CN102243289A - Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization - Google Patents

Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization Download PDF

Info

Publication number
CN102243289A
CN102243289A CN2011101659046A CN201110165904A CN102243289A CN 102243289 A CN102243289 A CN 102243289A CN 2011101659046 A CN2011101659046 A CN 2011101659046A CN 201110165904 A CN201110165904 A CN 201110165904A CN 102243289 A CN102243289 A CN 102243289A
Authority
CN
China
Prior art keywords
frequency
sensor
signal
wideband
power
Prior art date
Application number
CN2011101659046A
Other languages
Chinese (zh)
Other versions
CN102243289B (en
Inventor
陈铮铮
赵健康
蒙绍新
刘惠民
Original Assignee
国网电力科学研究院
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 国网电力科学研究院 filed Critical 国网电力科学研究院
Priority to CN201110165904.6A priority Critical patent/CN102243289B/en
Publication of CN102243289A publication Critical patent/CN102243289A/en
Application granted granted Critical
Publication of CN102243289B publication Critical patent/CN102243289B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The invention provides a method and an apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization. The apparatus comprises a main-broadband high-frequency sensor, an auxiliary- broadband high-frequency sensor, a power-frequency voltage sensor and a calculating host of synchronous analysis. The calculating host of synchronous analysis, which comprises a data acquisition module, a data processing module, an interference filtering module, and an input and output module, is used for collecting a partial discharging signal, a background interference signal, and a power frequency voltage signal as well as eliminating an interference and storing data. The main-broadband high-frequency sensor, the auxiliary- broadband high-frequency sensor, and the power-frequency voltage sensor are accessed in parallel to the data acquisition module of the calculating host of synchronous analysis. An advantage of the invention is to utilize hardware; that is, the auxiliary- broadband high-frequency sensor collects alone an interference signal of background noise; and then a difference of the noise signal and the partial discharging signal on a frequency spectrum is utilized, so that an objective of realization of resistance of the background noise interference of the hardware is achieved.

Description

Adopt the high voltage electric power equip ment detection method for local discharge and the device of hardware anti-interference
Technical field
The present invention relates to a kind of method and apparatus that is used for the high voltage electric power equip ment Partial Discharge Detection, belong to high voltage electric power equip ment detection technique field, relate in particular to a kind of high voltage electric power equip ment detection method for local discharge and device that adopts hardware anti-interference.
Background technology
Development along with high pressure and ultrahigh voltage power equipment, make its important step, particularly based on transformer, sleeve pipe, power cable and the gas-insulated switch GIS(Gas Insulated Switchgear of interior insulation as urban electricity supply and main grid structure) etc. in electrical network, occupy more and more important position.How realizing the state-detection of insulating power equipment in these high pressure, guarantee the safe and reliable operation of electrical network, is the focus of studying both at home and abroad at present.Shelf depreciation is the important behaviour form of insulating power equipment major insulation deterioration in the high pressure.The detection of shelf depreciation is present judgement, estimate in the high pressure insulating power equipment effective method the most directly perceived,, is the most important technological means of high voltage electric power equip ment repair based on condition of component.
At present both at home and abroad the high voltage electric power equip ment local discharge detection device of development is a lot, but that great majority can only be applied to ground unrest is very little or do not have the laboratory of ground unrest, and ground unrest is simple or ground unrest than the little scene of power equipment major insulation defective.What extensively adopt for off-line both domestic and external or online local discharge detection device at present is to utilize software and expert system to carry out the differentiation and the elimination of ground unrest, also have and utilize the inside and outside dual sensor of equipment to carry out signal magnitude individually to concern filtering, because software and expert system denoising remain rule of thumb to programme noise is judged and eliminated, and the inside and outside dual sensor utilization of equipment is to contain the office's discharge signal of ambient noise signal and the comparison of ambient noise signal amplitude size, cause the complicated electromagnetic interference (EMI) of the local discharge detection device of present rig-site utilization for the scene, particularly the ground unrest noise stronger than fault local discharge signal can't be eliminated, thereby can't be accurate, reliable extraction office discharge signal.Therefore, how eliminate to greatest extent and disturb, the office of extraction fast and accurately discharge signal becomes the important means of the on-the-spot office of high voltage electric power equip ment discharge examination.
Summary of the invention
The objective of the invention is: provide a kind of hardware means of utilizing to eliminate the method and apparatus that Partial Discharge Detection is disturbed, only utilize software to eliminate noise to solve prior art, the amplitude of perhaps only utilizing the inside and outside dual sensor acquired signal of equipment is eliminated noise and can't effectively be suppressed the problem of the on-the-spot various interference that exist.
Technical scheme of the present invention is: a kind of high voltage electric power equip ment local discharge detection device that adopts hardware anti-interference, it comprises main wideband high-frequency sensor, secondary wideband high-frequency sensor, power-frequency voltage sensor and Synchronization Analysis computation host, and described main wideband high-frequency sensor is used for being coupled and contains the local discharge signal of ground unrest; Secondary wideband high-frequency sensor is used for the ambient noise signal that is coupled; The power-frequency voltage sensor is used for producing the power-frequency voltage signal; The Synchronization Analysis computation host comprises data acquisition module, data processing module, interference filtering module and input/output module, be used for finishing collection to major-minor wideband high-frequency sensor and power-frequency voltage sensor generation signal, elimination and the data storage disturbed, it is characterized in that: described main wideband high-frequency sensor, secondary wideband high-frequency sensor, the power-frequency voltage sensor all walks abreast and inserts the data acquisition module of described Synchronization Analysis computation host, and data acquisition module is connected with data processing module in the described Synchronization Analysis computation host, data processing module is connected with the interference filtering module, the interference filtering module is connected with input/output module.
The invention provides a kind of high voltage electric power equip ment detection method for local discharge that adopts hardware anti-interference, adopt aforesaid high voltage electric power equip ment local discharge detection device, described method comprises the steps:
(1) socket master wideband high-frequency sensor on high voltage electric power equip ment ground wire or other earthing device is used for being coupled and contains the local discharge signal of ground unrest; Install secondary wideband high-frequency sensor in the co-located of isolating with the ground connection facility, be used for the ambient noise signal that is coupled; Two sensors all insert the Synchronization Analysis computation host;
(2) connect the power-frequency voltage sensor in lead-in wire on the high voltage electric power equip ment or outlet, the power-frequency voltage sensor inserts the Synchronization Analysis computation host, is used for the triggering of local discharge signal acquisition channel, to determine the power-frequency voltage phase place of local discharge signal;
