CN111337797A - XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model - Google Patents

XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model Download PDF

Info

Publication number
CN111337797A
CN111337797A CN202010072574.5A CN202010072574A CN111337797A CN 111337797 A CN111337797 A CN 111337797A CN 202010072574 A CN202010072574 A CN 202010072574A CN 111337797 A CN111337797 A CN 111337797A
Authority
CN
China
Prior art keywords
power cable
thermal aging
debye model
main insulation
xlpe power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010072574.5A
Other languages
Chinese (zh)
Inventor
张镱议
刘捷丰
蒋丰宇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangxi University
Original Assignee
Guangxi University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangxi University filed Critical Guangxi University
Priority to CN202010072574.5A priority Critical patent/CN111337797A/en
Publication of CN111337797A publication Critical patent/CN111337797A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
    • G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
    • G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
    • G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)

Abstract

The invention discloses a method for evaluating the nonuniform thermal aging state of main insulation of an XLPE power cable based on a modified Debye model, which comprises the following steps: (1) obtaining a temperature field on the main insulation of the XLPE power cable, and carrying out isothermal zone division on the main insulation; (2) obtaining a modified Debye model based on the isothermal zone by utilizing an extended Debye model construction principle; (3) obtaining a parameter identification mode in a modified Debye model comprising a plurality of isothermal zones; (4) manufacturing an equivalent sample of uneven thermal aging of the main insulation and an even aging sample of the main insulation; (5) obtaining PDC data; (6) and calculating the corrected aging factors of all the nonuniform thermal aging states and all the uniform aging states, and performing comparison analysis. The invention considers the uneven phenomenon of the internal temperature field in the actual XLPE power cable operation process, and the diagnosis is more convenient and accurate, so that the power system operation is more reliable, safe and stable.

