CN111562440A - Insulating dielectric resistivity measurement principle based on time domain least square fitting - Google Patents
Insulating dielectric resistivity measurement principle based on time domain least square fitting Download PDFInfo
- Publication number
- CN111562440A CN111562440A CN202010461194.0A CN202010461194A CN111562440A CN 111562440 A CN111562440 A CN 111562440A CN 202010461194 A CN202010461194 A CN 202010461194A CN 111562440 A CN111562440 A CN 111562440A
- Authority
- CN
- China
- Prior art keywords
- current
- insulating dielectric
- polarization
- time domain
- resistivity
- 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.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses a measuring principle of the resistivity of an insulating dielectric medium based on time domain least square fitting, belongs to the field of dielectric parameter measurement of the insulating dielectric medium, and solves the defects that the existing measuring method of the resistivity of the insulating dielectric medium is low in efficiency and is easily influenced by polarization absorption current and thermal noise. The method comprises the following steps of testing and recording a polarization current time domain spectrum of a tested insulating dielectric medium under the action of direct-current voltage, performing time domain least square fitting on the polarization current by respectively adopting a universal relaxation polarization current model and an extended Debye model, determining an optimal polarization absorption current model by taking a residual time sequence which is irrelevant to time and a residual average value which is not more than one percent of a steady-state conduction current component as a criterion, and accurately obtaining a steady-state conduction current IdcAnd the current density J is conducted from the steady statedcAnd calculating the electric field intensity to obtain the resistivity rho.
Description
Technical Field
The invention belongs to the field of dielectric parameter measurement of insulating dielectrics, and particularly relates to a measuring principle of resistivity of the insulating dielectrics based on time domain least square fitting.
Background
The excellent insulating properties of insulating dielectrics are an important basic guarantee for the safe operation of electrical equipment and electronic devices. Volume resistivity is one of the important dielectric parameters characterizing the insulating properties of insulating dielectrics. The volume resistivity of an insulating dielectric is generally measured using a test system as shown in fig. 1, which is mainly to apply a dc high voltage to the insulating dielectric for a certain time and measure the quasi-steady state leakage current flowing through the insulating dielectric. In the initial stage of the applied voltage, the polarization absorption current component caused by relaxation polarization is large. The absorption current component gradually decreases with time. After a sufficiently long time, the absorbed current component is almost zero, and the current flowing through the insulating dielectric is mainly a quasi-steady state leakage current. In engineering, a value of a current flowing through the insulating dielectric at 1 minute of applied voltage is generally taken as a quasi-steady state leakage current value to save test time, but is easily affected by a polarization absorption current. In order to accurately obtain the leakage current flowing through the insulating dielectric sample, a method is generally adopted in which the time for reading the leakage current flowing through the insulating dielectric is prolonged, the efficiency is low, and the influence of thermal noise is large. Under the action of the direct-current high voltage, the polarization absorption current component of the insulating dielectric needs a long time to decay to zero, but the specific time required for the polarization absorption current component to decay to zero is difficult to define, so the leakage current obtained by prolonging the reading time usually also comprises the polarization absorption current component, which affects the accuracy of the volume resistivity.
SUMMARY OF THE PATENT FOR INVENTION
In order to overcome the defects that the existing insulating dielectric resistivity measuring method is low in efficiency and is easily influenced by polarization absorption current and thermal noise, the invention aims to provide a measuring principle of insulating dielectric resistivity based on time domain least square fitting.
The invention is realized by the following technical scheme:
the measurement principle of the resistivity of the insulating dielectric based on time domain least square fitting is characterized by comprising the following steps ofThe small second-product fitting method eliminates the influence of polarization absorption current and thermal noise, thereby accurately obtaining the steady-state conduction current IdcAnd the current density J is conducted from the steady statedcAnd calculating the electric field intensity to obtain the resistivity rho.
Further, a universal relaxation polarization current model and an extended Debye model are respectively adopted to carry out time domain least square fitting on the polarization current, and an optimal polarization absorption current model is judged according to the fitting effect.
Further, the criterion for the least squares best fit effect is that the residual time series is time independent and the residual mean does not exceed one percent of the steady state conduction current component.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a measuring principle of the resistivity of an insulating dielectric medium based on time domain least square fitting, which is based on the time domain characteristic of universal relaxation polarization absorption current and eliminates the influence of the polarization absorption current and thermal noise on steady-state conduction current and resistivity by a least square fitting method.
The insulating dielectric resistivity measuring principle based on time domain least square fitting disclosed by the invention is easy to realize, can improve the measuring efficiency of the insulating dielectric resistivity, is generally suitable for insulating dielectrics with universal relaxation polarization characteristics, and has a wide application range.
Drawings
FIG. 1 is a schematic diagram of an insulation dielectric response current test system under the action of a DC electric field;
FIG. 2 is a test current and a fitted current for an insulating dielectric of an embodiment;
FIG. 3 is a residual of the insulating dielectric test current and the fitted current of the embodiment;
in the figure: 1. an insulating dielectric; 2. a high voltage electrode; 3. a measuring electrode; 4. a guard electrode; 5. a high voltage electrode lead; 6. a measurement electrode lead; 7. a guard electrode lead; 8. an electrometer; 9. computer data communication line.
