Whole-process waveform generation method and device for cable insulation defect degradation fault

Abstract

The invention relates to the technical field of power system fault detection and diagnosis, in particular to a whole-process waveform generation method and device for a cable insulation defect degradation fault, and the method comprises the steps: building a target whole-process fault waveform of the cable insulation defect degradation fault; obtaining the breakdown voltage change condition of the residual insulating layer except the cable insulation defect deterioration fault; and in combination with the breakdown voltage change condition and the target whole-process fault waveform, obtaining the whole-process fault waveform of the cable insulation defect degradation fault according to the cycle number of the cable insulation defect degradation fault. Therefore, the problems that the boundary of different stages of the cable local insulation defect degradation process is difficult to determine due to lack of mechanism analysis, the obtained whole-process fault waveform is greatly different from the actual fault development process, the application value does not exist and the like in the prior art are solved.

Description

Technical Field

[0001] The present application relates to the technical field of power system fault detection and diagnosis, and in particular to a method and device for generating a full-process waveform of a cable insulation defect degradation fault. Background Art

[0002] The cable local insulation defect degradation fault refers to the fault that gradually evolves from local defects in the internal insulation material of the cable due to the cable itself or external reasons. The main causes of the fault include mechanical damage, manufacturing defects, insulation aging, etc. The cable fault has intermittent and high resistance fault characteristics in the early stage, and is accompanied by a long development process.

[0003] In the related technology, transient oscillation waveform, semi-steady-state arc waveform and steady-state arc waveform can be used to represent them respectively, and features can be extracted from them to obtain the local waveform characteristics of the cable fault; the entire fault process can also be modeled, and the duration of different fault stages can be artificially specified according to empirical values, so as to obtain the waveforms of each stage of the cable fault.

[0004] However, in the related technology, only local waveform features can be extracted, and global waveform features cannot be obtained. In addition, there is a lack of analysis of the mechanism, making it difficult to determine the boundaries of different stages of the local insulation defect degradation process of the cable. The obtained full-process fault waveform is quite different from the actual fault development process, has no application value, and urgently needs to be improved. Summary of the invention

[0005] The present application provides a method and device for generating a full-process waveform of a cable insulation defect degradation fault, in order to solve the problems in the related art that, due to the lack of analysis of the mechanism, it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process, the obtained full-process fault waveform is quite different from the actual fault development process, and has no application value.

[0006] The first aspect of the present application provides a method for generating a full-process waveform of a cable insulation defect degradation fault, comprising the following steps: establishing a target full-process fault waveform of a cable insulation defect degradation fault; obtaining a breakdown voltage change of the remaining insulation layer excluding the cable insulation defect degradation fault; combining the breakdown voltage change with the target full-process fault waveform, and obtaining the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault.

[0007] Optionally, in one embodiment of the present application, the target full-process fault waveform may include, but is not limited to, at least one of a transient oscillation waveform, a semi-steady-state arc waveform, and a steady-state arc waveform.

[0008] Optionally, in one embodiment of the present application, the combination of the breakdown voltage change and the target full-process fault waveform, and the full-process fault waveform of the cable insulation defect degradation fault are obtained according to the frequency of the cable insulation defect degradation fault, including: judging whether the breakdown voltage change meets the preset uniform degradation condition; if the breakdown voltage change meets the preset uniform degradation condition, based on the transient oscillation waveform, when the frequency meets the preset first condition, switching the transient oscillation waveform to a semi-steady-state arc waveform, so as to obtain a first fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; based on the semi-steady-state arc waveform, when the frequency meets the preset second condition, switching the semi-steady-state arc waveform to the steady-state arc waveform, so as to obtain a second fault waveform based on the semi-steady-state arc waveform and the steady-state arc waveform.

