CN112505483A - Cable partial discharge positioning method based on online transfer function - Google Patents

Cable partial discharge positioning method based on online transfer function Download PDF

Info

Publication number
CN112505483A
CN112505483A CN202011333067.9A CN202011333067A CN112505483A CN 112505483 A CN112505483 A CN 112505483A CN 202011333067 A CN202011333067 A CN 202011333067A CN 112505483 A CN112505483 A CN 112505483A
Authority
CN
China
Prior art keywords
cable
partial discharge
detected
transfer function
reference signal
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
CN202011333067.9A
Other languages
Chinese (zh)
Inventor
卫永琴
高建峰
吴杰
王学智
李震
李金穗
唐巧巧
岳玉丹
岳召
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.)
Shandong University of Science and Technology
Original Assignee
Shandong University of Science and Technology
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 Shandong University of Science and Technology filed Critical Shandong University of Science and Technology
Priority to CN202011333067.9A priority Critical patent/CN112505483A/en
Publication of CN112505483A publication Critical patent/CN112505483A/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
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/083—Locating faults in cables, transmission lines, or networks according to type of conductors in cables, e.g. underground
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
    • G01R23/16—Spectrum analysis; Fourier analysis
    • 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
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • 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

Abstract

The invention discloses a cable partial discharge positioning method based on an online transfer function, and belongs to the field of cable partial discharge detection and positioning research. Firstly establishing a model, injecting a reference signal into the first end of the cable to be detected and solving the transfer function of the cable to be detected, then sequentially arranging n detection points from the first end of the cable, wherein the distance between every two adjacent detection points is L2, detecting partial discharge signals at different detection points, and calculating the amplitude of an estimated reference signal corresponding to the cable with the length of L1 at different detection points by using the established model along with the successive movement of the detection points. And dividing the frequency band of the estimated reference signal frequency spectrum into a plurality of sub-frequency bands with equal width, and finally calculating the estimated distance value of the partial discharge. The method of the invention does not need to know the geometric structure and material specification of the cable and does not need to stop the operation of the cable system, the injected signal is taken as a reference signal, the calculation formula of the positioning is simple and reliable, and the parameters are easy to obtain.

