Insulation interface breakdown voltage evaluation method and device, terminal equipment and storage medium

Abstract

The invention discloses an insulation interface breakdown voltage evaluation method and device, terminal equipment and a storage medium. The method comprises the following steps: acquiring a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of an insulation interface; determining an insulation interface coefficient for representing an insulation interface state; according to the insulation interface coefficient, correcting a preset Barchen formula or a derivation formula of the Barchen formula to obtain a corrected formula; and calculating the breakdown voltage of the insulation interface based on the corrected formula. According to the method, the Barchen formula is corrected, an important reference is provided for expanding the universality of solid-gas-solid composite insulation interface discharge for a classical gas discharge theory system, and the accuracy of insulation interface breakdown voltage calculation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of insulation detection, and in particular to a method, a device, a terminal device and a storage medium for calculating insulation interface breakdown electrical rating. Background Art

[0002] Power cable accessories include cable intermediate joints and cable terminals, which are key components for connecting power transmission and distribution lines and related distribution equipment. At present, faults caused by discharge at the cross-linked polyethylene (XLPE)-silicone rubber (SiR) insulation interface of cable accessories in my country occur frequently, and the explosion and combustion accidents caused by them are extremely dangerous. For the analysis of insulation interface discharge, the classical gas discharge theory is currently used for qualitative explanation, such as Baschen's law, Thomson theory and streamer theory. However, due to the complex and difficult to quantify structure of the "solid-gas-solid" insulation interface, and unlike air discharge, the XLPE-SiR interface insulation does not have insulation recovery. During long-term discharge, the state evolution of the interface insulation directly affects the characteristics of the XLPE-SiR insulation interface discharge. Therefore, the method of directly applying the classical gas discharge theory has limitations. For the Baschen law in the classical gas discharge theory, it is clearly revealed that the breakdown voltage (U b ) and the product of pressure (p) and electrode spacing (d), namely, the Baschen formula U b =f(pd). The Paschen law can reflect the discharge law of the XLPE-SiR insulation interface to a certain extent, but this relationship lacks consideration of the changes in the state of the XLPE-SiR insulation interface. Summary of the invention

[0003] The present invention provides an insulation interface breakdown voltage evaluation method, device, terminal equipment and storage medium to solve the technical problem that the Paschen formula lacks consideration of insulation interface state changes.

[0004] In order to solve the above technical problems, an embodiment of the present invention provides a method for evaluating the breakdown voltage of an insulating interface, comprising:

[0005] Obtaining a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of an insulating interface;

[0006] Determine a first insulating interface coefficient or a second insulating interface coefficient for characterizing an insulating interface state according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulating interface coefficient is generated by data fitting with the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; and the second insulating interface coefficient is generated by data fitting with the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance;

[0007] When the first insulating interface coefficient is determined according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, a preset Paschen formula is corrected according to the first insulating interface coefficient to obtain a corrected Paschen formula; based on the corrected Paschen formula and the first electrode spacing-pressure parameter, a breakdown voltage of the insulating interface is determined;

[0008] When the second insulating interface coefficient is determined based on the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance is obtained according to the preset Paschen formula; the derivation formula is corrected according to the second insulating interface coefficient to obtain a corrected derivation formula; based on the corrected derivation formula and the first breakdown equivalent resistance, the breakdown voltage of the insulating interface is determined.

[0009] As a preferred solution, the determining of the first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance includes:

[0010] Obtaining first experimental results of several first discharge experiments; wherein, in the first discharge experiment, an insulating interface and air are used as discharge interface materials to set a control group, the first breakdown equivalent resistance is used as a constant, and the electrode spacing-pressure parameter is used as a variable, and several experiments are set according to each preset second electrode spacing-pressure parameter to test the breakdown voltage of the two discharge interface materials under different second electrode spacing-pressure parameter conditions; the first experimental results include: a first insulating interface breakdown voltage and a first air breakdown voltage;

[0011] For each of the second electrode spacing-pressure parameters, according to the corresponding experimental results, the ratio of the first insulating interface breakdown voltage to the first air breakdown voltage under the second electrode spacing-pressure parameter condition is calculated as the first breakdown voltage ratio corresponding to the second electrode spacing-pressure parameter;

[0012] According to the first breakdown voltage ratios corresponding to different second electrode spacing-pressure parameters, a functional relationship between the second electrode spacing-pressure parameter and the first breakdown voltage ratio is determined by a mathematical statistical fitting method as a calculation formula for the first insulating interface coefficient;

[0013] The first insulation interface coefficient is calculated according to the first insulation interface coefficient calculation formula and the first electrode spacing-pressure parameter.