[0009] Optionally, in one embodiment of the present application, the combination of the breakdown voltage change and the target full-process fault waveform, and obtaining the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault, also includes: if the breakdown voltage change does not meet the preset uniform degradation condition, then judging whether the breakdown voltage change meets the preset accelerated degradation condition; if the breakdown voltage change meets the preset accelerated degradation condition, then based on the transient oscillation waveform, when the frequency meets the preset third condition, switching the transient oscillation waveform to the semi-steady-state arc waveform, so as to obtain a third fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; based on the semi-steady-state arc waveform, when the frequency meets the preset fourth condition, switching the semi-steady-state arc waveform to the steady-state arc waveform, so as to obtain a fourth fault waveform with the semi-steady-state arc waveform and the steady-state arc waveform; obtaining the full-process fault waveform of the cable insulation defect degradation fault based on the first fault waveform, the second fault waveform, the third fault waveform and / or the fourth fault waveform.

[0010] Optionally, in one embodiment of the present application, the expression of the transient oscillation waveform may be, but is not limited to,:

[0011]

[0012] Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function.

[0013] The expression of the semi-steady arc waveform may be, but is not limited to,:

[0014]

[0015] Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, N is d is the heat dissipation constant in the arc region, τ D is the arc time constant, and σ0 is the volume conductivity constant of the arc.

[0016] The expression of the steady-state arc waveform may be, but is not limited to,:

[0017]

[0018] Where ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

[0019] The second aspect of the present application provides a device for generating a full-process waveform of a cable insulation defect degradation fault, including: an establishment module for establishing a target full-process fault waveform of a cable insulation defect degradation fault; an acquisition module for acquiring changes in breakdown voltage of the remaining insulation layers other than the cable insulation defect degradation fault; and a generation module for combining the breakdown voltage changes and the target full-process fault waveform to obtain the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault.

[0020] Optionally, in one embodiment of the present application, the target full-process fault waveform may include, but is not limited to, at least one of a transient oscillation waveform, a semi-steady-state arc waveform, and a steady-state arc waveform.

[0021] Optionally, in one embodiment of the present application, the generation module includes: a first judgment unit, used to judge whether the breakdown voltage change meets the preset uniform degradation condition; a first generation unit, used to switch the transient oscillation waveform to a semi-steady-state arc waveform based on the transient oscillation waveform when the breakdown voltage change meets the preset uniform degradation condition, when the frequency meets the preset first condition, so as to obtain a first fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; a second generation unit, used to switch the semi-steady-state arc waveform to the steady-state arc waveform based on the semi-steady-state arc waveform when the frequency meets the preset second condition, so as to obtain a second fault waveform based on the semi-steady-state arc waveform and the steady-state arc waveform.

[0022] Optionally, in one embodiment of the present application, the generation module also includes: a third judgment unit, used to judge whether the breakdown voltage change meets the preset accelerated degradation condition when the breakdown voltage change does not meet the preset uniform degradation condition; a third generation unit, used to switch the transient oscillation waveform to the semi-steady-state arc waveform based on the transient oscillation waveform when the frequency meets the preset third condition, so as to obtain a third fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; a fourth generation unit, used to switch the semi-steady-state arc waveform to the steady-state arc waveform based on the semi-steady-state arc waveform when the frequency meets the preset fourth condition, so as to obtain a fourth fault waveform with the semi-steady-state arc waveform and the steady-state arc waveform; a fifth generation unit, used to obtain the full-process fault waveform of the cable insulation defect degradation fault based on the first fault waveform, the second fault waveform, the third fault waveform and / or the fourth fault waveform.

[0023] Optionally, in one embodiment of the present application, the expression of the transient oscillation waveform may be, but is not limited to,:

[0024]

[0025]

[0026] Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function.

[0027] The expression of the semi-steady arc waveform may be, but is not limited to,:

[0028]

[0029] Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, N is d is the heat dissipation constant in the arc region, τ D is the arc time constant, and σ0 is the volume conductivity constant of the arc.

[0030] The expression of the steady-state arc waveform may be, but is not limited to,:

[0031]

[0032] Where ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

[0033] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the full-process waveform generation method for cable insulation defect degradation fault as described in the above embodiment.

[0034] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned full-process waveform generation method for cable insulation defect degradation fault.

[0035] The fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, implements the full-process waveform generation method for cable insulation defect degradation fault as described above.

