CN108051712B - 10kV XLPE power cable insulation aging evaluation method and system - Google Patents
10kV XLPE power cable insulation aging evaluation method and system Download PDFInfo
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- 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
Abstract
The invention discloses a 10kV XLPE power cable insulation aging evaluation method and a system, which comprises the following steps: measuring polarization-depolarization currents of a polarization voltage polarization process and a short circuit grounding depolarization process applied to the evaluated 10kV XLPE power cable; calculating to obtain characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage; and evaluating the insulation aging degree of the 10kV XLPE power cable based on the characteristic quantity and an evaluation standard. The cable insulation protection circuit does not damage cable insulation, has higher sensitivity to overall cable aging and serious local defects, and has wide application prospect in practical application.
Description
Technical Field
The invention relates to the field of cable insulation diagnosis, in particular to a 10kV XLPE power cable insulation aging evaluation method and system.
Background
Crosslinked polyethylene (XLPE) cables have been used extensively in power transmission due to their excellent electrical and mechanical properties, ease of installation and deployment, relatively reasonable cost, and the like. And the 10kV XLPE cable is widely applied to urban distribution network systems, and the problem of stable operation is very important in the distribution network systems. Therefore, the problem of the insulation level of 10kV XLPE cables of urban distribution networks is a topic which is generally and increasingly concerned at present.
Along with the increase of service time and the influence of operating condition factors of the cable, the inside of the part of the cable insulation gradually ages under the action of factors such as electricity, heat, chemical corrosion, moisture penetration, mechanical stress and the like. Under the action of a multi-stress strong electric field, the defects and aging can develop rapidly, so that the insulation level of the cable is reduced gradually, and the risk of insulation breakdown in a short time exists at any time, so that the stable operation of a power system and the personal safety are damaged. Therefore, the aging degree and the residual service life of the 10kV XLPE cable are tested and evaluated, and therefore, it is important to take corresponding measures before an accident occurs.
For the detection and evaluation of the insulation aging state of the cable, a plurality of diagnostic methods are available at present. However, the conventional diagnostic techniques have the following problems: (1) insulation resistance and absorption ratio measurement, the principle and operation of the method are very simple, but the test result often cannot accurately reflect and define the aging condition of the cable and is only suitable for rough diagnosis; (2) the dielectric loss tangent value test is carried out, the dielectric loss tangent test under resonance is usually carried out on a long cable and a large-capacitance test product, but the problems of large equipment volume, difficult transportation and the like exist, and the local insulation defect in the long cable cannot be well reflected; (3) in a leakage current test (namely a direct current withstand voltage test), space charge is injected in the test process by the method, so that unpredictable breakdown accidents are generated on part of tested samples, and the test method is not recommended by IEC (International electrotechnical Commission).
To this end, it is desirable to seek a solution that at least alleviates the above problems.
Disclosure of Invention
The invention aims to provide a method and a system for evaluating insulation aging of a 10kV XLPE power cable, so as to evaluate the overall aging of the cable without damaging the insulation of the cable.
In order to solve the technical problems, the invention adopts the following technical scheme.
A10 kV XLPE power cable insulation aging assessment method comprises the following steps:
measuring polarization-depolarization currents of a polarization voltage polarization process and a short circuit grounding depolarization process applied to the evaluated 10kV XLPE power cable;
calculating to obtain characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage;
and evaluating the insulation aging degree of the 10kV XLPE power cable based on the characteristic quantity and an evaluation standard.
The characteristic quantity includes a direct current conductivity σ00.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigma0In S/m, and a low frequency dielectric loss factor tan delta of 0.1Hz in%.
The method for calculating the non-linear coefficient DONL is as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
The evaluation criteria were: when sigma is0≤1×10-14When the 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and the DONL is less than or equal to 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be good; or, when 1 × 10 is satisfied-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 when one or more of the power cables are aged, evaluating the insulation aging state of the 10kV XLPE power cable to be slightly aged; or, when σ is satisfied0≥1×10-12When the tan delta is more than or equal to one of 0.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be serious aging; at the same time, when DONL>1.2, the cable was evaluated for possible bridging water tree degradation.
A10 kV XLPE power cable insulation aging evaluation system comprises the following steps:
a measuring unit for measuring polarization-depolarization currents of a polarization voltage polarization process and a short-circuit ground depolarization process applied to the evaluated 10kV XLPE power cable;
a calculating unit, which is used for calculating and obtaining the characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage;
and the evaluation unit is used for evaluating the insulation aging degree of the 10kV XLPE power cable based on the characteristic quantity and an evaluation standard.
The characteristic quantity includes a direct current conductivity σ00.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigma0In S/m, and a low frequency dielectric loss factor tan delta of 0.1Hz in%.
The method for calculating the non-linear coefficient DONL is as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma'0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
The evaluation criteria were: when sigma is0≤1×10-14When the 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and the DONL is less than or equal to 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be good; or, when 1 × 10 is satisfied-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 when one or more of the power cables are aged, evaluating the insulation aging state of the 10kV XLPE power cable to be slightly aged; or, when σ is satisfied0≥1×10-12When the tan delta is more than or equal to one of 0.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be serious aging; at the same time, when DONL>1.2, evaluating the possible presence of the cableBridge water tree aging.
The present invention has the following advantageous technical effects.
The invention calculates the characteristic quantity for representing the insulation aging state of the cable based on the polarization-depolarization current obtained by measuring the evaluated cable and the applied polarization voltage, and evaluates the insulation aging degree of the cable based on the characteristic quantity and the evaluation standard. The polarization/depolarization current (PDC) test voltage is low, the insulation of the cable cannot be damaged, and the sensitivity to the overall aging of the cable and serious local defects is high, so that the PDC test voltage has wide application prospects in practical application.
Drawings
FIG. 1 is a schematic diagram of an experimental structure of a short 10kV XLPE power cable for accelerating water tree aging.
FIG. 2 is a schematic diagram of an experimental structure of a long 10kV XLPE power cable.
FIG. 3 is a graph showing the DC conductivity of short 10kV XLPE power cable samples before and after treatment as a function of aging time.
FIG. 4 is a graph showing the change of the nonlinear coefficient of a short 10kV XLPE power cable sample with aging time before and after treatment.
Fig. 5 schematically shows a schematic of the structure of the system of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The embodiments and features of the embodiments of the present invention may be arbitrarily combined with each other without conflict. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.
The invention discloses a 10kV XLPE power cable insulation aging evaluation method, which comprises the following steps:
measuring polarization-depolarization currents of a polarization voltage polarization process and a short circuit grounding depolarization process applied to the evaluated 10kV XLPE power cable;
calculating to obtain characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage;
and evaluating the insulation aging degree of the 10kV XLPE power cable based on the characteristic quantity and an evaluation standard.
In the method of the invention, the characteristic quantity comprises the direct current conductivity σ00.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigma0In S/m, and a low frequency dielectric loss factor tan delta of 0.1Hz in%.
DC conductivity σ0The calculation method of (2) is as follows:
when the 10kV XLPE power cable is a coaxial cable, the vacuum capacitor C0Calculated by formula (1);
in the formula (1), epsilon0Is a vacuum dielectric constant; r issThe inner radius of the shielding layer of the XLPE power cable is 10 kV; r iscIs the core radius of a 10kV XLPE power cable. Based on vacuum capacitor C0Polarization-depolarization current and polarization voltage, calculating to obtain DC conductivity sigma0。
DC conductivity σ0Is calculated by the formula (2),
in the formula (2), UcA polarization voltage applied for polarization-depolarization current measurement; i.e. ipol(t) is the polarization current at the corresponding time; i.e. idepol(t) depolarization at the corresponding timeAnd (4) streaming.
The calculation method of the low-frequency dielectric loss factor tan delta at 0.1Hz is as follows:
calculating the vacuum capacitance C of the evaluated 10kV XLPE power cable0Wherein the vacuum capacitor C0Calculated from equation (1):
in the formula (1), ε 0 represents a vacuum dielectric constant; r issThe inner radius of the shielding layer of the XLPE power cable is 10 kV; r iscThe radius of a core of the XLPE power cable is 10 kV;
calculating the medium response function f (t) of the depolarizing current:
fourier transform is carried out on the medium response function f (t) to obtain
In the formula (4), χ (ω) is a repolarization rate; χ' (ω) is the real part of the repolarization ratio; χ "(ω) is the imaginary component of the repolarization rate;
the dielectric loss factor is:
in the formula (5), epsilon∞A high frequency component that is a dielectric constant;
and selecting the low-frequency dielectric loss factor at 0.1Hz as a reference characteristic quantity.
The nonlinear coefficient DONL is calculated as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
Table 1 shows the old insulation aging state evaluation table of 10kV XLPE power cable
| Insulation aging state evaluation | DC conductivity σ0 | 0.1Hz Low frequency dielectric loss tan delta (%) | Nonlinear coefficient DONL |
| Good condition | σ0≤1×10-14 | tanδ≤0.05 | DONL≤1.2 |
| It is worth noting that | 1×10-14<σ0<1×10-12 | 0.05<tanδ<0.2 | DONL>1.2 |
| Deterioration of insulation | σ0≥1×10-12 | tanδ≥0.2 |
See Table 1 for evaluation criteria when σ0≤1×10-14And when the 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and less than or equal to 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be good, and in this case, no measures need to be taken.
When satisfying 1X 10-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 at least one of the said 10kV XLPE power cable insulation aging state is evaluated as slight aging, in this case, the normal operation is not affected, and the insulation state diagnosis is needed to be carried out periodically.
When sigma is satisfied0≥1×10-12And when the tan delta is more than or equal to 0.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be serious aging, in this case, accidents can happen when the power cable is continuously operated, and further detection and repair or replacement measures are required to be taken.
The non-linear coefficient DONL has better sensitivity to serious concentrated defects such as bridging water trees of the 10kV XLPE power cable, and when the DONL is larger than 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be possible bridging water tree aging.
Fig. 5 schematically shows a schematic of the structure of the system of the present invention. Referring to fig. 5, the insulation aging evaluation system 1 for 10kV XLPE power cables of the present invention includes a measuring unit 11, a calculating unit 12, and an evaluating unit 13.
The measurement unit 11 is used to measure the polarization-depolarization currents of the polarization process and the short-circuit-to-ground depolarization process applied to the evaluated 10kV XLPE power cable. The measuring unit 11 may be a polarization-depolarization current measuring system as disclosed in chinese patent document (publication No. CN106908654A, published: 2017.06.30). The method for measuring polarization-depolarization current can be a method for measuring polarization-depolarization current of XLPE cable as disclosed in chinese patent document (publication No. CN 105467190a, published: 2016.04.06).
The calculation unit 12 is configured to calculate a characteristic quantity characterizing an aging state of the insulation of the cable based on the measured polarization-depolarization current and the applied polarization voltage.
The evaluation unit 13 is used for evaluating the cable insulation aging degree based on the characteristic quantity and an evaluation standard.
Wherein the characteristic quantity comprises a DC conductivity σ00.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigma0The unit of (a) is S/m,
DC conductivity σ0The calculation method of (2) is as follows:
when the 10kV XLPE power cable is a coaxial cable, the vacuum capacitor C0Calculated by formula (1);
in the formula (1), epsilon0Is a vacuum dielectric constant; r issThe inner radius of the shielding layer of the XLPE power cable is 10 kV; r iscThe radius of a core of the XLPE power cable is 10 kV;
based on the vacuum capacitor C0Polarization-depolarization current and polarization voltage, and calculating to obtain the DC conductivity sigma0。
DC conductivity σ0Calculated by formula (2);
in the formula (2), UcA polarization voltage applied for polarization-depolarization current measurement; i.e. ipol(t) is the polarization current at the corresponding time; i.e. idepol(t) is the depolarization current at the corresponding time.
The calculation method of the low-frequency dielectric loss factor tan delta at 0.1Hz is as follows:
calculating the vacuum capacitance C of the evaluated 10kV XLPE power cable0When the 10kV XLPE power cable is a coaxial cable, the vacuum capacitor C0Calculated by formula (1);
in the formula (1), epsilon0Is a vacuum dielectric constant; r issThe inner radius of the shielding layer of the XLPE power cable is 10 kV; r iscThe radius of a core of the XLPE power cable is 10 kV;
calculating the medium response function f (t) of the depolarizing current:
fourier transform is carried out on the medium response function f (t) to obtain
In the formula (4), χ (ω) is a repolarization rate; χ' (ω) is the real part of the repolarization ratio; χ "(ω) is the imaginary component of the repolarization rate;
the dielectric loss factor is:
in the formula (5), epsilon∞A high frequency component that is a dielectric constant;
and selecting the low-frequency dielectric loss factor at 0.1Hz as a reference characteristic quantity.
The nonlinear coefficient DONL is calculated as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
When sigma is0≤1×10-14And a 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and DONL is less than or equal to 1.2, the cable insulation aging state is evaluated to be good.
See Table 1, when 1X 10 is satisfied-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 at least one of the above points, the cable insulation aging state is evaluated as slight aging.
See Table 1, when σ is satisfied0≥1×10-12And tan delta is more than or equal to 0.2, the insulation aging state of the cable is evaluated to be serious aging.
Referring to table 1, the cable insulation aging status was evaluated as possible bridging water tree aging when DONL > 1.2.
The invention is further illustrated by the following examples.
In the embodiment, 10kV XLPE 50cm short cable samples are selected for the evaluated cable to carry out accelerated water tree aging and natural damping experiments; and selecting 10kV XLPE 95m long cable B, C two phases to perform the accelerated water tree aging experiment without puncturing and puncturing. Specifically, as shown in fig. 1 and 2, the aging voltage is 7.5kV and 400Hz high frequency high voltage.
And carrying out polarization-depolarization current tests on the aged and unaged long and short cable samples, and carrying out data processing such as filtering and fitting on test data, wherein the goodness of fit is more than 0.98.
Calculating the direct current conductivity sigma of the short cable sample by using the formulas (2), (4) and (6)0Non-linearity factor DONL and direct current conductivity σ of the long cable0And the 0.1Hz low-frequency dielectric loss factor tan delta and the nonlinear coefficient DONL are used for comprehensively evaluating the insulation aging state of the cable.
The direct current conductivity sigma of the short cable shown in figures 3 and 4 is obtained0And the increase of the non-linearity factor DONL with aging time. In order to reduce the influence of specificity and contingency of the test samples on experimental results, the distribution points of the direct current conductivity and the nonlinear coefficient in the graph are the arithmetic mean values of the test results of the test samples under the same aging conditions. The direct current conductivity and the nonlinear coefficient of a new sample of the untreated short cable are hardly changed; of naturally-damped cable samplesThe direct current conductivity and the nonlinear coefficient are not changed greatly, but have an increasing trend; the direct current conductivity and the nonlinear coefficient of the cable sample for accelerating the water tree aging are obviously increased and are larger than the critical aging limit value provided by the criterion of the invention.
The direct current conductivity σ of the long cable was obtained as shown in Table 200.1Hz low frequency dielectric loss factor tan delta (0.1Hz low frequency dielectric loss tan delta), and a non-linearity coefficient DONL. According to the method, the two phases of the cable B, C are aged to different degrees after the water tree is aged with or without the pricking, wherein the water tree aging phenomenon possibly exists in the C phase of the cable.
TABLE 2
In the embodiments provided by the present invention, it should be understood that the disclosed system and method can be implemented in other ways. For example, the above-described system embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, systems or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, i.e. may be located in one place, or may be distributed over a plurality of network elements. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium/unit includes: various media capable of storing program codes, such as a Universal Serial Bus flash disk (usb flash disk), a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, and an optical disk.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (4)
1. A10 kV XLPE power cable insulation aging assessment method is characterized by comprising the following steps:
measuring polarization-depolarization currents of a polarization voltage polarization process and a short circuit grounding depolarization process applied to the evaluated 10kV XLPE power cable;
calculating to obtain characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage;
based on the characteristic quantity and an evaluation standard, evaluating the insulation aging degree of the 10kV XLPE power cable;
the characteristic quantity includes a direct current conductivity σO0.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigmaOHas the unit of S/m, and has the unit of 0.1Hz low-frequency dielectric loss factor tan delta;
the evaluation criteria were: when sigma is0≤1×10-14When the 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and the DONL is less than or equal to 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be good; or, when 1 × 10 is satisfied-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 when one or more of the power cables are aged, evaluating the insulation aging state of the 10kV XLPE power cable to be slightly aged; or, when σ is satisfied0≥1×10-12And when the tan delta is more than or equal to 0.2, evaluating the insulation aging state of the 10kV XLPE power cable to be serious aging.
2. The insulation aging evaluation method of 10kV XLPE power cable according to claim 1, wherein the calculation method of the non-linearity coefficient DONL is as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
3. The 10kV XLPE power cable insulation aging evaluation system is characterized by comprising the following steps:
a measuring unit for measuring polarization-depolarization currents of a polarization voltage polarization process and a short-circuit ground depolarization process applied to the evaluated 10kV XLPE power cable;
a calculating unit, which is used for calculating and obtaining the characteristic quantity representing the insulation aging state of the 10kV XLPE power cable based on the measured polarization-depolarization current and the applied polarization voltage;
the evaluation unit is used for evaluating the insulation aging degree of the 10kV XLPE power cable based on the characteristic quantity and an evaluation standard;
the characteristic quantity includes a direct current conductivity σO0.1Hz low frequency dielectric loss factor tan delta, a non-linear coefficient DONL, wherein the direct current conductivity sigmaOHas the unit of S/m, and has the unit of 0.1Hz low-frequency dielectric loss factor tan delta;
the evaluation criteria were: when sigma is0≤1×10-14When the 0.1Hz low-frequency dielectric loss factor tan delta is less than or equal to 0.05 and the DONL is less than or equal to 1.2, the insulation aging state of the 10kV XLPE power cable is evaluated to be good; or, when 1 × 10 is satisfied-14<σ0<1×10-12、0.05<tanδ<0.2、DONL>1.2 when one or more of the power cables are aged, evaluating the insulation aging state of the 10kV XLPE power cable to be slightly aged; or, when σ is satisfied0≥1×10-12And when the tan delta is more than or equal to 0.2, evaluating the insulation aging state of the 10kV XLPE power cable to be serious aging.
4. The 10kV XLPE power cable insulation aging evaluation system according to claim 3, wherein the calculation method of the non-linearity coefficient DONL is as follows:
in the formula (6), DONL is the insulation nonlinear coefficient of the 10kV XLPE power cable; sigma0(2kV) is the direct current conductivity at a polarization voltage of 2 kV; sigma'0(1kV) is the direct current conductivity at a polarization voltage of 1 kV.
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| CN111650482A (en) * | 2020-05-21 | 2020-09-11 | 国网河北省电力有限公司电力科学研究院 | High-success-rate cable water tree defect rapid culture device and method |
| CN111766481B (en) * | 2020-07-03 | 2022-02-08 | 四川大学 | XLPE cable water tree aging detection method based on time stability |
| CN113138325B (en) * | 2021-04-14 | 2022-08-19 | 长江大学 | Rapid diagnosis method for loss decoupling of insulating low-frequency medium of crosslinked polyethylene cable |
| CN113295978B (en) * | 2021-06-09 | 2023-01-24 | 广东电网有限责任公司 | Cable detection device, method, terminal device and computer readable storage medium |
| CN114184907B (en) * | 2021-11-08 | 2022-08-05 | 西南交通大学 | Rail transit cable aging degree evaluation method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091611A (en) * | 2013-01-14 | 2013-05-08 | 江苏省电力公司电力科学研究院 | Oiled paper insulation power equipment insulation aging state detecting method |
| CN105259486A (en) * | 2015-11-17 | 2016-01-20 | 华中科技大学 | Aging site rapid diagnosis method for 10 kV XLPE cable based on polarization current measurement |
| CN105699864A (en) * | 2016-01-26 | 2016-06-22 | 大连理工大学 | A method for assessing oilpaper insulating aging state on the basis of polarization and depolarization charge differences |
| CN106908654A (en) * | 2015-12-23 | 2017-06-30 | 华中科技大学 | A kind of polarization-depolarization current measuring system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3794290B2 (en) * | 2001-06-29 | 2006-07-05 | 株式会社日立製作所 | Article deterioration diagnosis method, quality inspection method, material judgment method and diagnostic device, article deterioration management method |
-
2017
- 2017-12-14 CN CN201711337741.9A patent/CN108051712B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103091611A (en) * | 2013-01-14 | 2013-05-08 | 江苏省电力公司电力科学研究院 | Oiled paper insulation power equipment insulation aging state detecting method |
| CN105259486A (en) * | 2015-11-17 | 2016-01-20 | 华中科技大学 | Aging site rapid diagnosis method for 10 kV XLPE cable based on polarization current measurement |
| CN106908654A (en) * | 2015-12-23 | 2017-06-30 | 华中科技大学 | A kind of polarization-depolarization current measuring system |
| CN105699864A (en) * | 2016-01-26 | 2016-06-22 | 大连理工大学 | A method for assessing oilpaper insulating aging state on the basis of polarization and depolarization charge differences |
Non-Patent Citations (3)
| Title |
|---|
| "基于PDC法的水树老化电缆绝缘诊断";蔡钢 等;《绝缘材料》;20161231;第49卷(第7期);61-64、71 * |
| Condition assessment of XLPE cable insulation using short-time polarisation and depolarisation current measurements;B. Oyegoke 等;《 IET SCIENCE MEASUREMENT & TECHNOLOGY》;20081231;第2卷(第1期);25-31 * |
| Dielectric Spectroscopy in Time and Frequency Domain for HVPower Equipment, Part I:Theoretical Considerations;Walter S. Zaengl;《FEATURE ARTICLE》;20031031;第19卷(第5期);5-19 * |
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