CN104698375A - SF6 breaker electrical endurance monitor system based on weak signal processing - Google Patents
SF6 breaker electrical endurance monitor system based on weak signal processing Download PDFInfo
- Publication number
- CN104698375A CN104698375A CN201510117941.8A CN201510117941A CN104698375A CN 104698375 A CN104698375 A CN 104698375A CN 201510117941 A CN201510117941 A CN 201510117941A CN 104698375 A CN104698375 A CN 104698375A
- Authority
- CN
- China
- Prior art keywords
- signal
- module
- signal processing
- conversion module
- filtration
- 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
Links
Landscapes
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
Abstract
The invention relates to an SF6 breaker electrical endurance monitor system based on weak signal processing. The SF6 breaker electrical endurance monitor system based on the weak signal processing is mainly composed of portions of a signal conversion module, a range choosing module, a filtration module, an A/D (analog to digital) module, a signal processing module and the like, wherein the signal conversion module comprises an operational amplifier with a low bias current, completes conversion from a current signal to a voltage signal, and outputs the voltage signal to the filtration module, the range choosing module comprises a plurality of dry reed relays, and completes range automatic switching when a wide dynamic signal is input, the filtration module comprises an integrated filter, completes filtration of an output signal of a voltage conversion module, and outputs the output signal to the A/D module, the A/D module comprises a 24 bit A/D convertor, completes conversion from an analog signal to a digital signal, and outputs the digital signal to the signal processing module, and the signal processing module completes reading of the output signal of the A/D convertor, digital filtration, liquid crystal display and communications with an upper computer.
Description
Technical field
The present invention's design relates to the on-line monitoring of electric system appliance field switchgear, is specifically related to the on-line monitoring of high-voltage sf6 circuit breaker electric life.
Background technology
Along with the development of electric system, the capacity of electric system grows with each passing day.As switchgear important in electric system; SF6 gas is used insulating medium as primary cut-out and arc-extinguishing medium using its excellent insulating property; therefore make SF6 isolating switch in 72.5kV and above electric system occupy absolute advantage, control and protection is play dual parts to electric system.Electric life refers to the continuous connecting-disconnecting function of isolating switch without maintenance, the regulation that also namely burnouts the wear extent of contact material.The electric life of SF6 isolating switch diagnoses the information referred to by obtaining various detection method, analyzes through science Comprehensive, and grasp the present situation and the life-span expectation of equipment, it is basis and the prerequisite of Diagnostic Examination And Repair of Electric Power Facilities.
The leading indicator affecting SF6 circuit breaker electrical endurance is electrical wear degree, comprise contact, arc-chutes and arc-extinguishing medium three parts, the electrical wear of the normally contact wherein played a decisive role, by known to the research of electrical wear, the main determining factor of electrical wear is the dropout current I of isolating switch, the structure of arc time t, arc-chutes and the travelling speed etc. of moving contact thereof.The assessment of electrical wear was judged it is record accumulative dropout current (I) or accumulative arc energy (I in the past
2t) for foundation.In fact, same isolating switch successively cut-offs onesize current value for twice under same external condition, and its scaling loss degree is also not the same, and when dropout current differs greatly, the burning principle of contact of breaker is different, and scaling loss difference is larger.Although arc energy is depended in electrical wear in addition, also relevant with contact breaking speed etc., and electrical wear and arc energy do not have proportionate relationship.Therefore to monitor for further study to contact of breaker electrical wear, electric life, electric life be carried out to contact of breaker and assesses the concept and engineering construction method problem that need to solve electric life.
The method mainly dropout current cumulative method of existing calculating circuit breaker electrical endurance, it calculates electric life according to the quality loss of contact, is the cumulative method of the electric life curve based on primary cut-out.But the contact electrical wear degree under different short-circuit current is different, and its wear extent and short-circuit current size not linear.Only judge that contact burning amount is inadequate with accumulative dropout current.Therefore, judge that contact burning amount will consider the different wear extenies of cut-offfing different short-circuit current at every turn and producing, thus bring very large difficulty to the detection of the electric life of SF6 isolating switch.Therefore, need to reform existing electric life detected status, can not only depend on dropout current size, and monitor and assess the electric life of isolating switch by reflection SF6 isolating switch arcing contact ablation situation, thus be expected to obtain electric life monitoring result comparatively accurately, make up the defect that there is no the effective electric life monitoring technology of high-voltage sf6 circuit breaker and method at present both at home and abroad, the upgrading for high-voltage sf6 circuit breaker "smart" products provides Theory and technology to instruct.
Research shows, SF6 isolating switch is with the combustion process of electric arc in interrupting process, and contact ablation produces a large amount of metal vapors, the decomposition of simultaneous SF6 gas, and metal vapors Sum decomposition thing long-term existence is in arc-chutes.Therefore, the electric life of the content of metal vapors and SF6 analyte concentration and the ablation degree of contact and isolating switch is closely related, can reflect the degree of decomposition of SF6 gas and the arcing situation of arc-chutes by the detection of SF6 analyte concentration.Can think that SF6 analyte concentration is the key feature amount of diagnosis SF6 circuit breaker electrical endurance.
In recent years, along with developing by leaps and bounds of carbon nanotube technology, carbon nano tube sensor is progressively applied to the monitoring of high pressure GIS partial discharge with the advantage of its uniqueness, has made it possess to be applied to the possibility of high-voltage sf6 circuit breaker electric life monitoring.Gas sensor monitors SF6 analyte concentration is utilized to have certain feasibility to the electric life reacting isolating switch, but the electric current that sensor exports is receiving peace level and following, so how to detect that faint current signal is the key of SF6 analyte density real-time monitoring accurately.Therefore, develop a set of skin that can detect and pacify level electric current, input current dynamic range can reach 10
6and above detection system is very necessary, then this cover system and sensing technology are applied to the life appraisal of SF6 isolating switch, the technical barrier of SF6 circuit breaker electrical endurance on-line monitoring can be solved.
Summary of the invention
The object of the invention is to propose a kind of SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing, skin peace level that gas sensor sends can be detected to milliampere level current signal, and finally realize the accurate measurement of SF6 analyte concentration, thus reflect the electric life of SF6 isolating switch by SF6 analyte concentration.
For reaching this object, the present invention by the following technical solutions:
A kind of SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing, comprise: signal conversion module, measurement range selection module, filtration module, A/D module and signal processing module, wherein: described signal conversion module comprises the operational amplifier of pole Low-bias Current, utilize the operational amplifier of pole Low-bias Current to be pacified by the skin that sensor exports and be converted to voltage signal to milliampere current signal, and export filtration module to; Described measurement range selection module comprises dry-reed relay, utilizes microprocessor and dry-reed relay to coordinate the automatic switchover realizing range; Described filtration module comprises integrated filter, utilizes described integrated filter to carry out filtering to described voltage signal, and exports signal processing module to; Described signal processing module utilizes signal gathering unit realization to the digital filtering of described voltage signal and collection, and exports.
Preferably, all there is two-layer shielding described signal conversion module, measurement range selection module, filtration module, A/D module and signal processing module outside, and outer shielding material adopts copper, and internal layer shielding material adopts iron, is arranged on outside isolating switch.
Preferably, the output of described gas sensor adopts concentric cable to be connected with signal conversion module, to reduce the interference of external signal.
Preferably, the operational amplifier of described pole Low-bias Current is the maximum LMC6042 family chip at several femto-ampere of bias current of TI company.
Preferably, described integrated filter is the MAX274 high-performance four-step filter that MAXIM company produces.
Preferably, described analog to digital converter is the ADS1254 A/D converter with high speed and high precision that TI company produces.
Preferably, described signal gathering unit uses STM32F4 series microprocessor, and it has lower price and processing speed faster.The flash memory of outside expansion 256MB and 4MB static random access memory, to complete the storage of image data.
Therefore, the present invention can detect the pA level current signal that microsensor sends, and input current dynamic range is 10
9, and finally realize the accurate measurement of SF6 analyte concentration, foundation can be provided for the on-line monitoring of electrical endurance of SF6 isolating switch.Have easy to operate, can on the spot and remote monitoring, the advantages such as antijamming capability is strong.
Accompanying drawing explanation
Fig. 1 is the structural representation of the SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing according to the specific embodiment of the invention.
