Low-voltage AC arc digital twin model

Abstract

The present invention proposes a digital twin model of a low-voltage AC arc, comprising: an arc physical experiment platform and a COMSOL arc simulation model; the interaction mapping of arc information between the virtual and real platforms of the arc is carried out with the wavelet energy spectrum eigenvalue of the arc voltage; by collecting the characteristic data of the arc voltage change in the arc physical experiment, the parameters of the simulation model are dynamically corrected to make the simulation model closer to the actual movement process of the arc, and the results obtained from the simulation model are fed back to the physical platform of the arc experiment.

Description

Technical Field

[0001] The present invention belongs to the technical field of arc research, and particularly relates to a digital twin model of a low-voltage alternating current arc. Background Art

[0002] With the development of science and technology and social economy, in order to meet people's demand for electric energy, more and more low-voltage switch electrical equipment is put into use, making people pay more attention to the reliable performance of the breaking of low-voltage electrical contacts. Among them, the arc is the main factor restricting its breaking reliable performance. In order to reduce the harm of the arc to low-voltage switch electrical appliances and ensure the safe and reliable operation of power supply, the research on low-voltage arcs is of great significance. In current research, the research between arc experiments and arc model simulations is fragmented, and there is no effective method to connect the two, and the integration of the arc physical experimental system and the simulation model cannot be achieved. With the digital transformation of low-voltage switch equipment and the development in the direction of intelligentization, constructing a digital twin interaction model of low-voltage alternating current arcs has become an urgent problem to be solved in the intelligent development of low-voltage electrical appliances.

[0003] Existing research shows that the voltage waveform of the arc contains rich arc feature information. Whether the arc extinguishes depends on the competition between the dielectric recovery strength and the voltage recovery strength in a very short time after the current passes through zero. Summary of the Invention

[0004] Considering that the voltage waveform of the arc contains useful information reflecting the arc burning trend characteristics, extracting the wavelet energy spectrum eigenvalue of the arc voltage, and using the characteristic that the wavelet energy spectrum eigenvalue is correlated with the arc burning trend, the wavelet energy spectrum eigenvalue can be used as a link to realize data transmission and information exchange between the virtual and real elements of the digital twin. At the same time, with the development of information perception technology, virtual-real mapping technology, and digital-analog linkage technology, it has become possible to construct an arc digital twin model using an arc physical experimental platform and simulation software.

[0005] Aiming at the defects and deficiencies of the existing technology, as well as the unachieved concepts and designs, the present invention proposes a digital twin model of a low-voltage alternating current arc applicable to systems of 380V and below in alternating current by taking the arc physical experimental system as the physical platform in the digital twin model, taking the arc simulation experimental platform based on COMSOL as the virtual platform, and taking the wavelet energy spectrum eigenvalue of the arc voltage as the bridge for interaction and connection between the virtual and real platforms.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] A digital twin model of a low-voltage AC arc, characterized in that it includes: an arc physical experiment platform and a COMSOL arc simulation model; the interaction mapping of arc information between the virtual and physical arc platforms is completed through the wavelet energy spectrum eigenvalue of the arc voltage; by collecting the characteristic data of the arc voltage change in the arc physical experiment platform, the parameters of the simulation model are dynamically corrected to make the simulation model closer to the actual movement process of the arc, and the results obtained from the simulation model are fed back to the physical platform of the arc experiment.

[0008] Further, in the arc physical experiment platform, the closing and opening movement of the electrode is controlled by setting arc experiment parameters, and the arc experiment parameters at least include: electrode gap, electrode opening speed, load type, background gas composition, ambient air pressure; to make the arc generating device generate a corresponding arc; the arc physical experiment platform has the function of obtaining the waveform data of the arc voltage during the whole process of arc combustion in real time, and further analyzing and processing these waveform data by using the wavelet energy spectrum transformation algorithm embedded in the system to extract the wavelet energy spectrum characteristic parameters.

[0009] Further, the COMSOL arc simulation model is an arc simulation platform built based on the computer system and the COMSOL simulation software. A virtual mirror image of the arc voltage waveform measured in the arc physical experiment platform is simulated through the simulation platform. The simulation optimization of the arc extinction trend is carried out by using the virtual mirror image of the arc voltage waveform obtained from the simulation to achieve the purpose of optimizing the real with the virtual in the digital twin model; the arc simulation platform uses the arc magnetohydrodynamic model as the simulation model, constructs the geometric model of the arc generating device from the experimental device in the arc physical experiment platform, and uses the dynamic mesh technology in the simulation software to simulate the movement process of the electrode. The simulation parameter settings include the arc experiment parameters in the arc physical experiment platform and the settings of resistance and heat source in the simulation model. Finally, an arc voltage waveform similar to the voltage waveform measured in the arc experiment is calculated after the mesh division.

[0010] Furthermore, after collecting the data of the arc voltage waveform in the arc experiment, the arc physical experiment platform extracts the wavelet energy eigenvalue and transmits it to the COMSOL arc simulation model. In the simulation parameter setting section of the COMSOL arc simulation model, the numerical values and time periods of the set resistance and heat source in the magnetohydrodynamic model are determined according to the wavelet eigenvalue, so as to simulate and obtain an arc voltage waveform similar to the measured value in the experiment. Then, the simulation optimization result parameters of the arc extinction trend are transmitted to the arc experiment parameter setting section of the arc physical experiment platform, enabling the arc physical experiment platform to obtain the experimental results predicted in the virtual experiment platform under the condition of setting more reasonable experimental parameters. The conclusions obtained in the arc physical experiment platform are compared with the conclusions obtained from the simulation optimization in the COMSOL arc simulation model. If they are inconsistent, it returns to the arc experiment parameter setting section of the arc physical experiment platform. If the results are consistent, the finally obtained conclusion is output, achieving the purpose of arc information interaction.

[0011] Compared with the prior art, the present invention and its preferred solutions have the following two innovative points and advantages:

[0012] 1. Introduce the concept of the digital twin model into the research of the arc model, and use the wavelet energy spectrum eigenvalue as the interaction bridge of the digital twin model to combine the arc experiment platform and the simulation platform.

[0013] 2. Utilize the digital twin model to realize the full-process dynamic simulation of the low-voltage alternating current arc, making up for the deficiency that the existing simulation models can only perform stable arc analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following further details the present invention in conjunction with the drawings and specific embodiments:

[0015] Figure 1 It is the structure diagram of the arc digital twin model in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the features and advantages of this patent more obvious and understandable, specific embodiments are given below for detailed description as follows:

[0017] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] The arc digital twin model of the embodiment solution of the present invention combines an arc physical experiment platform and a COMSOL arc simulation model, uses the wavelet energy spectrum eigenvalue of the arc voltage as the relationship link between the virtual and real platforms of the arc, completes the interactive mapping of arc information, dynamically corrects the simulation model parameters by collecting the characteristic data of the arc voltage change in the arc physical experiment, and makes the simulation model closer to the actual movement process of the arc. At the same time, the results obtained from the simulation model are fed back to the physical platform of the arc experiment. The structure of this arc digital twin model is as Figure 1 shown.

[0020] In the figure, module 1 is the arc physical experiment platform. Appropriate arc experiment parameters are set through this platform to control the closing and opening movement of the electrode. The arc experiment parameters include electrode gap, electrode opening speed, load type, background gas composition, ambient air pressure, etc., so that the arc generating device generates a corresponding arc. At the same time, this platform can accurately obtain the waveform data of the arc voltage during the entire process of arc combustion in real time, and further analyze and process these waveform data using the wavelet energy spectrum transformation algorithm embedded in the system to extract the wavelet energy spectrum characteristic parameters.

[0021] In the figure, module 2 is the arc simulation platform. This platform is built based on the COMSOL simulation software. A virtual mirror image of the arc voltage waveform measured in module 1 is simulated through this simulation platform, and the simulation optimization of the arc extinction trend is carried out using the virtual mirror image of the arc voltage waveform obtained from the simulation to achieve the purpose of optimizing the real with the virtual in the digital twin model. The arc simulation platform uses the arc magnetohydrodynamic model as the simulation model, constructs the geometric model of the arc generating device from the experimental device in module 1, and uses the dynamic mesh technology in the simulation software to simulate the movement process of the simulation electrode. The simulation parameter settings in module 2 include the arc experiment parameters in module 1 and the settings of resistance and heat source in the simulation model. Finally, after the mesh is divided, an arc voltage waveform similar to the voltage waveform measured in the arc experiment is calculated.