Detailed Description
The present invention will be described in detail with reference to the following embodiments and examples. It should be emphasized that this summary is intended to be illustrative, and not limiting, of the invention.
Detailed description of the invention
A measurement principle of insulation dielectric resistivity based on time domain least square fitting specifically eliminates the influence of polarization absorption current and thermal noise by a least square fitting method, thereby accurately obtaining steady state conduction current IdcAnd the current density J is conducted from the steady statedcAnd calculating the electric field intensity to obtain the resistivity rho.
Detailed description of the invention
On the basis of the first specific embodiment, specifically, a universal relaxation polarization current model and an extended debye model are respectively adopted to perform time-domain least square fitting on the polarization current, and the optimal polarization absorption current model is judged according to the fitting effect.
Detailed description of the invention
On the basis of the second embodiment, specifically, the criterion of the least square best fit effect is that the residual time series is independent of time and the residual average value is not more than one percent of the steady-state conduction current component.
Detailed description of the invention
On the basis of the first embodiment, specifically, the calculation formula of the resistivity is
Specifically, in the formula, U is an externally applied dc voltage, S is an area of the insulating dielectric, and d is a thickness of the insulating dielectric.
Detailed description of the invention
On the basis of the second embodiment, specifically, the calculation formula of the residual Δ I is
ΔIi(t)＝Ii(t)-Ifi(t)
In particular, the residual mean value Δ IavIs calculated by the formula
In particular, I in the formulai(t) is the ith test value of the response current flowing through the insulating dielectric, Ifi(t) is the ith fitted value for the response current flowing through the insulating dielectric.
Examples
The insulating dielectric of this example is a 10 wt% silicon carbide/polyethylene composite insulating dielectric, and the electrode area S is 2122.64mm2The thickness d is 0.2mm, the applied direct current voltage U is 1kV, the model of the electrometer is Gishili 6517B, the test time t is 0-1000 s, and the change curve of the response current I along with the time t is shown in figure 2.
The fitted currents obtained using the current fitting method are shown in fig. 2. The fitting parameters obtained in this example were a-909.74 pA, n-0.96, and I, respectivelydc0.87 pA. As shown in fig. 3, the residual Δ I time series is time independent. Residual mean value Δ Iav＝-0.794×10-3pA, less than IdcIn one hundredth of the embodiments, the relaxation polarization mechanism of the insulating dielectric conforms to the universal relaxation polarization law, and the resistivity p is 7.90 × 1013Ω · m, and resistivity ρ of a test time extended alone to t 7000s0＝8.05×1013The relative error of omega m is 1.9 percent and is within the allowable range of the test error.
Claims (3)
1. The insulation dielectric resistivity measuring principle based on time domain least square fitting is characterized in that the influence of polarization absorption current and thermal noise is eliminated through a least square fitting method, and therefore steady-state conduction current I is accurately obtaineddcAnd the current density J is conducted from the steady statedcAnd calculating the electric field intensity to obtain the resistivity rho.
2. The method of claim 1, wherein the polarization current is subjected to time-domain least squares fitting using a general relaxation polarization current model and an extended debye model, respectively, and the optimal polarization absorption current model is determined according to the fitting effect.
3. The criterion for least squares best fit effect in claim 2 is that the residual time series is time independent and the residual mean value is no more than one percent of the steady state conduction current component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010461194.0A CN111562440B (en) | 2020-05-27 | 2020-05-27 | Method for measuring resistivity of insulating dielectric medium based on time domain least square fitting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010461194.0A CN111562440B (en) | 2020-05-27 | 2020-05-27 | Method for measuring resistivity of insulating dielectric medium based on time domain least square fitting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111562440A true CN111562440A (en) | 2020-08-21 |
| CN111562440B CN111562440B (en) | 2022-11-15 |
Family
ID=72072463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010461194.0A Active CN111562440B (en) | 2020-05-27 | 2020-05-27 | Method for measuring resistivity of insulating dielectric medium based on time domain least square fitting |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111562440B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2273990A (en) * | 1992-12-31 | 1994-07-06 | American Telephone & Telegraph | Surface resistivity measurements |
| CN102508774A (en) * | 2011-10-28 | 2012-06-20 | 哈尔滨工程大学 | Modeling method for software reliability growth model based on novel environmental factor function |
| CN104267264A (en) * | 2014-09-16 | 2015-01-07 | 国家电网公司 | Transformer insulation oil dielectric loss and electrical resistivity automatic detecting system |
| CN105239608A (en) * | 2015-09-28 | 2016-01-13 | 中国地质大学（武汉） | Landslide displacement prediction method based on wavelet transform-rough set-support vector regression (WT-RS-SVR) combination |
| CN106526329A (en) * | 2016-11-10 | 2017-03-22 | 广东电网有限责任公司电力科学研究院 | Method and device for measuring resistivity from land surface to deep earth |
| CN107064239A (en) * | 2017-02-24 | 2017-08-18 | 三峡大学 | A kind of method that transformer insulating paper conductance property is analyzed based on differential charge |
| CN109408885A (en) * | 2018-09-19 | 2019-03-01 | 上海电力学院 | A kind of insulator space charge density model optimization method under high voltage direct current |
| CN109918776A (en) * | 2019-03-05 | 2019-06-21 | 北京航空航天大学 | The engineering prediction on fatigue crack growth method of engineering goods based on two-step least square method |
-
2020
- 2020-05-27 CN CN202010461194.0A patent/CN111562440B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2273990A (en) * | 1992-12-31 | 1994-07-06 | American Telephone & Telegraph | Surface resistivity measurements |
| CN102508774A (en) * | 2011-10-28 | 2012-06-20 | 哈尔滨工程大学 | Modeling method for software reliability growth model based on novel environmental factor function |
| CN104267264A (en) * | 2014-09-16 | 2015-01-07 | 国家电网公司 | Transformer insulation oil dielectric loss and electrical resistivity automatic detecting system |
| CN105239608A (en) * | 2015-09-28 | 2016-01-13 | 中国地质大学（武汉） | Landslide displacement prediction method based on wavelet transform-rough set-support vector regression (WT-RS-SVR) combination |
| CN106526329A (en) * | 2016-11-10 | 2017-03-22 | 广东电网有限责任公司电力科学研究院 | Method and device for measuring resistivity from land surface to deep earth |
| CN107064239A (en) * | 2017-02-24 | 2017-08-18 | 三峡大学 | A kind of method that transformer insulating paper conductance property is analyzed based on differential charge |
| CN109408885A (en) * | 2018-09-19 | 2019-03-01 | 上海电力学院 | A kind of insulator space charge density model optimization method under high voltage direct current |
| CN109918776A (en) * | 2019-03-05 | 2019-06-21 | 北京航空航天大学 | The engineering prediction on fatigue crack growth method of engineering goods based on two-step least square method |
Non-Patent Citations (6)
| Title |
|---|
| JEONGMIN OH ET AL.: ""The dependence of dielectric properties on the thickness of (Ba,Sr)TiO3 thin films"", 《CURRENT APPLIED PHYSICS》 * |
| M. ACEDO ET AL.: ""Dielectric Characterization and Conduction Modelling of a Water Tree Degraded LDPE"", 《IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION》 * |
| 赵艾萱等: ""基于PDC 法的在运XLPE 电缆绝缘状态评估"", 《高电压技术》 * |
| 邓佳欣等: ""星用FR-4材料本征介电性能随温度的变化研究"", 《航天器环境工程》 * |
| 郑欢等: ""非线性绝缘电介质AC 介电特性参数及其测量"", 《中国电机工程学报》 * |
| 魏莹莹: ""非线性绝缘介质在交、直流激励下响应特性的仿真分析"", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111562440B (en) | 2022-11-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102944777B (en) | Cable detection method in serviceable life | |
| 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 | |
| CN103149452A (en) | Method for evaluating ageing state of paper oil insulation | |
| CN104749503A (en) | XLPE cable insulation aging state determining method | |
| CN109142991B (en) | Porcelain insulator infrared zero temperature threshold judgment method based on Burr distribution | |
| CN113917293A (en) | Method and system for evaluating insulation aging state of high-voltage dry-type sleeve based on frequency domain and time domain | |
| CN115902477A (en) | Lightning arrester operation state detection method based on digital twinning | |
| CN111562440B (en) | Method for measuring resistivity of insulating dielectric medium based on time domain least square fitting | |
| da Silva et al. | Analysis of electrical tracking by energy absorption during surface discharge in polymeric materials | |
| Gajare et al. | Model verification of fixed series compensation devices using synchronized data | |
| Torkaman et al. | Influence of ambient and test conditions on insulation resistance/polarization index in HV electrical machines-a survey | |
| CN112269105A (en) | Moisture prediction and aging evaluation method for field bushing oil-immersed cellulose insulation | |
| CN115712043A (en) | Damp diagnosis method for cold-shrinkage intermediate joint of distribution cable | |
| Yuan et al. | Simulation analysis on FDS of power transformer by FEM approach | |
| CN115932503A (en) | Insulation health assessment method for epoxy resin in high and low temperature environment | |
| CN113075268B (en) | Insulation sleeve X-wax defect detection method and system based on FDS | |
| CN113376548B (en) | Cable state monitoring method and device based on cable aging characteristic extraction | |
| CN116087698A (en) | Method and system for evaluating thermal ageing state of high-voltage sleeve | |
| CN115327254A (en) | Metalized film capacitor state online evaluation method and system based on temperature detection | |
| Mingotti et al. | Effects on the Accuracy Performance of Rogowski Coils Due to Temperature and Humidity | |
| CN111913046B (en) | Method for measuring steady-state relaxation polarizability of insulating dielectric | |
| ZA200603232B (en) | Coil residual life predicting method and apparatus | |
| Li et al. | A new method for on-line cable tanδ monitoring | |
| KR20110066693A (en) | Static monitoring device for high voltage motor |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |