CN109813949A - A kind of cable slack layer current detection means - Google Patents
A kind of cable slack layer current detection means Download PDFInfo
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- CN109813949A CN109813949A CN201811602666.9A CN201811602666A CN109813949A CN 109813949 A CN109813949 A CN 109813949A CN 201811602666 A CN201811602666 A CN 201811602666A CN 109813949 A CN109813949 A CN 109813949A
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- giant magnetoresistance
- cable
- detection means
- current detection
- cable slack
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Abstract
The invention discloses a kind of cable slack layer current detection means, described device includes: giant magnetoresistance sensor, the display terminal and power supply connecting with the giant magnetoresistance sensor；The giant magnetoresistance sensor includes magnetism gathering rings, and the magnetism gathering rings are used to obtain the current signal of cable；The display terminal is used to adjust the operation of the giant magnetoresistance sensor, and exports the display current signal.The present invention can effectively improve the precision of cable slack layer defects current detecting, ensure the normal operation of power cable, greatly improve the security reliability of operation of power networks by setting giant magnetoresistance sensor and magnetism gathering rings.
Description
Technical field
The present invention relates to electrician's detection technique fields, and in particular to a kind of cable slack layer current detection means.
Background technique
The operational reliability of power cable is directly related to the essential safety of power grid, the high pressure caused by buffer layer ablation
Cross-linked polyethylene insulated cable failure occurs often, even occurs insulation screen complete penetration when the failure is serious, causes electricity
Cable insulation breakdown, causes power outage.
Currently, cable O&M overhaul unit there is no effective technological means and method detect insulation screen burn or
Discharge defect can not take measures to prevent defect from spreading and spreading, if this phenomenon causes electricity without finding and handling in time
When cable ontology insulation breakdown leads to cable operation fault, new cable can only be scrapped and laid again with failure cable by whole, it will
Substantially reduce the security reliability of operation of power networks.In addition, either replacing the cost of cable, or by having a power failure in economy
Caused by Socie-economic loss will be very huge.
Find that the probability of such defect is lower using the means of Partial Discharge Detection, mainly due to Partial Discharge Detection
The sensitivity of device, scene interference caused by working voltage is lower and Partial discharge signal itself has intermittence, therefore need
Novel detection means is expanded, and then effectively finds cable fault caused by buffer layer ablation defect.
Summary of the invention
To solve the problems mentioned above in the background art, the present invention provides a kind of cable slack layer current detection means,
By the way that the magnetism gathering rings of giant magnetoresistance sensor are arranged, the precision of cable slack layer defects current detecting can be effectively improved.
The present invention provides a kind of cable slack layer current detection means, and described device includes: giant magnetoresistance sensor, with
The display terminal and power supply of the giant magnetoresistance sensor connection；The giant magnetoresistance sensor includes magnetism gathering rings, the poly- magnetic
Ring is used to obtain the current signal of cable；The display terminal is used to adjust the operation of the giant magnetoresistance sensor, and exports
Show the current signal.
Alternatively, the giant magnetoresistance sensor further include: magnetoresistive chip, difference amplifier, low pass filtered
Wave device, analog-digital converter and communication module；The magnetoresistive chip and the magnetism gathering rings are electrically connected, and are used for sensed current signal；
The difference amplifier and the magnetoresistive chip are electrically connected, and receive the current signal of magnetoresistive chip output；The low-pass filtering
Device and the difference amplifier are electrically connected, and are used for filtering interference signals；The analog-digital converter and low-pass filter electricity
Gas connection, for analog current signal to be converted to digital signal；The communication module electrically connects with the analog-digital converter
It connects, for being communicated with other devices
Alternatively, the magnetism gathering rings are the discontinuous circular cylinder with air gap, including magnetic core is gentle
Gap, the magnetic core are the magnetic material with high poly- magnetic energy power.
Alternatively, the magnetism gathering rings further include degaussion coil, and the degaussion coil is intertwined and connected described
On magnetic core.
Alternatively, core material is the magnetic material with high poly- magnetic energy power.