[0022] In terms of the information interaction of the model, after Module 1 collects the data of the arc voltage waveform in the arc experiment, it extracts the wavelet energy eigenvalues and transmits them to Module 2. In the simulation parameter setting section of Module 2, the values and time periods of the set resistance and heat source in the magnetohydrodynamic model are determined according to the wavelet eigenvalues, so as to simulate and obtain an arc voltage waveform similar to the measured value in the experiment. Then, the simulation optimization result parameters of the arc extinction trend are transmitted to the arc experiment parameter setting section of Module 1, enabling Module 1 to obtain the experimental results predicted in the virtual experiment platform under the condition of setting more reasonable experimental parameters. Subsequently, the experimental conclusions obtained in Module 1 are compared with the simulation optimization conclusions obtained in Module 2. If they are inconsistent, it returns to the arc experiment parameter setting section in Module 1; if the results are consistent, the finally obtained conclusions are output, thus achieving the purpose of arc information interaction.

[0023] This solution mainly involves an arc generation experimental device, an arc simulation technology platform, and a digital twin model conceptual framework. This model mainly targets alternating current arcs of 220V and below, aiming to overcome the problem of information islands easily formed between arc experimental research and simulation research, facilitating information interaction between the arc virtual simulation platform and the experimental platform, and making the arc simulation model closer to the entire process of an actual arc from initiation to extinction.

[0024] As an optimal design solution, it mainly includes the following key modules:

[0025] (1) Arc experiment physical platform (Module 1): The system circuit in Module 1 consists of an AC 220V power frequency power supply, a load, and electrodes connected in series. The electrodes are detachable and can be replaced and installed according to the arc ignition experiments with different materials. The circuit parameters of the arc experiment, such as the load size type, etc., can be achieved in the external circuit, while the electrode parameters, including the electrode breaking distance, electrode movement speed, etc., can be set on the upper computer interface of the system. The movement of the electrode is controlled by a stepping motor connected to the electrode, and the stepping electrode drives the electrode to perform closing and breaking actions and generate an arc; the replacement of background gas and environmental air pressure are carried out in a sealed experimental device; in terms of data acquisition, an Advantech PCI-1710U multifunctional data acquisition card is used as the core to mainly collect the arc voltage data at both ends of the contact. The voltage transformer uses LV25-P. The collected arc voltage waveform is transformed through the wavelet energy spectrum algorithm embedded in the system to obtain its eigenvalues, and finally the upper computer transmits the obtained wavelet energy spectrum eigenvalues to Module 2.

[0026] (2)Arc Simulation Virtual Platform (Module 2): Module 2 is an arc simulation virtual platform established based on COMSOL simulation software. The purpose of Module 2 is to simulate a waveform similar to the arc voltage waveform collected by Module 1. Since the arc experiment in Module 1 is conducted under the condition of a 220V power frequency alternating current power supply, and the generated arc satisfies local thermodynamic equilibrium, it is reasonable to construct a magnetohydrodynamic arc model in the arc simulation module of Module 2. Then, a geometric model corresponding to the electrode model in Module 1 is constructed. When setting the simulation parameters, the corresponding simulation parameters are set according to the arc experiment parameters of Module 1, and the wavelet energy spectrum eigenvalue extracted from Module 1 is used in the COMSOL software to divide the arc voltage waveform into a stable combustion part and an unstable combustion part for simulation by adding a heat source piecewise function of 8×10 11 W / m 3 . Secondly, a corresponding resistance piecewise function is set. The resistance value is 5Ω during the stable arc combustion stage of the arc, and the resistance value is 50Ω during the unstable arc combustion stage of the arc. The arc voltage waveform data similar to the measured arc voltage waveform is obtained through simulation. To verify the correctness of the simulation, the wavelet energy spectrum eigenvalue of the simulation waveform is extracted and compared with the measured data at the corresponding moment. The difference between the two at this moment is divided by the wavelet energy eigenvalue of the measured waveform at this moment. If the ratio does not exceed 8%, the process should return to the parameter setting step to modify the piecewise functions of the resistance and the heat source. Otherwise, proceed to the next step. In the simulation optimization link of the arc extinction trend, the wavelet energy spectrum eigenvalues of the arc voltage under different simulation parameter conditions are compared. When the arc is in the unstable arc combustion stage tending to extinguish, the wavelet energy spectrum eigenvalue of the arc voltage is 2.5 times or less of the order of magnitude during stable arc combustion; when the arc extinguishes, the wavelet energy spectrum eigenvalue of the arc voltage will increase to more than 3 times of the order of magnitude during its stable arc combustion. That is, the extinction effect of the arc is evaluated based on the numerical change of the wavelet energy spectrum eigenvalue of the arc voltage under different simulation parameter conditions, and the conclusion data is fed back to the arc experiment parameter setting in Module 1, so that the arc experiment in Module 1 adjusts the experiment parameters according to the simulation optimization results, and the wavelet energy spectrum eigenvalue of the arc voltage waveform after resetting the parameters is extracted and compared with the simulation optimization results in Module 2. If the results are inconsistent, return to the parameter setting step in Module 2 to modify the piecewise functions of the resistance and the heat source. Otherwise, it is considered that the experiment and the simulation results are consistent, and the current experiment parameters and simulation parameter settings are maintained to achieve the full-process dynamic simulation of the low-voltage alternating current arc.