The technical characteristic that Reference numeral in figure refers to respectively is:
1, gas sensor; 2, signal conversion module; 3, measurement range selection module; 4, filtration module; 5, A/D module; 6, signal processing module.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described in further detail.Be understandable that, specific embodiment described herein is only for explaining the present invention, but not limitation of the invention.It also should be noted that, for convenience of description, illustrate only part related to the present invention in accompanying drawing but not entire infrastructure.
See Fig. 1, disclose the structural representation of the SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing according to the specific embodiment of the invention, a kind of SF6 isolating switch life monitoring system based on Weak Signal Processing, comprise:, signal conversion module 2, measurement range selection module 3, filtration module 4, A/D module 5 and signal processing module 6, wherein:
Described signal conversion module comprises the operational amplifier of pole Low-bias Current, utilizes the operational amplifier of pole Low-bias Current that current output sensor signal is converted to voltage signal, and exports filtration module to;
Described measurement range selection module comprises dry-reed relay, utilizes the threshold voltage settings of described dry-reed relay and processor to realize the automatic switchover of range;
Described filtration module comprises integrated filter, utilizes described integrated filter to carry out filtering to described voltage signal, and exports A/D module to;
Described A/D module comprises analog to digital converter, utilizes described analog to digital converter to change filtration module output voltage signal, and exports signal processing module to;
Described signal processing module utilizes signal acquiring system realization to the digital filtering of described voltage signal and collection, and exports;
The outer surface cover of described whole system has electro-magnetic shielding cover.
Therefore, the SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing of the present invention, first solves the problem of current-voltage signal conversion, reduces Signal transmissions power consumption, is beneficial to signal subsequent acquisition and process; Secondly the present invention realizes pacifying level to the measurement of milliampere level signal to skin by the operational amplifier in signal conversion module, effectively suppresses common mode noise signal, improves measuring accuracy; Again, the present invention adopts the core of controller as signal gathering unit of ARM microcontroller, by the correlated digital algorithm optimization of ARM microcontroller, realizes the extraction of feeble signal and reduces noise signal, ensureing the accuracy requirement of collecting unit.So, after current signal sends by gas sensor, in signal conversion module, the conversion of current-voltage signal is realized, then by being extracted by signal processing module after filtration module filtering and A/D module, thus achieve the accurate measurement of SF6 analyte concentration.
Described electro-magnetic shielding cover material outer layer adopts copper, and inner layer material adopts iron, and when electromagnetic field passes through, by copper product armoured magnetic field, iron material electric field shielding, can reach good effectiveness.Copper product and iron material thickness are 1mm, reach higher reflection loss and refraction loss on the one hand, reduce design cost on the other hand.
In another specific embodiment, the current signal of described gas sensor adopts BNC connector to draw, by shielded cable output current signal.In the present embodiment, described BNC connector connects shielded cable, can current signal described in long range propagation holding signal stablize.Especially, described shielded cable in arc-chutes interface encapsulation process, to avoid revealing SF6 gas.
In described signal conversion module embodiment, the LMC6042 family chip of the operational amplifier of described pole Low-bias Current to be the input current of TI company be skin peace level.The bias current representative value of this device is 2fA, and offset current is 2pA to the maximum, and supply current is 4fA, has extremely low power consumption.It has extremely low voltage noise and current noise, and at 25 DEG C, supply voltage is 5V, and signal frequency is under 1kHz condition, and current noise is 0.2fA/
voltage noise is 83nV/
common-mode rejection ratio is minimum is 68dB.
In described filtration module embodiment, the MAX274 integrated filter that described integrated filter adopts MAXIM company to produce.This device is continuous time filter, can not bring clocking noise.Butterworth, Chebyshev, Bessel wave filter can be configured as by user.It has low-noise characteristic, and THD is-86dB.Wideband noise representative value is 42 μ Vrms.Be applicable to doing rear class signal filter circuit.
In described A/D module and signal processing unit embodiment, described signal processing unit uses STM32F4 series microprocessor, and the flash memory of outside expansion 256MB and 4MB static random access memory, signal gathering unit can realize communicating with host computer.For this embodiment, convert the single-ended signal that filtration module exports to differential signal and transmit.Single-ended transfer difference circuit adopts OPA4350 operational amplifier, and differential signal is converted into digital signal by Differential Input A/D chip ADS1254, and this A/D conversion chip has the sampling precision of 24, is provided the reference voltage of 4.096V by outside.ADS1254 is at digital power system 1.8V, and simulation power supply 5V, maximum power dissipation when clock frequency 8M is 6.5mW.After ADC converts, by negative edge triggered interrupts pin, notice arm processor reads data to data memory block, and after data storage area is filled with, communication starts, and data can transfer to CPU.