[0014] As a preferred solution, the determining of the second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance includes:

[0015] Obtaining the second experimental results of several second discharge experiments; wherein, in the second discharge experiment, the insulating interface and air are used as the discharge interface materials to set a control group, the first electrode spacing-pressure parameter is used as a constant, the breakdown equivalent resistance is used as a variable, and several experiments are set according to each preset second breakdown equivalent resistance to test the breakdown voltages of the two discharge interface materials under different second breakdown equivalent resistance conditions; the second experimental results include: the second insulating interface breakdown voltage and the second air breakdown voltage;

[0016] For each of the second breakdown equivalent resistances, according to the corresponding experimental results, calculating the ratio of the second insulating interface breakdown voltage to the second air breakdown voltage under the second breakdown equivalent resistance condition as the second breakdown voltage ratio corresponding to the second breakdown equivalent resistance;

[0017] According to the second breakdown voltage ratios corresponding to different second breakdown equivalent resistances, and by means of a mathematical statistical fitting method, a functional relationship between the second breakdown equivalent resistance and the second breakdown voltage ratio is determined as a calculation formula for the second insulation interface coefficient;

[0018] The second insulation interface coefficient is calculated according to the second insulation interface coefficient calculation formula and the first breakdown equivalent resistance.

[0019] As a preferred solution, the preset Bashen formula is:

[0020] U b =f(pd);

[0021] Where pd represents the electrode spacing-pressure parameter; U b represents the breakdown voltage of air calculated according to the Paschen formula;

[0022] The calculation formula of the first insulation interface coefficient is:

[0023] α pd =q(pd);

[0024] In the formula, αpd It represents the first insulation interface coefficient when the electrode spacing-pressure parameter is pd under specific breakdown equivalent resistance conditions;

[0025] The modified Bashen formula is:

[0026] U p d(pd)=α pd f(pd);

[0027] Where U pd (pd) represents the breakdown voltage of the insulating interface under specific breakdown equivalent resistance conditions when the electrode spacing-pressure parameter is pd.

[0028] As a preferred solution, the derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance obtained according to the preset Baschen formula includes:

[0029] Acquire experimental data of several groups of air discharge experiments; wherein the experimental data include: air breakdown equivalent resistance and air electrode spacing-pressure parameters;

[0030] According to the air electrode spacing-pressure parameters of each set of experimental data, the corresponding air breakdown voltage is calculated according to the Paschen formula;

[0031] According to the air breakdown equivalent resistance and the corresponding air breakdown voltage of each set of experimental data, a functional relationship between the air breakdown voltage and the discharge breakdown equivalent resistance is determined according to a mathematical method as the derivation formula.

[0032] As a preferred solution, the derivation formula is:

[0033] U b ′ = h(R);

[0034] Where, R represents the breakdown equivalent resistance; U b ′ represents the breakdown voltage of air calculated according to the derived formula;

[0035] The calculation formula of the second insulation interface coefficient is:

[0036] α R = g(R);

[0037] In the formula, α pd It indicates the second insulation interface coefficient when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions;

[0038] The modified derivation formula is:

[0039] U R (R) = α R h(R);

[0040] Where U R (R) represents the breakdown voltage of the insulating interface when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions.

[0041] Based on the above embodiment, another embodiment of the present invention provides an insulation interface breakdown voltage evaluation device, including: a data acquisition module, an insulation coefficient determination module and a breakdown voltage calculation module;

[0042] The data acquisition module is used to acquire a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of the insulating interface;

[0043] The insulation coefficient determination module is used to determine a first insulation interface coefficient or a second insulation interface coefficient for characterizing an insulation interface state according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulation interface coefficient is generated by fitting data with the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; the second insulation interface coefficient is generated by fitting data with the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance;

[0044] The breakdown voltage calculation module is used to correct a preset Paschen formula according to the first insulation interface coefficient to obtain a corrected Paschen formula when determining a first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; determine the breakdown voltage of the insulation interface based on the corrected Paschen formula and the first electrode spacing-pressure parameter; when determining a second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, obtain a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance according to the preset Paschen formula; correct the derivation formula according to the second insulation interface coefficient to obtain a corrected derivation formula; and determine the breakdown voltage of the insulation interface based on the corrected derivation formula and the first breakdown equivalent resistance.

[0045] Based on the above embodiments, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the insulation interface breakdown voltage evaluation method described in the above invention embodiment is implemented.

[0046] Based on the above embodiments, another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the insulation interface breakdown voltage evaluation method described in the above invention embodiment.

[0047] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0048] The present invention obtains the first electrode spacing-pressure parameter and the first breakdown equivalent resistance of the insulating interface; determines the insulating interface coefficient used to characterize the state of the insulating interface; modifies the preset Paschen formula or the derived formula of the Paschen formula according to the insulating interface coefficient to obtain the modified formula; and calculates the breakdown voltage of the insulating interface based on the modified formula. The present invention considers the influence of the insulating interface state and its evolution on pure gas discharge, modifies the Paschen formula, provides an important reference for the expansion of the universality of the "solid-gas-solid" composite insulating interface discharge in the classical gas discharge theory system, and improves the accuracy of the calculation of the insulating interface breakdown voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of a method for evaluating the breakdown voltage of an insulating interface provided by one embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of a parallel plate air gap discharge sample provided by an embodiment of the present invention;

[0051] Figure 3 It is a schematic diagram of a parallel-plate XLPE-SiR insulating interface sample provided by one embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of an XLPE-SiR insulation interface discharge experimental platform provided by one embodiment of the present invention;

[0053] Figure 5 It is a structural schematic diagram of an insulation interface breakdown voltage evaluation device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Embodiment 1

[0056] Please refer to Figure 1, a method for evaluating the breakdown voltage of an insulating interface provided by an embodiment of the present invention, comprising:

[0057] S1. Obtaining a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of an insulating interface.

[0058] It should be noted that the insulating interface refers to the XLPE-SiR insulating interface.

[0059] S2. Determine a first insulating interface coefficient or a second insulating interface coefficient for characterizing an insulating interface state based on the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulating interface coefficient is generated by fitting data using the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; and the second insulating interface coefficient is generated by fitting data using the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance.

[0060] S31. When the first insulating interface coefficient is determined according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, the preset Paschen formula is corrected according to the first insulating interface coefficient to obtain a corrected Paschen formula; based on the corrected Paschen formula and the first electrode spacing-pressure parameter, the breakdown voltage of the insulating interface is determined.

[0061] In a preferred embodiment, determining the first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance includes:

[0062] Obtaining first experimental results of several first discharge experiments; wherein, in the first discharge experiment, an insulating interface and air are used as discharge interface materials to set a control group, the first breakdown equivalent resistance is used as a constant, and the electrode spacing-pressure parameter is used as a variable, and several experiments are set according to each preset second electrode spacing-pressure parameter to test the breakdown voltage of the two discharge interface materials under different second electrode spacing-pressure parameter conditions; the first experimental results include: a first insulating interface breakdown voltage and a first air breakdown voltage;

[0063] For each of the second electrode spacing-pressure parameters, according to the corresponding experimental results, the ratio of the first insulating interface breakdown voltage to the first air breakdown voltage under the second electrode spacing-pressure parameter condition is calculated as the first breakdown voltage ratio corresponding to the second electrode spacing-pressure parameter;

[0064] According to the first breakdown voltage ratios corresponding to different second electrode spacing-pressure parameters, a functional relationship between the second electrode spacing-pressure parameter and the first breakdown voltage ratio is determined by a mathematical statistical fitting method as a calculation formula for the first insulating interface coefficient;

[0065] The first insulation interface coefficient is calculated according to the first insulation interface coefficient calculation formula and the first electrode spacing-pressure parameter.

