CN205880124U - A time domain test system for insulating medium condition assessment that ages - Google Patents
A time domain test system for insulating medium condition assessment that ages Download PDFInfo
- Publication number
- CN205880124U CN205880124U CN201520996382.8U CN201520996382U CN205880124U CN 205880124 U CN205880124 U CN 205880124U CN 201520996382 U CN201520996382 U CN 201520996382U CN 205880124 U CN205880124 U CN 205880124U
- Authority
- CN
- China
- Prior art keywords
- module
- current
- electrode
- measuring
- measurement
- 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.)
- Active
Links
Abstract
The utility model belongs to the technical field of insulating medium's ageing condition assessment, concretely relates to a time domain test system for insulating medium condition assessment that ages. This system includes power module, measuring electrode module, current measuring module, data acquisition module, high -pressure stage that power module passes through current source for measurement line connection three electrode systems to the measuring electrode module in is extremely gone up with measuring, and the measurement of three electrode systems extremely links to each other through the current input of coaxial cable shielded wire with current measuring module in the measuring electrode module, and current measuring module's output links to each other with data acquisition module's oscilloscope input. The utility model discloses can improve current measurement's accuracy, overcome traditional insulation ageing condition assessment method operation process complicacy, longer problem consuming time, the sample that the measurement needs is little, noise proof effectual, and is sensitive to the heat ageing, and can carry out quantitative analysis to the ageing state, all can measure solid and liquid insulating medium.
Description
Technical field
This utility model belongs to the ageing state assessment technology field of dielectric, is specifically related to a kind of for dielectric
The Time-Domain Measuring System of ageing state assessment.
Background technology
Power transmission and transforming equipment is safe and stable, reliably run, and is the properly functioning important leverage of power system.Due to needs
Facing the various mal-conditions under outdoor outdoor working environment, under long-term hanging net operation, the dielectric of electrical equipment can not
Avoid there will be catabiosis, break down, and then cause accident.Therefore, electrical equipment is carried out periodic monitoring, assesses it old
Change state is the most necessary.
At present, the more commonly used in engineering isolation diagnostic method has two kinds: physico-chemical analysis method and electrical measurements.Wherein
Physics that physico-chemical analysis method mainly causes by insulation ag(e)ing, chemical parameters characterize the state of insulation of dielectric, and electric
Measuring rule is to carry out homeostasis state of insulation with the change of dielectric electric parameter.Traditional physico-chemical analysis method is as strong to stretching
Degree, the measurement of the degree of polymerization, measure difficulty relatively big, and operating process be more complicated, the longest.Electrical measurements is grasped because of it in recent years
Make convenient, lossless feature, by the extensive concern of insider, but the most still have significant limitation:
Sample size is had certain demand, as cable generally requires the sample of more than several meters when surveying its electric property, for measuring band
It is inconvenient to come；Measurement result is more sensitive to noise ratio, significantly impacts the accuracy of assessment result；To the heat ageing of dielectric and
Radiation aging is insensitive, and the coupling means simultaneously lacking necessity carry out quantitative analysis；Medium form there is certain requirement.
Summary of the invention
The purpose of this utility model is to provide a kind of Time-Domain Measuring System for the assessment of dielectric ageing state, with
Improve the accuracy of current measurement, overcome conventional insulator ageing state appraisal procedure operating process longer asking complicated, time-consuming
Topic, measures the sample needed little, and anti-noise is effective, sensitive to heat ageing, and ageing state can be carried out quantitative analysis, to solid
Body and liquid insulating medium all can measure, and can be used for the dielectric sample detecting of engineering site, it is achieved dielectric is old
The assessment fast and effectively of change state.
For reaching above-mentioned purpose, technical solution adopted in the utility model is:
A kind of for dielectric ageing state assessment Time-Domain Measuring System, including power module, measure electrode module,
Current measurement module, data acquisition module；Power module is connected to measure three electrode systems in electrode module by measuring power line
The high-pressure stage of system is extremely gone up with measuring, and measures the measurement pole of three-electrode system in electrode module and passes through coaxial cable shield line and electric current
The current input terminal of measurement module is connected, the oscillograph input phase of the outfan of current measurement module and data acquisition module
Even.