More excellent, in another embodiment: described current-voltage signal conversion module, filtration module, A/D module and signal processing module outer cover have electro-magnetic shielding cover, are arranged on outside isolating switch.For this embodiment, each described module cover has electro-magnetic shielding cover to be in order to avoid signal disturbing.Further, the pick-up unit of whole detection system also can be arranged in the idle space outside arc-chutes, not affect normal operation of circuit breaker, to avoid each element over-temperature of system to be as the criterion.
In sum, the SF6 circuit breaker electrical endurance monitoring system based on Weak Signal Processing of the present invention has the following advantages:
(1) the present invention proposes a kind of system of the monitoring breaker electric life based on Weak Signal Processing completely newly, as long as gas sensor electric discharge generation current, just can realize the conversion of current-voltage signal and the amplification of signal and acquisition, and the size reflection SF6 analyte concentration of discharge current, therefore the present invention accurately can detect SF6 analyte concentration;
(2) adopt the operational amplifier LMC6042 of pole Low-bias Current to realize the conversion of current-voltage signal, low in energy consumption, result is accurate, and circuit is simple, is convenient to realize;
(3) dry-reed relay and processor threshold voltage settings is adopted to realize the automatic switchover of range, without manual switching;
(4) in the present invention, filtration module adopts MAX274 integrated filter, is configured to quadravalence Chebyshev wave filter easily, does not have clock to disturb, have excellent filtering performance;
(5) in the present invention, A/D module adopts ADS1254 analog to digital converter, has the sampling rate of 24 sampling precisions and the highest 20.8kHz;
(6) anti-electromagnetic interference capability is strong, and the Weak current that sensor exports delivers to pick-up unit through shielded cable, and whole signal transmission path keeps good electromagnetic screen;
(7) based on the signal acquiring system of arm processor owing to introducing the management scheduling system of process, system cloud gray model is more efficient, under the prerequisite meeting performance requirement, has advantage low in energy consumption, can take into account several aspects such as performance, code density and price;
(8) volume is little, is easy to carry, with low cost, and large-scale production cost is lower.Generally speaking, monitoring system of the present invention can detect gas concentration based on gas sensor very well, detects degree of accuracy high, and sensing range is wide, and anti-electromagnetic interference capability is strong, with low cost, easily realizes, is suitable for practical implementation.
Above content is in conjunction with concrete preferred implementation further description made for the present invention; can not assert that the specific embodiment of the present invention is only limitted to this; for general technical staff of the technical field of the invention; without departing from the inventive concept of the premise; some simple deduction or replace can also be made, all should be considered as belonging to the present invention by submitted to claims determination protection domain.
Claims (10)
1. based on a SF6 circuit breaker electrical endurance monitoring system for Weak Signal Processing, it is characterized in that: described system comprises: signal acquisition module, signal conversion module, filtration module, A/D module, signal processing module and measurement range selection module, wherein:
Described signal acquisition module comprises gas sensor, and described signal acquisition module utilizes gas sensor that the change of the gas concentration of breaker arc extinguishing chamber interior is converted into current signal, and exports described current signal to signal conversion module;
Described signal conversion module comprises operational amplifier, and described signal conversion module utilizes described operational amplifier that the current signal of input is converted to voltage signal, and exports filtration module to;
Described filtration module comprises integrated filter, utilizes described integrated filter to carry out filtering to the voltage signal that signal conversion module exports, and exports A/D module to;
Described A/D module comprises the A/D converter of 24 precision, and described filtered voltage signal is converted to digital voltage signal and exports signal processing module to by described A/D converter;
Described signal processing module comprises signal gathering unit, and described signal gathering unit comprises microprocessor and LCDs, and described microprocessor carries out digital filtering and collection to described digital voltage signal, and completes the display of liquid crystal;
Described measurement range selection module is all connected with signal processing module with signal conversion module, comprising multiple dry-reed relay, utilizing the microprocessor of described signal processing module and dry-reed relay cooperation to realize the automatic switchover of range for solving signal conversion module enlargement factor deficiency.
