CN105974244A - Operating cable grounding state detection circuit and method using variable frequency resonant partial voltage - Google Patents
Operating cable grounding state detection circuit and method using variable frequency resonant partial voltage Download PDFInfo
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- CN105974244A CN105974244A CN201610503824.XA CN201610503824A CN105974244A CN 105974244 A CN105974244 A CN 105974244A CN 201610503824 A CN201610503824 A CN 201610503824A CN 105974244 A CN105974244 A CN 105974244A
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- 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
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- 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
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- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
-
- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/58—Testing of lines, cables or conductors
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- General Physics & Mathematics (AREA)
- Locating Faults (AREA)
Abstract
The invention provides an operating cable grounding state detection circuit and detection method using variable frequency resonant partial voltage. The detection circuit is used for measuring the grounding state between an end A and an end B on a grounding line of a power cable armor layer, and comprises a variable high frequency signal source, an LC resonant circuit unit and a voltage signal acquisition unit; the end B is grounded, the high frequency signal source is connected in parallel to the LC resonant circuit unit, one end of the parallel structure is connected to the end A, the other end is grounded, and the LC resonant circuit unit is used for implementing frequency resonance with the high frequency signal source; and the voltage signal acquisition unit is used for acquiring voltage at two ends of the LC resonant circuit unit. The circuit is simple in structure and low in implementation cost, and can simply and effectively detect the grounding state of the operating cable armor layer.
Description
Technical field
The present invention relates to a kind of testing circuit running cable grounding state and detection method.
Background technology
Underground power cable is safe and reliable and can significantly improve urban electricity supply line environment, in the power supply mode of urban power distribution network, the most gradually instead of the power supply mode of overhead transmission line.At present, the usage amount of buried cable is far beyond the usage amount of overhead transmission line.Along with the sharply increasing of power cable quantity in electrical network, the fault of cable increases the most accordingly.
Cable is the most all laid in underpass, and during daily operation management, in addition to the fault of cable own, the phenomenon of artificial pilferage or destruction cable outer layer is the most extremely serious.In particularly, pressure 10kV power cable shield layer is happened occasionally by shelling phenomenon, and the fault of this artificial destruction the most causes very big personnel's economic loss to electric power network.
For this situation, the most domestic various types of low-voltage lighting cable alarm system, aerial cable guard against theft and alarm system, the power failure Stealing-proof Alarming System for Power Cable of in succession occurring in that, but the burglar alarm and fault positioning products for middle pressure 10kV operation power cable is few.Universal power cable anti-theft device only achieves the detection running cable grounding state, but is difficult to the particular location to running when cable grounding system suffers brokenly ring and positions.Utilize the high frequency signal transmission passage formed between power cable shield and ground to carry out power cable antitheft, when the high frequency signal transmission passage formed is destroyed, represent that monitored cable has abnormal same alarm between power cable steel sheath and ground.
But, having accessed other media because giving in the middle of power cable shield layer, having brought unreliable factor to the operation of power cable.Meanwhile, monitored power cable of must stopping transport during in-site installation, change the mounting structure of original power cable, waste time and energy and be inconvenient to install.
Summary of the invention
The present invention proposes a kind of new Circuits System realizing running cable grounding state-detection, it is possible to simply and effectively detection runs cable grounding state.
Technical scheme is as follows:
The operation cable grounding state detection circuit of a kind of frequency conversion resonance vibration dividing potential drop mode, for measuring A end on the earth lead of power cable steel sheath to the ground state between B end, including variable-frequency high-frequency signal source, LC resonance circuit unit and voltage signal acquisition unit；Described B end ground connection, described high-frequency signal source is in parallel with LC resonance circuit unit, and an end of parallel-connection structure is connected to described A end, and other end ground connection, for realizing the resonance with high-frequency signal source frequency；Voltage signal acquisition unit is used for gathering LC resonance circuit unit both end voltage.