Description

Cable partial discharge positioning method based on online transfer function
Technical Field
The invention belongs to the technical field of cable partial discharge detection and positioning research, and particularly relates to a cable partial discharge positioning method based on an online transfer function.
Background
The method for positioning and detecting the partial discharge of the cable comprises an off-line method and an on-line method, the off-line method is restricted to a certain extent due to the fact that a power grid system in China is huge and a power failure test is very difficult, and the actual running state of the cable cannot be simulated by the off-line detection, so that the method has great significance for the on-line positioning research of the partial discharge of the power cable.
At present, the cable on-line partial discharge detection and positioning method mainly comprises a capacitive coupling method, an ultrahigh frequency method, a temperature method, an ultrasonic detection method and an electromagnetic coupling method. The capacitive coupling method needs to destroy the structure of the cable, has higher requirements on technical personnel, and needs to perform cable restoration and waterproof work subsequently; the ultrahigh frequency method can better realize the positioning of the partial discharge source by arranging a plurality of ultrahigh frequency sensors, but ultrahigh frequency signals are quickly attenuated, the transmission range is only a few meters, detection antennas meeting the requirements are required to be arranged, and the cost is higher; the temperature method is less affected by external electromagnetic noise and has high reliability, but the method cannot judge the strength and the discharge type of the partial discharge signal, has a narrow application range, and has the temperature change under different power loads, weather conditions and laying conditions, so that the temperature monitoring is required for a long time. The ultrasonic detection method has strong anti-electromagnetic interference capability, continuously improves the sensitivity and has wider and wider application. The electromagnetic coupling method can directly reflect the strength of the partial discharge degree by obtaining the waveform of the partial discharge signal, but the partial discharge signal is weak, and the signal similar to the partial discharge pulse is difficult to filter only by a preposed filtering and amplifying unit.
Disclosure of Invention
In order to solve the problems, the invention provides a cable partial discharge positioning method based on an online transfer function, which is reasonable in design, overcomes the defects of the prior art and has a good effect.
In order to achieve the purpose, the invention adopts the following technical scheme:
a cable partial discharge positioning method based on an online transfer function comprises the following steps:
step 1: establishing a model; comprising the following substeps:
step 11: assuming that the length of the cable to be detected is L, a partial discharge signal generated by a partial discharge calibrator is used as a reference signal, and the frequency spectrum is SR(j ω); the first high-frequency current sensor injects a reference signal into a shielding layer at the first end of the cable to be detected;
step 12: the first end of the cable to be detected is used as a signal injection point and is connected with the second high-frequency current sensor, the second end of the cable to be detected is used as a detection point and is connected with the third high-frequency current sensor, and the transfer function H of the cable to be detected is obtainedL(jω)；
Step 13: after partial discharge, a partial discharge signal is transmitted in the cable core wire and the shielding layer along the left direction and the right direction, a certain length of cable with the length of L1 is selected from the cables to be detected, and the transfer function of the cable with the length of L1 is as follows:
Figure BDA0002796364120000021
after propagation, the frequency spectrum of the partial discharge signal detected by the high-frequency current sensor at the other end of the cable having a length of L1 is SP(j ω), reference signal SR(j ω) and SPThe relationship between (j ω) is:
SP(jω)＝HL1(jω)·SR(jω) (2)
estimated reference signal S corresponding to cable with length L1RThe amplitude of (j ω)' is:
Figure BDA0002796364120000022
wherein, | SP(j ω) | is the amplitude of the propagated detected partial discharge signal, | HL1(j ω) | is the magnitude of the transfer function for a cable of length L1;
step 2: the first end of the cable to be detected is a signal injection point, n detection points are sequentially arranged from the first end of the cable to be detected, the distance between every two adjacent detection points is L2, the high-frequency current sensor detects partial discharge signals at different detection points, and along with the gradual movement of the detection points, the model in the step 1 is utilized to calculate the estimation reference signal S corresponding to the cable with the length of L1 at different detection pointsR(j ω)' wherein:
L1＝n·L2 (4)
and step 3: dividing the frequency band of the estimated reference signal frequency spectrum into a plurality of sub-frequency bands with equal width;
and 4, step 4: and calculating a partial discharge estimation distance value.
Preferably, in step 12, a transfer function H of a cable of length L is obtainedL(j ω) comprises the sub-steps of:
step 121: the second high-frequency current sensor and the third high-frequency current sensor respectively detect partial discharge signals of the first end and the second end of the cable;
step 122: at the first end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the first oscilloscope is as follows:
S1(jω)＝HI(jω)×HD(jω)×I(jω) (5)
at the second end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the second oscilloscope is as follows:
S2(jω)＝HI(jω)×HD(jω)×HL(jω)I(jω) (6)
where I (j ω) is the frequency spectrum of the signal generated by the PD calibrator at the first end of the cable, HI(j ω) and HD(j ω) is the total transfer function, H, of the first and second ends, respectively, of the cable to be testedL(j ω) is the transfer function of the cable to be tested, ω is the angular frequency;
step 123: hL(jω)＝S2(jω)S1(jω) (7)
The transfer function H of the cable to be detected is obtained by the formula (7)L(jω)。
Preferably, the second high frequency current sensor and the third high frequency current sensor are of the same type.
Preferably, the experimental system is assumed to be linear time invariant.
Preferably, step 4 comprises the following sub-steps:
step 41: calculating the square error of the reference signal and the estimated reference signal spectrum;
step 42: selecting the length L1 with the smallest square error of the frequency spectrum in each sub-frequency band as an estimated distance value;
step 43: and removing the maximum and minimum estimated distance values, and calculating the average value of the residual estimated distance values as the estimated partial discharge distance value.
Preferably, the method is suitable for long cables with partial discharge frequency within 30 Mhz.
The invention has the following beneficial technical effects:
1. in the invention, the transfer function of the on-line cable is obtained without knowing the geometric structure and material specification of the cable;
2. this positioning method does not require the cable system to be taken out of service.
3. The transfer function of the cable can be identified by identifying the injected current through the cable shield by a high frequency current sensor (HFCT) and measuring the injected signal at two different locations of the cable by high frequency current sensors clamped on the shield (the propagation and attenuation characteristics of any given length of cable are known).
4. The injected signal is used as a reference signal, a calculation formula of positioning is simple and reliable, parameters are easy to obtain, and real-time communication is not needed between the measurement units.
Drawings
FIG. 1 is a schematic view of the installation of a high frequency current sensor according to the present invention;
FIG. 2 is a schematic diagram illustrating the propagation of partial discharge signals in two directions of a cable after the partial discharge occurs in the present invention;
FIG. 3 is a schematic diagram of the acquisition of a reference partial discharge signal and a propagated partial discharge signal after the occurrence of partial discharge in the present invention;
Detailed Description
To facilitate understanding and practice of the invention by those of ordinary skill in the art, embodiments of the invention are further described below with reference to the accompanying drawings and specific examples:
a cable discharge positioning method based on an online transfer function, as shown in fig. 1 to 3, includes the following steps:
step 1: establishing a model; comprising the following substeps:
step 11: assuming that the length of the cable to be detected is L, a partial discharge signal generated by a partial discharge calibrator is used as a reference signal, and the frequency spectrum is SR(j ω); the first high-frequency current sensor injects a reference signal into a shielding layer at the first end of the cable to be detected;
step 12: the first end of the cable to be detected is used as a signal injection point and is connected with the second high-frequency current sensor, the second end of the cable to be detected is used as a detection point and is connected with the third high-frequency current sensor, and the transfer function H of the cable to be detected is obtainedL(jω)；
Step 13: after partial discharge, a partial discharge signal is transmitted in the cable core wire and the shielding layer along the left direction and the right direction, a certain length of cable with the length of L1 is selected from the cables to be detected, and the transfer function of the cable with the length of L1 is as follows:
Figure BDA0002796364120000041
after propagation, a partial discharge was detected at the other end of the cable of length L1 with a high-frequency current sensorThe frequency spectrum of the signal being SP(j ω), reference signal SR(j ω) and SPThe relationship between (j ω) is:
SP(jω)＝HL1(jω)·SR(jω) (2)
estimated reference signal S corresponding to cable with length L1RThe amplitude of (j ω)' is:
Figure BDA0002796364120000042
wherein, | SP(j ω) | is the amplitude of the propagated detected partial discharge signal, | HL1(j ω) | is the magnitude of the transfer function for a cable of length L1;
step 2: the first end of the cable to be detected is a signal injection point, n detection points are sequentially arranged from the first end of the cable to be detected, the distance between every two adjacent detection points is L2, the high-frequency current sensor detects partial discharge signals at different detection points, and along with the gradual movement of the detection points, the model in the step 1 is utilized to calculate the estimation reference signal S corresponding to the cable with the length of L1 at different detection pointsR(j ω)' wherein:
L1＝n·L2 (4)
and step 3: dividing the frequency band of the estimated reference signal frequency spectrum into a plurality of sub-frequency bands with equal width;
and 4, step 4: and calculating a partial discharge estimation distance value.
In particular, in step 12, the transfer function H of the cable to be tested is obtainedL(j ω) comprises the sub-steps of:
step 121: the second high-frequency current sensor and the third high-frequency current sensor respectively detect partial discharge signals of the first end and the second end of the cable;
step 122: at the first end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the first oscilloscope is as follows:
S1(jω)＝HI(jω)×HD(jω)×I(jω) (5)
at the second end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the second oscilloscope is as follows:
S2(jω)＝HI(jω)×HD(jω)×HL(jω)I(jω) (6)
where I (j ω) is the frequency spectrum of the signal generated by the PD calibrator at the first end of the cable to be tested, HI(j ω) and HD(j ω) is the total transfer function, H, of the first and second ends, respectively, of the cable to be testedL(j ω) is the transfer function of the cable to be tested, ω is the angular frequency;
step 123: hL(jω)＝S2(jω)S1(jω) (7)
The transfer function H of the cable to be detected is obtained by the formula (7)L(jω)。
Specifically, the second high-frequency current sensor and the third high-frequency current sensor are of the same type.
In particular, the experimental system is assumed to be linear time invariant.
Specifically, step 4 comprises the following substeps:
step 41: calculating the square error of the reference signal and the estimated reference signal spectrum;
step 42: selecting the length L1 with the smallest square error of the frequency spectrum in each sub-frequency band as an estimated distance value;
step 43: and removing the maximum and minimum estimated distance values, and calculating the average value of the residual estimated distance values as the estimated partial discharge distance value.
Particularly, the method is suitable for long cables with partial discharge frequency within 30 Mhz.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.

Claims (6)

1. A cable partial discharge positioning method based on an online transfer function is characterized by comprising the following steps:
step 1: establishing a model; comprising the following substeps:
step 11: assuming that the length of the cable to be detected is L, a partial discharge signal generated by a partial discharge calibrator is used as a reference signal, and the frequency spectrum is SR(j ω); the first high-frequency current sensor injects a reference signal into a shielding layer at the first end of the cable to be detected;
step 12: the first end of the cable to be detected is used as a signal injection point and is connected with the second high-frequency current sensor, the second end of the cable to be detected is used as a detection point and is connected with the third high-frequency current sensor, and the transfer function H of the cable to be detected is obtainedL(jω)；
Step 13: after partial discharge, a partial discharge signal is transmitted in the cable core wire and the shielding layer along the left direction and the right direction, a certain length of cable with the length of L1 is selected from the cables to be detected, and the transfer function of the cable with the length of L1 is as follows:
Figure FDA0002796364110000011
after propagation, the frequency spectrum of the partial discharge signal detected by the high-frequency current sensor at the other end of the cable having a length of L1 is SP(j ω), reference signal SR(j ω) and SPThe relationship between (j ω) is:
SP(jω)＝HL1(jω)·SR(jω) (2)
estimated reference signal S corresponding to cable with length L1RThe amplitude of (j ω)' is:
Figure FDA0002796364110000012
wherein, | SP(j ω) | is the amplitude of the propagated detected partial discharge signal, | HL1(j ω) | is the magnitude of the transfer function for a cable of length L1;
step 2: the first end of the cable to be detected is a signal injection point, n detection points are sequentially arranged from the first end of the cable to be detected, and the distance between every two adjacent detection points is equalL2, the high frequency current sensor detects partial discharge signals at different detection points, and calculates the estimated reference signal S corresponding to the cable with the length of L1 at different detection points by using the model in the step 1 as the detection points move graduallyR(j ω)' wherein:
L1＝n·L2 (4)
and step 3: dividing the frequency band of the estimated reference signal frequency spectrum into a plurality of sub-frequency bands with equal width;
and 4, step 4: and calculating a partial discharge estimation distance value.
2. The method for positioning cable discharge based on-line transfer function as claimed in claim 1, wherein in step 12, the transfer function H of the cable to be detected is obtainedL(j ω) comprises the sub-steps of:
step 121: the second high-frequency current sensor and the third high-frequency current sensor respectively detect partial discharge signals of the first end and the second end of the cable;
step 122: at the first end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the first oscilloscope is as follows:
S1(jω)＝HI(jω)×HD(jω)×I(jω) (5)
at the second end of the cable to be detected, the frequency spectrum of the partial discharge signal detected by the second oscilloscope is as follows:
S2(jω)＝HI(jω)×HD(jω)×HL(jω)I(jω) (6)
where I (j ω) is the frequency spectrum of the signal generated by the PD calibrator at the first end of the cable to be tested, HI(j ω) and HD(j ω) is the total transfer function, H, of the first and second ends, respectively, of the cable to be testedL(j ω) is the transfer function of the cable to be tested, ω is the angular frequency;
step 123: hL(jω)＝S2(jω)/S1(jω) (7)
The transfer function H of the cable to be detected is obtained by the formula (7)L(jω)。
3. The method for locating partial discharge of cable according to claim 1, wherein the second high frequency current sensor and the third high frequency current sensor are of the same type.
4. The method as claimed in claim 1, wherein the experimental system is assumed to be linear and time-invariant.
5. The method for positioning partial discharge of cable based on-line function as claimed in claim 1, wherein step 4 comprises the following sub-steps:
step 41: calculating the square error of the reference signal and the estimated reference signal spectrum;
step 42: selecting the length L1 with the smallest square error of the frequency spectrum in each sub-frequency band as an estimated distance value;
step 43: and removing the maximum and minimum estimated distance values, and calculating the average value of the residual estimated distance values as the estimated partial discharge distance value.
6. The method for locating partial discharge of cable according to claim 1, wherein the method is suitable for long cable with partial discharge frequency within 30 Mhz.
CN202011333067.9A 2020-11-25 2020-11-25 Cable partial discharge positioning method based on online transfer function Pending CN112505483A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011333067.9A CN112505483A (en) 2020-11-25 2020-11-25 Cable partial discharge positioning method based on online transfer function