[0027] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in any other form. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

[0028] This patent is not limited to the above best implementation mode. Anyone can obtain various other forms of low-voltage AC arc digital twin models under the inspiration of this patent. All equal changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by this patent.

Claims

1. A digital twin model of a low-voltage AC arc, characterized in that: Including: An arc physics experimental platform and a COMSOL arc simulation model; using the wavelet energy spectrum eigenvalue of the arc voltage as a medium to complete the interactive mapping of arc information between the virtual and physical arc platforms; By collecting the characteristic data of the arc voltage change in the arc physics experimental platform, dynamically correcting the simulation model parameters to make the simulation model closer to the actual movement process of the arc, and feeding back the results obtained from the simulation model to the physical platform of the arc experiment; In the arc physics experimental platform, the closing and opening movements of the electrodes are controlled by setting arc experiment parameters, and the arc experiment parameters at least include: electrode gap, electrode opening speed, load type, background gas composition, ambient air pressure; Enabling the arc generating device to generate a corresponding arc; the arc physics experimental platform has the function of acquiring the waveform data of the arc voltage during the entire process of arc combustion in real time, and further analyzing and processing these waveform data using the wavelet energy spectrum transformation algorithm embedded in the system to extract wavelet energy spectrum characteristic parameters; The COMSOL arc simulation model is an arc simulation platform built based on the computer system using COMSOL simulation software. By simulating a virtual mirror image of the arc voltage waveform measured in the arc physics experimental platform on the simulation platform, the simulation optimization of the arc extinguishing trend is carried out using the virtual mirror image of the arc voltage waveform obtained from the simulation, so as to achieve the purpose of optimizing the physical model with the virtual one in the digital twin model; the arc simulation platform uses the arc magnetohydrodynamic model as the simulation model, constructs the geometric model of the arc generating device from the experimental device in the arc physics experimental platform, and uses the dynamic mesh technology in the simulation software to simulate the movement process of the electrodes. The simulation parameter settings include the arc experiment parameters in the arc physics experimental platform and the settings of resistance and heat source in the simulation model. Finally, after the mesh is divided, an arc voltage waveform similar to the one measured in the arc experiment is calculated.

2. The digital twin model of the low-voltage AC arc according to claim 1, wherein: After collecting the data of the arc voltage waveform in the arc experiment, the arc physics experimental platform extracts the wavelet energy eigenvalues and transmits them to the COMSOL arc simulation model. The simulation parameter setting link in the COMSOL arc simulation model sets the values and time periods of resistance and heat source in the magnetohydrodynamic model according to the wavelet eigenvalues, so as to simulate and obtain an arc voltage waveform similar to the measured one in the experiment, and transmits the simulation optimization result parameters of the arc extinguishing trend to the arc experiment parameter setting link in the arc physics experimental platform, enabling the arc physics experimental platform to obtain the experimental results predicted in the virtual experimental platform under the condition of setting more reasonable experimental parameters, and comparing the conclusions obtained in the arc physics experimental platform with the conclusions obtained from the simulation optimization in the COMSOL arc simulation model. If they are inconsistent, it returns to the arc experiment parameter setting link in the arc physics experimental platform. If the results are consistent, the finally obtained conclusion is output to achieve the purpose of arc information interaction.

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