Description

XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model
Technical Field
The invention relates to the technical field of electrical equipment fault diagnosis, in particular to an XLPE power cable main insulation non-uniform thermal aging state evaluation method based on a modified Debye model.
Background
The power cable is one of important power devices in an urban power transmission and distribution network. Nowadays, plastic-insulated cables are widely used in power grids, and crosslinked polyethylene insulated cables are unique in 98.68% ratio in 6 kV-500 kV power grid grades. The crosslinked polyethylene cable is affected by various factors such as electricity, heat, water, machinery and the like in the long-term operation process, and the insulation performance and the mechanical performance are gradually deteriorated. The cable faults can generate obvious influence on a power transmission and distribution system, the operation age of the XLPE power cable in China is 20 to 30 years, and the design life is generally 30 years. The XLPE insulating layer is used as a main insulating part of the cable, and the aging degree of the XLPE insulating layer determines whether the cable can continuously run safely and stably and ensures safe power supply of cities. According to recent fault statistics, power cable faults in long term in the operating life are more frequent at the main insulation position, so that the problem that the influence of aging on the main insulation state of the XLPE power cable is urgently solved at present is researched.
Currently, the evaluation of XLPE power cables mainly adopts a Polarization Depolarization Current (PDC) method, and an extended Debye model is established by using polarization characteristics to identify parameters, so as to characterize the aging state of the cable. Through the existing research, the heat of the XLPE cable is emitted by the copper core or the aluminum core during the actual operation, and the heat transfer occurs at the end of the sheath which is outward along the radial direction. The main insulating layer of the medium-high voltage cable has a certain thickness, so that a radial temperature gradient is generated in an internal temperature field, and simulation analysis shows that the temperature difference range is between 10 and 30 degrees, and the temperature gradually decreases along the outward sheath end of the wire core. In addition, the existing research results are based on the research of an analysis evaluation method of a uniform thermal aging sample in a laboratory, but due to the radial temperature gradient existing in the long-term practical operation of the cable, the nonuniform thermal aging of the XLPE insulating layer can be caused. Therefore, the reliability of evaluating the thermal aging state of the main insulation of the XLPE power cable with temperature gradient on site by using the experimental result and the method of the uniform thermal aging sample is poor.
Today's assessment of the thermal aging state of XLPE power cables is mainly a qualitative assessment by calculating the aging factor from the polarized depolarized current data measured in the field. The basis of the existing evaluation method for the expanded Debye model is uniform thermal aging, and an analysis object is also uniform thermal aging, but the radial temperature gradient of the cable in long-term actual operation can cause the nonuniform thermal aging of an XLPE insulating layer. Therefore, the extent of the non-uniform thermal aging in the actual situation is assessed by the extended Debye model analysis to be questionable.
Disclosure of Invention
The invention provides an XLPE power cable main insulation uneven thermal aging state assessment method based on a modified Debye model aiming at the technical problems of the background art, and the unevenness of an insulation layer temperature field in the actual cable operation process is considered, so that the diagnosis is more convenient and accurate, and the power system is more reliable, safe and stable in operation.
In order to achieve the purpose, the method for evaluating the uneven thermal aging state of the main insulation of the XLPE power cable based on the modified Debye model comprises the following steps:
(1) obtaining a temperature field of main insulation of the XLPE power cable, and carrying out isothermal zone division on the main insulation;
(2) the structure of the extended Debye model is improved, a modified Debye model based on the isothermal zone is established, and an equivalent structure of the modified Debye model is established;
(3) obtaining a parameter identification mode in the modified Debye model comprising a plurality of isothermal zones in the step (2) through a parameter identification formula of a circuit principle;
(4) manufacturing an equivalent sample of main insulation uneven thermal aging and a main insulation uniform aging sample of the XLPE power cable;
(5) performing PDC testing on all samples in the step (4) by using a three-electrode system to obtain PDC data, and obtaining a parameter identification result for the PDC data by using the method in the step (3); comparing the actual measurement curve with the PDC curve synthesized by the parameter identification result, and verifying the effectiveness of the method;
(6) and (5) calculating all non-uniform thermal aging states and all correction aging factors of the uniform aging states according to the parameter identification result in the step (5), and performing comparison analysis, wherein the correction aging factors can represent the results of the non-uniform thermal aging states.
Particularly, the method for obtaining the temperature field of the main insulation of the XLPE power cable in the step (1) is to obtain the temperature field distribution of the XLPE power cable in long-term operation by applying a COMSOL finite element simulation technology, and the radial temperature distribution of the temperature field of the main insulation has a gradient.