2. system according to claim 1, is characterized in that:
Preferably, described signal acquisition module uses 12 gas sensors composition array formats, and the gas sensor of described array format can detect 12 kinds of different SF6 educt gas simultaneously, and can complete the collection of 12 road signals simultaneously.
3. system according to claim 1, is characterized in that:
The operational amplifier of described signal conversion module adopts LMC6042 family chip, and minimum input current can reach pA level, and input current dynamic range is 10
9.
4. system according to claim 1, is characterized in that:
The automatic switchover of described range is realized by the folding of the threshold value setup control dry-reed relay of microprocessor, the range of described measurement range selection module is divided into ten gears, controlled by ten dry-reed relays respectively, when the interval range that the amplitude of the input current of signal conversion module exceeds place range arrives another scope, microprocessor sends two pulse signals, the dry-reed relay that pulse signal controls working disconnects, another pulse signal controls corresponding dry-reed relay and closes, and realizes the automatic switchover of range.
5. system according to claim 1, is characterized in that:
Described filtration module comprises quadravalence Chebyshev integrated filter MAX274.
6. system according to claim 1, is characterized in that:
Described A/D module adopts 24 analog to digital converter ADS1254.
7. system according to claim 1, is characterized in that:
Described signal gathering unit uses STM32 series microprocessor, and the flash memory of outside expansion 256MB and 4MB static random access memory, signal gathering unit can realize communicating with host computer.
8. the system according to claim 1-7, is characterized in that:
All there is two-layer shielding described signal acquisition module, signal conversion module, measurement range selection module, filtration module, A/D module and signal processing module outside, outer shielding material adopts copper, internal layer shielding material adopts iron, adopts shielded cable to be connected between signal acquisition module with signal conversion module.
9. system according to claim 1, is characterized in that:
Described shielded cable is in arc-extinguishing chamber of circuit breaker interface encapsulation process, and owing to being filled with the SF6 gas of extinguish arcs in arc-chutes, encapsulation process is in order to prevent Leakage Gas in arc-chutes.
10. system according to claim 1, is characterized in that:
Realize the interconnective printed circuit plate substrate of each electronic devices and components in insulating medium between described shield layer of shielded cable and transfer wire and modules and all adopt polytetrafluoroethylmaterial material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510117941.8A CN104698375A (en) | 2015-03-17 | 2015-03-17 | SF6 breaker electrical endurance monitor system based on weak signal processing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510117941.8A CN104698375A (en) | 2015-03-17 | 2015-03-17 | SF6 breaker electrical endurance monitor system based on weak signal processing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104698375A true CN104698375A (en) | 2015-06-10 |
Family
ID=53345703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510117941.8A Pending CN104698375A (en) | 2015-03-17 | 2015-03-17 | SF6 breaker electrical endurance monitor system based on weak signal processing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104698375A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105093103A (en) * | 2015-08-04 | 2015-11-25 | 平高集团有限公司 | SF6 breaker state monitoring method and thionyl fluoride gas concentration monitoring device |
| CN108983059A (en) * | 2018-09-11 | 2018-12-11 | 西安理工大学 | A kind of apparatus insulated condition monitoring system of high-tension electricity based on gas decomposition components |
| CN112532186A (en) * | 2020-11-04 | 2021-03-19 | 杭州爱华仪器有限公司 | Measuring amplifier for audio signal measurement |
| CN113162599A (en) * | 2020-01-07 | 2021-07-23 | 中核控制系统工程有限公司 | Small current signal multi-range acquisition and switching device for nuclear measurement |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020093652A1 (en) * | 2000-11-29 | 2002-07-18 | Gary Powell | Method and device utilizing real-time gas sampling |
