Method and device for establishing single-phase earth fault arc model

Abstract

The invention relates to a method and a device for establishing a single-phase earth fault arc model. The method comprises the following steps: collecting arc data and load data in an arc stage, and establishing an arc model according to the arc data and the load data: for an arc starting stage, obtaining arc starting resistance according to arc current, arc voltage, load current and load voltage in the arc starting stage; for the steady-state arcing stage, arcing resistance is obtained according to the arc current, the arc voltage, the load current and the load voltage of the steady-state arcing stage; and for the arc quenching stage, obtaining the arc quenching resistance according to the arc current, the arc voltage, the load current and the load voltage in the arc quenching stage. According to the method, the arc models are established in stages from the arc starting stage, the steady-state arcing stage and the arc extinguishing stage, so that the arc model of each arc stage better conforms to the arc characteristics of each stage, and the actual single-phase earth fault arc can be better simulated.

Description

Technical Field

[0001] The present application relates to the technical field of power faults, and in particular to a method and device for establishing a single-phase grounding fault arc model. Background Art

[0002] With the rapid advancement of urbanization, cables have become the main form of power transmission in urban power distribution networks, and the length of single-circuit cable lines and their transmission capacity are also increasing with the increasing urban power load. Compared with traditional overhead lines, cable lines are usually laid in multiple channels, which makes it very easy for a cable line fault to spread to other cable lines. In serious cases, it may even cause the loss of the cross-section of the entire cable channel, causing serious large-scale power outages, seriously affecting power supply reliability and quality power supply service levels.

[0003] The number of distribution cable line faults is higher than that of the main network cable line, and single-phase grounding faults are the main faults in distribution cable lines. Under the current situation where the distribution network is widely operated with resonant grounding, after a single-phase grounding fault occurs in the distribution line, if the fault is transient, it can be quickly restored to operation, which improves the power supply reliability of the distribution network. However, if the fault is a permanent single-phase grounding fault, the arc caused by the single-phase grounding of the distribution line continues to exist, which may ignite other equipment such as optical cables, secondary cables, and main network cables laid in the cable tunnel, leading to the expansion of the accident. Therefore, it is necessary to study the arc during a single-phase grounding fault.

[0004] In the related art, the existing arc model only regards the arc as a fixed resistor when describing the arc characteristics of a single-phase ground fault, and completely ignores the complex physical changes of the arc at different stages. For example, in the arc starting stage, the arc undergoes a violent gas ionization and electron emission process from nothing, and its resistance characteristics are not fixed; in the steady-state arc burning stage, the stability of the arc is affected by many factors, such as load current, voltage, etc., and the traditional model fails to effectively consider these factors; in the arc extinction stage, the attenuation process of the plasma plays a key role in the arc resistance, but the traditional model lacks an accurate description of this. These limitations make it difficult for the existing arc model to accurately simulate the actual single-phase ground fault arc, and cannot provide a reliable basis for fault analysis of the power system and the optimal design of protection devices.

[0005] Therefore, it is necessary to provide a new technical solution to improve one or more problems existing in the above solutions.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] The purpose of the present application is to provide a method and device for establishing a single-phase grounding fault arc model, thereby overcoming one or more problems caused by limitations and defects of related technologies at least to a certain extent.

[0008] According to a first aspect of an embodiment of the present application, there is provided a method for establishing a single-phase grounding fault arc model, the method comprising:

[0009] Collecting arc data and load data of the arc stage, wherein the arc stage includes an arc starting stage, a steady-state arc burning stage and a full arc extinguishing stage, the arc data includes an arc current and an arc voltage, and the load data includes a load current and a load voltage;

[0010] An arc model is established according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data comprises:

[0011] For the arc starting stage, an arc starting resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc starting stage;

[0012] For the steady-state arcing stage, the arcing resistance is obtained according to the arc current, arc voltage, load current and load voltage in the steady-state arcing stage;

[0013] For the arc extinction stage, the arc extinction resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc extinction stage.