In above-mentioned LC resonance circuit unit, the impedance of L is more preferably less than 1 ohm, and the swept frequency range of high-frequency signal source is between 1KHz～20KHz.
Use foregoing circuit to realize the method running cable grounding state-detection, comprise the following steps:
(1) normal data of complete power cable steel sheath ground state is obtained
For the power cable that steel sheath is intact, first ensure that at cable under stoppage in transit state, the steel sheath earth lead (the most now cable B end is earth-free) of unsettled cable termination, then high-frequency signal source passes through variable-frequency scanning, according to formula (1), being automatically found resonant frequency f, now voltage signal acquisition unit measures voltage magnitude the record of LC resonance circuit unit, and record keeps this frequency f constant simultaneously；
Formula (1):
(2) real-time monitoring power cable state
For operation power cable steel sheath ground state to be measured, resonant frequency f that high-frequency signal source implantation step (1) records, voltage signal acquisition unit measures the voltage magnitude of LC resonance circuit unit, if the voltage magnitude that this voltage records less than step (1), then judge that this power cable steel sheath ground state has breakage；
(3) location of cable open failure position
High-frequency signal source is by frequency sweep again, find new resonant frequency f ', voltage signal acquisition unit measures the optimum voltage amplitude of LC resonance circuit unit, record now resonant frequency f ', the variable quantity of electric capacity C is calculated according to formula (1), in conjunction with every kilometer of the cable distributed capacitance to the earth, finally give cable open position.
The invention have the advantages that
Circuit structure is simple, it is achieved low cost, it is possible to simply and effectively detection runs Steel armor of cable layer ground state.
Monitoring, does not affect the properly functioning of cable in real time.
Can quickly can accurate failure judgement position.
It is applicable to the system of the multiple two sides earth such as 6kV, 10kV, 35kV, highly versatile, adaptation face width.
Accompanying drawing explanation
Fig. 1 is the measuring principle schematic diagram of the present invention.
Wherein, 1-power cable, 2-high-frequency signal source (variable ratio frequency changer regulation).
Detailed description of the invention
Measuring principle of the present invention, as it is shown in figure 1, be to utilize the high frequency signal transmission loop formed between power cable steel sheath and the earth, realizes running accurately cable grounding state and the calculating of fault location by frequency conversion resonance vibration principle.
In Fig. 1 Vf be variable frequency signal source, R0 be singal source resistance, L be impedance be less than 1 ohm of inductance, C be and the high-voltage capacitance that connects, Cx be the distribution capacity (distribution capacity is the most linear with its length) between power cable steel sheath and the earth, Vx be the both end voltage (voltage magnitude) of the LC resonance circuit unit that voltage signal acquisition unit is measured.Variable frequency signal source is in parallel with LC resonance circuit unit, and entirety is serially connected with in the earth lead of power cable steel sheath to be measured, and voltage signal acquisition unit is used for gathering LC resonance circuit unit both end voltage and delivering to data processing unit.
Electric capacity C, the parallel relationship of distribution capacity Cx, it is possible to achieve with the resonance of high-frequency signal source frequency.The R0 impact on LC resonance circuit in negligible high-frequency signal source, the impedance of LC is less than 1 ohm, therefore draws inductance L maximum under power frequency 50Hz environment, and the swept frequency range of high-frequency signal source is between 1KHz～20KHz simultaneously.
Formula (1):
Formula (2): XL=2 π f*L
When power cable steel sheath ground state changes (as opened a way in somewhere), necessarily great changes have taken place for the Vx value real-time monitored and the Vx under normal ground state.Compared by the process that Vx is changed, can effectively judge whether power cable has disengagement failure, the digital signal that specifically can be collected by high speed processor, compares through equivalent network model algorithm process and the data feature values set up, the disengagement failure of available power cable steel sheath.
