storage unit and an external storage device of the terminal device 8. The memory 81 is used to store the computer program and other programs and data required by the terminal device. The memory 81 may also be used to temporarily store data that has been output or is to be output.

[0106] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0107] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0108] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0109] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0110] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0111] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0112] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0113] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A distribution network topology identification method, characterized in that: include: The actual voltage phase value of each node in the process of the distribution network topology change is obtained by a micro-synchronous phasor measurement device, and a first moment is determined according to the actual voltage phase value of each node in the process of the topology change, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes; Modeling multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between nodes relative to the topology before the distribution network topology changes; for each candidate topology, performing power flow calculation based on the simulation model of the candidate topology and the electrical quantities of each node in the distribution network topology at the first moment to obtain an estimated voltage phase value of each node in the candidate topology; determining the distribution network topology structure at the first moment from the multiple candidate topologies based on the estimated voltage phase value of each node in each candidate topology and the actual voltage phase value of each node at the first moment; The determining the distribution network topology structure at the first moment from the multiple candidate topologies based on the estimated voltage phase of each node in each candidate topology and the actual voltage phase of each node at the first moment includes: According to the estimated voltage phase of each node in the candidate topology and the actual voltage phase of each node at the first moment, the difference D between each candidate topology and the distribution network topology structure at the first moment is calculated in sequence; Determine the candidate topology whose difference D is closest to 0 as the distribution network topology at the first moment; The difference D is: Among them, D is the difference value, M is the number of nodes, θ l represents the estimated node voltage phase at node l, θ lm Represents the actual value of the node voltage phase at node l.

2. The distribution network topology identification method according to claim 1, characterized in that: The determining the first moment according to the actual value of the voltage phase of each node during the topology change process includes: Select the time window w and determine the calculation function Δ(t); Calculating the function value of the calculation function Δ(t) in different time windows according to the actual value of the voltage phase of each node during the distribution network topology change process, determining the moment when the function value increases sharply as the second moment; the increase of the function value at the moment when the function value increases sharply relative to the third moment exceeds a threshold, and the third moment is before the second moment; The first moment is after the second moment, and when the difference between the maximum value and the minimum value of the function Δ(t) within a preset time period is less than a threshold, the end moment of the preset time period is determined to be the first moment.

3. The distribution network topology identification method according to claim 2, characterized in that: The calculation function Δ(t) is: Wherein, Δ(t) is a 1-norm function with time t as a variable, θ(t) is a vector composed of the actual values ​​of the node voltage phase at time t, θ(ti) is a vector composed of the actual values ​​of the node voltage phase at time ti, and w is the time window of the function Δ(t).

4. The distribution network topology identification method according to claim 2, characterized in that: The method of modeling a plurality of candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between nodes relative to the topology before the distribution network topology changes, further includes: Based on the branch settings in the first topology of the distribution network, the connection state of a branch in the first topology of the distribution network is changed in sequence to obtain a plurality of different candidate topologies, wherein the first topology is the distribution network topology at the third moment.

5. The distribution network topology identification method according to claim 4, characterized in that: The step of performing power flow calculation for each candidate topology based on the simulation model of the candidate topology and the electrical quantity of each node of the distribution network topology at the first moment to obtain a voltage phase estimation value of each node in the candidate topology includes: Acquire the electrical quantities of each node of the distribution network topology at the first moment by means of a micro-synchronous phasor measurement device, wherein the electrical quantities include node voltage amplitude and node power; For each candidate topology, a power flow calculation is performed based on the simulation model of the candidate topology and the electrical quantities of each node of the distribution network topology at the first moment to obtain a power flow calculation result of the candidate topology; The candidate topologies with convergent power flow are screened according to the power flow calculation results, and the estimated voltage phase values ​​of each node in the power flow calculation results of the candidate topologies with convergent power flow are saved.

6. A distribution network topology identification device, characterized in that: include: A data acquisition module, used to obtain the actual value of the voltage phase of each node during the distribution network topology change process through a micro-synchronous phasor measurement device, and determine a first moment according to the actual value of the voltage phase of each node during the topology change process, wherein the first moment is the moment when the measurable electrical quantity of each node is stable after the distribution network topology changes; A topology modeling module is used to model multiple candidate topologies to obtain a simulation model of each candidate topology, wherein the candidate topology has a different branch connection state between nodes relative to the topology before the distribution network topology changes; A power flow calculation module, configured to perform power flow calculation for each candidate topology based on a simulation model of the candidate topology and electrical quantities of each node in the distribution network topology at the first moment, to obtain an estimated voltage phase value of each node in the candidate topology; A topology identification module, configured to determine a distribution network topology structure at the first moment from the plurality of candidate topologies based on an estimated voltage phase of each node in each candidate topology and an actual voltage phase of each node at the first moment; The topology identification module is specifically used for: According to the estimated voltage phase of each node in the candidate topology and the actual voltage phase of each node at the first moment, the difference D between each candidate topology and the distribution network topology structure at the first moment is calculated in sequence; Determine the candidate topology whose difference D is closest to 0 as the distribution network topology at the first moment; The difference D is: Among them, D is the difference value, M is the number of nodes, θ l represents the estimated node voltage phase at node l, θ lm Represents the actual value of the node voltage phase at node l.

7. A terminal device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the computer program, the steps of the distribution network topology identification method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the distribution network topology identification method according to any one of claims 1 to 5 are implemented.

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