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011333067.9A CN112505483A (en) 2020-11-25 2020-11-25 Cable partial discharge positioning method based on online transfer function

Publications (1)

Publication Number Publication Date
CN112505483A true CN112505483A (en) 2021-03-16

Family

ID=74959792

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011333067.9A Pending CN112505483A (en) 2020-11-25 2020-11-25 Cable partial discharge positioning method based on online transfer function

Country Status (1)

Country Link
CN (1) CN112505483A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113514733A (en) * 2021-09-07 2021-10-19 中国南方电网有限责任公司超高压输电公司广州局 Fault positioning method and device, computer equipment and storage medium
CN116699257A (en) * 2023-08-02 2023-09-05 合肥航太电物理技术有限公司 High-intensity radiation field testing device of low-level scanning field and testing method thereof
CN116973702A (en) * 2023-07-31 2023-10-31 上海莫克电子技术有限公司 Signal identification method and system applied to GIS partial discharge test
CN116973672A (en) * 2023-09-25 2023-10-31 合肥航太电物理技术有限公司 Low-level scanning current testing device and testing method thereof

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102565634A (en) * 2012-01-10 2012-07-11 广东电网公司电力科学研究院 Power cable fault location method based on transfer function method
CN202383238U (en) * 2011-12-06 2012-08-15 山东电力集团公司青岛供电公司 Power cable partial discharge on-line monitoring device based on electromagnetic wave and high frequency CT
CN106771922A (en) * 2016-12-28 2017-05-31 华中科技大学 A kind of high-tension electricity system of detecting partial discharge in equipment and Recognition of Partial Discharge
CN107390100A (en) * 2017-08-03 2017-11-24 四川大学 A kind of power cable partial discharge positioning method based on time reversal
CN108562834A (en) * 2018-02-06 2018-09-21 武汉康电电气有限公司 A kind of high-tension cable partial discharge monitoring system and the method for correcting amplitude
CN109143002A (en) * 2018-10-26 2019-01-04 重庆大学 Capacitive pick-up optimum design method built in a kind of cable connector shelf depreciation
CN109581150A (en) * 2018-12-18 2019-04-05 国网天津市电力公司电力科学研究院 Cable fault independent positioning method based on spectral decay characteristic

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202383238U (en) * 2011-12-06 2012-08-15 山东电力集团公司青岛供电公司 Power cable partial discharge on-line monitoring device based on electromagnetic wave and high frequency CT
CN102565634A (en) * 2012-01-10 2012-07-11 广东电网公司电力科学研究院 Power cable fault location method based on transfer function method
CN106771922A (en) * 2016-12-28 2017-05-31 华中科技大学 A kind of high-tension electricity system of detecting partial discharge in equipment and Recognition of Partial Discharge
CN107390100A (en) * 2017-08-03 2017-11-24 四川大学 A kind of power cable partial discharge positioning method based on time reversal
CN108562834A (en) * 2018-02-06 2018-09-21 武汉康电电气有限公司 A kind of high-tension cable partial discharge monitoring system and the method for correcting amplitude
CN109143002A (en) * 2018-10-26 2019-01-04 重庆大学 Capacitive pick-up optimum design method built in a kind of cable connector shelf depreciation
CN109581150A (en) * 2018-12-18 2019-04-05 国网天津市电力公司电力科学研究院 Cable fault independent positioning method based on spectral decay characteristic

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
MAHDI MAHDIPOUR，ET.: "Partial Discharge Localization on Power Cables Using On-Line Transfer Function", 《IEEE TRANSACTIONS ON POWER DELIVERY》 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113514733A (en) * 2021-09-07 2021-10-19 中国南方电网有限责任公司超高压输电公司广州局 Fault positioning method and device, computer equipment and storage medium
CN116973702A (en) * 2023-07-31 2023-10-31 上海莫克电子技术有限公司 Signal identification method and system applied to GIS partial discharge test
CN116973702B (en) * 2023-07-31 2024-04-05 上海莫克电子技术有限公司 Signal identification method and system applied to GIS partial discharge test
CN116699257A (en) * 2023-08-02 2023-09-05 合肥航太电物理技术有限公司 High-intensity radiation field testing device of low-level scanning field and testing method thereof
CN116699257B (en) * 2023-08-02 2023-11-28 合肥航太电物理技术有限公司 High-intensity radiation field testing device of low-level scanning field and testing method thereof
CN116973672A (en) * 2023-09-25 2023-10-31 合肥航太电物理技术有限公司 Low-level scanning current testing device and testing method thereof
CN116973672B (en) * 2023-09-25 2023-12-29 合肥航太电物理技术有限公司 Low-level scanning current testing device and testing method thereof

Similar Documents

Publication Publication Date Title
CN112505483A (en) Cable partial discharge positioning method based on online transfer function
CN108896872B (en) SSTDR-based handheld cable fault detection system and method
WO2016019666A1 (en) Method and device for detecting partial discharge of cable
CN105021953B (en) Grounding net of transformer substation corrosion detection system and method based on earth's surface magnetic induction intensity
Khan et al. A review of condition monitoring of underground power cables
WO2014075584A1 (en) Method for in-situ detection of partial discharge of damped oscillation wave of large-length ultrahigh-voltage crosslinked cable
CN103048635B (en) Anti-interference performance evaluation method for high voltage cable partial discharge on-line monitoring device
CN103344891B (en) Method and device for locating partial discharge of high voltage cable
CN203133230U (en) Short-wave antenna feeder fault detecting instrument
CN203643553U (en) Cable fault positioning and insulation aging test device
CN104914313A (en) Grounding grid fault diagnosis method based on sweep frequency impedance measurement
CN204028289U (en) A kind of distributed mine cable on-line PD monitoring and fault locator
CN103869206A (en) Grounding network state detection system for high-frequency pulse inverse scattering imaging
CN103267931B (en) Method for positioning intersecting interconnection cable intermediate head partial discharge
Sheng et al. A novel on-line cable pd localisation method based on cable transfer function and detected pd pulse rise-time
CN204679586U (en) A kind of grounding net of transformer substation corrosion detection system based on earth's surface magnetic induction density
CN209764997U (en) transient grounding voltage coupling device for cable body insulation partial discharge
CN203798969U (en) Cable partial discharge detection system based on frequency conversion resonance voltage resistance
CN101614582B (en) Method for improving anti-interference ability of rotary mechanical shaft vibration measurement system
CN116859182A (en) Method and system for positioning defects of high-voltage cable by considering frequency domain reflection spectrum of cable connector
CN114675145B (en) High-frequency partial discharge double-end monitoring partial discharge source positioning method for high-voltage cable
CN102901912B (en) Local discharge monitoring method for multiple intensively arranged power equipment
CN115144693A (en) Cable fault positioning device and method based on electromagnetic method
CN115389869A (en) Non-contact detection positioning device and method for underground cable fault
CN103913685A (en) Cable partial discharge detection system based on frequency conversion resonance voltage resistance

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

Application publication date: 20210316

RJ01 Rejection of invention patent application after publication