[0036] The embodiment of the present application can calculate the switching time of different fault stages through the target full-process fault waveform of the cable insulation defect degradation fault and the change of the breakdown voltage of the remaining insulation layer, and then generate the full-process fault waveform. The embodiment of the present application proposes a fault modeling method that finely depicts the entire development process of the cable local insulation defect degradation fault based on mechanism analysis, which provides a theoretical basis for the research on cable fault warning and identification, and has positive significance for reducing the risk of distribution network accidents and reducing line hidden dangers. Therefore, it solves the problems in the related technology that due to the lack of analysis of the mechanism, it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process, and the obtained full-process fault waveform is quite different from the actual fault development process and has no application value.

[0037] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0039] Figure 1 A flowchart of a method for generating a full-process waveform of a cable insulation defect degradation fault provided according to an embodiment of the present application;

[0040] Figure 2 A block diagram of a full-process fault waveform provided according to an embodiment of the present application;

[0041] Figure 3 A flowchart of the working principle of a method for generating a full-process waveform of a cable insulation defect degradation fault provided according to an embodiment of the present application;

[0042] Figure 4 It is a block diagram of a device for generating a waveform of a whole process of a cable insulation defect degradation fault according to an embodiment of the present application;

[0043] Figure 5 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0045] The following describes the full-process waveform generation method and device of the cable insulation defect degradation fault of the embodiment of the present application with reference to the accompanying drawings. In view of the problem mentioned in the above background technology that it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process due to the lack of analysis of the mechanism, the obtained full-process fault waveform is greatly different from the actual fault development process, and has no application value, the present application provides a full-process waveform generation method for cable insulation defect degradation fault, in which the switching time of different fault stages can be calculated by the target full-process fault waveform of the cable insulation defect degradation fault and the breakdown voltage change of the remaining insulation layer, and then the full-process fault waveform is generated. The embodiment of the present application proposes a fault modeling method for finely depicting the entire development process of the cable local insulation defect degradation fault based on the mechanism analysis, which provides a theoretical basis for the research on cable fault warning and identification, and has positive significance for reducing the risk of distribution network accidents and reducing line hidden dangers. Therefore, it solves the problems in the related technology that it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process due to the lack of analysis of the mechanism, and the obtained full-process fault waveform is greatly different from the actual fault development process, and has no application value.

[0046] Specifically, Figure 1 The present invention is a flowchart of a method for generating a full-process waveform of a cable insulation defect degradation fault provided according to an embodiment of the present application.

[0047] like Figure 1 As shown, the whole process waveform generation method of the cable insulation defect degradation fault includes the following steps:

[0048] In step S101, a target full-process fault waveform of a cable insulation defect degradation fault is established, wherein the target full-process fault waveform may include but is not limited to at least one of a transient oscillation waveform, a semi-steady-state arc waveform and a steady-state arc waveform.

[0049] As a possible implementation method, the embodiment of the present application can establish a target full-process fault waveform for a cable insulation defect degradation fault. The target full-process fault waveform may include but is not limited to a transient oscillation waveform, a semi-steady-state arc waveform, and a steady-state arc waveform, etc. The present application does not impose any specific restrictions.

[0050] Optionally, in one embodiment of the present application, the expression of the transient oscillation waveform may be, but is not limited to,:

[0051]

[0052] Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function.

[0053] The expression of the semi-steady arc waveform can be, but is not limited to:

[0054]

[0055] Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, N is d is the heat dissipation constant in the arc region, τ D is the arc time constant, and σ0 is the volume conductivity constant of the arc.

[0056] The expression of the steady-state arc waveform can be, but is not limited to:

[0057]

[0058] Where ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

[0059] In some embodiments, the transient oscillation waveform of the embodiment of the present application can be characterized by a normal pulse function, which can be but is not limited to:

[0060]

[0061] Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function.

[0062] Further, in the embodiment of the present application, the rectangular window function W(n) is composed of a step function θ(t), wherein the expression of the rectangular window function may be, but is not limited to,:

[0063] W(n)=θ[t0(n)+3σ]-θ[t0(n)-3σ],

[0064] In some embodiments, the semi-steady arc waveform of the embodiment of the present application can be represented by a combined model, which can be but is not limited to:

[0065]

[0066] Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, and constant N is d is the heat dissipation constant in the arc region, τ D is the arc time constant, and σ0 is the volume conductivity constant of the arc.

[0067] In some embodiments, the steady-state arc waveform of the present application embodiment can be characterized by an arc gap energy balance equation, which can be but is not limited to:

[0068]

[0069] Where ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

[0070] Further, in the embodiment of the present application, the expression of the steady-state breakdown arc waveform appearance time may be, but is not limited to,:

[0071]

[0072] Among them, U g is the breakdown voltage of the local insulation defect region, U b is the breakdown voltage of the remaining insulation layer.

[0073] In step S102, the breakdown voltage change of the remaining insulation layer except the cable insulation defect degradation fault is obtained.

[0074] It can be understood that the degree of decrease in the breakdown voltage of the remaining insulating layer in the embodiment of the present application can represent the degree of progress of the insulation defect degradation process. For example, according to different operation scenarios, the insulation defect degradation process in the embodiment of the present application has a variety of change rules, namely uniform degradation, accelerated degradation, etc. The corresponding breakdown voltage decrease rules of the remaining insulating layer can be expressed by U b (t) indicates.

[0075] In the embodiment of the present application, during the uniform degradation process, the uniform degradation U b (t) Take a linear function, which can be expressed as but not limited to:

[0076] U b (t) = U0-kt,

[0077] Wherein, U0 is the initial breakdown voltage and k is the breakdown voltage drop coefficient.

[0078] In the embodiment of the present application, during the accelerated degradation process, the accelerated degradation U b (t) takes an exponential function, which can be expressed as, but not limited to:

[0079]

[0080] Among them, U r is the residual voltage constant, t B , q is a constant related to the material.

[0081] As a possible implementation method, the embodiment of the present application can obtain the breakdown voltage change of the remaining insulation layer except for the cable insulation defect degradation fault, that is, calculate the breakdown voltage change of the remaining insulation layer.

[0082] For example, the embodiment of the present application can obtain the breakdown voltage change of the remaining insulating layer as shown in Table 1, wherein Table 1 is a breakdown voltage calculation table provided according to an embodiment of the present application.

[0083] Table 1

[0084]

[0085]

[0086] In step S103, the full-process fault waveform of the cable insulation defect degradation fault is obtained according to the frequency of the cable insulation defect degradation fault in combination with the breakdown voltage change and the target full-process fault waveform.

[0087] As a possible implementation method, the embodiment of the present application can calculate the switching moments of different fault stages according to the breakdown voltage change and the target full-process fault waveform to generate a full-process fault waveform.

[0088] For example, the whole process fault waveform generated by the embodiment of the present application is as follows: Figure 2 As shown, the switching time is n b1 =1.8s, n b2 =3.1s.

[0089] Optionally, in one embodiment of the present application, in combination with the breakdown voltage change and the target full-process fault waveform, the full-process fault waveform of the cable insulation defect degradation fault is obtained according to the frequency of the cable insulation defect degradation fault, including: judging whether the breakdown voltage change meets the preset uniform degradation condition; if the breakdown voltage change meets the preset uniform degradation condition, based on the transient oscillation waveform, when the frequency meets the preset first condition, switching the transient oscillation waveform to a semi-steady-state arc waveform, so as to obtain a first fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; based on the semi-steady-state arc waveform, when the frequency meets the preset second condition, switching the semi-steady-state arc waveform to a steady-state arc waveform, so as to obtain a second fault waveform based on the semi-steady-state arc waveform and the steady-state arc waveform.

[0090] In some embodiments, the embodiments of the present application assume that the cable insulation defect degradation fault starts from a transient oscillation waveform, and the breakdown voltage change satisfies a certain uniform degradation condition, wherein the certain uniform degradation condition can be set by a technician in this field according to actual conditions, and the present application does not impose any specific restrictions.