(3) the Synchronization Analysis computation host is at first gathered the signal of major-minor wideband high-frequency sensor and the generation of power-frequency voltage sensor by data acquisition module, demarcate phase place by data processing module with the power frequency voltage signal then, generation contains the phase place of the local discharge signal of ground unrest, the three-dimensional spectrogram of amplitude and frequency and the phase place of having only ambient noise signal, the three-dimensional spectrogram of amplitude and frequency, the last signal of the major-minor sensor being gathered by the interference filtering module carries out the comparison of frequency spectrum, filtering master wideband high-frequency sensor and secondary wideband high-frequency sensor have the ambient noise signal of same frequency spectrum, thereby catch an innings discharge signal;
(4) thus Synchronization Analysis processing host input/output module demonstrates the local discharge signal spectrogram that comprises apparent discharge capacity, discharge phase, discharge frequency by the data after the filter out background noise are handled, and measurement result is stored.
The invention has the beneficial effects as follows: the invention has the advantages that and utilize hardware, promptly secondary sensor is gathered the ground unrest undesired signal separately, utilizes noise signal and the local discharge signal difference on frequency spectrum then, thereby realizes the purpose that the anti-ground unrest of hardware disturbs; With only depend in the past software and amplitude size relatively the method for anti-noise the raising of matter has been arranged, make local discharge detection device can clearly demonstrate noise, thereby make the filtering noise can be more fast, accurately.
Description of drawings
Fig. 1 is the process flow diagram of the high voltage electric power equip ment detection method for local discharge of the embodiment of the invention.
Fig. 2 is the structural representation of the high voltage electric power equip ment local discharge detection device of the embodiment of the invention.
Embodiment
The present invention is described further below in conjunction with drawings and Examples.
As shown in Figure 1, the method that high voltage electric power equip ment detection method for local discharge of the present invention is eliminated noise is as follows: two wideband high-frequency sensors are set on tested high voltage electric power equip ment synchronously, main wideband high-frequency sensor sleeve is connected on the local discharge signal that is used for containing on the coupled high voltage power equipment ground unrest on the ground wire of high voltage electric power equip ment or the grounding apparatus, and another secondary wideband high-frequency sensor is positioned at same position but isolates with the high voltage electric power equip ment ground wire and is used to be coupled the on-the-spot noise that produces because of the background electromagnetic interference (EMI).Write down the spectrogram (or frequency diagram) of these two broadband high-frequency signals simultaneously; And the frequency spectrum (or frequency) of these two signals relatively synchronously, eliminate main wideband high-frequency sensor that caught with signal secondary wideband high-frequency sensor same frequency spectrum (or frequency), disturb thereby reach to eliminate, quick and precisely catch the purpose of local discharge signal.The frequency range of wideband high-frequency sensor is 30kHz-20MHz.
As shown in Figure 2, the high voltage electric power equip ment local discharge detection device that provides of the embodiment of the invention mainly is made of main wideband high-frequency sensor, secondary wideband high-frequency sensor, power-frequency voltage sensor and Synchronization Analysis computation host.The Synchronization Analysis computation host comprises data acquisition module, data processing module, interference filtering module and input/output module, is used for finishing the collection to major-minor wideband high-frequency sensor and power-frequency voltage sensor generation signal, the elimination of interference and data storage.Wherein main wideband high-frequency sensor, secondary wideband high-frequency sensor, power-frequency voltage sensor all walk abreast and insert the data acquisition module of Synchronization Analysis computation host, and data acquisition module is connected with data processing module in the Synchronization Analysis computation host, data processing module is connected with the interference filtering module, the interference filtering module is connected with input/output module.
The workflow of this device is as follows:
(1) socket master wideband high-frequency sensor on high voltage electric power equip ment ground wire or other earthing device is used for being coupled and contains the local discharge signal of ground unrest; Install secondary wideband high-frequency sensor in the co-located of isolating with the ground connection facility, be used for the ambient noise signal that is coupled; Two sensors all insert the Synchronization Analysis computation host.
(2) connect the power-frequency voltage sensor in lead-in wire on the high voltage electric power equip ment or outlet, the power-frequency voltage sensor inserts the Synchronization Analysis computation host, is used for the triggering of local discharge signal acquisition channel, to determine the power-frequency voltage phase place of local discharge signal.
(3) the Synchronization Analysis computation host is to the data of major-minor wideband high-frequency sensor acquisition, at first demarcate phase place with the power frequency voltage signal, generate the three-dimensional discharge spectrogram that two width of cloth contain signal phase, amplitude, frequency (or frequency), the signal that the major-minor sensor is gathered carries out the comparison of frequency spectrum (or frequency) then, the signal of filtering master wideband high-frequency sensor and secondary wideband high-frequency sensor same frequency spectrum (or frequency), thus an innings discharge signal caught.
(4) thus the Synchronization Analysis processing host by filtering data later being handled the shelf depreciation spectrogram that shows apparent discharge capacity, discharge phase and discharge frequency (or discharge frequency), and measurement result is stored.