[0014] In an embodiment of the present application, the step of obtaining the arc starting resistance according to the arc current, arc voltage and load current in the arc starting stage for the arc starting stage includes:

[0015] The initial arc resistance is obtained according to the initial arc voltage and the initial arc current;

[0016] The minimum resistance after the arc is fully ionized is obtained according to the minimum voltage after the arc is fully ionized and the minimum current after the arc is fully ionized;

[0017] The arc starting resistance is obtained according to the arc starting initial resistance, the minimum resistance after the arc starting arc is fully ionized, the load current in the arc starting stage, and the load voltage in the arc starting stage.

[0018] In the embodiment of the present application, the calculation formula of the arc starting resistance is as follows:

[0019]

[0020] Where U 1 Indicates the initial arc resistance, I 1 Indicates the initial arc current, U 1minIndicates the minimum voltage after the arc is fully ionized, I 1min Indicates the minimum current after the arc is fully ionized, U L1 Indicates the load voltage during the arc starting phase, I L1 Indicates the load current during the arc starting stage, k 1 represents the load factor in the arc starting stage, α represents the resistance attenuation coefficient, t 1 Indicates arc starting time, R L Represents the load reference resistance.

[0021] In an embodiment of the present application, the step of obtaining the arcing resistance according to the arc current, arc voltage and load current in the steady-state arcing stage comprises:

[0022] Obtaining the arc resistance in the steady-state arc burning stage according to the arc voltage in the steady-state arc burning stage and the arc current in the steady-state arc burning stage;

[0023] The arcing resistance is obtained according to the arc resistance in the steady-state arcing stage, the load current in the steady-state arcing stage and the load voltage in the steady-state arcing stage.

[0024] In the embodiment of the present application, the calculation formula of the arcing resistance is as follows:

[0025]

[0026] Where U 1 Indicates the arc voltage in the steady-state arcing stage, I 1 Indicates the arc current in the steady-state arcing stage, U L2 Indicates the load voltage during the steady-state arcing phase, I L2 Table 1 shows the load current in the steady-state arcing stage, k 2 Indicates the load factor during the steady-state arcing stage.

[0027] In an embodiment of the present application, the step of obtaining the arc extinction resistance according to the arc current, arc voltage, load current and load voltage in the arc extinction stage comprises:

[0028] Obtaining an instantaneous minimum resistance in the arc extinction stage according to an instantaneous minimum arc voltage in the arc extinction stage and an instantaneous minimum arc current in the arc extinction stage;

[0029] Obtaining an instantaneous maximum resistance in the arc extinction stage according to an instantaneous maximum arc voltage in the arc extinction stage and an instantaneous maximum arc current in the arc extinction stage;

[0030] The arc-extinguishing resistance is obtained according to the instantaneous minimum resistance in the arc-extinguishing stage, the instantaneous maximum resistance in the arc-extinguishing stage, the load current in the arc-extinguishing stage and the load current in the arc-extinguishing stage.

[0031] In the embodiment of the present application, the calculation formula of the arc extinguishing resistance is as follows:

[0032]

[0033] Where U min Indicates the instantaneous minimum arc voltage during the arc extinction stage, I min Indicates the instantaneous minimum arc current during the arc extinction stage, U max Indicates the instantaneous maximum arc voltage during the arc extinction stage, I max represents the instantaneous maximum arc current in the arc extinction stage, β represents the attenuation coefficient, t 3 Indicates the arc extinction time, k 3 Indicates the load factor during the arc extinction phase, U L3 Indicates the load voltage during the arc extinction phase, I L3 Indicates the load current during the arc extinction stage.

[0034] In the embodiment of the present application, the arc model is:

[0035]

[0036] Where t represents the arc time.

[0037] In an embodiment of the present application, after the step of collecting arc data and load data in the arc stage, the method further includes:

[0038] The arc data and the load data are preprocessed to obtain the preprocessed arc data.

[0039] In an embodiment of the present application, the acquisition module is used to acquire arc data of an arc stage, wherein the arc stage includes an arc starting stage, a steady-state arc burning stage and a full arc extinguishing stage, and the arc data includes arc current, arc voltage, load current and load voltage;

[0040] An establishing module is used to establish an arc model according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data includes:

[0041] For the arc starting stage, an arc starting resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc starting stage;

[0042] For the steady-state arcing stage, the arcing resistance is obtained according to the arc current, arc voltage, load current and load voltage in the steady-state arcing stage;

[0043] For the arc extinction stage, the arc extinction resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc extinction stage.

[0044] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0045] In one embodiment of the present application, through the above method, on the one hand, the arc data and load data corresponding to each of the arc starting stage, the steady-state arc burning stage and the full extinction stage are collected, covering the complete process from the generation to the extinction of the arc, so that the collected data is rich and comprehensive, and provides rich and comprehensive data for the subsequent establishment of the arc model. On the other hand, because the arcs in different arc stages are different, the arc model is established in stages from the three arc stages of the arc starting stage, the steady-state arc burning stage and the arc extinction stage, so that the arc model of each arc stage is more in line with the arc characteristics of the respective stages, so that the actual single-phase grounding fault arc can be better simulated, and a more reliable basis is provided for the subsequent research and analysis of single-phase grounding faults.

[0046] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0048] Figure 1 A flowchart schematically illustrates a method for establishing a single-phase ground fault arc model in an exemplary embodiment of the present application;

[0049] Figure 2 A block diagram schematically shows a device for establishing a single-phase ground fault arc model in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0050] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0051] In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0052] In this example implementation, a method for establishing a single-phase ground fault arc model is first provided. Figure 1 As shown in , the method may include: step S101 to step S102.

[0053] Among them, step S101: collect arc data and load data of the arc stage, wherein the arc stage includes arc starting stage, steady-state arc burning stage and full arc extinction stage, the arc data includes arc current and arc voltage, and the load data includes load current and load voltage.

[0054] Step S102: establishing an arc model according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data includes:

[0055] For the arc starting stage, the arc starting resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc starting stage;

[0056] For the steady-state arcing stage, the arcing resistance is obtained according to the arc current, arc voltage, load current and load voltage in the steady-state arcing stage;

[0057] For the arc extinction stage, the arc extinction resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc extinction stage.

[0058] In one embodiment of the present application, through the above method, on the one hand, the arc data and load data corresponding to each of the arc starting stage, the steady-state arc burning stage and the full extinction stage are collected, covering the complete process from the generation to the extinction of the arc, so that the collected data is rich and comprehensive, and provides rich and comprehensive data for the subsequent establishment of the arc model. On the other hand, because the arcs in different arc stages are different, the arc model is established in stages from the three arc stages of the arc starting stage, the steady-state arc burning stage and the arc extinction stage, so that the arc model of each arc stage is more in line with the arc characteristics of the respective stages, so that the actual single-phase grounding fault arc can be better simulated, and a more reliable basis is provided for the subsequent research and analysis of single-phase grounding faults.

[0059] Next, we will refer to Figure 1Each step of the above method in this example implementation is described in more detail.

[0060] In step S101, an arc phenomenon will occur when a cable grounding fault occurs. The arc stages involved in the arc phenomenon generally include an arc starting stage, a steady-state arc burning stage, and a full arc extinction stage. The arc starting stage is generally the arc generation stage, the steady-state arc burning stage is generally the steady-state burning stage of the arc, and the full arc extinction stage is generally the arc extinction stage. Therefore, when studying the establishment of a single-phase grounding fault arc model, the present application divides the arc stage into an arc starting stage, a steady-state arc burning stage, and a full arc extinction stage, and collects arc data and load data corresponding to each arc stage.

[0061] It should be noted that the arc data and load data collected in this application can be obtained from channels such as power system monitoring equipment or experimental test platforms, and this application does not impose any restrictions on this.

[0062] Furthermore, arc data includes arc current and arc voltage, and load data includes load current and load voltage. Therefore, when collecting arc data and load data corresponding to each arc stage, the arc current, arc voltage, load current and load voltage corresponding to each arc stage are collected. The collected arc data and load data cover the complete process from arc generation to arc extinction, making the collected arc data and load data rich and comprehensive, providing a data basis for the subsequent establishment of an arc model.

[0063] In step S102, establishing an arc model according to arc data and load data corresponding to each arc stage includes the following contents:

[0064] In one embodiment, for the arc starting stage, the step of obtaining the arc starting resistance according to the arc current, arc voltage and load current in the arc starting stage includes:

[0065] The initial arc resistance is obtained according to the initial arc voltage and the initial arc current;

[0066] The minimum resistance after the arc is fully ionized is obtained according to the minimum voltage after the arc is fully ionized and the minimum current after the arc is fully ionized;

[0067] The arc starting resistance is obtained according to the arc starting initial resistance, the minimum resistance after the arc starting arc is fully ionized, the load current in the arc starting stage, and the load voltage in the arc starting stage.

[0068] It is understandable that the initial arc resistance and the minimum resistance after the arc is fully ionized can better reflect the change law of resistance in the arc starting stage. In addition, based on the influence of the load on the arc starting resistance in the actual circuit, the load current and load voltage in the arc starting stage are included in the determination process of the arc starting resistance, making the arc model in the arc starting stage more accurate, and improving the practicality and reliability of the arc model in the arc starting stage.

[0069] Furthermore, the calculation formula of arc starting resistance is as follows:

[0070]

[0071] Where U 1 Indicates the initial arc resistance, I 1 Indicates the initial arc current, U 1min Indicates the minimum voltage after the arc is fully ionized, I 1min Indicates the minimum current after the arc is fully ionized, U L1 Indicates the load voltage during the arc starting phase, I L1 Indicates the load current during the arc starting stage, k 1 represents the load factor in the arc starting stage, α represents the resistance attenuation coefficient, t 1 Indicates arc starting time, R L Represents the load reference resistance.

[0072] It can be understood that the arc model in the arc starting stage, namely the arc starting resistance, can be determined according to the above formula (1) and formula (2), and the arc generation is reflected by the arc starting resistance.

[0073] It should be noted that the load reference resistance is the theoretical resistance of the load. After the arc is struck in the circuit, the real resistance of the load will be affected. Therefore, the load coefficient can be determined based on the real resistance of the load and the theoretical resistance of the load. The load coefficient in the arcing stage will affect the arcing resistance in the arcing stage. Therefore, when determining the arcing resistance in the arcing stage, the load coefficient is taken into account, so that the determined arc resistance in the arcing stage is more real and reliable.

[0074] In one embodiment, for the steady-state arcing stage, the step of obtaining the arcing resistance according to the arc current, arc voltage and load current in the steady-state arcing stage includes:

[0075] The arc resistance in the steady-state arc burning stage is obtained according to the arc voltage in the steady-state arc burning stage and the arc current in the steady-state arc burning stage;

[0076] The arcing resistance is obtained according to the arc resistance in the steady-state arcing stage, the load current in the steady-state arcing stage and the load voltage in the steady-state arcing stage.

[0077] It is understandable that the load affects the arc model not only in the arc starting stage, but also in the steady-state arc burning stage. Therefore, in the steady-state arc burning stage, based on the influence of the load on the arc burning resistance in the actual circuit, the present application incorporates the load current and load voltage in the steady-state arc burning stage into the determination process of the arc burning resistance, so that the arc model in the steady-state arc burning stage is more in line with the actual situation, and the practicality and reliability of the arc model in the steady-state arc burning stage are improved.

[0078] Furthermore, the calculation formula of arcing resistance is as follows:

[0079]

[0080] Where U 1 Indicates the arc voltage in the steady-state arcing stage, I 1 Indicates the arc current in the steady-state arcing stage, U L2 Indicates the load voltage during the steady-state arcing phase, I L2 Table 1 shows the load current in the steady-state arcing stage, k 2 Indicates the load factor during the steady-state arcing stage.

[0081] It can be understood that the arc model of the steady-state arc burning stage, namely the arc burning resistance, can be determined according to the above formula (3) and formula (4). That is, the steady-state burning process of the arc can be reflected by the arc burning resistance.

[0082] It should be noted that the load coefficient in the steady-state arcing stage will affect the arcing resistance in the steady-state arcing stage. Therefore, when determining the arcing resistance in the steady-state arcing stage, the corresponding load coefficient is taken into account, so that the determined arcing resistance in the steady-state arcing stage is more real and reliable.

[0083] In one embodiment, for the arc extinction stage, the step of obtaining the arc extinction resistance according to the arc current, arc voltage, load current and load voltage in the arc extinction stage includes:

[0084] According to the instantaneous minimum arc voltage and the instantaneous minimum arc current in the arc extinction stage, the instantaneous minimum resistance in the arc extinction stage is obtained;

[0085] According to the instantaneous maximum arc voltage and the instantaneous maximum arc current in the arc extinction stage, the instantaneous maximum resistance in the arc extinction stage is obtained;

[0086] The arc-extinguishing resistance is obtained according to the instantaneous minimum resistance in the arc-extinguishing stage, the instantaneous maximum resistance in the arc-extinguishing stage, the load current in the arc-extinguishing stage, and the load current in the arc-extinguishing stage.

[0087] It can be understood that after the arc enters the arc extinction stage, considering the fluctuation range of the arc voltage in the arc extinction stage and the influence of the load conditions on the arc extinction resistance, the present application determines the arc extinction resistance through the instantaneous minimum arc voltage in the arc extinction stage, the instantaneous minimum current in the arc extinction stage, and the load current and load voltage in the arc extinction stage, thereby improving the simulation accuracy of the single-phase ground fault arc model in the arc extinction stage.

[0088] Furthermore, the calculation formula of the arc extinguishing resistance is as follows:

[0089]

[0090] Where U min Indicates the instantaneous minimum arc voltage during the arc extinction stage, I min Indicates the instantaneous minimum arc current during the arc extinction stage, U max Indicates the instantaneous maximum arc voltage during the arc extinction stage, I max represents the instantaneous maximum arc current in the arc extinction stage, β represents the attenuation coefficient, t 3 Indicates the arc extinction time, k 3 Indicates the load factor during the arc extinction phase, U L3 Indicates the load voltage during the arc extinction phase, I L3 Indicates the load current during the arc extinction stage.

[0091] It should be noted that the arc model in the arc extinction stage, that is, the arc extinction resistance, can be determined by the above formula (5) and formula (6), and the arc extinction process of the arc can be reflected by the arc extinction resistance.

[0092] In one embodiment, the arc model is:

[0093]

[0094] Where t represents the arc time.

[0095] It can be understood that the arc model includes the arc-starting resistance during the arc-starting time, the arc-burning resistance during the arc-burning time, and the arc-extinguishing resistance during the arc-extinguishing time. The arc-starting resistance, the arc-burning resistance, and the arc-extinguishing resistance correspond to the arc-starting stage, the steady-state arc-burning stage, and the extinction stage of the arc, respectively, and completely cover the entire process from the generation to the extinction of the arc. Therefore, the arc model can fully reflect the changes in the resistance characteristics of different arc stages.

[0096] By analyzing the resistance characteristics of different arc stages, it is easy to locate the time node and fault type of the fault. For example, the abnormal arc starting resistance can infer the change of arc starting conditions, the change of arc burning resistance can reflect the energy loss and stability during arc burning, and the characteristics of arc extinguishing resistance are related to the residual effect at the end of the fault, providing rich and targeted information for fault analysis.

[0097] It should be noted that by studying the resistance characteristics at different arc stages, it is convenient to improve the arc characteristics in the future. For example, improving cable materials, optimizing arc starting resistance to reduce arc starting shock, and optimizing arc extinction resistance to achieve faster and more thorough arc extinction, thereby improving the safety of the power system.

[0098] In one embodiment, after the step of collecting arc data and load data in the arc stage, the method further includes:

[0099] The arc data and the load data are preprocessed to obtain preprocessed arc data and load data.

[0100] It is understandable that after the arc data and load data are collected, the present application needs to pre-process them to obtain accurate arc data and load data. Pre-processing mainly includes data cleaning and data normalization. Among them, when performing data cleaning, a filtering algorithm (such as mean filtering, median filtering or wavelet filtering) is generally used to remove abnormal values ​​such as noise and spikes in the data to ensure data accuracy. When performing data normalization, the minimum-maximum normalization method is generally used to map data of different ranges and types to the same scale, so that the data is comparable and convenient for subsequent model training and learning.

[0101] It should be noted that data cleaning and data normalization can be understood by referring to the prior art, and this application will not elaborate on this.

[0102] It should be noted that, although the steps of the method in the present application are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution, etc. In addition, it is also easy to understand that these steps may be, for example, executed synchronously or asynchronously in multiple modules / processes / threads.

[0103] Furthermore, in this exemplary embodiment, a device for establishing a single-phase ground fault arc model is also provided. Figure 2As shown in , the device 200 may include a collection module 210 and an establishment module 220. Wherein: the collection module 210 is used to collect arc data of the arc stage, wherein the arc stage includes the arc starting stage, the steady-state arc burning stage and the full arc extinction stage, and the arc data includes arc current, arc voltage, load current and load voltage; the establishment module 220 is used to establish an arc model according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data includes: for the arc starting stage, according to the arc current, arc voltage, load current and load voltage in the arc starting stage, the arc starting resistance is obtained; for the steady-state arc burning stage, according to the arc current, arc voltage, load current and load voltage in the steady-state arc burning stage, the arc burning resistance is obtained; for the arc extinction stage, according to the arc current, arc voltage, load current and load voltage in the arc extinction stage, the arc extinction resistance is obtained.

[0104] In one embodiment, the apparatus further comprises:

[0105] The first establishment submodule is used to obtain the initial arcing resistance according to the initial arcing voltage and the initial arcing current;

[0106] The minimum resistance after the arc is fully ionized is obtained according to the minimum voltage after the arc is fully ionized and the minimum current after the arc is fully ionized;

[0107] The arc starting resistance is obtained according to the arc starting initial resistance, the minimum resistance after the arc starting arc is fully ionized, the load current in the arc starting stage, and the load voltage in the arc starting stage.

[0108] In one embodiment, the apparatus further comprises:

[0109] The second establishment submodule is used to obtain the arc resistance in the steady-state arc burning stage according to the arc voltage in the steady-state arc burning stage and the arc current in the steady-state arc burning stage;

[0110] The arcing resistance is obtained according to the arc resistance in the steady-state arcing stage, the load current in the steady-state arcing stage and the load voltage in the steady-state arcing stage.

[0111] In one embodiment, the apparatus further comprises:

[0112] The third establishment submodule is used to obtain the instantaneous minimum resistance in the arc extinction stage according to the instantaneous minimum arc voltage in the arc extinction stage and the instantaneous minimum arc current in the arc extinction stage;

[0113] According to the instantaneous maximum arc voltage and the instantaneous maximum arc current in the arc extinction stage, the instantaneous maximum resistance in the arc extinction stage is obtained;

[0114] The arc-extinguishing resistance is obtained according to the instantaneous minimum resistance in the arc-extinguishing stage, the instantaneous maximum resistance in the arc-extinguishing stage, the load current in the arc-extinguishing stage, and the load current in the arc-extinguishing stage.

[0115] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0116] It should be noted that although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the implementation mode of the present application, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of a module or unit described above can be further divided into multiple modules or units for concretization. The components displayed as modules or units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the present application scheme. Those of ordinary skill in the art can understand and implement it without paying creative work.

[0117] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

Claims

1. A method for establishing a single-phase grounding fault arc model, characterized in that: The method includes: Collecting arc data and load data of the arc stage, wherein the arc stage includes an arc starting stage, a steady-state arc burning stage and a full arc extinguishing stage, the arc data includes an arc current and an arc voltage, and the load data includes a load current and a load voltage; An arc model is established according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data comprises: For the arc starting stage, an arc starting resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc starting stage; For the steady-state arcing stage, the arcing resistance is obtained according to the arc current, arc voltage, load current and load voltage in the steady-state arcing stage; For the arc extinction stage, the arc extinction resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc extinction stage.

2. The method for establishing a single-phase grounding fault arc model according to claim 1, characterized in that: The step of obtaining the arc starting resistance according to the arc current, arc voltage and load current in the arc starting stage for the arc starting stage includes: The initial arc resistance is obtained according to the initial arc voltage and the initial arc current; The minimum resistance after the arc is fully ionized is obtained according to the minimum voltage after the arc is fully ionized and the minimum current after the arc is fully ionized; The arc starting resistance is obtained according to the arc starting initial resistance, the minimum resistance after the arc starting arc is fully ionized, the load current in the arc starting stage, and the load voltage in the arc starting stage.