Described power module is used for being charged for tested sample, controls whole polarization process and process of depolarization simultaneously
Beginning and end, and the switching of polarization process and process of depolarization；It includes DC source and time relay group, direct current
Power supply selects one group of direct-flow storage battery connected, and according to measuring the size needing to change voltage, time relay group passes through three
The connection of the time relay, combination, it is achieved the control to polarization process Yu process of depolarization, polarization process and process of depolarization
The time start, continue, terminated can be by being set for regulation to the time relay.
Described measurement electrode module is used for placing tested sample, and it includes shielded box and three-electrode system；When tested
When sample is solid, selecting three-electrode system as the electrode of measurement electrode module, its portable protective gaps distance is 2mm, measures electrode
A diameter of 50mm, by three-electrode system shielded box shielding get up.
Described current measurement module is used for being changed by tested electric current and amplifying, and obtaining subsequent data acquisition module can
With the voltage signal measured, it includes micro-current magnification circuit, range switching device and metal shielding box；Described micro-electric current is put
Big circuit is divided into two parts: the first half of amplifying circuit includes the INA116 for improving input impedance effect and big resistance electricity
Resistance, decoupling capacitor, current-limiting resistance, the anti-thunder tube 2RM600-8 of protection circuit；The latter half of amplifying circuit include two panels OP07,
Regulate potentiometer and decoupling capacitor, the current-limiting resistance of offset voltage and be connected to amplify the filter high-frequency electrical between amplifier pin
Hold；Tested electric current sequentially passes through big valued resistor, INA116, plays the OP07 of amplification and plays follower effect
OP07, finally gives the voltage signal after amplification, and separate two parts are mutually connected vertically by contact pin；Described range
Switching device: be connected in parallel with a capacitor C amplifying resistance two endsf, electric capacity CfSelect the temperature compensating ceramic condenser that electric leakage is less,
And its size meets RsCin≤RfCf, wherein RsFor singal source resistance, RfFor amplifying resistance, amplify resistance and select glaze resistance,
The amplification resistance of amplifying circuit is accessed, it is achieved the switching of range, C by switchinginInput parasitic capacitance for several pF to tens of pF；
Whole micro-current magnification circuit and range switching device length are respectively the metal shielding box screen of 11.5cm, 6cm, 11cm
Cover, and shielding box shell is connected with the earth, shielding box has the switch of gear switch, be used for converting amplification resistance, complete
Become the switching of range；Front end lower position at shielding box also has tested electric current input coaxial cable interface and measures electrode mould
Block is connected.
Described data acquisition module is used for measuring the voltage of current measurement module output and by the result recorded through counting
Calculation processes, and obtains the IA factor, thus qualitative assessment dielectric ageing state, it includes oscillograph and computer.
Having the beneficial effect that acquired by this utility model
Solid and liquid insulating medium be can be carried out measuring by this utility model, and it is little to measure the sample needed, only
Needing a diameter of 10cm, thickness is less than disc-shaped solid sample or the liquor sample of 40ml of 2mm.This utility model institute
The system used reduces noise and the external interference impact on measurement result by many kinds of measures, is effectively improved measurement result
Accuracy (precision is up to pA level).Fig. 3 is the comparison diagram of the output voltage waveforms before and after employing interference protection measure, is computed figure
The signal to noise ratio snr b=20dB of measurement result in signal to noise ratio snr a=4dB, Fig. 3 b of measurement result in 3a, it is seen that use anti-interference
After measure, the signal to noise ratio of measurement result is significantly improved, and the accuracy of measurement result effectively improves.This utility model can
The ageing state of the IA factor tested dielectric of direct quantization signifying to be obtained by measurement, it is achieved engineering site quick
Measure assessment.
Accompanying drawing explanation
Fig. 1 is that the aging waving map of dielectric assesses system module connection figure；
Fig. 2 is the linearity of measured value；
Fig. 3 is interference protection measure effect contrast figure；
Fig. 4 is dielectric aging waving map estimation flow figure；
Fig. 5 is the polarization depolarization current curve of the insulating paper sample of different ageing time；
Fig. 6 changes over curve for the different aging sample quantities of electric charge；
Fig. 7 is the relation of the IA factor and ageing time t；
Fig. 8 is (1/DP)-(1/DP0) and the relation of ageing time t；
Fig. 9 is the relation curve of DP Yu the IA factor.
Detailed description of the invention
With specific embodiment, this utility model is described in detail below in conjunction with the accompanying drawings.
