Traveling wave function test method and system for small-analog distribution automation terminal

Abstract

The invention discloses a small-analog distribution automation terminal traveling wave function test method and system, and relates to the technical field of traveling wave positioning terminal test, and the method comprises the following steps: constructing a distribution network simulation model basic scene corresponding to different overhead line structures, cable line structures and neutral point grounding structure combinations in a distribution network system; constructing a distribution network simulation model interference scene by switching interference, distribution transformer branch interference and line branch interference; a basic positioning test and an interference positioning test are executed through a distribution network simulation model basic scene and a distribution network simulation model interference scene according to small-analog distribution automation terminal traveling wave parameters and fault test requirements; and obtaining a traveling wave function test result of the small-analog distribution automation terminal according to the basic positioning test result and the interference positioning test result. The traveling wave function testing method has the beneficial effects that the traveling wave function of the small-analog distribution automation terminal in various scenes and in the presence of dynamic switching of a power grid is tested.

Description

Technical Field

[0001] This application relates to the field of traveling wave positioning terminal testing technology, and in particular to a method and system for testing the traveling wave function of small analog power distribution automation terminals. Background Technology

[0002] With the rapid development of power distribution networks towards intelligence and distributed systems, the timeliness and accuracy of fault location have become core aspects of ensuring power supply reliability. Small analog distribution automation terminals, as key equipment for distribution network fault monitoring, utilize their traveling wave function to collect transient traveling wave signals generated by faults and leverage the propagation characteristics of traveling waves to achieve precise fault location. Compared to traditional fault location methods, this offers significant advantages such as high location accuracy and immunity to load fluctuations.

[0003] However, in related technologies, the testing of the traveling wave function of small analog distribution automation terminals is limited to simulation scenarios constructed with a single line type or a single grounding structure, resulting in differences between the test results and the application results under actual complex distribution network topologies, and the test accuracy is low.

[0004] Meanwhile, various interference factors exist in the distribution network operating environment, directly affecting the acquisition quality of the terminal traveling wave signal. Existing tests mostly target single interference sources such as electromagnetic radiation, and the test results are more consistent with the static operation of the distribution network, making it impossible to assess the anti-interference capability under dynamic operation conditions of the distribution network.

[0005] The patent, "A Method for Performance Testing of a Traveling Wave Ranging Device," publication number CN110716168A, published on January 21, 2020, specifically discloses the following steps: Step 1, sampling function testing; Step 2, waveform recording and storage function testing; Step 3, time accuracy testing; Step 4, activation element testing; Step 5, alarm function testing; Step 6, ranging response time testing; and Step 7, ranging accuracy testing. However, its ranging accuracy testing is limited to fixed AC and DC transmission line models, resulting in a limited scope of application.

[0006] The patent "Test Method and Device for Traveling Wave Fault Location Device in Cable-Overhead Hybrid Lines," publication number CN111693821A, published on September 22, 2020, specifically discloses a method for establishing a simulation model of a regional power grid containing cable-overhead hybrid lines on a testing platform equipped with a traveling wave location device for the fault under test. Fault simulation is performed within the simulation model, and the fault location results of the traveling wave location device after the fault simulation are recorded. Finally, the fault location results are compared with the obtained test results. However, this method only simulates cable-overhead hybrid lines and still cannot obtain the location deviation of the terminal under dynamic power grid operation. Summary of the Invention

[0007] This application addresses the limitations of existing technologies in testing the traveling wave function of small analog distribution automation terminals, which is limited by their simplistic approach and unsuitability for dynamic switching scenarios in distribution networks. It provides a method and system for testing the traveling wave function of small analog distribution automation terminals. The system constructs basic scenarios under different distribution network conditions using combinations of overhead line structures, cable line structures, and neutral grounding structures. Simultaneously, it constructs interference scenarios corresponding to switching interference, transformer interference, and branch interference based on typical dynamic operations of the power grid. Through the combined simulation of basic and interference scenarios, the system achieves testing of the traveling wave function of small analog distribution automation terminals under various scenarios, including dynamic power grid switching.

[0008] To achieve the above technical objectives, this application provides a technical solution: a method for testing the traveling wave function of a small analog distribution automation terminal, comprising the following steps: constructing a basic scenario of a distribution network simulation model corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system; constructing an interference scenario of the distribution network simulation model using switching interference, distribution transformer branch interference, and line branch interference; performing basic positioning tests and interference positioning tests respectively based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements using the basic scenario and interference scenario of the distribution network simulation model, and obtaining the basic positioning test results and interference positioning test results; obtaining the traveling wave function test results of the small analog distribution automation terminal based on the deviation results of the basic positioning test results and interference positioning test results from the actual information of the fault point.

[0009] Furthermore, the construction of the basic scenario for the distribution network simulation model corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system includes: constructing a single-radial grid structure, a single-radial overhead cable hybrid grid structure, and a long-line single-connection overhead line grid structure according to typical line combination methods for different overhead line structures and cable line structures; and constructing a neutral grounding structure with arc suppression coil grounding, no grounding, and low-resistance grounding for each grid structure to obtain the basic scenario for the distribution network simulation model.

[0010] Furthermore, the interference scenarios for constructing the distribution network simulation model based on switching interference, distribution transformer branch interference, and line branch interference include: constructing a switching interference scenario based on long cable switching and motor switching; constructing a distribution transformer branch interference scenario based on different numbers of distribution branches; constructing a line branch interference scenario based on different numbers of line branches; and constructing the distribution network simulation model interference scenario based on the switching interference scenario, distribution branch interference scenario, and line branch interference scenario.

[0011] Furthermore, the step of performing basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the distribution network simulation model, respectively, and obtaining the basic positioning test results and interference positioning test results, includes: retrieving the basic scenario and interference scenario of the distribution network simulation model according to the fault test requirements, with each basic scenario and all interference scenarios of the distribution network simulation model constituting a test sequence; synchronously executing the following steps according to each test sequence: constructing a distribution network simulation model under the basic scenario by combining the distribution network equipment model based on the basic scenario; performing basic positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements using the distribution network simulation model under the basic scenario, and obtaining the basic positioning test results; constructing a distribution network simulation model under the interference scenario by combining the distribution network equipment model based on the distribution network simulation model under the basic scenario; and performing interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements using the distribution network simulation model under the interference scenario, and obtaining the interference positioning test results.

[0012] Furthermore, the step of performing basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the distribution network simulation model to obtain the basic positioning test results and interference positioning test results includes: pre-calculating the scene similarity between the basic scenario of the distribution network simulation model, between the interference scenario of the distribution network simulation model, and between the basic scenario of the distribution network simulation model and the interference scenario of the distribution network simulation model; retrieving the basic scenario and interference scenario of the distribution network simulation model according to the fault test requirements, and planning the construction order of the distribution network simulation model under different scenarios based on the maximum scene similarity; sequentially executing the construction of the distribution network simulation model under different scenarios according to the construction order of the distribution network simulation model, and performing basic positioning tests or interference positioning tests according to the traveling wave parameters of the small analog distribution automation terminal and fault test requirements after each construction, and obtaining the basic positioning test results and interference positioning test results.

[0013] Furthermore, the step of performing basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements using the basic scenario and interference scenario of the distribution network simulation model to obtain the basic positioning test results and interference positioning test results includes: retrieving the basic scenario of the distribution network simulation model based on the topology of the distribution network system under test, and retrieving the interference scenario of the distribution network simulation model based on the historical interference factors of the distribution network system under test; constructing a distribution network simulation model based on the distribution network equipment model, the retrieved basic scenario of the distribution network simulation model, and the interference scenario of the distribution network simulation model, using the traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test as inputs to the distribution network simulation model, and outputting the basic positioning test results and interference positioning test results.

[0014] Furthermore, the process of performing basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the distribution network simulation model, respectively, and obtaining the basic positioning test results and interference positioning test results, also includes: performing deviation correlation based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test to obtain the nodes affecting the traveling wave positioning deviation of historical equipment aging under the same life sequence of historical traveling wave terminals; obtaining the aging parameters to be tested based on the nodes affecting the traveling wave positioning deviation of historical equipment aging; incorporating the aging parameters to be tested into the basic parameters of the distribution network system under test; and using the traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test as inputs to the distribution network simulation model, and outputting the basic positioning test results and interference positioning test results.

[0015] Furthermore, the step of performing basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the distribution network simulation model to obtain the basic positioning test results and interference positioning test results also includes: performing deviation correlation based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test to obtain the traveling wave positioning deviation value of different historical traveling wave positioning terminal life sequences under the same historical equipment aging sequence, and constructing a terminal aging deviation curve; obtaining the traveling wave positioning terminal aging offset parameter using the inflection point of the terminal aging deviation curve; incorporating the traveling wave positioning terminal aging offset parameter into the traveling wave parameter of the small analog distribution automation terminal, using the small analog distribution automation terminal traveling wave parameter, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test as inputs to the distribution network simulation model, and outputting the basic positioning test results and interference positioning test results.

[0016] Furthermore, obtaining the traveling wave function test result of the small analog power distribution automation terminal based on the deviation results of the basic positioning test result and the interference positioning test result from the actual information of the fault point includes: obtaining a first deviation result based on the distance between the basic positioning test result and the actual location of the fault point; obtaining a second deviation result based on the distance between the interference positioning test result and the actual location of the fault point; and outputting the first deviation result and the second deviation result as the traveling wave function test result of the small analog power distribution automation terminal.

[0017] Another technical solution provided in this application is a small analog distribution automation terminal traveling wave function test system, used to implement the method described above, including: a data acquisition unit for acquiring the small analog distribution automation terminal traveling wave parameters and fault test requirements; a basic scenario construction unit for constructing a basic scenario of the distribution network simulation model based on different combinations of overhead line structures, cable line structures, and neutral grounding structures; an interference scenario construction unit for constructing interference scenarios of the distribution network simulation model based on switching interference, distribution transformer interference, and branch interference; a simulation unit for performing basic positioning tests and interference positioning tests respectively based on the basic scenario and interference scenario of the distribution network simulation model according to the small analog distribution automation terminal traveling wave parameters and fault test requirements, and outputting the basic positioning test results and interference positioning test results; and an analysis unit for obtaining the small analog distribution automation terminal traveling wave function test results based on the deviation of the basic positioning test results and interference positioning test results from the actual information of the fault point.

[0018] The beneficial effects of this application are as follows: 1. By constructing basic simulation scenarios of distribution networks under different combinations of overhead line structures, cable line structures, and neutral grounding structures based on line component parameters, the actual topology characteristics of the distribution network are simulated to test the positioning accuracy of the terminal under normal operating conditions. Furthermore, by constructing three types of distribution network-specific interference scenarios—switching, transformer branching, and line branching—typical disturbances that small analog distribution automation terminals face in actual operation are simulated to test the terminal's anti-interference capability under complex interference conditions. The deviation between the basic positioning test results and the actual fault information is used to obtain the traveling wave positioning accuracy of the small analog distribution automation terminal under interference-free conditions. The deviation between the interference positioning test results and the actual fault information is used to obtain the traveling wave positioning accuracy of the small analog distribution automation terminal under interference conditions. The accuracy differences under different scenarios are also shown to reflect the factors affecting the accuracy of the terminal's traveling wave function, providing support for the optimization and improvement of the terminal's traveling wave function.