Specifically, the specific method for establishing the modified Debye model in the step (2) is as follows: each polarization type of the main insulation of the XLPE power cable is equivalent to a series branch of a capacitor and a resistor, and different polarization types do not influence each other to form a parallel branch; and (2) dividing the impedance of each series branch into a corresponding number of impedances according to a plurality of radial isothermal zones divided in the temperature field in the step (1), wherein each impedance represents the polarization characteristic in the isothermal zone. The characteristic of considering different aging states and different polarization types can be reflected by a corrected Debye model, and the characteristic can be represented by related characteristic parameters.
In particular, the parameter identification mode in the step (3) can realize the numerical division of the isothermal zone.
In particular, the method for manufacturing the main insulation uneven thermal aging sample in the step (4) adopts the overlapping of XLPE discs in multiple thermal aging states.
Specifically, the expression for correcting the aging factor in the step (6) is as follows:
Figure BDA0002377679270000021
wherein the content of the first and second substances,
Figure BDA0002377679270000031
and
Figure BDA0002377679270000032
respectively representing the electric quantity of the branch circuit with the second maximum and the maximum time constant of the average value of each isothermal zone in the corrected Debye model based on the uneven thermal aging,
Figure BDA0002377679270000033
and
Figure BDA0002377679270000034
refers to the average value of time constants of isothermal zones of a certain branch.
The principle of parameter identification based on the circuit principle in the step (3) is as follows:
Figure BDA0002377679270000035
Figure BDA0002377679270000036
for depolarizing current, K is the number of branches, n is the number of isothermal zones, V0For polarizing voltage, the change rule of the total impedance of the main insulation along with time can be obtained by the above formula, and the tail end of the main insulation can be represented by a branch with the maximum time constant in a model. Thus, the end curve can be equally divided into n shares, first order exponential fit for each share, and the regions with parameter errors less than 2% are merged as one isothermal region, as follows:
Figure BDA0002377679270000037
Rj(k)＝Re(Zj(k,t))，
Figure BDA0002377679270000038
wherein, in the formulaj(k) Is the time constant, Z, of the jth isothermal zone of the kth branchj(k, s) is the impedance of the jth isothermal zone of the kth branch, Rj(k) And Cj(k) Respectively the resistance and the capacitance of the jth isothermal zone of the kth branch. Using the above formulaThe impedance of each isothermal zone can be obtained, and the impedance is subtracted from the total impedance, and the process is repeated to realize parameter identification.
The validity of the XLPE disc stacking method adopting various thermal ageing states proves that the process is as follows:
each polarization type of the physical cable and the test disc sample can be regarded as being uniformly distributed in the material, and the formula for the physical cable is as follows:
Figure RE-GDA0002497988830000041
wherein R in the formulan *、C* n、σ* n、ε* n、τ* nAnd correcting the resistance, the capacitance, the conductivity, the dielectric constant and the attenuation time of a certain isothermal zone of each branch in the Debye model for the physical cable. The formula for the disc sample is as follows:
Figure RE-GDA0002497988830000042
in the formula Rn、Cn、σn、εn、τnAnd correcting the resistance, the capacitance, the conductivity, the dielectric constant and the decay time of a certain isothermal zone of each branch in the Debye model for the disc sample. Therefore, the time constant tau of the isothermal zone of the experimental sample and each branch of the time cable is the sameiExactly the same, with respect to τ, modified Debye model of this sampleiThe characteristic quantity of the cable is very effective in representing the uneven thermal aging degree of the physical cable.
The corrected aging factor calculated in step (6) is obviously different from the traditional aging factor. The traditional aging factor expression is as follows:
Figure BDA0002377679270000041
Id(τ2)τ2and Id(τ3)τ3Respectively on the basis of homogeneous thermal ageingThe electric quantity of the sub-maximum and maximum time constant branches in the Debye model, and tau2And τ3Refers to the time constant of a certain branch as a whole. The modified aging factor is expressed as follows:
Figure BDA0002377679270000042
Figure BDA0002377679270000043
and
Figure BDA0002377679270000044
respectively representing the electric quantities of the branches with the sub-maximum and maximum time constants of the average value of each isothermal zone in the modified Debye model based on the uneven thermal aging, and
Figure BDA0002377679270000045
and
Figure BDA0002377679270000046
refers to the average value of time constants of isothermal zones of a certain branch.
The invention has the beneficial effects that:
according to the invention, the main insulation uneven thermal aging state of the XLPE power cable is evaluated by correcting the Debye model according to the phenomenon of uneven temperature field where the actual cable ages in operation, the problem of difficulty in simulating the uneven thermal aging of the cable in a laboratory is solved by using an equivalent sample method, so that the diagnosis of the main insulation thermal aging state of the XLPE power cable based on a polarization depolarization current method is more convenient and accurate, and the problem of the defect of the accuracy of the current aging criterion is explained to a certain extent. The method is beneficial to discovering potential faults of the transmission cable, and provides important reference basis for operation maintenance and overhaul of the cable, so that the transmission and distribution network can operate more reliably, safely and stably.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a flow chart of an embodiment of the present invention;