[0066] In a preferred embodiment, the preset Paschen formula is:

[0067] U b =f(pd);

[0068] Where pd represents the electrode spacing-pressure parameter; U b represents the breakdown voltage of air calculated according to the Paschen formula;

[0069] The calculation formula of the first insulation interface coefficient is:

[0070] α pd =q(pd);

[0071] In the formula, α pd It represents the first insulation interface coefficient when the electrode spacing-pressure parameter is pd under specific breakdown equivalent resistance conditions;

[0072] The modified Bashen formula is:

[0073] U p d(pd)=α pd f(pd);

[0074] Where U pd (pd) represents the breakdown voltage of the insulating interface under specific breakdown equivalent resistance conditions when the electrode spacing-pressure parameter is pd.

[0075] In this embodiment, in order to determine the difference between pure gas (air) discharge and XLPE-SiR insulating interface discharge, the present invention carried out a pure gas and XLPE-SiR insulating interface discharge comparison experiment under the same system. The specific technical scheme is as follows:

[0076] 1. Experimental sample preparation: Preparation of parallel plate air gap discharge sample C air Parallel plate XLPE-SiR insulation interface sample C X-S ,like Figure 2 and Figure 3 As shown. air and sample C X-S The electrode spacing d and pressure p are set to be consistent. airThe pressure can be increased by injecting air into the sealed box through the air injection pipe through the air pump, so that the internal pressure of the sealed box reaches the target value; Sample C X-S The pressure can be set by adjusting the spring in combination with the rigid plexiglass pressure plate and calculating the target pressure value according to Hooke's law.

[0077] 2. DC discharge breakdown experiment setup: Build a DC discharge breakdown experiment platform to ensure that the temperature T is consistent with the sample C air and sample C X-S Conduct DC discharge breakdown experiments, such as Figure 4 A dual-port oscilloscope and a capacitive voltage divider are used to obtain the voltage value in the loop, wherein port 1 measures the voltage value u1 on the capacitive voltage divider 1 at the power supply side, and port 2 measures the voltage value u2 on the capacitive voltage divider 2 at the r side.

[0078] 3. Obtaining the parameters of the DC discharge breakdown test results: Based on the experimental parameters obtained from the DC discharge breakdown test platform, the current value i at the time of discharge breakdown and the sample voltage u at the time of discharge breakdown can be obtained by the following formula C , and finally the discharge breakdown equivalent resistance R is obtained;

[0079] i=u2 / r;

[0080] u C =u1-u2;

[0081] R=u C / i.

[0082] 4. Determination of XLPE-SiR insulation interface coefficient under specific XLPE-SiR insulation interface state: Through the above experimental method, adjust the sample C air The pd value can be calculated based on the Baschen formula U b =f(pd) to obtain the breakdown voltage of pure gas. Similarly, the specific XLPE-SiR insulating interface state sample C is adjusted in the same way. X-S The pd value can be used to obtain the insulation interface discharge breakdown voltage U of n different pd values. bx (x=1~n). Introducing the insulation interface coefficient α under the xth pd value x (x=1~n), there is the following relationship:

[0083] U bx =α x f(pd);

[0084] Obtain a large amount of α through experiments x The function relationship about pd is obtained by statistical fitting of the data:

[0085] α pd =q(pd).

[0086] Finally, the pd-discharge quantitative correlation formula under the specific XLPE-SiR insulating interface state was constructed, and the following formula was obtained:

[0087] U p d(pd)=α pd f(pd);

[0088] 5. Based on the above experiments, we can further construct the modified general Bashen formula for XLPE-SiR insulation interface discharge: the insulation interface coefficient α is related to the insulation interface state (R) and pd, and there is an obvious coupling relationship between the insulation interface state (R) and the pd value. Therefore, it is very difficult to directly statistically fit the functional relationship α = f (R, pd). In this regard, the present invention adopts a piecewise function to calculate the U under the typical insulation interface state. pd -pd, the modified Bashen formula for XLPE-SiR insulation interface discharge can be obtained as shown below:

[0089]

[0090] In the formula, α pdx · is the XLPE-SiR insulation interface coefficient under a specific insulation interface state x (x=1~n).