Claims (2)

1. high voltage electric power equip ment local discharge detection device that adopts hardware anti-interference, it comprises main wideband high-frequency sensor, secondary wideband high-frequency sensor, power-frequency voltage sensor and Synchronization Analysis computation host, and described main wideband high-frequency sensor is used for being coupled and contains the local discharge signal of ground unrest; Secondary wideband high-frequency sensor is used for the ambient noise signal that is coupled; The power-frequency voltage sensor is used for producing the power-frequency voltage signal; The Synchronization Analysis computation host comprises data acquisition module, data processing module, interference filtering module and input/output module, be used for finishing collection to main wide secondary wideband high-frequency sensor and power-frequency voltage sensor generation signal, elimination and the data storage disturbed, it is characterized in that: described main wideband high-frequency sensor, secondary wideband high-frequency sensor, the power-frequency voltage sensor all walks abreast and inserts the data acquisition module of described Synchronization Analysis computation host, and data acquisition module is connected with data processing module in the described Synchronization Analysis computation host, data processing module is connected with the interference filtering module, the interference filtering module is connected with input/output module.
2. a high voltage electric power equip ment detection method for local discharge that adopts hardware anti-interference adopts high voltage electric power equip ment local discharge detection device as claimed in claim 1, and described method comprises the steps:
(1) socket master wideband high-frequency sensor on high voltage electric power equip ment ground wire or other earthing device is used for being coupled and contains the local discharge signal of ground unrest; Install secondary wideband high-frequency sensor in the co-located of isolating with the ground connection facility, be used for the ambient noise signal that is coupled; Two sensors all insert the Synchronization Analysis computation host;
(2) connect the power-frequency voltage sensor in lead-in wire on the high voltage electric power equip ment or outlet, the power-frequency voltage sensor inserts the Synchronization Analysis computation host, is used for the triggering of local discharge signal acquisition channel, to determine the power-frequency voltage phase place of local discharge signal;
(3) the Synchronization Analysis computation host is at first gathered the signal of major-minor wideband high-frequency sensor and the generation of power-frequency voltage sensor by data acquisition module, demarcate phase place by data processing module with the power frequency voltage signal then, generation contains the phase place of the local discharge signal of ground unrest, the three-dimensional spectrogram of amplitude and frequency and the phase place of having only ambient noise signal, the three-dimensional spectrogram of amplitude and frequency, the last signal of the major-minor sensor being gathered by the interference filtering module carries out the comparison of frequency spectrum, filtering master wideband high-frequency sensor and secondary wideband high-frequency sensor have the ambient noise signal of same frequency spectrum, thereby catch an innings discharge signal;
(4) thus Synchronization Analysis processing host input/output module demonstrates the local discharge signal spectrogram that comprises apparent discharge capacity, discharge phase, discharge frequency by the data after the filter out background noise are handled, and measurement result is stored.
CN201110165904.6A 2011-06-20 2011-06-20 Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization Active CN102243289B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201110165904.6A CN102243289B (en) 2011-06-20 2011-06-20 Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201110165904.6A CN102243289B (en) 2011-06-20 2011-06-20 Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization

Publications (2)

Publication Number Publication Date
CN102243289A true CN102243289A (en) 2011-11-16
CN102243289B CN102243289B (en) 2014-08-20

Family

ID=44961448

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110165904.6A Active CN102243289B (en) 2011-06-20 2011-06-20 Method and apparatus for partial discharge detection of high-voltage electrical power equipment with hardware anti-interference utilization

Country Status (1)

Country Link
CN (1) CN102243289B (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102944765A (en) * 2012-11-30 2013-02-27 中国船舶重工集团公司第七二二研究所 Low-frequency-stage magnetic sensor background noise measuring method
CN104007371A (en) * 2014-05-15 2014-08-27 深圳供电局有限公司 Device and method used for checking partial discharge signals of cable
CN104360242A (en) * 2014-10-01 2015-02-18 玉林市科邦技术服务有限公司 System for online monitoring discharging failures of high-voltage switch cabinet
CN104483602A (en) * 2014-11-28 2015-04-01 北京兴迪仪器有限责任公司 Local discharge signal identification method and device
CN104977515A (en) * 2015-07-17 2015-10-14 许继集团有限公司 Method for identifying discharge type in three-phase same-cylinder GIS partial discharge monitoring
CN105606975A (en) * 2016-03-09 2016-05-25 武汉华威众科电力有限公司 Localizable ultrahigh-frequency cable partial discharge detection method and device
CN105629144A (en) * 2016-03-11 2016-06-01 华乘电气科技(上海)股份有限公司 High voltage switchgear partial discharge diagnosis method and system based on fingerprint database
CN107329067A (en) * 2017-06-16 2017-11-07 中国南方电网有限责任公司超高压输电公司检修试验中心 A kind of circuit for eliminating 12 pulsation interference
CN107942206A (en) * 2017-10-16 2018-04-20 国网河北能源技术服务有限公司 A kind of GIS partial discharge on-Line Monitor Device and localization method
CN108333487A (en) * 2018-02-05 2018-07-27 南通尚力机电工程设备有限公司 A kind of power equipment partial discharge detecting system
CN108333482A (en) * 2018-01-17 2018-07-27 南通尚力机电工程设备有限公司 A kind of measurement method of GIS partial discharge pattern-recognition
CN108646151A (en) * 2018-05-10 2018-10-12 东南大学 Cable discharge acoustic detector based on adaptive noise reduction
CN109254227A (en) * 2017-07-13 2019-01-22 全球能源互联网欧洲研究院 Detection method, apparatus and system towards electric network state