Alternatively, the display terminal includes control unit, the control unit include gear unit,
Demagnetize unit, communication unit, and the gear unit is corresponding described low for controlling to adjust the difference amplifier amplification factor
The filtering parameter of bandpass filter, to realize the measurement function of different tested current ranges；The demagnetization unit is described for controlling
Degaussion coil, repeatedly to correct detection device zero point；The communication unit is for controlling giant magnetoresistance sensor and display terminal
Communication mode.
Alternatively, the display terminal further includes working status indication component, output display unit, leads to
Believe interface and power interface；The working status indication component is used to indicate the work shape of cable slack layer current detection means
State；The output display unit is electrically connected by communication interface and the giant magnetoresistance sensor, for exporting display detection
The digital signal of electric current, the communication interface with other devices for connecting, and the power interface is for connecting power supply.
Alternatively, the magnetoresistive chip is installed in the air gap of the magnetism gathering rings, with the degaussion coil
Electrical connection.
Alternatively, the communication module or communication interface and the connection type of PERCOM peripheral communication include wired
Connection is wirelessly connected.
The present invention has the advantages that cable slack layer current detection means provided by the invention, by the way that giant magnetoresistance is arranged
Sensor and magnetism gathering rings can effectively improve the precision of cable slack layer defects current detecting, ensure the normal fortune of power cable
Row, greatly improves the security reliability of operation of power networks.
Detailed description of the invention
Fig. 1 is a kind of cable slack layer current detection means functional block diagram of the present invention
1- giant magnetoresistance sensor；2- display terminal；3- power supply
Fig. 2 is the magnetism gathering rings structural schematic diagram of giant magnetoresistance sensor in the embodiment of the present invention
Fig. 3 is the magnetoresistive chip structural schematic diagram of giant magnetoresistance sensor in the embodiment of the present invention
Fig. 4 is the differential amplifier circuit schematic diagram of giant magnetoresistance sensor in the embodiment of the present invention
Fig. 5 is the structural schematic diagram the invention shows terminal
Fig. 6 is scheme of installation of the embodiment of the present invention in the detection buffer layer defective currents of cable system
4- cable termination；5- power cable；6- cable grounding line；7- protective grounding case
Fig. 7 is the power cable schematic diagram of the embodiment of the present invention
Specific embodiment
To make those skilled in the art more fully understand technical solution of the present invention, with reference to the accompanying drawings and tool is combined
The embodiment of body, the present invention is described in further detail.
Embodiment one
Fig. 1 is please referred to, the embodiment of the present invention provides a kind of cable slack layer current detection means functional block diagram, the cable
Buffer layer current detection means includes: giant magnetoresistance sensor 1, display terminal 2 and power supply 3.
Specifically, giant magnetoresistance sensor 1 includes magnetism gathering rings 11, magnetoresistive chip 12, difference amplifier 13, low-pass filtering
Device 14, analog-digital converter 15 and communication module 16.
Magnetism gathering rings 11 are the discontinuous circular cylinder with air gap, including magnetic core 111, air gap 112 and degaussion coil
113, the magnetic material with high poly- magnetic energy power may be selected in 111 material of magnetic core, such as permalloy, ferrite, silicon steel sheet, amorphous
Alloy etc..Winding is provided with degaussion coil 113 on magnetism gathering rings 11, repeatedly to measure post-equalization detection device zero point, reduces and surveys
Measure error.
Giant magnetoresistance sensor provided in this embodiment uses circular cylinder structure, the concentric circles with cable grounding line
Column structure matches, and when ensure that cable slack layer defects electric current is flowed through by ground line, the magnetic line of force is uniform in magnetism gathering rings
Accumulation, and the sensitive axes of magnetoresistive chip are penetrated, improve the precision of cable slack layer defects current detecting.
Winding has degaussion coil 113 on the magnetism gathering rings 11 of giant magnetoresistance sensor 1, can control by display terminal 2
Giant magnetoresistance sensor 1 demagnetizes, and realizes the zero point of repeatedly measurement post-equalization detection device, cable slack is reduced from hardware
Layer defects current measurement errors.
Magnetoresistive chip 12 is rectangular parallelepiped structure, is installed in the air gap 112 of magnetism gathering rings 11, with the demagnetization line on magnetism gathering rings
113 electrical connection of circle, size needs match with 112 size of air gap, and magnetoresistive chip 12 can be by Hall element, giant magnetoresistance
Element etc. is constituted.
Further, in the embodiment of the present invention as shown in connection with fig. 3 giant magnetoresistance sensor magnetoresistive chip structural representation
Figure has operating voltage (Vbias, GND) and output voltage (V+, V-) pin, and operating voltage pin is for accessing external direct current
Power supply, output voltage pin are proportional to tested current signal for exporting detection output voltage signal, the voltage linear.Such as Fig. 3
Shown, 4 magneto-resistors R11, R12, R21, R22 are connected with full bridge formation, and permanent steady operating voltage is applied to Vbias, GND pin
On, when applying an outfield H to it, 4 magneto-resistor resistance values can increase or reduce accordingly.
Thus the output voltage for being proportional to cable slack layer defects electric current is detected are as follows:
V (H)=V+ (H)-V- (H)
Difference amplifier 13 and magnetoresistive chip 12 are electrically connected, and receive the current signal that magnetoresistive chip directly detects, including
Operational amplifier and multiple resistance, part of resistance is resistance value changeable terminals, to realize the enlarging function of different multiples.
Further, the differential amplifier circuit of giant magnetoresistance sensor shows in the embodiment of the present invention as shown in connection with fig. 4
It is intended to, due to output voltage both ends potential, none is grounded, and differential amplifier circuit is chosen, for the ease of adjusting resistance
Value obtains different amplification factors, and R1 and R3 resistance value stationary phase etc. in the circuit, R2 and R4 are made of electric resistance array, wherein R2
It is made of the specific resistances such as n and control switch, respectively R21 and K21, R22 and K22 ... R2n and K2n, R4 is waited by n than electricity
Resistance and control switch are constituted, respectively R41 and K41, R42 and K42 ... R4n and K4n.In practical applications, for convenient for gear tune
Section, when one amplification factor of every adjustings, K2n and K4n are moved at the same time, the corresponding following relational expression establishment of resistance:
R2n=R4n
Pass through the amplified output voltage of difference amplifier 13 at this time are as follows:
13 partial ohmic of difference amplifier uses the resistance of resistance value changeable terminals, cooperates reality with the control unit 21 of display terminal 2
The enlarging function for having showed different multiples, widened the test scope of cable slack layer current detection means, it can be achieved that (10-6~
102) testing range of A.
Low-pass filter 14 and difference amplifier 13 are electrically connected, and to propose sensed current signal after amplifying, filter out height
Frequency interference signal.
Analog-digital converter 15 and low-pass filter 14 are electrically connected, and the analog signal that will test electric current is converted to digital letter
Number.
Communication module 16 is integrated with wireless and wired two kinds of communication modes.Wired communication mode provides two kinds of communication interfaces,
Communication cable interface and telecommunication optical fiber interface respectively with shielding, communication provide the communication mould of wifi and bluetooth
Block.
Display terminal 2 by control unit 21, working status indication component 22, output display unit 23, communication interface 24,
Power interface 25 is constituted.
Control unit 21 is made of gear unit 211, demagnetization unit 212, communication unit 213.Gear unit 211 controls
The filtering parameter of the corresponding low-pass filter 14 of 13 amplification factor of difference amplifier is adjusted, realizes different tested current ranges
Measure function.Demagnetization unit 212 directly controls the degaussion coil 113 on magnetism gathering rings 11, repeatedly to measure post-equalization detection dress
Zero setting point reduces measurement error.Communication unit 213 directly controls the communication mode of giant magnetoresistance sensor 1 Yu display terminal 2,
Different communication types can be selected according to test site environmental condition.
Working condition of the working status indication component 22 to indicate cable slack layer current detection means, includes at least
Three kinds of states: normal, overload, closed state.
Output display unit 23 is technical grade liquid crystal display, can also be made of industrial personal computer, for exporting display detection electricity
The digital signal of stream.
Communication interface 24 is communicated to the current signal detected with giant magnetoresistance sensor 1, is sensed with giant magnetoresistance
Device 1 connects by way of wirelessly or non-wirelessly, and coaxial communications cable or light with shielded layer can be used in the wired connection of outfit
Fibre is wirelessly connected and passes through wifi or bluetooth approach.
In the present embodiment, giant magnetoresistance sensor 1 and display terminal 2 provide coaxial cable, optical fiber, wifi and bluetooth 4
Kind of communication mode can effectively shorten survey according to tested cable at a distance from display terminal 2 and field condition is selected
The time is tried, improves on-the-spot test efficiency, while reserved multiple communication interface is conducive to on-line monitoring and two kinds of live detection detections
The switching of mode extends the application scenarios of detection device.
Power interface 25 is to provide the operating voltage of display terminal.
Power supply 3 is made of power supply 31 and power supply 32, and power supply 31 is that giant magnetoresistance sensor 1 provides required operating voltage,
Power supply 32 is that display terminal 2 provides required operating voltage.The voltage that magnetoresistive chip 12 requires is DC voltage, voltage magnitude
≤15V.The voltage of display terminal 2 can provide the line voltage of exchange 50Hz or the DC voltage of certain amplitude according to design.
Cable slack layer current detection means live detection work step are as follows:
1, giant magnetoresistance sensor 1 is installed in test article；
2, it is separately connected communication module 16 and communication interface 24, leads to giant magnetoresistance sensor 1 with display terminal 2
Letter.
3, power supply 31 is opened, keeps giant magnetoresistance sensor 1 in running order, to avoid burning giant magnetoresistance sensor
1, gear is adjusted to the maximum value of testing range before connecting；
4, power supply 32 is opened, display terminal 2 is made to work, when observation working status indication component 22 is in normal condition, is opened
Begin to test；
5, the gear unit 211 of regulation control part 21 selects suitable measurement range, is read by output display unit 23
Take test number；
6, it when needing continuous several times to measure, needs to directly control magnetism gathering rings 11 by the demagnetization unit 212 of control unit 21
On degaussion coil 113, realize detection device zero correction, reduce measurement error.
7, after measuring, power supply 32 and power supply 31 are closed, disconnects communication module 16 and communication interface 24, it will be by huge magnetic
Electric resistance sensor 1 is dismantled from product to be tested.
8, when cable slack layer current detection means on-line monitoring test job mode, each certain time repeats above-mentioned
Step 4~6.
Embodiment two
In order to better illustrate the present invention in cable slack layer defects electric current detecting method, the scheme of being implemented as follows is provided:
Fig. 6 is scheme of installation of the embodiment of the present invention in the detection buffer layer defective currents of cable system, such as Fig. 6 institute
Show, cable system is made of cable termination 4, power cable 5, cable grounding line 6 and protective grounding case 7.The allusion quotation of power cable 5
Type structure is as shown in fig. 7, comprises conductor 51, conductor shielding 52, insulating layer 53, insulation shielding 54, buffer layer 55, metal sheath
56 and outer jacket 57.In Operation of Electric Systems, the typical earthing mode of cable system is directly grounded for one end, and one end passes through guarantor
Grounding box 7 is protected to be grounded.
Giant magnetoresistance sensor 1 is installed on the cable grounding line 6 for being directly grounded end, passes through communication module 16 and display
Terminal 2 is communicated, and the cable slack layer current detection means that the present embodiment provides works in the field of wireless communication mode
Scape.Specific test process is as described in embodiment one, and details are not described herein again.
Above-mentioned technical proposal provided in an embodiment of the present invention and attached drawing, for further explanation of the invention rather than limit
System, in addition it should be noted that those of ordinary skill in the art are it is to be understood that still can be to documented by previous embodiment
Technical solution is modified, and is perhaps equivalently replaced and these modifications or is replaced to part of or all technical features
It changes, the range for technical solution of the present invention that it does not separate the essence of the corresponding technical solution.
Claims (9)
1. a kind of cable slack layer current detection means, which is characterized in that described device includes:
Giant magnetoresistance sensor, the display terminal and power supply being connect with the giant magnetoresistance sensor；
The giant magnetoresistance sensor includes magnetism gathering rings, and the magnetism gathering rings are used to obtain the current signal of cable；
The display terminal is used to adjust the operation of the giant magnetoresistance sensor, and exports the display current signal.
2. a kind of cable slack layer current detection means according to claim 1, which is characterized in that the giant magnetoresistance passes
Sensor further include:
Magnetoresistive chip, difference amplifier, low-pass filter, analog-digital converter and communication module；
The magnetoresistive chip and the magnetism gathering rings are electrically connected, and cooperate detection to obtain the current signal with the magnetism gathering rings；
The difference amplifier and the magnetoresistive chip are electrically connected, and receive the current signal of magnetoresistive chip output；
The low-pass filter and the difference amplifier are electrically connected, and are used for filtering interference signals；
The analog-digital converter and the low-pass filter are electrically connected, for analog current signal to be converted to digital signal；
The communication module and the analog-digital converter are electrically connected, for communicating with other devices.
3. a kind of cable slack layer current detection means according to claim 2, which is characterized in that the magnetism gathering rings are band
There are the discontinuous circular cylinder of air gap, including magnetic core and air gap, the magnetic core is the magnetic material with high poly- magnetic energy power.
4. a kind of cable slack layer current detection means according to claim 3, which is characterized in that the magnetism gathering rings also wrap
Degaussion coil is included, the degaussion coil is intertwined and connected on the magnetic core.
5. a kind of cable current detection device according to claim 4, which is characterized in that core material is with high poly- magnetic
The magnetic material of ability.
6. a kind of cable slack layer current detection means according to any one of claims 2 to 5, which is characterized in that described
Display terminal includes control unit, and the control unit includes gear unit, demagnetize unit, communication unit,
The gear unit is used to control to adjust the filtering of the corresponding low-pass filter of the difference amplifier amplification factor
Parameter, to realize the measurement function of different tested current ranges；
The demagnetization unit is for controlling the degaussion coil, repeatedly to correct detection device zero point；
The communication unit is used to control the communication mode of giant magnetoresistance sensor and display terminal.
7. a kind of cable slack layer current detection means according to claim 6, which is characterized in that the display terminal is also
Including working status indication component, output display unit, communication interface and power interface；
The working status indication component is used to indicate the working condition of cable slack layer current detection means；
The output display unit is electrically connected by communication interface and the giant magnetoresistance sensor, for exporting display detection
The digital signal of electric current；
The communication interface with other devices for connecting, and the power interface is for connecting power supply.
8. a kind of cable slack layer current detection means according to claim 8, which is characterized in that the magnetoresistive chip peace
In air gap loaded on the magnetism gathering rings, it is electrically connected with the degaussion coil.
9. a kind of cable slack layer current detection means according to claim 8, which is characterized in that the communication module or
Communication interface and the connection type of PERCOM peripheral communication include wired connection or wireless connection.
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| CN201811602666.9A CN109813949A (en) | 2018-12-26 | 2018-12-26 | A kind of cable slack layer current detection means |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110389283A (en) * | 2019-08-09 | 2019-10-29 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of cable slack layer ablation condition detecting system and detection method |
| CN110806529A (en) * | 2019-11-27 | 2020-02-18 | 云南电网有限责任公司电力科学研究院 | Capacitive type equipment insulation performance on-line monitoring system |
| CN111551833A (en) * | 2020-06-12 | 2020-08-18 | 天津大学 | Cable buffer layer partial discharge test system under extremely inhomogeneous electric field |
| CN111579851A (en) * | 2020-05-08 | 2020-08-25 | 国网电力科学研究院武汉南瑞有限责任公司 | Buffer layer ablation current live detection system and method based on magnetic field effect |
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| CN111579851A (en) * | 2020-05-08 | 2020-08-25 | 国网电力科学研究院武汉南瑞有限责任公司 | Buffer layer ablation current live detection system and method based on magnetic field effect |
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