[0019] 2. Simultaneously output the location test results of all test sequences. After obtaining the basic location test results based on the distribution network simulation model under the basic scenario, simultaneously execute the construction of the distribution network simulation model under the interference scenario and output the interference test results based on all distribution network simulation models under the interference scenario. Since the interference scenario is included in the basic scenario, it is not necessary to re-combine the models of each distribution network device. Only some switching and branch modifications need to be performed, which reduces the steps of building the distribution network simulation model under the interference scenario. By using the distribution network simulation model under each basic scenario to build and test synchronously, and the distribution network simulation model under each interference scenario to build and test synchronously, the testing efficiency is improved.

[0020] 3. Construct traveling wave positioning deviation curves for historical traveling wave terminals under the same life sequence but different equipment aging sequences. When the curve shows a clear inflection point, it is considered that the equipment aging in this case has interfered with the traveling wave positioning of the traveling wave terminal. The equipment parameters under this aging sequence are used as the aging parameters to be tested to simulate the interference of wave speed, path and signal changes caused by equipment aging. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating a method for testing the traveling wave function of a small analog power distribution automation terminal according to one embodiment of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of this application is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely one preferred embodiment of this application and are only used to explain this application. They do not limit the scope of protection of this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] like Figure 1 As shown in the first embodiment of this application, the method for testing the traveling wave function of a small analog power distribution automation terminal includes the following steps: The basic scenarios of the distribution network simulation model are constructed corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system. Interference scenarios in the distribution network simulation model are constructed using switching interference, distribution transformer branch interference, and line branch interference. Based on the traveling wave parameters of the small analog power distribution automation terminal and the fault test requirements, the basic positioning test and the interference positioning test are performed in the basic scenario and interference scenario of the power distribution network simulation model, respectively, and the basic positioning test results and the interference positioning test results are obtained. The traveling wave function test results of the small analog power distribution automation terminal are obtained by comparing the deviation results of the basic positioning test results and the interference positioning test results with the actual information of the fault point.

[0024] In this embodiment, by constructing basic simulation scenarios of distribution networks with different combinations of overhead line structures, cable line structures, and neutral grounding structures, the actual topology characteristics of the distribution network are simulated to test the positioning accuracy of the terminal under normal operating conditions. Furthermore, by constructing three distribution network-specific interference scenarios—switching, transformer branching, and line branching—typical disturbances that the small analog distribution automation terminal would face in actual operation are simulated to test the terminal's anti-interference capability under complex interference conditions. The deviation between the basic positioning test results and the actual fault information is used to obtain the traveling wave positioning accuracy of the small analog distribution automation terminal under interference-free conditions. The deviation between the interference positioning test results and the actual fault information is used to obtain the traveling wave positioning accuracy of the small analog distribution automation terminal under interference conditions. The accuracy differences under different scenarios are displayed to reflect the factors affecting the accuracy of the terminal's traveling wave function, providing support for the optimization and improvement of the terminal's traveling wave function.

[0025] Specifically, the basic scenarios for constructing distribution network simulation models corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system include: Corresponding to different overhead line structures and cable line structures, a single-radial grid structure, a single-radial overhead cable hybrid grid structure, and a long-line single-connection overhead line grid structure are constructed according to typical line combination methods. For each type of grid structure, neutral grounding structures with arc suppression coil grounding, no grounding, and grounding with small resistance are constructed respectively to obtain the basic scenario of the distribution network simulation model.

[0026] In this embodiment, the combination of different overhead line structures and cable line structures includes a single-radial overhead grid structure, a single-radial overhead cable hybrid grid structure, and a long-line single-tie overhead grid structure. The neutral grounding structure includes a grounding structure via an arc suppression coil, an ungrounded structure, and a grounding structure via a small resistor. The single-radial overhead grid structure, single-radial overhead cable hybrid grid structure, and long-line single-tie overhead grid structure are constructed according to typical distribution network line combinations using typical overhead grid and cable line structures to cover typical topological scenarios in actual distribution network operation. Among these, the single-radial overhead grid structure, due to its simple structure and few branches, is commonly used in rural distribution networks. The single-radial overhead cable hybrid grid structure balances the economic efficiency of overhead lines with the spatial adaptability of cables and is commonly used in urban and suburban distribution networks. The long-line single-tie overhead grid structure offers high power supply reliability and is commonly used in distribution networks for long-distance power supply scenarios such as industrial parks and remote areas. This allows for the simulation of small-scale analog distribution automation terminals operating in different regions and distribution network environments with varying power supply demands. Furthermore, by combining different neutral grounding methods, diverse basic scenario combinations are formed, facilitating subsequent testing of the terminal's traveling wave propagation characteristics and traveling wave function accuracy in different scenarios. It is understood that this embodiment only provides a typical distribution network architecture construction method; in practical applications, the network structure can be simulated and constructed according to the actual distribution network architecture.