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004328810A (en) * 2003-04-21 2004-11-18 Hitachi Eng Co Ltd Method and device for partial discharge diagnosis of gas insulated switch
CN1580797A (en) * 2004-05-17 2005-02-16 西安交通大学 Power cable local discharge on-line monitoring method and device
CN1673762A (en) * 2005-04-26 2005-09-28 重庆大学 Gasinsulation combined electric device local discharge analog experimental apparatus and experimental method
CN101650406A (en) * 2009-09-18 2010-02-17 国网电力科学研究院武汉南瑞有限责任公司 Local discharge on-line detection method and device of high-voltage cross-linking polythene cable system
CN101788582A (en) * 2010-02-03 2010-07-28 华北电力大学 Interference suppression method and device for local discharge detection of equipment
CN202159113U (en) * 2011-06-20 2012-03-07 国网电力科学研究院 Shelf depreciation detecting device, adopting hardware for anti-interference, of high voltage electric power equipment

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004328810A (en) * 2003-04-21 2004-11-18 Hitachi Eng Co Ltd Method and device for partial discharge diagnosis of gas insulated switch
CN1580797A (en) * 2004-05-17 2005-02-16 西安交通大学 Power cable local discharge on-line monitoring method and device
CN1673762A (en) * 2005-04-26 2005-09-28 重庆大学 Gasinsulation combined electric device local discharge analog experimental apparatus and experimental method
CN101650406A (en) * 2009-09-18 2010-02-17 国网电力科学研究院武汉南瑞有限责任公司 Local discharge on-line detection method and device of high-voltage cross-linking polythene cable system
CN101788582A (en) * 2010-02-03 2010-07-28 华北电力大学 Interference suppression method and device for local discharge detection of equipment
CN202159113U (en) * 2011-06-20 2012-03-07 国网电力科学研究院 Shelf depreciation detecting device, adopting hardware for anti-interference, of high voltage electric power equipment