[0091] Furthermore, when the frequency satisfies a certain first condition, the transient oscillation waveform is switched to a semi-stable arc waveform. The certain first condition can be set by a person skilled in the art according to actual conditions, and this application does not impose any specific limitation.

[0092] For example, when the frequency n b When a certain first condition is met, the transient oscillation waveform is switched to a semi-stable arc waveform. The certain first condition may be, but is not limited to, expressed as:

[0093] k·U i =U b (n b T0),

[0094] Where k is the external voltage U i The voltage division coefficient to the insulation layer, T0 is the power system power frequency period.

[0095] At this time, n b Denoted as n b1 .

[0096] Furthermore, when the frequency satisfies a certain second condition, the semi-steady-state arc waveform is switched to a steady-state arc waveform.

[0097] For example, when the frequency n b When a certain second condition is met, the semi-steady-state arc waveform is switched to a steady-state arc waveform. The certain second condition may be, but is not limited to, expressed as:

[0098] U g=U b (n b T0),

[0099] At this time, n b Denoted as n b2 .

[0100] Optionally, in one embodiment of the present application, in combination with the breakdown voltage change and the target full-process fault waveform, the full-process fault waveform of the cable insulation defect degradation fault is obtained according to the frequency of the cable insulation defect degradation fault, and also includes: if the breakdown voltage change does not meet the preset uniform degradation condition, then determine whether the breakdown voltage change meets the preset accelerated degradation condition; if the breakdown voltage change meets the preset accelerated degradation condition, then based on the transient oscillation waveform, when the frequency meets the preset third condition, the transient oscillation waveform is switched to a semi-steady-state arc waveform, so as to obtain a third fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform; based on the semi-steady-state arc waveform, when the frequency meets the preset fourth condition, the semi-steady-state arc waveform is switched to a steady-state arc waveform, so as to obtain a fourth fault waveform with the semi-steady-state arc waveform and the steady-state arc waveform; based on the first fault waveform, the second fault waveform, the third fault waveform and / or the fourth fault waveform, the full-process fault waveform of the cable insulation defect degradation fault is obtained.

[0101] In some embodiments, the embodiments of the present application assume that the cable insulation defect degradation failure starts from a transient oscillation waveform, and the breakdown voltage change satisfies certain accelerated degradation conditions, wherein the certain accelerated degradation conditions can be set by technicians in this field according to actual conditions, and this application does not impose specific restrictions.

[0102] Furthermore, when the frequency satisfies a certain third condition, the transient oscillation waveform is switched to a semi-stable arc waveform. The certain third condition can be set by a person skilled in the art according to actual conditions, and this application does not impose any specific limitation.

[0103] For example, when the frequency n b When a certain third condition is met, the transient oscillation waveform is switched to a semi-steady-state arc waveform.

[0104] Among them, the third condition can be expressed as but not limited to:

[0105]

[0106] At this time, n b Denoted as n b1 .

[0107] Furthermore, when the frequency satisfies a certain fourth condition, the semi-steady-state arc waveform is switched to a steady-state arc waveform.

[0108] For example, when the frequency n b When a certain fourth condition is met, the semi-steady-state arc waveform is switched to a steady-state arc waveform.

[0109] Among them, the fourth condition can be expressed as but not limited to:

[0110]

[0111] At this time, n b Denoted as n b2 .

[0112] The working principle of the full-process waveform generation method for cable insulation defect degradation fault proposed in the embodiment of the present application is introduced in detail below in conjunction with a specific embodiment.

[0113] in, Figure 3 The present invention is a flowchart of the working principle of a method for generating a full-process waveform of a cable insulation defect degradation fault provided according to an embodiment of the present application.

[0114] Step S301: Establish a transient oscillation model.

[0115] It can be understood that the embodiment of the present application can obtain the expression of the transient oscillation waveform as shown above.

[0116] Step S302: Establish a steady-state arc model.

[0117] It can be understood that the embodiment of the present application can obtain the expression of the semi-steady-state arc waveform as shown above.

[0118] Step S303: Establish a semi-steady-state arc model.

[0119] It can be understood that the embodiment of the present application can obtain the expression of the steady-state arc waveform as shown above.

[0120] Step S304: calculating the insulation layer breakdown voltage.

[0121] It can be understood that the embodiment of the present application can obtain the breakdown voltage variation of the remaining insulating layer as shown in Table 1.

[0122] Step S305: Calculate the waveform switching time.

[0123] It can be understood that the embodiment of the present application can assume that the cable insulation defect degradation fault starts from a transient oscillation waveform. When the breakdown voltage change meets a certain uniform degradation condition, if the frequency n b When the first condition is met, the transient oscillation waveform is switched to a semi-stable arc waveform fault; when the breakdown voltage change meets certain accelerated degradation conditions, if the frequency n bIf the third condition is met, the transient oscillation waveform is switched to a semi-stable arc waveform fault. The first condition and the third condition can be as shown above, and can be set by technicians in this field according to the situation, and this application does not impose any specific restrictions. At this time, n b Denoted as n b1 .

[0124] When the breakdown voltage changes to meet a certain uniform degradation condition, if the frequency n b When a certain second condition is met, the semi-steady-state arc waveform is switched to a steady-state arc waveform; when the breakdown voltage change meets a certain accelerated degradation condition, if the frequency n b If the fourth condition is met, the semi-steady-state arc waveform is switched to a steady-state arc waveform. The second condition and the fourth condition can be as shown above, and can be set by a person skilled in the art according to the situation, and this application does not impose any specific restrictions. At this time, n b Denoted as n b2 .

[0125] Furthermore, the switching time obtained in the embodiment of the present application is n b1 =1.8s, n b2 =3.1s.

[0126] Step S306: Generate the whole process waveform.

[0127] It can be understood that the embodiment of the present application can generate Figure 2 The whole process fault waveform is shown.

[0128] According to the full-process waveform generation method of the cable insulation defect degradation fault proposed in the embodiment of the present application, the switching time of different fault stages can be calculated through the target full-process fault waveform of the cable insulation defect degradation fault and the breakdown voltage change of the remaining insulation layer, and then the full-process fault waveform is generated. The embodiment of the present application proposes a fault modeling method that finely depicts the entire development process of the cable local insulation defect degradation fault based on mechanism analysis, which provides a theoretical basis for the research on cable fault warning and identification, and has positive significance for reducing the risk of distribution network accidents and reducing line hidden dangers. Therefore, the problem in the related technology that it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process due to the lack of analysis of the mechanism, and the obtained full-process fault waveform is quite different from the actual fault development process and has no application value is solved.

[0129] Next, a full-process waveform generating device for a cable insulation defect degradation fault proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0130] Figure 4 It is a block diagram of a full-process waveform generation device for a cable insulation defect degradation fault provided according to an embodiment of the present application.

[0131] like Figure 4 As shown, the whole process waveform generating device 10 of the cable insulation defect degradation fault includes: an establishing module 100, an acquiring module 200 and a generating module 300.

[0132] The module 100 is established to establish a target full-process fault waveform of a cable insulation defect degradation fault.

[0133] The acquisition module 200 is used to obtain the breakdown voltage change of the remaining insulation layer except for the cable insulation defect degradation fault.

[0134] The generating module 300 is used to obtain the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault by combining the breakdown voltage change and the target full-process fault waveform.

[0135] Optionally, in one embodiment of the present application, the target full-process fault waveform may include, but is not limited to, at least one of a transient oscillation waveform, a semi-steady-state arc waveform, and a steady-state arc waveform.

[0136] Optionally, in one embodiment of the present application, the generation module 300 includes: a first judgment unit, a first generation unit and a second generation unit.

[0137] The first judgment unit is used to judge whether the change of the breakdown voltage meets the preset uniform degradation condition.

[0138] The first generating unit is used for switching the transient oscillation waveform to a semi-steady-state arc waveform based on the transient oscillation waveform when the breakdown voltage change meets the preset uniform degradation condition and when the frequency meets the preset first condition, so as to obtain a first fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform.

[0139] The second generating unit is used to switch the semi-steady-state arc waveform to a steady-state arc waveform based on the semi-steady-state arc waveform when the frequency meets a preset second condition, so as to obtain a second fault waveform based on the semi-steady-state arc waveform and the steady-state arc waveform.

[0140] Optionally, in one embodiment of the present application, the generation module 300 further includes: a third judgment unit, a third generation unit, a fourth generation unit and a fifth generation unit.

[0141] The third judgment unit is used to judge whether the breakdown voltage change condition meets the preset accelerated degradation condition when the breakdown voltage change condition does not meet the preset uniform degradation condition.

[0142] The third generating unit is used for switching the transient oscillation waveform to a semi-steady-state arc waveform based on the transient oscillation waveform when the breakdown voltage change meets the preset accelerated degradation condition and when the frequency meets the preset third condition, so as to obtain a third fault waveform based on the transient oscillation waveform and the semi-steady-state arc waveform.

[0143] The fourth generating unit is used to switch the semi-steady-state arc waveform to a steady-state arc waveform based on the semi-steady-state arc waveform when the frequency meets the preset fourth condition, and obtain a fourth fault waveform with the semi-steady-state arc waveform and the steady-state arc waveform.

[0144] The fifth generating unit is used to obtain a full-process fault waveform of the cable insulation defect degradation fault based on the first fault waveform, the second fault waveform, the third fault waveform and / or the fourth fault waveform.

[0145] Optionally, in one embodiment of the present application, the expression of the transient oscillation waveform may be, but is not limited to,:

[0146]

[0147] Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function.

[0148] The expression of the semi-steady arc waveform can be, but is not limited to:

[0149]

[0150] Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, N is d is the heat dissipation constant in the arc region, τ D is the arc time constant, and σ0 is the volume conductivity constant of the arc.

[0151] The expression of the steady-state arc waveform can be, but is not limited to:

[0152]

[0153] Where ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

[0154] It should be noted that the above explanation of the embodiment of the method for generating a full-process waveform for a cable insulation defect degradation fault is also applicable to the device for generating a full-process waveform for a cable insulation defect degradation fault of this embodiment, and will not be repeated here.

[0155] According to the full-process waveform generation device for cable insulation defect degradation fault proposed in the embodiment of the present application, the switching time of different fault stages can be calculated through the target full-process fault waveform of the cable insulation defect degradation fault and the change of the breakdown voltage of the remaining insulation layer, and then the full-process fault waveform is generated. The embodiment of the present application proposes a fault modeling method that finely depicts the entire development process of the cable local insulation defect degradation fault based on mechanism analysis, which provides a theoretical basis for the research on cable fault warning and identification, and has positive significance for reducing the risk of distribution network accidents and reducing line hidden dangers. Therefore, the problem in the related technology that due to the lack of analysis of the mechanism, it is difficult to determine the boundaries of different stages of the cable local insulation defect degradation process, and the obtained full-process fault waveform is quite different from the actual fault development process and has no application value is solved.

[0156] Figure 5 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. The electronic device may include:

[0157] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0158] When the processor 502 executes the program, the full-process waveform generation method for the cable insulation defect degradation fault provided in the above embodiment is implemented.

[0159] Furthermore, the electronic device further comprises:

[0160] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0161] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0162] The memory 501 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0163] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0164] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0165] The processor 502 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0166] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for generating a full-process waveform of a cable insulation defect degradation fault.

[0167] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed, implements the above-mentioned full-process waveform generation method for cable insulation defect degradation fault.

[0168] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0169] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0170] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0171] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0172] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0173] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0174] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0175] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for generating a full-process waveform of a cable insulation defect degradation fault, characterized in that: The following steps are involved: Establish the target full-process fault waveform of cable insulation defect degradation fault; Obtaining the breakdown voltage change of the remaining insulation layer except for the cable insulation defect degradation fault; In combination with the breakdown voltage change and the target full-process fault waveform, the full-process fault waveform of the cable insulation defect degradation fault is obtained according to the frequency of the cable insulation defect degradation fault.