3. The method for establishing a single-phase grounding fault arc model according to claim 2, characterized in that: The calculation formula of the arc starting resistance is as follows: In the formula, U1 represents the initial arc resistance, I1 represents the initial arc current, U 1min Indicates the minimum voltage after the arc is fully ionized, I 1min Indicates the minimum current after the arc is fully ionized, U L1 Indicates the load voltage during the arc starting phase, I L1 represents the load current in the arc starting stage, k1 represents the load factor in the arc starting stage, α represents the resistance attenuation coefficient, t1 represents the arc starting time, R L Represents the load reference resistance.

4. The method for establishing a single-phase grounding fault arc model according to claim 3, characterized in that: The step of obtaining the arcing resistance according to the arc current, arc voltage and load current in the steady-state arcing stage comprises: Obtaining the arc resistance in the steady-state arc burning stage according to the arc voltage in the steady-state arc burning stage and the arc current in the steady-state arc burning stage; The arcing resistance is obtained according to the arc resistance in the steady-state arcing stage, the load current in the steady-state arcing stage and the load voltage in the steady-state arcing stage.

5. The method for establishing a single-phase grounding fault arc model according to claim 4, characterized in that: The calculation formula of the arcing resistance is: Where U1 represents the arc voltage in the steady-state arc burning stage, I1 represents the arc current in the steady-state arc burning stage, and U L2 Indicates the load voltage during the steady-state arcing phase, I L2 k2 represents the load current in the steady-state arcing stage, and k2 represents the load factor in the steady-state arcing stage.

6. The method for establishing a single-phase grounding fault arc model according to claim 5, characterized in that: The step of obtaining the arc extinction resistance according to the arc current, arc voltage, load current and load voltage in the arc extinction stage comprises: Obtaining an instantaneous minimum resistance in the arc extinction stage according to an instantaneous minimum arc voltage in the arc extinction stage and an instantaneous minimum arc current in the arc extinction stage; Obtaining an instantaneous maximum resistance in the arc extinction stage according to an instantaneous maximum arc voltage in the arc extinction stage and an instantaneous maximum arc current in the arc extinction stage; The arc-extinguishing resistance is obtained according to the instantaneous minimum resistance in the arc-extinguishing stage, the instantaneous maximum resistance in the arc-extinguishing stage, the load current in the arc-extinguishing stage and the load current in the arc-extinguishing stage.

7. The method for establishing a single-phase grounding fault arc model according to claim 6, characterized in that: The calculation formula of the arc extinguishing resistance is as follows: Where U min Indicates the instantaneous minimum arc voltage during the arc extinction stage, I min Indicates the instantaneous minimum arc current during the arc extinction stage, U max Indicates the instantaneous maximum arc voltage during the arc extinction stage, I max represents the instantaneous maximum arc current in the arc extinction stage, β represents the attenuation coefficient, t3 represents the arc extinction time, k3 represents the load factor in the arc extinction stage, U L3 Indicates the load voltage during the arc extinction phase, I L3 Indicates the load current during the arc extinction stage.

8. The method for establishing a single-phase grounding fault arc model according to claim 6, characterized in that: The arc model is: Where t represents the arc time.

9. The method for establishing a single-phase grounding fault arc model according to claim 6, characterized in that: After the step of collecting arc data and load data in the arc stage, the method further includes: The arc data and the load data are preprocessed to obtain the preprocessed arc data and the load data.

10. A device for establishing a single-phase grounding fault arc model, characterized in that: The device includes: An acquisition module is used to acquire arc data of an arc stage, wherein the arc stage includes an arc starting stage, a steady-state arc burning stage and a full arc extinguishing stage, and the arc data includes arc current, arc voltage, load current and load voltage; An establishing module is used to establish an arc model according to the arc data and the load data; wherein the step of establishing the arc model according to the arc data and the load data includes: For the arc starting stage, an arc starting resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc starting stage; For the steady-state arcing stage, the arcing resistance is obtained according to the arc current, arc voltage, load current and load voltage in the steady-state arcing stage; For the arc extinction stage, the arc extinction resistance is obtained according to the arc current, arc voltage, load current and load voltage in the arc extinction stage.

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