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
夏荣 等: "阻尼振荡波电压下110kV交联电缆绝缘性能检测", 《高电压技术》, vol. 36, no. 7, 31 July 2010 (2010-07-31), pages 1753 - 1760 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102944765A (en) * 2012-11-30 2013-02-27 中国船舶重工集团公司第七二二研究所 Low-frequency-stage magnetic sensor background noise measuring method
CN102944765B (en) * 2012-11-30 2015-02-11 中国船舶重工集团公司第七二二研究所 Low frequency magnetic sensor background noise measuring method
CN104007371A (en) * 2014-05-15 2014-08-27 深圳供电局有限公司 Device and method used for checking partial discharge signals of cable
CN104360242A (en) * 2014-10-01 2015-02-18 玉林市科邦技术服务有限公司 System for online monitoring discharging failures of high-voltage switch cabinet
CN104483602A (en) * 2014-11-28 2015-04-01 北京兴迪仪器有限责任公司 Local discharge signal identification method and device
CN104977515A (en) * 2015-07-17 2015-10-14 许继集团有限公司 Method for identifying discharge type in three-phase same-cylinder GIS partial discharge monitoring
CN104977515B (en) * 2015-07-17 2017-10-31 许继集团有限公司 The recognition methods of electric discharge type in a kind of common cylinder GIS partial discharge monitoring of three-phase
CN105606975A (en) * 2016-03-09 2016-05-25 武汉华威众科电力有限公司 Localizable ultrahigh-frequency cable partial discharge detection method and device
CN105629144A (en) * 2016-03-11 2016-06-01 华乘电气科技(上海)股份有限公司 High voltage switchgear partial discharge diagnosis method and system based on fingerprint database
CN105629144B (en) * 2016-03-11 2018-12-04 华乘电气科技(上海)股份有限公司 High-tension switch gear partial discharge diagnostic method and system based on fingerprint base
CN107329067A (en) * 2017-06-16 2017-11-07 中国南方电网有限责任公司超高压输电公司检修试验中心 A kind of circuit for eliminating 12 pulsation interference
CN109254227A (en) * 2017-07-13 2019-01-22 全球能源互联网欧洲研究院 Detection method, apparatus and system towards electric network state
CN107942206A (en) * 2017-10-16 2018-04-20 国网河北能源技术服务有限公司 A kind of GIS partial discharge on-Line Monitor Device and localization method
CN107942206B (en) * 2017-10-16 2020-10-23 国网河北能源技术服务有限公司 GIS partial discharge positioning method
CN108333482A (en) * 2018-01-17 2018-07-27 南通尚力机电工程设备有限公司 A kind of measurement method of GIS partial discharge pattern-recognition
CN108333487A (en) * 2018-02-05 2018-07-27 南通尚力机电工程设备有限公司 A kind of power equipment partial discharge detecting system
CN108646151A (en) * 2018-05-10 2018-10-12 东南大学 Cable discharge acoustic detector based on adaptive noise reduction

Also Published As

Publication number Publication date
CN102243289B (en) 2014-08-20

Similar Documents

Publication Publication Date Title
Rönnberg et al. On waveform distortion in the frequency range of 2 kHz–150 kHz—Review and research challenges
CN102305891B (en) On-line monitoring method of low-frequency oscillation of power system
Larsson et al. Measurements of high-frequency (2–150 kHz) distortion in low-voltage networks
EP3045930B1 (en) Testing system of gis electronic mutual inductor and method therefor
CN203054162U (en) Comprehensive tester for partial discharge of high-voltage cable
CN102680860B (en) Automatic fault-point locating method for traveling-wave based fault location of high-voltage electric power lines
CN103207351B (en) A kind of power transmission line fault locating method based on reclosing
CN103605053B (en) Local discharge of gas-insulator switchgear test unit and method under surge voltage
CN103293443B (en) A kind of distribution network overhead line Earth design method
CN203249989U (en) Transformer partial discharge on-line monitoring system
CN101188354B (en) Test simulation method for failure line selection of small current ground system
CN102103183B (en) Partial discharge measurement device under impulse voltage on site and signal processing method thereof
US20150362536A1 (en) High-voltage direct current broad frequency-domain corona current measurement system
CN103278751B (en) Partial discharge comprehensive itinerant detector for high voltage electric power equipment
CN105277857B (en) A kind of bushing shell for transformer of monitoring on-line makes moist the method for defect
CN103135031B (en) Coal mine high-voltage grid system insulation state monitoring method
US10794965B2 (en) Smart device to detect faults in primary substation power feeders
JP5349036B2 (en) Insulation diagnostic system
CN102072982B (en) Device and system for acquiring very fast transient overvoltage sensing signal
CN102735968B (en) GIS (Geographic Information System) fault diagnosis system and method based on vibration signal spectrum analysis
CN105606975B (en) A kind of orientable superfrequency cable local discharge detection method and device
CN103913679B (en) High-tension switch cabinet partial discharge monitoring system
CN202433482U (en) Portable partial discharge acoustic-electric joint detection apparatus for GIS
CN202421420U (en) Ultrahigh frequency and pulse current based GIS (gas insulated switchgear) partial-discharge online monitoring device
CN102721464A (en) Method and system for detecting winding deformation faults of power transformer

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
GR01 Patent grant
C14 Grant of patent or utility model