2. The method for generating the full-process waveform of a cable insulation defect degradation fault according to claim 1, characterized in that: The target full-process fault waveform includes at least one of a transient oscillation waveform, a semi-steady-state arc waveform and a steady-state arc waveform.

3. The method for generating the full-process waveform of a cable insulation defect degradation fault according to claim 2, characterized in that: The method of combining the breakdown voltage change and the target full-process fault waveform and obtaining the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault comprises: Determining whether the breakdown voltage change satisfies a preset uniform degradation condition; If the breakdown voltage change meets the preset uniform degradation condition, based on the transient oscillation waveform, when the frequency meets the preset first condition, the transient oscillation waveform is switched to a semi-stable arc waveform, so as to obtain a first fault waveform based on the transient oscillation waveform and the semi-stable arc waveform; Based on the semi-steady-state arc waveform, when the frequency satisfies a preset second condition, the semi-steady-state arc waveform is switched to the steady-state arc waveform to obtain a second fault waveform based on the semi-steady-state arc waveform and the steady-state arc waveform.

4. The method for generating the full-process waveform of a cable insulation defect degradation fault according to claim 3 is characterized in that: The method of combining the breakdown voltage change and the target full-process fault waveform and obtaining the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault also includes: If the breakdown voltage change does not satisfy the preset uniform degradation condition, determining whether the breakdown voltage change satisfies the preset accelerated degradation condition; If the breakdown voltage change meets the preset accelerated degradation condition, based on the transient oscillation waveform, when the frequency meets the preset third condition, the transient oscillation waveform is switched to the semi-stable arc waveform, so as to obtain a third fault waveform based on the transient oscillation waveform and the semi-stable arc waveform; Based on the semi-steady-state arc waveform, when the frequency number meets a preset fourth condition, the semi-steady-state arc waveform is switched to the steady-state arc waveform, and a fourth fault waveform is obtained by using the semi-steady-state arc waveform and the steady-state arc waveform; The full-process fault waveform of the cable insulation defect degradation fault is obtained based on the first fault waveform, the second fault waveform, the third fault waveform and / or the fourth fault waveform.

5. The method for generating the full-process waveform of a cable insulation defect degradation fault according to claim 2, characterized in that: in, The expression of the transient oscillation waveform is: Where σ is the standard deviation, t0 is the time delay, W(n) is the rectangular window function, G(t) is the normal distribution fitting function, and G0 is used to control the oscillation amplitude of the G(t) normal distribution function. The expression of the semi-steady arc waveform is: Among them, variables u and i are arc voltage and current, g is arc conductance, D is arc channel diameter, N is f is the heat dissipation constant in the arc region, τ F is the arc time constant, and σ0 is the volume conductivity constant of the arc. The expression of the steady-state arc waveform is: Where, ω is the angular frequency of the power system operation, U i is the input voltage, t g is the moment when the transient oscillation waveform appears, t b The moment when the steady-state breakdown arc waveform appears.

6. A full-process waveform generation device for cable insulation defect degradation fault, characterized in that: include: Establishing a module for establishing a target full-process fault waveform of a cable insulation defect degradation fault; An acquisition module, used to acquire the breakdown voltage change of the remaining insulation layer except for the cable insulation defect degradation fault; A generating module is used to combine the breakdown voltage change and the target full-process fault waveform, and obtain the full-process fault waveform of the cable insulation defect degradation fault according to the frequency of the cable insulation defect degradation fault.

7. The whole process waveform generating device of cable insulation defect degradation fault according to claim 6 is characterized in that: The target full-process fault waveform includes at least one of a transient oscillation waveform, a semi-steady-state arc waveform and a steady-state arc waveform.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the full-process waveform generation method for cable insulation defect degradation fault as described in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the full-process waveform generation method for cable insulation defect degradation fault as described in any one of claims 1-5.

10. A computer program product, characterized in that It comprises a computer program, which, when executed, is used to implement the full-process waveform generation method for cable insulation defect degradation fault as described in any one of claims 1-5.

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