This employing frequency conversion resonance vibration dividing potential drop mode carries out the method that power cable is monitored in real time, comprises the following steps:
(1) normal data of complete power cable steel sheath ground state is obtained
For the power cable that steel sheath is intact, first ensure that at cable under stoppage in transit state, the steel sheath earth lead of unsettled cable termination, then variable frequency signal source passes through frequency sweep, according to formula 1, searching out resonant frequency f, now voltage signal acquisition unit measures voltage magnitude the record of LC resonance circuit unit, and record keeps this frequency f constant simultaneously.
Formula 1:
(2) real-time monitoring power cable state
For operation power cable steel sheath ground state to be measured, variable frequency signal source injects frequency f of record under serviceable condition, voltage signal acquisition unit measures the voltage magnitude of LC resonance circuit unit, if the voltage magnitude that this voltage records less than step (1), then judge that this power cable steel sheath ground state has breakage, send alarm.
(3) location of cable open failure position
When suffering artificial destruction for operation power cable steel sheath to be measured, variable frequency signal source is by frequency sweep again, according to formula 1, search out new resonant frequency f, voltage signal acquisition unit measures the optimum voltage amplitude of LC resonance circuit unit, records now frequency, calculates the variable quantity Cx of C according to formula 1, in conjunction with every kilometer of the cable distributed capacitance to the earth, finally give cable open position.
Claims (3)
1. utilize an operation cable grounding state detection circuit for frequency conversion resonance vibration dividing potential drop, be used for measuring electric power
On the earth lead of Steel armor of cable layer, A end is to the ground state between B end, it is characterised in that: include variable
High-frequency signal source, LC resonance circuit unit and the voltage signal acquisition unit of frequency；Described B end ground connection, institute
Stating high-frequency signal source in parallel with LC resonance circuit unit, an end of parallel-connection structure is connected to described A end, separately
One end ground connection, for realizing the resonance with high-frequency signal source frequency；Voltage signal acquisition unit is used for gathering
LC resonance circuit unit both end voltage.
The operation cable grounding state-detection electricity utilizing frequency conversion resonance vibration dividing potential drop the most according to claim 1
Road, it is characterised in that: in described LC resonance circuit unit, the impedance of L is less than 1 ohm, high-frequency signal
The swept frequency range in source is between 1KHz～20KHz.
3. the detection method running cable grounding state, it is characterised in that: use claim 1 institute
The operation cable grounding state detection circuit utilizing frequency conversion resonance vibration dividing potential drop stated, comprises the following steps:
(1) normal data of complete power cable steel sheath ground state is obtained
For the power cable that steel sheath is intact, first ensure that at cable under stoppage in transit state, unsettled cable
The steel sheath earth lead of terminal, then high-frequency signal source passes through variable-frequency scanning, according to formula (1), automatically
Finding resonant frequency f, now voltage signal acquisition unit measures the voltage magnitude of LC resonance circuit unit also
Record, record keeps this frequency f constant simultaneously；
Formula (1):
(2) real-time monitoring power cable state
For operation power cable steel sheath ground state to be measured, high-frequency signal source implantation step (1) record
Resonant frequency f, voltage signal acquisition unit measure LC resonance circuit unit voltage magnitude, if this electricity
The voltage magnitude that pressure records less than step (1), then judge that this power cable steel sheath ground state has breakage；
(3) location of cable open failure position
High-frequency signal source, by frequency sweep again, finds new resonant frequency f ', voltage signal acquisition unit is surveyed
The optimum voltage amplitude of amount LC resonance circuit unit, records now resonant frequency f ', according to formula (1)
Calculate the variable quantity of electric capacity C, in conjunction with every kilometer of the cable distributed capacitance to the earth, finally give electricity
Cable open position.