FIG. 2 is a temperature field profile of an embodiment of the present invention;
FIG. 3 is an isothermal zone plot of an embodiment of the present invention;
FIG. 4 is a diagram of a modified Debye model according to an embodiment of the present invention.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention will be more clearly and clearly defined.
As shown in fig. 1, the method for evaluating the uneven thermal aging state of the main insulation of an XLPE power cable based on a modified Debye model in the embodiment includes the following steps:
(1) and analyzing the aging temperature of the cable in the perennial operation by combining the actual operation environment of the XLPE power cable, obtaining the temperature field distribution of the cable in the long-term operation by applying a COMSOL finite element simulation technology, and dividing the isothermal zone. As shown in FIG. 2, for the temperature field distribution of the cable of the experimental study object of this embodiment, the user can adjust the simulation parameters (typically, the temperature difference is 10 to 30 degrees) according to the actual situation of the study object. Fig. 3 shows the isothermal zone division of the present embodiment.
(2) And (3) improving the structure of the extended Debye model according to the polarization depolarization principle in the PDC test during uniform thermal aging, and establishing a modified Debye model based on the isothermal zone. The specific method for establishing the modified Debye model comprises the following steps: each polarization type of the main insulation of the XLPE power cable is equivalent to a series branch of a capacitor and a resistor respectively, different polarization types do not influence each other, and a parallel branch is formed; the impedance of each series branch can be divided into corresponding number of impedances according to a plurality of radial isothermal zones divided in the temperature field in the step (1), each impedance represents the polarization characteristic under the isothermal zone, and the equivalent structure of the modified Debye model is constructed and shown in FIG. 4. The characteristic of considering different aging states and different polarization types can be reflected by a corrected Debye model, and the characteristic can be represented by related characteristic parameters. The user can also customize the number of isothermal zones if the error allows.
(3) The parameter identification formula based on the circuit principle is as follows:
Figure BDA0002377679270000051
Figure BDA0002377679270000052
for depolarizing current, K is the number of branches, n is the number of isothermal zones, V0For polarizing the voltage, the change rule of the total impedance of the main insulation along with time is obtained by the above formula, the tail end of the main insulation is equally divided into n parts, and then first-order exponential fitting is carried out on each part, wherein the tail end is divided according to the point that the second derivative of the slope of the tail end of the curve is zero. And then combining the areas with the parameter error less than 2% as an isothermal area, wherein the formula is as follows:
Figure BDA0002377679270000061
Rj(k)＝Re(Zj(k,t))，
Figure BDA0002377679270000062
wherein, in the formulaj(k) Is the time constant, Z, of the jth isothermal zone of the kth branchj(k, s) is the impedance of the jth isothermal zone of the kth branch, Rj(k) And Cj(k) Respectively the resistance and the capacitance of the jth isothermal zone of the kth branch. The impedance of each isothermal zone can be obtained by the formula, and the impedance is subtracted from the total impedance, and the process is repeated to realize parameter identification. The parameter identification mode in the modified Debye model of the isothermal zones is obtained by the method.
(4) And (3) manufacturing an equivalent sample of main insulation uneven thermal aging and a main insulation even aging sample of the XLPE power cable. When main insulation uneven thermal aging samples of the XLPE power cable are manufactured, the aging temperature of each sample is determined according to the number of samples in different states and the temperature difference of the isothermal zone, and therefore uniform thermal aging is carried out. It should be noted that the aging temperature of the main insulated uniformly aged samples should be taken as the average of the aging temperatures of the non-uniform samples.
(5) And (3) carrying out PDC test on all samples in the step (4) by using a three-electrode system in a laboratory, wherein the samples need to be cleaned by absolute ethyl alcohol before test, and the purpose is to reduce the influence of surface impurities on the measurement result. In addition, after the three electrodes are placed, more air possibly existing in the three electrodes needs to be further squeezed out so as not to influence the test result. And (4) after testing, obtaining PDC data, and obtaining a parameter identification result for the PDC data through the method in the step (3). The specific setting of this embodiment PDC is: and a 200V direct current voltage is output, and the polarization time and the depolarization time are both 2000 seconds. And comparing the actual measurement curve with the PDC curve synthesized by the parameter identification result to verify the effectiveness of the method.
(6) And (5) calculating all non-uniform thermal aging states and all correction aging factors of the uniform aging states according to the parameter identification result in the step (5), and performing comparison analysis, wherein the correction aging factors can represent the results of the non-uniform thermal aging states.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, various changes or modifications may be made by the patentees within the scope of the appended claims, and within the scope of the invention, as long as they do not exceed the scope of the invention described in the claims.

Claims (7)

1. A method for evaluating the nonuniform thermal aging state of main insulation of an XLPE power cable based on a modified Debye model is characterized by comprising the following steps: the method comprises the following steps:
(1) obtaining a temperature field of main insulation of the XLPE power cable, and carrying out isothermal zone division on the main insulation;
(2) the structure of the extended Debye model is improved, a modified Debye model based on the isothermal zone is established, and an equivalent structure of the modified Debye model is established;
(3) obtaining a parameter identification mode in the modified Debye model comprising a plurality of isothermal zones in the step (2) through a parameter identification formula of a circuit principle;
(4) manufacturing an equivalent sample of main insulation uneven thermal aging and a main insulation uniform aging sample of the XLPE power cable;
(5) performing PDC testing on all samples in the step (4) by using a three-electrode system to obtain PDC data, and obtaining a parameter identification result for the PDC data by using the method in the step (3); comparing the actual measurement curve with the PDC curve synthesized by the parameter identification result, and verifying the effectiveness of the method;
(6) and (5) calculating all non-uniform thermal aging states and all correction aging factors of the uniform aging states according to the parameter identification result in the step (5), and performing comparison analysis, wherein the correction aging factors can represent the results of the non-uniform thermal aging states.
2. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the method for obtaining the main insulation temperature field of the XLPE power cable in the step (1) is to obtain the temperature field distribution of the XLPE power cable in long-term operation by applying a COMSOL finite element simulation technology.
3. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the radial temperature distribution of the temperature field of the main insulation in the step (1) has a gradient.
4. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the specific method for establishing the Debye model by correcting the Debye model in the step (2) comprises the following steps: each polarization type of the main insulation of the XLPE power cable is equivalent to a series branch of a capacitor and a resistor, and different polarization types do not influence each other to form a parallel branch; and (2) dividing the impedance of each series branch into a corresponding number of impedances according to a plurality of radial isothermal zones divided in the temperature field in the step (1), wherein each impedance represents the polarization characteristic in the isothermal zone.
5. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the parameter identification mode in the step (3) can realize the numerical division of the isothermal zone.
6. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the method for manufacturing the main insulation uneven thermal aging sample in the step (4) adopts the overlapping of XLPE discs in various thermal aging states.
7. The XLPE power cable primary insulation non-uniform thermal aging state evaluation method based on the modified Debye model as claimed in claim 1, wherein: the expression for correcting the aging factor in the step (6) is as follows:
Figure FDA0002377679260000021
wherein the content of the first and second substances,
Figure FDA0002377679260000022
and
Figure FDA0002377679260000023
respectively representing the electric quantity of the branch circuit with the second maximum and the maximum time constant of the average value of each isothermal zone in the corrected Debye model based on the uneven thermal aging,
Figure FDA0002377679260000024
and
Figure FDA0002377679260000025
refers to the average value of time constants of isothermal zones of a certain branch.
CN202010072574.5A 2020-01-21 2020-01-21 XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model Pending CN111337797A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010072574.5A CN111337797A (en) 2020-01-21 2020-01-21 XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010072574.5A CN111337797A (en) 2020-01-21 2020-01-21 XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model

Publications (1)

Publication Number Publication Date
CN111337797A true CN111337797A (en) 2020-06-26

Family

ID=71183355

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010072574.5A Pending CN111337797A (en) 2020-01-21 2020-01-21 XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model

Country Status (1)

Country Link
CN (1) CN111337797A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113297733A (en) * 2021-05-21 2021-08-24 福州大学 Transformer extension Debye model parameter identification method based on K-K transformation and spectral line differentiation
CN113419147A (en) * 2021-06-29 2021-09-21 广西电网有限责任公司电力科学研究院 Radar spectrum diagram based visualized cable insulation state diagnosis and evaluation method
CN113419143A (en) * 2021-05-24 2021-09-21 广西大学 Composite insulation state evaluation method based on finite element method and considering sleeve oil paper insulation non-uniform thermal aging effect

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011103676A1 (en) * 2011-06-09 2012-12-13 Rainer Patsch Method for characterization of insulation state of oiled paper insulated cable in high voltage power cable for determining ageing state, involves calculating p-factor from measured return voltage curves
CN103278756B (en) * 2013-05-29 2015-08-12 国家电网公司 A kind of method assessing transformer oil paper insulation ageing state
CN105866647A (en) * 2016-06-08 2016-08-17 西安交通大学 XLPE (Cross Linked Polythylene) insulation aging estimation method based on different frequency and dielectric loss ratios
CN107505542A (en) * 2017-07-25 2017-12-22 上海电力学院 Measuring method based on depolarization current method detection XLPE cable degree of aging
CN108627747A (en) * 2018-08-23 2018-10-09 武汉脉源电气有限公司 A kind of diagnostic model and its diagnostic method of the XLPE cable insulated water tree aging based on PDC methods

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011103676A1 (en) * 2011-06-09 2012-12-13 Rainer Patsch Method for characterization of insulation state of oiled paper insulated cable in high voltage power cable for determining ageing state, involves calculating p-factor from measured return voltage curves
CN103278756B (en) * 2013-05-29 2015-08-12 国家电网公司 A kind of method assessing transformer oil paper insulation ageing state
CN105866647A (en) * 2016-06-08 2016-08-17 西安交通大学 XLPE (Cross Linked Polythylene) insulation aging estimation method based on different frequency and dielectric loss ratios
CN107505542A (en) * 2017-07-25 2017-12-22 上海电力学院 Measuring method based on depolarization current method detection XLPE cable degree of aging
CN108627747A (en) * 2018-08-23 2018-10-09 武汉脉源电气有限公司 A kind of diagnostic model and its diagnostic method of the XLPE cable insulated water tree aging based on PDC methods

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
吴广宁等: "《基于修正Debye 模型的油浸绝缘纸不均匀老化时域介电特性》", 《高电压技术》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113297733A (en) * 2021-05-21 2021-08-24 福州大学 Transformer extension Debye model parameter identification method based on K-K transformation and spectral line differentiation
CN113297733B (en) * 2021-05-21 2022-12-16 福州大学 Transformer extension Debye model parameter identification method based on K-K transformation and spectral line differentiation
CN113419143A (en) * 2021-05-24 2021-09-21 广西大学 Composite insulation state evaluation method based on finite element method and considering sleeve oil paper insulation non-uniform thermal aging effect
CN113419147A (en) * 2021-06-29 2021-09-21 广西电网有限责任公司电力科学研究院 Radar spectrum diagram based visualized cable insulation state diagnosis and evaluation method

Similar Documents

Publication Publication Date Title
CN111337797A (en) XLPE power cable main insulation non-uniform thermal aging state evaluation method based on modified Debye model
CN110736905A (en) Insulation aging evaluation method for 110kV XLPE high-voltage cable
CN106291122B (en) A kind of test method and system of oil immersed type condenser bushing watered and wetting defect
CN108387824B (en) Oiled paper insulation state evaluation method for improving return voltage measurement mode
CN113064002B (en) Assessment method for insulation aging state of 10kV XLPE cable
CN107860894B (en) Method for predicting furfural content in transformer insulating oil based on frequency domain complex dielectric constant initial slope
CN103412244A (en) Method for measuring space charge characteristics of HVDC XLPE cable under thermal-cold cycling
CN104730436A (en) Cable aging estimation method combining step-by-step withstand voltage method and isothermal relaxation current method
CN106093614A (en) A kind of method of return voltage initial slope assessment transformer insulation state
CN110850196A (en) Service life electric stress and/or thermal stress test platform for crosslinked polyethylene power cable
WO2020207513A2 (en) Testing apparatus and evaluation method for evaluating emission performance of semi-conductive blocking material
CN111650479A (en) IRC (infrared radiation correlation) and electrothermal accelerated aging test method
CN113655098B (en) Method for measuring micro-water content of silicone oil for cable terminal based on current test
Arikan et al. Prediction of dielectric parameters of an aged MV cable: A comparison of curve fitting, decision tree and artificial neural network methods
CN111693826A (en) Nuclear power cable aging degree diagnosis method
CN114543896B (en) Capacitive equipment medium water content and aging evaluation method based on temperature drift electrical parameters
CN108535612B (en) SF6 insulating sleeve insulation detection database construction method and detection method and device thereof
CN111896849A (en) Oil paper insulation performance analysis method and device considering non-uniform medium
Tzimas et al. Qualitative analysis of PEA and TSM techniques on a 200kV extruded cable during a VSC ageing program
Joshi et al. Dielectric diagnosis of EHV current transformer using frequency domain spectroscopy (FDS) & polarization and depolarization current (PDC) techniques
CN110632396B (en) Cable dielectric loss measuring method
CN114414958A (en) Cable insulation aging evaluation device and method based on high-frequency signal characteristic impedance
CN113962078A (en) Calculation and judgment method for moisture content of cable body or intermediate joint affected with damp
CN114528726A (en) Method and device for correcting dielectric spectrum curve of oiled paper insulation frequency domain at time-varying temperature
CN111060565A (en) High-voltage direct-current cable material resistivity characteristic evaluation method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200626