| CN101074947A (en) * | 2007-06-27 | 2007-11-21 | 江苏大学 | Method and apparatus for inspecting two-kind gas sensor array combination odour |
| CN101655442A (en) * | 2009-09-03 | 2010-02-24 | 中科天融(北京)科技有限公司 | Range automatic switching circuit for fume concentration online monitoring system |
| CN203658433U (en) * | 2013-11-25 | 2014-06-18 | 中国船舶重工集团公司第七一九研究所 | High-sensitivity wide-range current amplification conversion circuit |
| CN103941185A (en) * | 2014-05-06 | 2014-07-23 | 西安交通大学 | Copper metal vapor concentration detection system based on micrometer scale sensor |
-
2015
- 2015-03-17 CN CN201510117941.8A patent/CN104698375A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020093652A1 (en) * | 2000-11-29 | 2002-07-18 | Gary Powell | Method and device utilizing real-time gas sampling |
| CN101074947A (en) * | 2007-06-27 | 2007-11-21 | 江苏大学 | Method and apparatus for inspecting two-kind gas sensor array combination odour |
| CN101655442A (en) * | 2009-09-03 | 2010-02-24 | 中科天融(北京)科技有限公司 | Range automatic switching circuit for fume concentration online monitoring system |
| CN203658433U (en) * | 2013-11-25 | 2014-06-18 | 中国船舶重工集团公司第七一九研究所 | High-sensitivity wide-range current amplification conversion circuit |
| CN103941185A (en) * | 2014-05-06 | 2014-07-23 | 西安交通大学 | Copper metal vapor concentration detection system based on micrometer scale sensor |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105093103A (en) * | 2015-08-04 | 2015-11-25 | 平高集团有限公司 | SF6 breaker state monitoring method and thionyl fluoride gas concentration monitoring device |
| CN108983059A (en) * | 2018-09-11 | 2018-12-11 | 西安理工大学 | A kind of apparatus insulated condition monitoring system of high-tension electricity based on gas decomposition components |
| CN113162599A (en) * | 2020-01-07 | 2021-07-23 | 中核控制系统工程有限公司 | Small current signal multi-range acquisition and switching device for nuclear measurement |
| CN112532186A (en) * | 2020-11-04 | 2021-03-19 | 杭州爱华仪器有限公司 | Measuring amplifier for audio signal measurement |
| CN112532186B (en) * | 2020-11-04 | 2024-03-08 | 杭州爱华仪器有限公司 | Measurement amplifier for measuring audio signals |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103278751B (en) | Partial discharge comprehensive itinerant detector for high voltage electric power equipment | |
| CN104698375A (en) | SF6 breaker electrical endurance monitor system based on weak signal processing | |
| CN104749498A (en) | Portable partial discharge detecting and diagnosing device | |
| CN203444063U (en) | Inspection and alarm apparatus for AC mixing and DC grounding | |
| CN104459493A (en) | Switch cabinet partial discharge on-line monitoring system | |
| CN203117320U (en) | A high-voltage capacitor testing device | |
| CN102103176A (en) | GIS (Geographic Information System) online monitoring system | |
| CN206531923U (en) | Embedded partial discharge monitoring intelligence instrument based on pulse current method | |
| CN202383241U (en) | Ultrahigh-frequency sensor for detecting GIS partial discharge | |
| CN103630266A (en) | Optical fiber temperature measurement host, optical fiber temperature measurement system and optical fiber temperature measurement method | |
| CN204405737U (en) | A kind of harmonic measurement device based on DSP | |
| CN204330849U (en) | A kind of Multi-function experimental virtual instrument | |
| CN203881905U (en) | Breaker operation condition on-line monitoring device | |
| CN204694273U (en) | A kind of variable-area capacitive sensor | |
| CN105548837B (en) | A kind of switch cubicle interior insulation part defect prior-warning device | |
| CN204857578U (en) | Explosion chamber vacuum on -line monitoring device | |
| CN105093103B (en) | SF6State-Inspect of High-Voltage Circuit method and fluorination thionyl gas concentration monitoring device | |
| CN203909242U (en) | Copper metal steam concentration detection system based on micrometer scale sensor | |
| CN202661433U (en) | Electrode combined type tomography capacitive sensor | |
| CN203310438U (en) | Sulfur hexafluoride online monitoring device | |
| CN215986330U (en) | Fault ultrasonic signal analysis system for power transformer | |
| CN204389630U (en) | A kind of jamproof Portable partial discharge detector | |
| CN203178365U (en) | Electric energy quality high-frequency harmonic wave monitoring apparatus | |
| CN203811688U (en) | Device for on-line monitoring of capacitor state for reactive compensation module | |
| CN203705082U (en) | Fiber temperature measurement host and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150610 |