[0091] In this embodiment, the influence of pd value on the discharge at the XLPE-SiR insulation interface of power cable accessories is analyzed: the fluctuation of the operating load of the power cable line will cause the pressure at the insulation interface to change. By substituting the fluctuation range of pd value, the U under a specific insulation interface state can be calculated. pd -pd, thereby determining the stage where the XLPE-SiR insulation interface is prone to discharge / breakdown (such as the load reduction stage or the no-load stage), which is the stage that the operation and maintenance department needs to pay special attention to.

[0092] It should be noted that Paschen's law clearly reveals that the pure gas discharge U under low pressure and small gap conditions is b =f(pd). However, for the case where the state of the "solid-gas-solid" XLPE-SiR insulation interface is constantly evolving, it is not necessary to directly apply U b=f(pd) has limitations, and its error comes from the fact that Paschen's law does not take into account the influence of the evolution of the insulating interface state on gas discharge. In order to overcome the above shortcomings, the present invention proposes a method for correcting and extending the Paschen formula based on XLPE-SiR insulating interface discharge. By establishing a quantitative correlation between the evolution of the XLPE-SiR insulating interface state and discharge, a modified Paschen formula for XLPE-SiR insulating interface discharge is proposed. The purpose of the present invention is to explore the relationship between XLPE-SiR insulating interface discharge and the evolution of the interface state and pd, and to provide an important reference for the expansion of the universality of the "solid-gas-solid" insulating interface discharge in the classical gas discharge theory system. At the same time, it provides important theoretical guidance for the insulation interface discharge fault detection technology and power cable accessories.

[0093] S32. When the second insulating interface coefficient is determined according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance is obtained according to a preset Paschen formula; the derivation formula is corrected according to the second insulating interface coefficient to obtain a corrected derivation formula; based on the corrected derivation formula and the first breakdown equivalent resistance, the breakdown voltage of the insulating interface is determined.

[0094] In a preferred embodiment, determining the second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance includes:

[0095] Obtaining the second experimental results of several second discharge experiments; wherein, in the second discharge experiment, the insulating interface and air are used as the discharge interface materials to set a control group, the first electrode spacing-pressure parameter is used as a constant, the breakdown equivalent resistance is used as a variable, and several experiments are set according to each preset second breakdown equivalent resistance to test the breakdown voltages of the two discharge interface materials under different second breakdown equivalent resistance conditions; the second experimental results include: the second insulating interface breakdown voltage and the second air breakdown voltage;

[0096] For each of the second breakdown equivalent resistances, according to the corresponding experimental results, calculating the ratio of the second insulating interface breakdown voltage to the second air breakdown voltage under the second breakdown equivalent resistance condition as the second breakdown voltage ratio corresponding to the second breakdown equivalent resistance;

[0097] According to the second breakdown voltage ratios corresponding to different second breakdown equivalent resistances, and by means of a mathematical statistical fitting method, a functional relationship between the second breakdown equivalent resistance and the second breakdown voltage ratio is determined as a calculation formula for the second insulation interface coefficient;

[0098] The second insulation interface coefficient is calculated according to the second insulation interface coefficient calculation formula and the first breakdown equivalent resistance.

[0099] In a preferred embodiment, the derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance obtained according to the preset Baschen formula includes:

[0100] Acquire experimental data of several groups of air discharge experiments; wherein the experimental data include: air breakdown equivalent resistance and air electrode spacing-pressure parameters;

[0101] According to the air electrode spacing-pressure parameters of each set of experimental data, the corresponding air breakdown voltage is calculated according to the Paschen formula;

[0102] According to the air breakdown equivalent resistance and the corresponding air breakdown voltage of each set of experimental data, a functional relationship between the air breakdown voltage and the discharge breakdown equivalent resistance is determined according to a mathematical method as the derivation formula.

[0103] In a preferred embodiment, the derivation formula is:

[0104] U b ′ = h(R);

[0105] Where, R represents the breakdown equivalent resistance; U b ′ represents the breakdown voltage of air calculated according to the derived formula;

[0106] The calculation formula of the second insulation interface coefficient is:

[0107] α R = g(R);

[0108] In the formula, α pd It indicates the second insulation interface coefficient when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions;

[0109] The modified derivation formula is:

[0110] U R (R) = α R h(R);

[0111] Where U R (R) represents the breakdown voltage of the insulating interface when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions.

[0112] In this embodiment, in order to determine the quantitative relationship between the XLPE-SiR insulation interface discharge and the insulation interface state evolution, the construction of the XLPE-SiR insulation interface state evolution-discharge quantitative correlation is carried out, and the specific technical scheme is as follows:

[0113] The R value corresponding to different XLPE-SiR insulation interface states is obtained by using the DC discharge breakdown test platform mentioned above to test the sample CX-S Perform n breakdown tests until the interface insulation is broken down to a point where it cannot be broken down, i.e., the insulation is lost. Calculate the XLPE-SiR insulation interface discharge breakdown equivalent resistance R under each breakdown test y (y=1~m). Through the above method, the insulating interface state and R x quantitative relationship.

[0114] 2. Determination of XLPE-SiR insulation interface coefficient αR under specific pd conditions: Through the above pure gas DC discharge breakdown test, obtain the sample C air Under certain pd conditions, the relationship U b On the other hand, under the same pd condition, according to the DC discharge breakdown experiment of XLPE-SiR insulation interface under different insulation interface states, the insulation interface discharge breakdown voltage U of n different insulation interface states can be obtained. by '(y=1~m). Introducing the insulation interface coefficient (y=1~m) in the insulation interface state y, the following relationship is obtained:

[0115] U by ′=α y ·U b ′=α x h(R);

[0116] Obviously, α y The value of the XLPE-SiR insulation interface discharge breakdown is different each time (caused by the change of the insulation interface state). Therefore, a large number of α y Value and R y Value data, through mathematical statistical fitting method to obtain the functional relationship about R: α R =g(R). Finally, the quantitative correlation formula of XLPE-SiR insulating interface state evolution (R)-discharge under specific pd conditions was constructed, and the following formula was obtained:

[0117] U R (R) = α R h(R);

[0118] 3. Based on the above experiments, we can continue to construct a general derivation formula of the modified XLPE-SiR insulation interface discharge Bashen formula: the insulation interface coefficient α is related to the insulation interface state (R) and pd, and there is an obvious coupling relationship between the insulation interface state (R) and the pd value. Therefore, it is very difficult to directly statistically fit the functional relationship α = f (R, pd). In this regard, the present invention adopts a piecewise function to calculate the U under the typical insulation interface state. R -R can be analyzed to obtain the modified Bashen formula for XLPE-SiR insulation interface discharge, as shown below:

[0119]

[0120] In the formula, α Ry is the XLPE-SiR insulation interface coefficient under specific pd condition y (y=1~m).

[0121] It should be noted that the present invention can analyze the influence of the evolution of the insulation interface state (R value) on the XLPE-SiR insulation interface discharge: according to the evolution of the insulation interface discharge fault of the target power cable accessories, the reasonable variation range of the R value corresponding to different fault stages (early, middle and late) is estimated, and the U value under a specific pd value can be calculated. R -R, thereby determining the evolution law of XLPE-SiR insulation interface discharge / breakdown of target power cable accessories, and providing theoretical guidance for the prediction of the subsequent evolution stage of XLPE-SiR insulation interface discharge fault of power cable accessories.

[0122] Embodiment 2

[0123] Please refer to Figure 5 , is a schematic structural diagram of an insulation interface breakdown voltage evaluation device provided by an embodiment of the present invention, the device comprising: a data acquisition module, an insulation coefficient determination module and a breakdown voltage calculation module;

[0124] The data acquisition module is used to acquire a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of the insulating interface;

[0125] The insulation coefficient determination module is used to determine a first insulation interface coefficient or a second insulation interface coefficient for characterizing an insulation interface state according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulation interface coefficient is generated by fitting data with the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; the second insulation interface coefficient is generated by fitting data with the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance;

[0126] The breakdown voltage calculation module is used to correct a preset Paschen formula according to the first insulation interface coefficient to obtain a corrected Paschen formula when determining a first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; determine the breakdown voltage of the insulation interface based on the corrected Paschen formula and the first electrode spacing-pressure parameter; when determining a second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, obtain a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance according to the preset Paschen formula; correct the derivation formula according to the second insulation interface coefficient to obtain a corrected derivation formula; and determine the breakdown voltage of the insulation interface based on the corrected derivation formula and the first breakdown equivalent resistance.

[0127] Embodiment 3

[0128] Accordingly, an embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the breakdown voltage evaluation method described in the above-mentioned embodiment of the invention is implemented.

[0129] Embodiment 4

[0130] Accordingly, an embodiment of the present invention provides a storage medium, wherein the storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute the breakdown voltage evaluation method described in the above-mentioned embodiment of the invention.

[0131] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as 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 may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0132] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0133] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0134] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the device, and various interfaces and lines are used to connect various parts of the entire device.

[0135] The memory can be used to store the computer program, and the processor realizes various functions of the device by running or executing the computer program stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0136] The storage medium is a storage medium, and the computer program is stored in the storage medium. When the computer program is executed by the processor, the steps of each method embodiment described above can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer readable media do not include electric carrier signals and telecommunication signals.

[0137] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for evaluating the breakdown voltage of an insulation interface, characterized in that: include: Obtaining a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of an insulating interface; Determine a first insulating interface coefficient or a second insulating interface coefficient for characterizing an insulating interface state according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulating interface coefficient is generated by data fitting with the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; and the second insulating interface coefficient is generated by data fitting with the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance; When the first insulating interface coefficient is determined according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, a preset Paschen formula is corrected according to the first insulating interface coefficient to obtain a corrected Paschen formula; based on the corrected Paschen formula and the first electrode spacing-pressure parameter, a breakdown voltage of the insulating interface is determined; When the second insulating interface coefficient is determined based on the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance is obtained according to the preset Paschen formula; the derivation formula is corrected according to the second insulating interface coefficient to obtain a corrected derivation formula; based on the corrected derivation formula and the first breakdown equivalent resistance, the breakdown voltage of the insulating interface is determined.

2. The insulation interface breakdown voltage evaluation method according to claim 1, characterized in that: The determining of the first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance includes: Obtaining first experimental results of several first discharge experiments; wherein, in the first discharge experiment, an insulating interface and air are used as discharge interface materials to set a control group, the first breakdown equivalent resistance is used as a constant, and the electrode spacing-pressure parameter is used as a variable, and several experiments are set according to each preset second electrode spacing-pressure parameter to test the breakdown voltage of the two discharge interface materials under different second electrode spacing-pressure parameter conditions; the first experimental results include: a first insulating interface breakdown voltage and a first air breakdown voltage; For each of the second electrode spacing-pressure parameters, according to the corresponding experimental results, the ratio of the first insulating interface breakdown voltage to the first air breakdown voltage under the second electrode spacing-pressure parameter condition is calculated as the first breakdown voltage ratio corresponding to the second electrode spacing-pressure parameter; According to the first breakdown voltage ratios corresponding to different second electrode spacing-pressure parameters, a functional relationship between the second electrode spacing-pressure parameter and the first breakdown voltage ratio is determined by a mathematical statistical fitting method as a calculation formula for the first insulating interface coefficient; The first insulation interface coefficient is calculated according to the first insulation interface coefficient calculation formula and the first electrode spacing-pressure parameter.

3. The insulation interface breakdown voltage evaluation method according to claim 1, characterized in that: The determining of the second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance comprises: Obtaining the second experimental results of several second discharge experiments; wherein, in the second discharge experiment, the insulating interface and air are used as the discharge interface materials to set a control group, the first electrode spacing-pressure parameter is used as a constant, the breakdown equivalent resistance is used as a variable, and several experiments are set according to each preset second breakdown equivalent resistance to test the breakdown voltages of the two discharge interface materials under different second breakdown equivalent resistance conditions; the second experimental results include: the second insulating interface breakdown voltage and the second air breakdown voltage; For each of the second breakdown equivalent resistances, according to the corresponding experimental results, calculating the ratio of the second insulating interface breakdown voltage to the second air breakdown voltage under the second breakdown equivalent resistance condition as the second breakdown voltage ratio corresponding to the second breakdown equivalent resistance; According to the second breakdown voltage ratios corresponding to different second breakdown equivalent resistances, and by means of a mathematical statistical fitting method, a functional relationship between the second breakdown equivalent resistance and the second breakdown voltage ratio is determined as a calculation formula for the second insulation interface coefficient; The second insulation interface coefficient is calculated according to the second insulation interface coefficient calculation formula and the first breakdown equivalent resistance.

4. The insulation interface breakdown voltage evaluation method according to claim 1, characterized in that: The preset Bashen formula is: U b =f(pd); Where pd represents the electrode spacing-pressure parameter; U b represents the breakdown voltage of air calculated according to the Paschen formula; The calculation formula of the first insulation interface coefficient is: α pd =q(pd); In the formula, α pd It represents the first insulation interface coefficient when the electrode spacing-pressure parameter is pd under specific breakdown equivalent resistance conditions; The modified Bashen formula is: U p d(pd)=α pd ·f(pd); Where U pd (pd) represents the breakdown voltage of the insulating interface under specific breakdown equivalent resistance conditions when the electrode spacing-pressure parameter is pd.

5. The insulation interface breakdown voltage evaluation method according to claim 1, characterized in that: The derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance obtained according to the preset Baschen formula includes: Acquire experimental data of several groups of air discharge experiments; wherein the experimental data include: air breakdown equivalent resistance and air electrode spacing-pressure parameters; According to the air electrode spacing-pressure parameters of each set of experimental data, the corresponding air breakdown voltage is calculated according to the Paschen formula; According to the air breakdown equivalent resistance and the corresponding air breakdown voltage of each set of experimental data, a functional relationship between the air breakdown voltage and the discharge breakdown equivalent resistance is determined according to a mathematical method as the derivation formula.

6. The insulation interface breakdown voltage evaluation method according to claim 1, characterized in that: The derivation formula is: U b ′=h(R); Where, R represents the breakdown equivalent resistance; U b ′ represents the breakdown voltage of air calculated according to the derived formula; The calculation formula of the second insulation interface coefficient is: a R =g(R); In the formula, α pd It indicates the second insulation interface coefficient when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions; The modified derivation formula is: U R (R)=α R ·h(R); Where U R (R) represents the breakdown voltage of the insulating interface when the breakdown equivalent resistance is R under specific electrode spacing-pressure parameter conditions.

7. An insulation interface breakdown voltage evaluation device, characterized in that: include: Data acquisition module, insulation coefficient determination module and breakdown voltage calculation module; The data acquisition module is used to acquire a first electrode spacing-pressure parameter and a first breakdown equivalent resistance of the insulating interface; The insulation coefficient determination module is used to determine a first insulation interface coefficient or a second insulation interface coefficient for characterizing an insulation interface state according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; wherein the first insulation interface coefficient is generated by fitting data with the first breakdown equivalent resistance as a constant, and each preset second electrode spacing-pressure parameter and the breakdown voltage corresponding to each preset second electrode spacing-pressure parameter; the second insulation interface coefficient is generated by fitting data with the first electrode spacing-pressure parameter as a constant, and each preset second breakdown equivalent resistance and the breakdown voltage corresponding to each preset second breakdown equivalent resistance; The breakdown voltage calculation module is used to correct a preset Paschen formula according to the first insulation interface coefficient to obtain a corrected Paschen formula when determining a first insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance; determine the breakdown voltage of the insulation interface based on the corrected Paschen formula and the first electrode spacing-pressure parameter; when determining a second insulation interface coefficient according to the first electrode spacing-pressure parameter and the first breakdown equivalent resistance, obtain a derivation formula for characterizing the relationship between the breakdown voltage and the breakdown equivalent resistance according to the preset Paschen formula; correct the derivation formula according to the second insulation interface coefficient to obtain a corrected derivation formula; and determine the breakdown voltage of the insulation interface based on the corrected derivation formula and the first breakdown equivalent resistance.

8. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for evaluating the insulation interface breakdown voltage according to any one of claims 1 to 6 is implemented.

9. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute the insulation interface breakdown voltage evaluation method according to any one of claims 1 to 6.

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