As it is shown in figure 1, the Time-Domain Measuring System for the assessment of dielectric ageing state described in the utility model includes electricity
Source module, measurement electrode module, current measurement module, data acquisition module；Power module is connected to survey by measuring power line
In amount electrode module, the high-pressure stage of three-electrode system is extremely gone up with measuring, and measures the measurement pole of three-electrode system in electrode module and passes through
Coaxial cable shield line is connected with the current input terminal of current measurement module, the outfan of current measurement module and data acquisition module
The oscillograph input of block is connected.
Described power module is used for being charged for tested sample, controls whole polarization process and process of depolarization simultaneously
Start and terminate, and the switching of polarization process and process of depolarization.It includes DC source and time relay group.In order to subtract
Micro current circuit is interfered by small power supply, impact measure accuracy, therefore DC source select one group connect straight
Stream accumulator, according to measuring the size needing to change voltage.Time relay group passes through the connection of three time relays, group
Close, it is achieved the control to polarization process Yu process of depolarization, the beginning of polarization process and process of depolarization, continue, end time
Between can by the time relay is set for regulation.
Measure electrode module to be used for placing tested sample, be connected into measurement loop.It includes shielded box and three electrode systems
System (or lubricating cup).When tested sample is solid, select three-electrode system as the electrode of measurement electrode module, its portable protective gaps
Distance is 2mm, measures a diameter of 50mm of electrode, and the advantage of three-electrode system is volumetric energy and surface current are separated survey
Amount, eliminates the impact of edge effect, and the shielding of whole three-electrode system shielded box is got up, and reduces the external interference shadow to measuring
Ring.When tested sample is liquid, selects lubricating cup as measuring electrode system, play the effect containing tested sample with electrode.
Current measurement module is used for being changed by tested electric current and amplifying, and obtaining subsequent data acquisition module can measure
Voltage signal.It includes micro-current magnification circuit, range switching device and metal shielding box；
Described micro-current magnification circuit is divided into two parts: the first half of amplifying circuit, mainly includes for improving defeated
Enter the INA116 of hindrance function and big valued resistor, decoupling capacitor, current-limiting resistance, the anti-thunder tube 2RM600-8 of protection circuit；Put
The latter half of big circuit, mainly includes two panels OP07 (being respectively used to amplification and follower effect), regulates offset voltage
Potentiometer, and decoupling capacitor, current-limiting resistance and be connected to amplify the filter high frequency capacitance between amplifier 2,6 pin.Tested electric current
Sequentially pass through big valued resistor, INA116, play the OP07 of amplification and play the OP07 of follower effect, finally giving and put
Voltage signal after great.Separate two parts are mutually connected vertically by contact pin.
Described range switching device: along with the increase of operational amplifier feedback resistance, easily there is vibration, now in circuit
There will be input parasitic capacitance C of several pF to tens of pFin, cause the bad stability of amplifier.In order to solve this problem, putting
Big resistance two ends are connected in parallel with a capacitor Cf, by the way of phase compensation, stop vibration.Electric capacity CfSelect the temperature that electric leakage is less
Compensatory ceramic condenser, and its size meets RsCin≤RfCf, wherein RsFor singal source resistance, RfFor amplifying resistance.This practicality is new
The Current amplifier mode that type is selected is high input impedance method, saves the measurement time compared with integration method.Amplify resistance and select glass
Glass glaze resistance, reduces the variations in temperature impact on measurement result.The amplification resistance of amplifying circuit is accessed by switching, it is achieved
The switching of range.
Whole micro-current magnification circuit and range switching device length are respectively the metal of 11.5cm, 6cm, 11cm
Shielding box shielding is got up, and is connected with the earth by shielding box shell, thus reaches to shield the purpose of external interference.Have on shielding box
The switch of gear switch, is used for converting amplification resistance, completes the switching of range；Front end lower position at shielding box also has quilt
Survey electric current input coaxial cable interface to be connected with measuring electrode module.Extraneous doing is reduced further by using of shielding box
Disturb, improve the accuracy measured.
Add shading ring at amplifier input, will it surround with metallic shield ring, and ground connection, to reduce leakage current and to connect
Touch noise.
The input current of micro current system of the present utility model and the relation of output voltage are Iin=Vout·10-n,
Wherein selected when being to measure for the n order of magnitude amplifying resistance.This measurement system is tested, the following institute of part measurement result
Show:
Measurement result above is carried out linearity analysis, and analysis result is as in figure 2 it is shown, amplified under resistance gear by difference
The linearity analysis of measured value is it can be seen that the data measured meet linear relationship.It is computed measurement result and actual value
Big relative error is 14.6%, can meet requirement of engineering.
Data acquisition module is used for measuring the voltage of current measurement module output and by the result that records at calculating
Reason, obtains the IA factor, thus qualitative assessment dielectric ageing state.It includes oscillograph and computer.
The dielectric aging waving map estimation flow figure that this utility model provides as shown in Figure 4, comprises the steps:
Step one: obtaining and need the dielectric sample carrying out ageing state assessment, solid sample takes a diameter of 10cm is thick
The degree disk less than 2mm, liquor sample takes 40ml, according to the working environment of measured medium, in laboratory environments, to tested
Sample is accelerated burin-in process, obtains the sample of different ageing state.
Step 2: select electrode (three electrodes selected by solid, and liquid selects lubricating cup) according to the physical aspect of sample, place
Sample, is that measuring circuit selects suitable gear by range switching device, and after being substantially discharged sample, opening time continues
The switch of electrical equipment group, starts the process of depolarization that polarizes, and by computer recording measurement result.
Step 3: process measurement result, is smoothed depolarization current measurement result, then by electric current
To time integral, the quantity of electric charge obtaining integration changes over curve matching, thus obtains the relational expression of the quantity of electric charge and time,
By the fitting result of different ageing state samples, find the IA factor and the relation of ageing time in fit correlation formula further,
And according to the relation between the standard parameter of different medium ageing time and its existing measurement ageing state, obtain the IA factor with
Functional relationship between standard parameter.
Step 4: in actual test jobs, obtains the dielectric sample needing to measure, and measured and data process
Obtain the IA factor, i.e. can obtain weighing the standard parameter of measured medium ageing state, thus quantitatively obtain the aging of measured medium
State.
Enforcement example:
(1) prepared by sample: the disk that first certain model cable insulating paper is cut into some diameter 10cm is carried out at 90 DEG C
It is vacuum dried 24 hours, then immersion oil 24 hours in the Vaccum Permeating fuel tank at 40 DEG C, the transformator paper after finally processing
Being placed in the ageing oven of 180 DEG C, be accelerated burin-in process, periodically taking out heat time heating time is 100h, 200h, 300h, 400h
Aging sample some, as measuring sample.Before measuring sample is placed in climatic chamber 12 hours, exists simultaneously
Keep stationary temperature during measurement as far as possible.
(2) process is measured: after placing sample, first sample is substantially discharged before measurement starts, to ensure
The accuracy of measurement result；The time relay group of power module is configured, the time relay that charging starts will be controlled
Set of time is 5s, and the time relay set of time controlling charging end is 125s, controls the time relay that electric discharge starts
Set of time is 125.1s, and is 50V by the DC voltage regulation being applied on sample；The range of regulation current measurement module is cut
Changing device, chooses the power supply of suitable gear, opening time relay and amplifier for measuring circuit, and measurement starts, successively
Polarize, process of depolarization；Observe that depolarization current is stable after zero, derived by data acquisition module and record reality
Test result；After treating that sample is substantially discharged, shut-in time relay and the power supply of amplifier, change sample, start the survey of a new round
Amount, repeats above step.
(3) the IA factor and the reckoning of standard parameter function relation: the polarization depolarization current of different aging samples is measured
Result is smoothed, and eliminates the interference of noise, and the result obtained is as shown in Figure 5；The measurement time is amassed by depolarization current
Point, the quantity of electric charge obtained changes over curve as shown in Figure 6；Utilize formula q=-Ae-t/BThe result of Fig. 6 is intended by+C
Closing, the fitting result of different ageing time samples is as shown in the table:
| Ageing time (h) | A(×10-6) | B | C(×10-6) |
| 100 | 3.71 | 19.89 | 4.82 |
| 200 | 6.56 | 25.33 | 7.51 |
| 300 | 9.81 | 17.63 | 10.42 |
| 400 | 11.85 | 13.71 | 12.44 |
The A value that matching obtains is the IA factor, the IA factor with the relation of ageing time as it is shown in fig. 7, matching obtains aging
Time t is t=35.87 × 10 with the relational expression of the IA factor6IA-36.29。
The standard parameter of this example selection is the degree of polymerization, and DP is the degree of polymerization of ageing time t insulating paper, DP0For not
Through the degree of polymerization of the insulating paper of overaging, measure the degree of polymerization of different ageing time insulating paper, (1/DP)-(1/DP0) with aging
The relation of time as shown in Figure 8, obtains degree of polymerization DP=1/ (5.96 × 10 by matching-6T+0.001), the therefore degree of polymerization and IA
The relation of the factor is DP=1/ (213.785IA+0.001), and the relation curve of DP Yu the IA factor is as shown in Figure 9.