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| CN201610503824.XA CN105974244B (en) | 2016-06-29 | 2016-06-29 | A kind of operation cable grounding condition detection method divided using frequency conversion resonance vibration |
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| CN201610503824.XA CN105974244B (en) | 2016-06-29 | 2016-06-29 | A kind of operation cable grounding condition detection method divided using frequency conversion resonance vibration |
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| CN105974244A true CN105974244A (en) | 2016-09-28 |
| CN105974244B CN105974244B (en) | 2018-12-21 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106707087A (en) * | 2017-02-04 | 2017-05-24 | 山西全安新技术开发有限公司 | Grounding monitoring and controlling method and system for underground electric equipment |
| CN107340416A (en) * | 2017-08-28 | 2017-11-10 | 国网江西省电力公司电力科学研究院 | A kind of distribution network failure indicator LC tunings are outer to apply signal source |
| CN111239542A (en) * | 2020-02-03 | 2020-06-05 | 华北电力大学 | Photovoltaic direct current collection branch fault positioning method based on high-frequency resonance identification |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001051006A (en) * | 1999-08-05 | 2001-02-23 | Ntt Advanced Technology Corp | Method of contrasting coaxial cables |
| CN203117345U (en) * | 2013-02-01 | 2013-08-07 | 西安秦骊成套电器有限公司 | Circuit detecting grounding state of operating cable via high-frequency signal injection |
| CN203117325U (en) * | 2013-02-01 | 2013-08-07 | 西安秦骊成套电器有限公司 | Operating cable grounding state detecting circuit in dc measurement manner |
| CN103337119A (en) * | 2013-06-08 | 2013-10-02 | 山东康威通信技术股份有限公司 | Burglary-resisting monitoring and positioning method for armored cable |
| CN103646488A (en) * | 2013-11-21 | 2014-03-19 | 广东电网公司惠州供电局 | An armored cable monitoring system and a method |
| CN206132867U (en) * | 2016-06-29 | 2017-04-26 | 西安秦骊成套电器有限公司 | Utilize operation cable grounding state detection circuitry of frequency conversion resonance partial pressure |
-
2016
- 2016-06-29 CN CN201610503824.XA patent/CN105974244B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001051006A (en) * | 1999-08-05 | 2001-02-23 | Ntt Advanced Technology Corp | Method of contrasting coaxial cables |
| CN203117345U (en) * | 2013-02-01 | 2013-08-07 | 西安秦骊成套电器有限公司 | Circuit detecting grounding state of operating cable via high-frequency signal injection |
| CN203117325U (en) * | 2013-02-01 | 2013-08-07 | 西安秦骊成套电器有限公司 | Operating cable grounding state detecting circuit in dc measurement manner |
| CN103337119A (en) * | 2013-06-08 | 2013-10-02 | 山东康威通信技术股份有限公司 | Burglary-resisting monitoring and positioning method for armored cable |
| CN103646488A (en) * | 2013-11-21 | 2014-03-19 | 广东电网公司惠州供电局 | An armored cable monitoring system and a method |
| CN206132867U (en) * | 2016-06-29 | 2017-04-26 | 西安秦骊成套电器有限公司 | Utilize operation cable grounding state detection circuitry of frequency conversion resonance partial pressure |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106707087A (en) * | 2017-02-04 | 2017-05-24 | 山西全安新技术开发有限公司 | Grounding monitoring and controlling method and system for underground electric equipment |
| CN106707087B (en) * | 2017-02-04 | 2024-04-05 | 山西全安新技术开发有限公司 | Underground electrical equipment grounding monitoring method and system |
| CN107340416A (en) * | 2017-08-28 | 2017-11-10 | 国网江西省电力公司电力科学研究院 | A kind of distribution network failure indicator LC tunings are outer to apply signal source |
| CN111239542A (en) * | 2020-02-03 | 2020-06-05 | 华北电力大学 | Photovoltaic direct current collection branch fault positioning method based on high-frequency resonance identification |
| CN111239542B (en) * | 2020-02-03 | 2021-05-25 | 华北电力大学 | Photovoltaic direct current collection branch fault positioning method based on high-frequency resonance identification |
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| CN105974244B (en) | 2018-12-21 |
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