[0027] Furthermore, the interference scenarios in the distribution network simulation model, constructed using switching interference, transformer branch interference, and line branch interference, include: A switching interference scenario is constructed by switching long cables and motors; Construct distribution transformer branch interference scenarios with varying numbers of distribution branches; Construct line branch interference scenarios with varying numbers of line branches; The interference scenarios of the distribution network simulation model are constructed based on the interference scenarios of switching interference, distribution branch interference, and line branch interference.

[0028] By constructing switching interference scenarios through long cable switching and motor switching, this study simulates operational disturbances such as capacitive charging and discharging inrush currents and transient start-up and shutdown of inductive equipment in the distribution network. It obtains the accuracy of small analog distribution automation terminals in the presence of operational interference waves and assesses the possibility that the terminal may misjudge normal equipment switching as a fault or cause distortion in traveling wave signal acquisition due to transient interference.

[0029] By constructing distribution transformer branch interference scenarios with different numbers of distribution branches, the disturbances caused by changes in distribution transformers in the distribution network are simulated, and the weak signal identification and positioning accuracy of small analog distribution automation terminals under operating conditions such as distribution transformer excitation inrush current diluting fault traveling wave signals and distribution transformer winding reflected traveling waves are obtained.

[0030] By constructing line branch interference with varying numbers of line branches, the phenomenon of traveling wave reflection superposition under the multi-branch topology of short-line distribution networks is simulated. For example, the secondary reflection of fault waves caused by sudden changes in the wave impedance of branch lines is obtained. The anti-interference capability of small analog distribution automation terminals in the presence of branch reflected traveling waves is obtained, and the traveling wave positioning accuracy of small analog distribution automation terminals is demonstrated.

[0031] By constructing switching interference scenarios, transformer branch interference scenarios, and line branch interference scenarios, the traveling wave function test of the small analog power distribution automation terminal can reflect the anti-interference capability of the current small analog power distribution automation terminal to different interferences based on the different accuracy differences under single interference scenarios and combined interference scenarios. This facilitates targeted functional optimization for corresponding interferences or accuracy compensation calculations when corresponding interferences exist.

[0032] It is understood that, in this embodiment, the interference scenarios of the distribution network simulation model include at least switching interference scenarios, distribution branch interference scenarios, line branch interference scenarios, and any combination of scenarios.

[0033] Correspondingly, based on the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements, the basic location test and the interference location test are performed using the basic scenario and interference scenario of the distribution network simulation model, respectively. The results of the basic location test and the interference location test are obtained as follows: Based on the basic scenario of the distribution network simulation model, a distribution network simulation model under the basic scenario is constructed by combining the distribution network equipment model; Based on the distribution network simulation model in the basic scenario, a distribution network simulation model under the interference scenario is constructed by combining the distribution network equipment model according to the interference scenario of the distribution network simulation model. Using the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements as inputs to the distribution network simulation model, basic positioning tests and interference positioning tests are performed to obtain the basic positioning test results and interference positioning test results.

[0034] The distribution network equipment model includes at least the following: infinite power source model, transformer model, load model, motor model, new energy source model, and fault control model.

[0035] In this embodiment, the infinite power supply model is constructed using a balanced three-phase voltage source with internal resistance-inductance impedance. The short-circuit capacity of the power supply can be indirectly set by directly inputting the resistance and inductance values.

[0036] The transformer model uses existing transformer models in the simulation system, such as saturated transformer model and grounding transformer model. The main parameters of the transformer include capacity, rated voltage, resistance and reactance of primary and secondary sides, excitation resistance and reactance, etc.

[0037] The load model is constructed using a three-phase parallel RLC (resistive-inductive-capacitive) load module, which implements a three-phase balanced load as a parallel combination of RLC elements. At a given frequency, the load exhibits a constant impedance. The active and reactive power absorbed by the load are proportional to the square of the applied voltage.

[0038] The motor model used is a three-phase asynchronous motor model available in the simulation system.

[0039] The new energy model is a general new energy converter and control model, and the converter adopts an equivalent model.

[0040] The fault model includes at least four single-phase switches. The on / off state of the switches of phase A, phase B, phase C, and phase N is controlled according to the fault test requirements to simulate the fault scenarios corresponding to the fault test requirements.

[0041] The simulation system uses the MATLAB / Simulink tool.

[0042] In this embodiment, a distribution network equipment model corresponding to the simulation system is pre-built and called or directly called by typical equipment in the distribution network system. The distribution network equipment model is combined according to the basic scenario of the distribution network simulation model to build a distribution network simulation model corresponding to the basic scenario test. On the basis of building the distribution network simulation model corresponding to the basic scenario test, the interference scenario of the distribution network simulation model is included to facilitate the execution of terminal traveling wave accuracy test under the interference scenario.

[0043] It should be noted that the distribution network equipment model type in this embodiment is only one example. In practical applications, the distribution network equipment model can be pre-built or called according to the actual equipment situation in the distribution network.

[0044] Specifically, the traveling wave parameters of the small analog distribution automation terminal should include at least the zero-sequence traveling wave sampling frequency, zero-sequence traveling wave over-limit threshold, zero-sequence traveling wave mutation threshold, zero-sequence traveling wave over-limit threshold level 2, zero-sequence traveling wave mutation threshold level 2, transient characteristic enable, transient characteristic zero-current start limit, transient characteristic zero-voltage start limit, transient characteristic direction, transient characteristic zero-current mutation, and wave velocity setting. Fault testing requirements should include at least: basic parameters of the distribution network system under test, fault location, fault type, and fault severity. The basic parameters of the distribution network system under test should include at least the distribution network equipment parameters and distribution network line parameters. The basic parameters of the distribution network system under test and the traveling wave parameters of the small analog distribution automation terminal are input into the distribution network simulation model to simulate the actual situation of the distribution network system under test connected to the small analog distribution automation terminal. Then, based on the fault location, fault type, and fault severity, the fault conditions during the operation of the distribution network system are simulated to obtain the simulated ranging results output by the small analog distribution automation terminal, i.e., the basic positioning test results and the interference positioning test results.

[0045] The traveling wave function test results of the small analog power distribution automation terminal are obtained by comparing the deviations of the basic positioning test results and the interference positioning test results with the actual information of the fault point. These results include: The first deviation result is obtained based on the distance between the basic positioning test results and the actual location of the fault point; The second deviation result is obtained based on the distance between the interference location test result and the actual location of the fault point; The first deviation result and the second deviation result are used as the output of the traveling wave function test results of the small analog power distribution automation terminal.

[0046] It should be noted that there are multiple basic scenarios and interference scenarios in this application. In the actual testing process, the traveling wave function test can be performed on the terminal under all scenarios, or some scenarios can be selected for simulation test according to the actual application scenario. The access location of the small analog power distribution automation terminal can also be simulated according to the access situation of the actual application scenario.

[0047] In this embodiment, the positioning deviation distance is obtained based on the distance between the ranging result of the small analog power distribution automation terminal and the actual location of the fault point. The deviation distance is presented to the operator in a clear way to show the operator the deviation of the terminal positioning, which facilitates the operator to adjust the accuracy of the terminal.

[0048] In other cases, the difference between the first deviation result and the second deviation result is used as the evaluation value for the anti-interference capability of the small analog distribution automation terminal. The smaller the difference, the stronger the anti-interference capability of the small analog distribution automation terminal. Conversely, the smaller the first deviation result, the higher the accuracy of the small analog distribution automation terminal.

[0049] As a second embodiment of this application, basic positioning tests and interference positioning tests are performed respectively based on the traveling wave parameters of the small analog power distribution automation terminal and the fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model. The results of the basic positioning test and the interference positioning test are obtained as follows: Based on the fault testing requirements, the basic scenario and interference scenario of the distribution network simulation model are retrieved. Each basic scenario of the distribution network simulation model and all interference scenarios of the distribution network simulation model constitute a test sequence. Synchronous execution is performed sequentially for each test sequence: Based on the basic scenario of the distribution network simulation model, a distribution network simulation model under the basic scenario is constructed by combining the distribution network equipment model; Based on the distribution network simulation model in the basic scenario, the basic positioning test is performed according to the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements to obtain the basic positioning test results. Based on the distribution network simulation model in the basic scenario, a distribution network simulation model under the interference scenario is constructed by combining the distribution network equipment model according to the interference scenario of the distribution network simulation model. Using a distribution network simulation model under interference scenarios, interference location tests are performed based on the traveling wave parameters of small-scale analog distribution automation terminals and fault test requirements to obtain interference location test results.

[0050] In this embodiment, the fault testing requirements also include interference testing requirements and scenario testing requirements. First, based on the fault testing requirements, the corresponding distribution network simulation model basic scenario and distribution network simulation interference scenario are invoked. Each invoked distribution network simulation model basic scenario and all invoked distribution network simulation interference scenarios are combined into a test sequence. The location test results of all test sequences are output synchronously. After obtaining the basic location test results based on the distribution network simulation model under the basic scenario, the construction of the distribution network simulation model under the interference scenario and the output of interference test results are executed synchronously based on all distribution network simulation model interference scenarios. Since incorporating interference scenarios into the basic scenario eliminates the need to recombine the various distribution network device models, only partial switching and branch modifications are required, reducing the steps in constructing the distribution network simulation model under the interference scenario. By synchronously constructing and testing the distribution network simulation model under each basic scenario and simultaneously constructing and testing the distribution network simulation model under each interference scenario, testing efficiency is improved.

[0051] In this embodiment, obtaining the traveling wave function test results of the small analog power distribution automation terminal based on the deviation of the basic positioning test results and the interference positioning test results from the actual information of the fault point includes: In response to the output of the basic positioning test results, the first deviation result is obtained based on the distance between the basic positioning test results and the actual location of the fault point; In response to the output of the interference location test results, a second deviation result is obtained based on the distance between the interference location test results and the actual location of the fault point; The first deviation result and the second deviation result are used as the output of the traveling wave function test results of the small analog power distribution automation terminal.

[0052] Specifically, when any basic positioning test result is output, the first deviation result is calculated directly. Information is provided to the operator in the order of basic and interference tests, so that the operator can first understand the deviation under the condition of no interference, and then understand the deviation under the condition of interference. The time spent calculating the deviation under the condition of interference is synchronized with the time for the operator to read the first deviation result, thus compensating for the reduced efficiency of modifying the model and resimulating under the condition of interference.

[0053] In this case, the synchronous construction of the distribution network simulation model improves the efficiency of multi-scenario simulation and terminal testing efficiency.

[0054] In another scenario, considering that synchronously constructing a distribution network simulation model relies on high computing power, basic location tests and interference location tests are performed based on the traveling wave parameters of the small analog distribution automation terminal and fault testing requirements, using the basic scenario and interference scenario of the distribution network simulation model. The results of the basic location test and interference location test are obtained as follows: Calculate the scene similarity between basic distribution network simulation scenarios, between interference scenarios of distribution network simulation models, and between basic distribution network simulation scenarios and interference scenarios of distribution network simulation models in advance; Based on the fault testing requirements, retrieve the basic scenario and interference scenario of the distribution network simulation model, and plan the construction order of the distribution network simulation model under different scenarios according to the maximum scenario similarity. The distribution network simulation model is constructed sequentially according to the construction order of the distribution network simulation model. After each construction is completed, the basic positioning test or interference positioning test is performed according to the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements to obtain the basic positioning test results and interference positioning test results.

[0055] In this embodiment, the similarity between basic distribution network simulation scenarios, the similarity between interference scenarios of distribution network simulation models, and the similarity between basic distribution network simulation scenarios and interference scenarios of distribution network simulation models are used to obtain the magnitude of model structure changes under different scenarios. This allows the distribution network simulation model construction order under different scenarios to be obtained with the maximum scenario similarity, so that each scenario switching simulation is performed with the minimum magnitude of change during testing. Although the efficiency is lower than that of synchronous test execution, it can balance efficiency and computational pressure, and is suitable for situations with low software computing power.

[0056] This involves retrieving the basic scenario and interference scenario of the distribution network simulation model, and calculating the path with the maximum overall scenario similarity based on the similarity between each pair of scenarios, which serves as the construction order of the distribution network simulation model.

[0057] It is understood that in this embodiment, interference testing requirements and scenario testing requirements can be selected according to the actual needs of the operator. For example, scenario selection and interference selection can be provided on the simulation platform. At this time, the basic parameters of the distribution network system under test can be preset fixed parameters or parameters set by the operator.

[0058] As a third embodiment of this application, in the traveling wave function test of a small analog distribution automation terminal applied to an actual distribution network system, basic positioning tests and interference positioning tests are performed according to the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements based on the basic scenario and interference scenario of the distribution network simulation model. The results of the basic positioning test and the interference positioning test are obtained as follows: Based on the topology of the distribution network system to be tested, retrieve the basic scenario of the distribution network simulation model; based on the historical interference factors of the distribution network system to be tested, retrieve the interference scenario of the distribution network simulation model. Based on the distribution network equipment model, the basic scenario of the distribution network simulation model, and the interference scenario of the distribution network simulation model, a distribution network simulation model is constructed. The traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test are used as inputs to the distribution network simulation model, and the basic positioning test results and interference positioning test results are output.

[0059] In this embodiment, the fault testing requirements include the topology of the distribution network system under test, historical interference factors of the distribution network system under test, basic parameters of the distribution network system under test, and fault information of the distribution network system under test. The distribution network system under test is the actual distribution network system that the small analog distribution automation terminal currently being tested will connect to in the future. By obtaining the basic and interference scenarios through the actual distribution network system, the basic parameters of the distribution network system under test are the parameters of the actual distribution network system, making the small analog distribution automation terminal more consistent with its actual application.

[0060] The fault information of the distribution network system under test includes at least the historical fault location, historical fault type, and historical fault severity. The test faults are set according to the faults that have occurred in the distribution network system under test in order to improve the adaptability of the test results.

[0061] It is understood that the construction of the distribution network simulation model and the acquisition of basic positioning test results and interference positioning test results are not limited to any of the methods mentioned in Embodiment 2 of this application.

[0062] Among these steps, the basic location test and interference location test are performed respectively based on the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements of the distribution network simulation model in the basic scenario and interference scenario of the distribution network simulation model. The results of the basic location test and interference location test are obtained by: Based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test, deviation correlation is performed to obtain the nodes that affect the aging of historical equipment on the traveling wave positioning deviation under the same life sequence of the historical traveling wave terminal. The aging parameters to be tested are obtained by using the impact of historical equipment aging on the positioning deviation of traveling waves. Incorporate the aging parameters to be tested into the basic parameters of the distribution network system to be tested; The system takes the traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test as inputs to the distribution network simulation model, and outputs the basic positioning test results and the interference positioning test results.

[0063] In this embodiment, deviation correlations are performed on the historical equipment aging, historical traveling wave positioning terminal lifecycle, and historical traveling wave positioning terminal positioning data of the distribution network system under test. The deviation of the historical traveling wave positioning terminal positioning data under the same historical traveling wave positioning terminal lifecycle, with different historical equipment aging sequences, is calculated. This identifies equipment aging nodes with significant deviations as influencing nodes, and the corresponding equipment aging parameters are used as the aging parameters to be tested. It can be understood that when the same historical traveling wave positioning terminal lifecycle shows a deviation in historical traveling wave positioning terminal positioning data with the historical equipment aging sequence, this inflection point is considered an influencing node. When multiple inflection points exist, multiple influencing nodes exist.

[0064] Since the maintenance cycle of the equipment corresponds to the aging sequence of normal operation when no sudden failure occurs, the traveling wave positioning deviation curves of the historical traveling wave terminals under the same life sequence of different equipment under the aging sequence are constructed. When the curve shows an obvious inflection point, it is considered that the equipment aging in this case has interfered with the traveling wave positioning of the traveling wave terminal. The equipment parameters under this aging sequence are used as the aging parameters to be tested to simulate the interference of wave speed, path and signal changes caused by equipment aging.

[0065] In other cases, the basic location test and interference location test are performed respectively based on the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements using the basic scenario and interference scenario of the distribution network simulation model. The results of the basic location test and interference location test are also obtained in the following ways: Based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test, deviation correlation is performed to obtain the traveling wave positioning deviation value of different historical traveling wave positioning terminal life sequences under the same historical equipment aging sequence, and to construct the terminal aging deviation curve. The aging offset parameters of the traveling wave positioning terminal are obtained from the inflection point of the terminal aging deviation curve. The aging offset parameters of the traveling wave positioning terminal are incorporated into the traveling wave parameters of the small analog distribution automation terminal. The traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test are used as inputs to the distribution network simulation model, and the basic positioning test results and interference positioning test results are output.

[0066] In this scenario, an aging deviation curve is constructed using the travel wave positioning deviation values ​​of different historical traveling wave positioning terminals within the same historical equipment aging time series. The inflection point of this curve is used as the aging influence node of the traveling wave positioning terminal to obtain the aging offset parameter. It is understandable that, due to potential differences between traveling wave positioning terminals, their aging-induced deviations may also differ. The parameter offset value is obtained by calculating the initial parameters of each traveling wave positioning terminal and the aging parameters corresponding to the inflection point. The aging offset parameter is then calculated based on the similarity between the initial parameters of the current small analog power distribution automation terminal and the initial parameters of historical traveling wave positioning terminals, thereby simulating the future positioning deviation of the small analog power distribution automation terminal during aging.

[0067] It should be noted that this embodiment only tests the positioning accuracy and anti-interference capability of the terminal. Therefore, only the inflection point test is required. The inflection point means that the terminal positioning is more affected by interference at that point. If the terminal still has good positioning accuracy under the parameters corresponding to the inflection point, it is considered that its anti-interference capability against aging is strong.

[0068] Understandably, in other cases, the aging parameters to be tested and the aging offset parameters of the traveling wave positioning terminal can also be included simultaneously to simulate the interference of future aging conditions.

[0069] It should be noted that during the basic positioning test and interference positioning test, the initial parameters in the traveling wave parameters of the small analog power distribution automation terminal, i.e., the initial parameters provided by the manufacturer, are first tested. Then, adjustments are made according to the aging parameters to be tested and / or the aging offset parameters of the traveling wave positioning terminal to simulate ranging under aging conditions, and the basic positioning test results and interference positioning test results under aging interference are obtained. These two results not only demonstrate the anti-interference capability of the small analog power distribution automation terminal, but also provide guidance for determining the maintenance sequence of the small analog power distribution automation terminal.

[0070] As a fourth embodiment of this application, a small analog power distribution automation terminal traveling wave function test system includes: The data acquisition unit is used to acquire traveling wave parameters of small analog power distribution automation terminals and to meet fault testing requirements. The basic scenario construction unit is used to construct the basic scenario of the distribution network simulation model based on different combinations of overhead line structure, cable line structure and neutral grounding structure. The interference scenario construction unit is used to construct interference scenarios for the distribution network simulation model based on switching interference, distribution transformer interference, and branch interference. The simulation unit is used to perform basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog power distribution automation terminal and the fault test requirements of the basic scenario and interference scenario of the power distribution simulation model, and output the basic positioning test results and interference positioning test results. The analysis unit is used to obtain the traveling wave function test results of the small analog power distribution automation terminal based on the deviation results of the basic positioning test results and the interference positioning test results from the actual information of the fault point.

[0071] In this embodiment, the data acquisition unit, the basic scenario construction unit, and the interference scenario construction unit are connected to the simulation unit, and the analysis unit is connected to both the data acquisition unit and the simulation unit.

[0072] The specific embodiments described above are preferred embodiments of the small analog power distribution automation terminal traveling wave function test method and system of this application, and are not intended to limit the specific implementation scope of this application. The scope of this application includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with the shape and structure of this application are within the protection scope of this application.

Claims

1. A method for testing the traveling wave function of a small analog power distribution automation terminal, characterized in that: Includes the following steps: The basic scenarios of the distribution network simulation model are constructed corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system. Interference scenarios in the distribution network simulation model are constructed using switching interference, distribution transformer branch interference, and line branch interference. Based on the traveling wave parameters of the small analog power distribution automation terminal and the fault test requirements, the basic positioning test and the interference positioning test are performed in the basic scenario and interference scenario of the power distribution network simulation model, respectively, and the basic positioning test results and the interference positioning test results are obtained. The traveling wave function test results of the small analog power distribution automation terminal are obtained by comparing the deviation results of the basic positioning test results and the interference positioning test results with the actual information of the fault point.

2. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The basic scenarios for constructing the distribution network simulation model, corresponding to different combinations of overhead line structures, cable line structures, and neutral grounding structures in the distribution network system, include: Corresponding to different overhead line structures and cable line structures, a single-radial grid structure, a single-radial overhead cable hybrid grid structure, and a long-line single-connection overhead line grid structure are constructed according to typical line combination methods. For each type of grid structure, neutral grounding structures with arc suppression coil grounding, no grounding, and grounding with small resistance are constructed respectively to obtain the basic scenario of the distribution network simulation model.

3. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The interference scenarios used to construct the distribution network simulation model based on switching interference, distribution transformer branch interference, and line branch interference include: A switching interference scenario is constructed by switching long cables and motors; Construct distribution transformer branch interference scenarios with varying numbers of distribution branches; Construct line branch interference scenarios with varying numbers of line branches; The interference scenarios of the distribution network simulation model are constructed based on the interference scenarios of switching interference, distribution branch interference, and line branch interference.

4. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The process involves performing basic location tests and interference location tests based on the traveling wave parameters of the small analog power distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model, respectively, and obtaining the basic location test results and interference location test results, including: Based on the fault testing requirements, the basic scenario and interference scenario of the distribution network simulation model are retrieved. Each basic scenario of the distribution network simulation model and all interference scenarios of the distribution network simulation model constitute a test sequence. Synchronous execution is performed sequentially for each test sequence: Based on the basic scenario of the distribution network simulation model, a distribution network simulation model under the basic scenario is constructed by combining the distribution network equipment model; Based on the distribution network simulation model in the basic scenario, the basic positioning test is performed according to the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements to obtain the basic positioning test results. Based on the distribution network simulation model in the basic scenario, a distribution network simulation model under the interference scenario is constructed by combining the distribution network equipment model according to the interference scenario of the distribution network simulation model. Using a distribution network simulation model under interference scenarios, interference location tests are performed based on the traveling wave parameters of small-scale analog distribution automation terminals and fault test requirements to obtain interference location test results.

5. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The process involves performing basic location tests and interference location tests based on the traveling wave parameters of the small analog power distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model, respectively, and obtaining the basic location test results and interference location test results, including: Calculate the scene similarity between basic distribution network simulation scenarios, between interference scenarios of distribution network simulation models, and between basic distribution network simulation scenarios and interference scenarios of distribution network simulation models in advance; Based on the fault testing requirements, retrieve the basic scenario and interference scenario of the distribution network simulation model, and plan the construction order of the distribution network simulation model under different scenarios according to the maximum scenario similarity. The distribution network simulation model is constructed sequentially according to the construction order of the distribution network simulation model. After each construction is completed, the basic positioning test or interference positioning test is performed according to the traveling wave parameters of the small analog distribution automation terminal and the fault test requirements to obtain the basic positioning test results and interference positioning test results.

6. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The process involves performing basic location tests and interference location tests based on the traveling wave parameters of the small analog power distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model, respectively, and obtaining the basic location test results and interference location test results, including: Based on the topology of the distribution network system to be tested, retrieve the basic scenario of the distribution network simulation model; based on the historical interference factors of the distribution network system to be tested, retrieve the interference scenario of the distribution network simulation model. Based on the distribution network equipment model, the basic scenario of the distribution network simulation model, and the interference scenario of the distribution network simulation model, a distribution network simulation model is constructed. The traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test are used as inputs to the distribution network simulation model, and the basic positioning test results and interference positioning test results are output.

7. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 6, characterized in that: The process of performing basic location tests and interference location tests based on the traveling wave parameters of the small analog power distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model, and obtaining the basic location test results and interference location test results, also includes: Based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test, deviation correlation is performed to obtain the nodes that affect the aging of historical equipment on the traveling wave positioning deviation under the same life sequence of the historical traveling wave terminal. The aging parameters to be tested are obtained by using the impact of historical equipment aging on the positioning deviation of traveling waves. Incorporate the aging parameters to be tested into the basic parameters of the distribution network system to be tested; The system takes the traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test as inputs to the distribution network simulation model, and outputs the basic positioning test results and the interference positioning test results.

8. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 6, characterized in that: The process of performing basic location tests and interference location tests based on the traveling wave parameters of the small analog power distribution automation terminal and fault test requirements in the basic scenario and interference scenario of the power distribution network simulation model, and obtaining the basic location test results and interference location test results, also includes: Based on the historical equipment maintenance cycle, historical traveling wave positioning terminal life sequence, and historical traveling wave positioning terminal positioning data of the distribution network system under test, deviation correlation is performed to obtain the traveling wave positioning deviation value of different historical traveling wave positioning terminal life sequences under the same historical equipment aging sequence, and to construct the terminal aging deviation curve. The aging offset parameters of the traveling wave positioning terminal are obtained from the inflection point of the terminal aging deviation curve. The aging offset parameters of the traveling wave positioning terminal are incorporated into the traveling wave parameters of the small analog distribution automation terminal. The traveling wave parameters of the small analog distribution automation terminal, the basic parameters of the distribution network system under test, and the fault information of the distribution network system under test are used as inputs to the distribution network simulation model, and the basic positioning test results and interference positioning test results are output.

9. The method for testing the traveling wave function of a small analog power distribution automation terminal as described in claim 1, characterized in that: The method of obtaining the traveling wave function test results of the small analog power distribution automation terminal based on the deviation results of the basic positioning test results and the interference positioning test results from the actual information of the fault point includes: The first deviation result is obtained based on the distance between the basic positioning test results and the actual location of the fault point; The second deviation result is obtained based on the distance between the interference location test result and the actual location of the fault point; The first deviation result and the second deviation result are used as the output of the traveling wave function test results of the small analog power distribution automation terminal.

10. A small analog power distribution automation terminal traveling wave function test system, used to implement the method as described in any one of claims 1 to 9, characterized in that: include: The data acquisition unit is used to acquire traveling wave parameters of small analog power distribution automation terminals and to meet fault testing requirements. The basic scenario construction unit is used to construct the basic scenario of the distribution network simulation model based on different combinations of overhead line structure, cable line structure and neutral grounding structure. The interference scenario construction unit is used to construct interference scenarios for the distribution network simulation model based on switching interference, distribution transformer interference, and branch interference. The simulation unit is used to perform basic positioning tests and interference positioning tests based on the traveling wave parameters of the small analog power distribution automation terminal and the fault test requirements of the basic scenario and interference scenario of the power distribution simulation model, and output the basic positioning test results and interference positioning test results. The analysis unit is used to obtain the traveling wave function test results of the small analog power distribution automation terminal based on the deviation results of the basic positioning test results and the interference positioning test results from the actual information of the fault point.

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