4) in-site measurement: take aging sample to be measured, the IA factor being obtained sample to be tested by measurement and data process is
32.34×10-6, it is 130 by being calculated its degree of polymerization.Standard according to the rules, when DP value is about 500, equipment is in the longevity
The hit phase, when DP is down to about 250, equipment is in late period in life-span, when DP is down to about 150, should not continue to run with, therefore be surveyed
Equipment should not be continuing with.
Claims (5)
1. the Time-Domain Measuring System for the assessment of dielectric ageing state, it is characterised in that: include power module, measurement
Electrode module, current measurement module, data acquisition module；Power module is connected to measure in electrode module by measuring power line
The high-pressure stage of three-electrode system is extremely gone up with measuring, and measures the measurement pole of three-electrode system in electrode module and passes through coaxial cable shield
Line is connected with the current input terminal of current measurement module, and the outfan of current measurement module is defeated with the oscillograph of data acquisition module
Enter end to be connected.
Time-Domain Measuring System for the assessment of dielectric ageing state the most according to claim 1, it is characterised in that: institute
The power module stated, for being charged for tested sample, controls whole polarization process and the beginning of process of depolarization and knot simultaneously
Bundle, and the switching of polarization process and process of depolarization；It includes DC source and time relay group, and DC source selects one
The direct-flow storage battery of group series connection, according to measuring the size needing to change voltage, time relay group passes through three time relays
Connection, combination, it is achieved the control to polarization process Yu process of depolarization, the beginning of polarization process and process of depolarization, continue,
The time terminated can be by being set for regulation to the time relay.
Time-Domain Measuring System for the assessment of dielectric ageing state the most according to claim 2, it is characterised in that: institute
The measurement electrode module stated is for placing tested sample, and it includes shielded box and three-electrode system；When tested sample is solid,
Selecting three-electrode system as the electrode of measurement electrode module, its portable protective gaps distance is 2mm, measures a diameter of of electrode
50mm, gets up the shielding of three-electrode system shielded box.
Time-Domain Measuring System for the assessment of dielectric ageing state the most according to claim 3, it is characterised in that: institute
The current measurement module stated, for being changed by tested electric current and amplifying, obtains the electricity that subsequent data acquisition module can be measured
Pressure signal, it includes micro-current magnification circuit, range switching device and metal shielding box；Described micro-current magnification circuit is divided into
Two parts: the first half of amplifying circuit includes the INA116 for improving input impedance effect and big valued resistor, decoupling electricity
Appearance, current-limiting resistance, the anti-thunder tube 2RM600-8 of protection circuit；The latter half of amplifying circuit includes two panels OP07, regulation imbalance
The potentiometer of voltage and decoupling capacitor, current-limiting resistance and be connected to amplify the filter high frequency capacitance between amplifier pin；Tested electricity
Stream sequentially passes through big valued resistor, INA116, plays the OP07 of amplification and plays the OP07 of follower effect, finally giving
Voltage signal after amplification, separate two parts are mutually connected vertically by contact pin；Described range switching device: putting
Big resistance two ends are connected in parallel with a capacitor Cf, electric capacity CfSelect the temperature compensating ceramic condenser that electric leakage is less, and its size meets
RsCin≤RfCf, wherein RsFor singal source resistance, RfFor amplifying resistance, amplify resistance and select glaze resistance, accessed by switching
The amplification resistance of amplifying circuit, it is achieved the switching of range, CinInput parasitic capacitance for several pF to tens of pF；Whole micro-electric current is put
The metal shielding box shielding of big circuit and range switching device length respectively 11.5cm, 6cm, 11cm is got up, and will
Shielding box shell is connected with the earth, and shielding box has the switch of gear switch, is used for converting amplification resistance, completes cutting of range
Change；Front end lower position at shielding box also has tested electric current input coaxial cable interface to be connected with measuring electrode module.
Time-Domain Measuring System for the assessment of dielectric ageing state the most according to claim 4, it is characterised in that: institute
The data acquisition module stated, for measuring the voltage of current measurement module output and the result recorded being processed through calculating, obtains
The IA factor, thus qualitative assessment dielectric ageing state, it includes oscillograph and computer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520996382.8U CN205880124U (en) | 2015-12-04 | 2015-12-04 | A time domain test system for insulating medium condition assessment that ages |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520996382.8U CN205880124U (en) | 2015-12-04 | 2015-12-04 | A time domain test system for insulating medium condition assessment that ages |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205880124U true CN205880124U (en) | 2017-01-11 |
Family
ID=57687011
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520996382.8U Active CN205880124U (en) | 2015-12-04 | 2015-12-04 | A time domain test system for insulating medium condition assessment that ages |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205880124U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106841935A (en) * | 2015-12-04 | 2017-06-13 | 核动力运行研究所 | For the Time-Domain Measuring System and appraisal procedure of the assessment of dielectric ageing state |
| CN107167667A (en) * | 2017-06-26 | 2017-09-15 | 哈尔滨理工大学 | Polymer matrix semiconductive shieldin material DC/AC dielectric properties test system and method |
| CN111025098A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | Cable insulation aging degree judgment method based on leakage current time domain variation factor |
-
2015
- 2015-12-04 CN CN201520996382.8U patent/CN205880124U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106841935A (en) * | 2015-12-04 | 2017-06-13 | 核动力运行研究所 | For the Time-Domain Measuring System and appraisal procedure of the assessment of dielectric ageing state |
| CN107167667A (en) * | 2017-06-26 | 2017-09-15 | 哈尔滨理工大学 | Polymer matrix semiconductive shieldin material DC/AC dielectric properties test system and method |
| CN111025098A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | Cable insulation aging degree judgment method based on leakage current time domain variation factor |
| CN111025098B (en) * | 2019-11-19 | 2022-07-29 | 云南电网有限责任公司临沧供电局 | Cable insulation aging degree judging method based on leakage current time domain variation factor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106841935A (en) | For the Time-Domain Measuring System and appraisal procedure of the assessment of dielectric ageing state | |
| CN100582808C (en) | Measurement method of ferroelectric materials electric hysteresis loop wire | |
| WO2020258835A1 (en) | Detection method and system for pplp insulation aging degree of superconducting cable | |
| CN106291122B (en) | A kind of test method and system of oil immersed type condenser bushing watered and wetting defect | |
| CN103149452B (en) | Method for evaluating ageing state of paper oil insulation | |
| CN102062746A (en) | Method for measuring oiled paper insulated micro water content on basis of dielectric response | |
| CN205880124U (en) | A time domain test system for insulating medium condition assessment that ages | |
| CN107860894B (en) | Method for predicting furfural content in transformer insulating oil based on frequency domain complex dielectric constant initial slope | |
| CN105510469B (en) | The detection method of furfural content in a kind of transformer insulating paper | |
| CN106855605A (en) | For the frequency domain test analysis system and method for cable entirety aging life-span assessment | |
| CN109001598A (en) | A kind of method of application depolarising electricity growth rate assessment transformer oil paper insulation ageing state | |
| CN104865311A (en) | Pulsed eddy current probe, testing device and testing method of testing device | |
| CN109856557A (en) | A kind of on-line monitoring lithium ion battery electrochemical impedance test method | |
| CN105738454B (en) | Water content computational methods in a kind of insulating paper based on insulating oil compensation of ageing | |
| CN105759121A (en) | Insulation monitoring method for non-grounded power supply system | |
| CN111948502B (en) | Method for evaluating oil paper insulation aging state of converter transformer | |
| CN104991210A (en) | Evaluation method for partial discharge detection device, and calibration device | |
| CN108279261A (en) | A kind of online device for detecting water content of cereal and method based on radio frequency resistance method | |
| CN111239663A (en) | Partial discharge online calibration method | |
| CN111693580B (en) | Capacitive soil moisture monitoring system and method | |
| CN102062848A (en) | Calibrating device of output voltage of insulating oil dielectric strength tester | |
| CN103105533B (en) | Intelligent analysis method and intelligent analysis system of sub-synchronous oscillation | |
| CN108872747B (en) | Surge protector resistive current extraction device and method based on correlation coefficient | |
| CN208076659U (en) | Compound field based on high-frequency method couples paper oil insulation partial discharge detecting system | |
| CN102645574A (en) | On-site transient overvoltage measuring method based on network transfer function calculation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant |