CN109917232A - A kind of fault distance-finding method and system of Automatic Optimal ranging parameters - Google Patents
A kind of fault distance-finding method and system of Automatic Optimal ranging parameters Download PDFInfo
- Publication number
- CN109917232A CN109917232A CN201910288940.8A CN201910288940A CN109917232A CN 109917232 A CN109917232 A CN 109917232A CN 201910288940 A CN201910288940 A CN 201910288940A CN 109917232 A CN109917232 A CN 109917232A
- Authority
- CN
- China
- Prior art keywords
- fault
- distance
- traveling wave
- pulse
- pulse width
- 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
- Locating Faults (AREA)
Abstract
The present invention discloses the fault distance-finding method and system of a kind of Automatic Optimal ranging parameters, and method and step is: respectively according to fault distance and optimum pulse width curve, fault distance and the equivalent velocity of wave curve of traveling wave, setting initial pulse width and initial traveling wave speed；With initial pulse width to the broad-adjustable direct impulse of test line injected pulse, and detects line fault point reflected impulse and carry out preliminary ranging；The pulse width of direct impulse is adjusted according to distance measurement result, and carries out ranging again；Distance measurement result twice if distance measurement result deviation is greater than threshold Thrd1 adjusts pulse width and ranging again again according to newest distance measurement result recently for comparison；Above procedure is repeated, distance measurement result deviation is not more than Thrd1 twice as of late.Such technical solution can solve the problem of that the pulse of fixed width is difficult to adapt to close-in fault and remote failure simultaneously while solve using travelling wave ranging error caused by fixed traveling wave speed, to adapt to different faults distance.
Description
Technical field
The invention belongs to technical field of HVDC transmission, in particular to a kind of fault localization of Automatic Optimal ranging parameters
Method and system.
Background technique
The ground connection polar conductor or metallic return of DC power transmission line are in ground potential in normal conditions, are not easy to carry out failure
Direct current system can be run when monitoring, but breaking down and cause security risk.Will to DC earthing polar conductor or metallic return into
Row malfunction monitoring need to detect reflected pulse waveform, and carry out failure survey based on single-ended traveling wave method to route injected pulse waveform
Away from as shown in Figure 1.When pulse traveling wave is along line transmission, it may occur that decaying and dispersion, and transmission range is longer, then traveling wave decays
It is more serious with dispersion.Traveling wave decaying will lead to traveling wave amplitude reduction, so that signal-to-noise ratio reduces.The pulse width for increasing injection helps
In increasing signal amplitude, reduce the influence of travelling wave signal decaying, but will affect the monitoring of close-in fault.The reason of traveling wave dispersion, exists
Though the increase of the various frequency content frequencies in traveling wave, velocity of wave and decaying can all increase, so that traveling-wave waveform is distorted.
It is slack-off that traveling wave dispersion will lead to the equivalent velocity of wave of traveling wave, and with the increase of traveling wave distance, the equivalent velocity of wave of traveling wave is slack-off tighter
Weight.Traveling wave decaying and effect of dispersion will cause negative effect to the malfunction monitoring of route, can reduce the reliability of malfunction monitoring with
The precision of travelling wave ranging.
The pulse that traditional fault monitoring method based on injected pulse uses pulsewidth fixed, this mode exist as follows not
Foot: when fault point is closer, blind area can be formed since pulse is wide；When fault point farther out when, and can it is narrow due to pulse and
Decay larger.In addition, traditional method carries out ranging using constant traveling wave speed, have ignored different faults apart from when traveling wave
Traveling wave speed caused by chromatic dispersion effects is different, so that range accuracy decreases.
Summary of the invention
The purpose of the present invention is for the ground connection polar conductor of DC power transmission line or the need of metallic return malfunction monitoring
It asks, solves the problems, such as that the pulse of fixed width is difficult to adapt to close-in fault and remote failure simultaneously, while solving using solid
The problem of determining travelling wave ranging error caused by traveling wave speed provides a kind of fault distance-finding method of Automatic Optimal ranging parameters and is
System can adjust pulse width and adapt to different faults distance.
In order to achieve the above objectives, solution of the invention is:
A kind of fault distance-finding method of Automatic Optimal ranging parameters, includes the following steps:
Step 1, according to the curve of fault distance and optimum pulse width, initial pulse width is set；According to fault distance
With the curve of the equivalent velocity of wave of traveling wave, initial traveling wave speed is set；
Step 2, to the broad-adjustable direct impulse of test line injected pulse, and its pulse width is what step 1 was set
Initial pulse width, and line fault point reflected impulse is detected, the initial traveling wave speed set in conjunction with step 1 carries out just pacing
Away from；
Step 3, the pulse width of direct impulse is adjusted according to preliminary distance measurement result, and is carried out according to fault point reflected impulse
Ranging again；
Step 4, distance measurement result twice is compared recently, if distance measurement result deviation is greater than threshold Thrd1, again according to most
New distance measurement result adjustment pulse width and ranging again；Above procedure is repeated, distance measurement result deviation is not more than twice as of late
Thrd1。
In above-mentioned steps 1, the acquisition methods of fault distance and the curve of optimum pulse width are:
Step 1a establishes the digital simulation model of test line, simulated line is divided into N sections, every section of position is denoted as dk,
d0Corresponding line head end, dNCorresponding line end, k=1~N；
Step 1b, in the different location point d of simulated linekFailure is respectively set, and applies different pulse widths respectively
Pulse, pulse width wkIt is incremented by with timing long-pressing step-length dT；When impulse amplitude reaches maximum value or pulse width reaches the upper limit,
Stop being incremented by, obtains corresponding relationship { dk, wk, to obtain the curve w of fault distance Yu optimum pulse widthk=f (dk)。
In above-mentioned steps 1b, pulse width wkIt is incremented by with the long 0.2 μ s of timing by step-length dT, wkValue range is 0.2~5 μ s.
In above-mentioned steps 1, the acquisition methods of fault distance and the curve of the equivalent velocity of wave of traveling wave are:
Step 1A establishes the digital simulation model of test line, simulated line is divided into N sections, every section of position is denoted as dk,
d0Corresponding line head end, dNCorresponding line end, k=1~N；
Fault point d is respectively set in the different location of simulated line in step 1Bk, according to { dk, wkApply respective pulses it is wide
The pulse of degree, according to transmitting pulse, the time difference dt of reflected impulse arrival timekCalculate traveling wave speed, it may be assumed that vk=2dk/
dtk, obtain the corresponding relationship { d of fault distance Yu the equivalent velocity of wave of traveling wavek, vk, to obtain fault distance and the equivalent velocity of wave of traveling wave
Curve vk=g (dk)。
In above-mentioned steps 1B, emit pulse, the traveling wave arrival time of reflected impulse determines method are as follows: it is oblique to calculate traveling wave forward position
Rate absolute value, using slope absolute value maximum point as traveling wave arrival time.
In above-mentioned steps 2, the method for carrying out preliminary ranging is: set fault distance as route M% at, M=0~100, then therefore
Hinder distance measurement result are as follows: x1=M%dt0·v0, wherein dt0For the time difference for emitting pulse and reflected impulse arrival time, v0For
Initial traveling wave speed.
In above-mentioned steps 4, Thrd1 is set as 300~500 meters.
A kind of fault localization system of Automatic Optimal ranging parameters, comprising:
Storage device, for store fault distance and optimum pulse width curve and fault distance and traveling wave it is equivalent
The curve of velocity of wave；
Adjustable pulse generation device for generating the direct impulse of specific pulse width, and injects in test line；
Detection device for detecting transmitting pulse and the time difference of line fault point reflected impulse arrival time, and is sent into
Computing device；
Computing device, the initial traveling wave speed of time difference and direct impulse for being exported according to detection device calculate
Distance measurement result is obtained, and is sent into control device；And
Control device is used for the curve of the fault distance and the equivalent velocity of wave of traveling wave according to fault distance, based on storage device
Initial traveling wave speed is set, and is sent into computing device；For according to fault distance, fault distance based on storage device and best
The curve setting initial pulse width of pulse width, and adjustable pulse generation device is controlled with this and generates direct impulse, for just
Pacing away from；Distance measurement result for being exported according to computing device, adjustment adjustable pulse generation device generate the pulse of direct impulse
Width；And for exporting distance measurement result when distance measurement result deviation is greater than Thrd1 twice recently.
The method that distance measurement result is calculated in above-mentioned computing device is: set fault distance as route M% at, M=0~100,
Then fault localization result are as follows: x1=M%dt0·v0, wherein dt0For the time for emitting pulse and reflected impulse arrival time
Difference, v0For initial traveling wave speed.
Above-mentioned Thrd1 is set as 300~500 meters.
After adopting the above scheme, the present invention can be full with adjust automatically excitation pulse to adapt to different fault distances
The burst pulse demand of sufficient close-in fault and the broad pulse demand of remote failure, to take into account the high-resolution of close-in fault
Rate needs and the high RST loudness demand of remote failure；Corresponding equivalent velocity of wave, Ke Yiti are used for different faults distance
The precision of high travelling wave ranging.The present invention can promote the malfunction monitoring reliability and range accuracy of time domain reflectometry.
Detailed description of the invention
Fig. 1 is the fault detection system figure of direct current grounding pole route or metallic return of the present invention；
Fig. 2 is fault distance of the present invention and pulse width curve synoptic diagram；
Fig. 3 is fault distance of the present invention and traveling wave speed curve synoptic diagram；
Fig. 4 is Single Terminal Traveling Wave Fault Location schematic illustration of the present invention；
Fig. 5 is flow chart of the invention.
Specific embodiment
As shown in figure 5, the present invention provides a kind of fault distance-finding method of Automatic Optimal ranging parameters, implementation step are as follows:
Step 51, according to the model of actual track, emulation obtains the curve of fault distance and pulse width；
Step 52, according to the model of actual track, emulation obtains the curve of fault distance and traveling wave speed；
Step 53, initial pulse width and traveling wave speed are set by 50% line length, carry out initial fault ranging:
Step 54, according to distance measurement result, pulse width and traveling wave speed is adjusted, carries out fault localization again；
Step 55, compare the difference of distance measurement result and threshold value Thrd1 twice recently, if distance measurement result difference is greater than
Thrd1 then goes to step 56, otherwise goes to step 57；
Step 56, if distance measurement result difference is greater than Thrd1,54 are entered step, again fault localization；
Step 57, if distance measurement result difference is not more than Thrd1, stop iteration, provide fault localization result.
Below in conjunction with specific embodiment, technical solution of the present invention and beneficial effect are described in detail.
Step 1 establishes simulated line, embodiments thereof are as follows:
For route to be measured, number is built according to its practical line parameter circuit value (conductor height, distance, diameter, resistivity etc.)
Simulation model.Simulated line is divided into N sections, segments N desirable 10~100.Route is longer, and segments N can be bigger.Every section of position
It sets and is denoted as dk, d0Corresponding line head end, dNCorresponding line end.
Step 2 determines the corresponding relationship curve w of fault distance and pulse widthk=f (dk), as shown in Fig. 2, it is implemented
Mode are as follows:
In the different location point d of simulated linekFailure (k=1~N) is respectively set, and applies the arteries and veins of different in width respectively
Punching, pulse width wkIt is incremented by by from 0.2 μ s by step-length dT, dT can use 0.1 μ s, wkValue range is 0.2~5μs.Work as impulse amplitude
Reach maximum value or when pulse width reaches the upper limit, show that the pulse width has reached optimum value, stop being incremented by this time, obtains pair
It should be related to { dk, wk}.Corresponding relationship { the d of fault distance and pulse widthk, wkIt is pulse width curve wk=f (dk), the song
Line is stored in tabular form in fault localization system, according to actual measurement fault distance x when fault detectionj(i=1,2 ...) table look-up
Pulse width T can be obtainedj=f (xj), j=0,1,2 ...；
Step 3 determines the corresponding relationship curve v of fault distance and traveling wave speedk=g (dk), as shown in figure 3, its embodiment party
Formula are as follows:
Fault point d is respectively set in the different location of simulated linek, according to { dk, wkApply the pulse for corresponding to width, root
According to transmitting pulse, the time difference dt of reflected impulsekCalculate traveling wave speed, it may be assumed that vk=2dk/dtk, which is route traveling wave
Decaying and effect of dispersion caused equivalent velocity of wave of traveling wave in different transmission ranges.At this point, obtaining fault distance and traveling wave etc.
Imitate the corresponding relationship { d of velocity of wavek, vk}.Corresponding relationship { the d of fault distance and the equivalent velocity of wave of traveling wavek, vkIt is velocity of wave curve vk=
g(dk), which is stored in tabular form in fault localization system, according to fault distance x when fault detectionjIt tables look-up and is gone
Wave velocity of wave vj。
Emit pulse, the traveling wave arrival time of reflected impulse determines method are as follows: traveling wave forward position slope absolute value is calculated, with oblique
Rate maximum absolute value point is as traveling wave arrival time；
Step 4 sets initial pulse width, traveling wave speed, and carries out fault localization, embodiments thereof are as follows:
Assuming that fault distance c is to look into pulse width curve at route 50% and obtain initial pulse width T0=f (x0), Cha Hang
Wave velocity of wave curve obtains traveling wave speed v0=g (x0)。
The direct impulse that fault localization system is T0 to practical test line injected pulse width, and detect line fault point
Reflected impulse.As shown in figure 4, Single Terminal Traveling Wave Fault Location principle is based on, according to the time of transmitting pulse and reflected impulse arrival time
Poor dt0Carry out initial fault ranging, it may be assumed that x1=0.5dt0·v0。
Step 5 adjusts pulse width, traveling wave speed, and carries out fault localization, embodiments thereof are as follows:
According to the distance measurement result x of previous stepi, table look-up the pulse width T after being adjustedi=f (xi), it tables look-up and is adjusted
Traveling wave speed v afterwardsi=g (xi).The direct impulse that fault localization system is Ti to practical test line injected pulse width, and
Detect line fault point reflected impulse.Based on Single Terminal Traveling Wave Fault Location principle, according to the time difference dt of transmitting pulse and reflected impulsei
Carry out i-th fault localization adjusted, it may be assumed that xi+1=0.5dti·vi。
According to this distance measurement result xi+1With last time distance measurement result xiCalculate distance measurement result deviation.If distance measurement result deviation
Greater than threshold Thrd1, then again according to newest distance measurement result xi+1Adjust output pulse width and traveling wave speed, and ranging again.
Above procedure is repeated, distance measurement result deviation is not more than Thrd1 twice as of late.Thrd1 can be according to the average departure of overhead line structures
From setting, usually 300~500 meters.
The hardware implementation method of adjust automatically pulse width method are as follows: fault localization system is using dsp chip and may be programmed
The mode that gate array FPGA cooperates realizes the adjust automatically of pulse width, and wherein dsp chip is responsible for acquisition pulse waveform, meter
Calculate fault distance, setting pulse width, the pulse width control pulse output triggering letter that FPGA module is set according to dsp chip
Number, with the width of the resolution ratio control output pulse of nanosecond.
The above examples only illustrate the technical idea of the present invention, and this does not limit the scope of protection of the present invention, all
According to the technical idea provided by the invention, any changes made on the basis of the technical scheme each falls within the scope of the present invention
Within.
Claims (10)
1. a kind of fault distance-finding method of Automatic Optimal ranging parameters, it is characterised in that include the following steps:
Step 1, according to the curve of fault distance and optimum pulse width, initial pulse width is set；According to fault distance and row
The curve of the equivalent velocity of wave of wave, sets initial traveling wave speed；
Step 2, to the broad-adjustable direct impulse of test line injected pulse, and its pulse width is the initial of step 1 setting
Pulse width, and line fault point reflected impulse is detected, the initial traveling wave speed set in conjunction with step 1 carries out preliminary ranging；
Step 3, the pulse width of direct impulse is adjusted according to preliminary distance measurement result, and is carried out again according to fault point reflected impulse
Ranging；
Step 4, distance measurement result twice is compared recently, if distance measurement result deviation is greater than threshold Thrd1, again according to newest survey
Pulse width and ranging again are adjusted away from result；Above procedure is repeated, distance measurement result deviation is not more than twice as of late
Thrd1。
2. fault distance-finding method as described in claim 1, it is characterised in that: in the step 1, fault distance and optimum pulse
The acquisition methods of the curve of width are:
Step 1a establishes the digital simulation model of test line, simulated line is divided into N sections, every section of position is denoted as dk, d0It is right
Answer route head end, dNCorresponding line end, k=1~N；
Step 1b, in the different location point d of simulated linekFailure is respectively set, and applies the pulse of different pulse widths respectively,
Pulse width wkIt is incremented by with timing long-pressing step-length dT；When impulse amplitude reaches maximum value or pulse width reaches the upper limit, stop
It is incremented by, obtains corresponding relationship { dk,wk, to obtain the curve w of fault distance Yu optimum pulse widthk=f (dk)。
3. fault distance-finding method as claimed in claim 2, it is characterised in that: in the step 1b, pulse width wkPeriodically to grow
0.2 μ s is incremented by by step-length dT, wkValue range is 0.2~5 μ s.
4. fault distance-finding method as described in claim 1, it is characterised in that: in the step 1, fault distance is equivalent with traveling wave
The acquisition methods of the curve of velocity of wave are:
Step 1A establishes the digital simulation model of test line, simulated line is divided into N sections, every section of position is denoted as dk, d0It is right
Answer route head end, dNCorresponding line end, k=1~N；
Fault point d is respectively set in the different location of simulated line in step 1Bk, according to { dk,wkApply respective pulses width
Pulse, according to transmitting pulse, the time difference dt of reflected impulse arrival timekCalculate traveling wave speed, it may be assumed that vk=2dk/dtk, obtain
To the corresponding relationship { d of fault distance and the equivalent velocity of wave of traveling wavek,vk, to obtain the curve of fault distance Yu the equivalent velocity of wave of traveling wave
vk=g (dk)。
5. fault distance-finding method as claimed in claim 4, it is characterised in that: in the step 1B, emit pulse, reflected impulse
Traveling wave arrival time determine method are as follows: calculate traveling wave forward position slope absolute value, arrived using slope absolute value maximum point as traveling wave
Up to the moment.
6. fault distance-finding method as claimed in claim 4, it is characterised in that: in the step 2, the method that carries out preliminary ranging
Be: set fault distance as route M% at, M=0~100, then fault localization result are as follows: x1=M%dt0·v0, wherein dt0
For the time difference for emitting pulse and reflected impulse arrival time, v0For initial traveling wave speed.
7. fault distance-finding method as described in claim 1, it is characterised in that: in the step 4, Thrd1 is set as 300~500
Rice.
8. a kind of fault localization system of Automatic Optimal ranging parameters, characterized by comprising:
Storage device, for storing the curve and fault distance and the equivalent velocity of wave of traveling wave of fault distance and optimum pulse width
Curve；
Adjustable pulse generation device for generating the direct impulse of specific pulse width, and injects in test line；
Detection device for detecting transmitting pulse and the time difference of line fault point reflected impulse arrival time, and is sent into calculating
Device；
Computing device, the initial traveling wave speed of time difference and direct impulse for being exported according to detection device, is calculated
Distance measurement result, and it is sent into control device；And
Control device is used for the curve setting of the fault distance and the equivalent velocity of wave of traveling wave according to fault distance, based on storage device
Initial traveling wave speed, and it is sent into computing device；For according to fault distance, fault distance and optimum pulse based on storage device
The curve setting initial pulse width of width, and adjustable pulse generation device is controlled with this and generates direct impulse, it is used for first pacing
Away from；Distance measurement result for being exported according to computing device, adjustment adjustable pulse generation device generate the pulse width of direct impulse；
And for exporting distance measurement result when distance measurement result deviation is greater than Thrd1 twice recently.
9. fault localization system as claimed in claim 8, it is characterised in that: distance measurement result is calculated in the computing device
Method is: set fault distance as route M% at, M=0~100, then fault localization result are as follows: x1=M%dt0·v0, wherein
dt0For the time difference for emitting pulse and reflected impulse arrival time, v0For initial traveling wave speed.
10. fault localization system as claimed in claim 8, it is characterised in that: the Thrd1 is set as 300~500 meters.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910288940.8A CN109917232A (en) | 2019-04-11 | 2019-04-11 | A kind of fault distance-finding method and system of Automatic Optimal ranging parameters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910288940.8A CN109917232A (en) | 2019-04-11 | 2019-04-11 | A kind of fault distance-finding method and system of Automatic Optimal ranging parameters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109917232A true CN109917232A (en) | 2019-06-21 |
Family
ID=66969538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910288940.8A Pending CN109917232A (en) | 2019-04-11 | 2019-04-11 | A kind of fault distance-finding method and system of Automatic Optimal ranging parameters |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109917232A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111896971A (en) * | 2020-08-05 | 2020-11-06 | 上海炬佑智能科技有限公司 | TOF sensing device and distance detection method thereof |
| CN114325226A (en) * | 2021-12-20 | 2022-04-12 | 国网山东省电力公司滨州供电公司 | High-frequency fault positioning method and system for single-end adaptive correction of power transmission line |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020196031A1 (en) * | 2001-06-11 | 2002-12-26 | General Dynamics Ots (Aerospace), Inc. | Parallel insulation fault detection system |
| CN102087332A (en) * | 2010-12-20 | 2011-06-08 | 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 | Direct current (DC) travelling wave fault location method based on wave velocity optimization |
| CN102213741A (en) * | 2011-05-26 | 2011-10-12 | 长沙理工大学 | Method and device for measuring distance of fault travelling wave of short-distance cable |
| CN102680855A (en) * | 2012-05-15 | 2012-09-19 | 东南大学 | Cable fault detecting and positioning method based on waveform replication |
| CN103818406A (en) * | 2013-11-12 | 2014-05-28 | 嘉兴中科声学科技有限公司 | Subway auxiliary collision avoidance system and subway auxiliary collision avoidance method |
| CN104412120A (en) * | 2012-06-18 | 2015-03-11 | 赫克斯冈技术中心 | Distance measuring method using dynamic pulse width adaptation |
| CN205941778U (en) * | 2016-08-01 | 2017-02-08 | 咸亨国际（杭州）电气制造有限公司 | Cable fault range unit |
-
2019
- 2019-04-11 CN CN201910288940.8A patent/CN109917232A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020196031A1 (en) * | 2001-06-11 | 2002-12-26 | General Dynamics Ots (Aerospace), Inc. | Parallel insulation fault detection system |
| CN102087332A (en) * | 2010-12-20 | 2011-06-08 | 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 | Direct current (DC) travelling wave fault location method based on wave velocity optimization |
| CN102213741A (en) * | 2011-05-26 | 2011-10-12 | 长沙理工大学 | Method and device for measuring distance of fault travelling wave of short-distance cable |
| CN102680855A (en) * | 2012-05-15 | 2012-09-19 | 东南大学 | Cable fault detecting and positioning method based on waveform replication |
| CN104412120A (en) * | 2012-06-18 | 2015-03-11 | 赫克斯冈技术中心 | Distance measuring method using dynamic pulse width adaptation |
| CN103818406A (en) * | 2013-11-12 | 2014-05-28 | 嘉兴中科声学科技有限公司 | Subway auxiliary collision avoidance system and subway auxiliary collision avoidance method |
| CN205941778U (en) * | 2016-08-01 | 2017-02-08 | 咸亨国际（杭州）电气制造有限公司 | Cable fault range unit |
Non-Patent Citations (1)
| Title |
|---|
| 白春涛: "电力电缆故障低压脉冲自动测距方法研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111896971A (en) * | 2020-08-05 | 2020-11-06 | 上海炬佑智能科技有限公司 | TOF sensing device and distance detection method thereof |
| CN111896971B (en) * | 2020-08-05 | 2023-12-15 | 上海炬佑智能科技有限公司 | TOF sensing device and distance detection method thereof |
| CN114325226A (en) * | 2021-12-20 | 2022-04-12 | 国网山东省电力公司滨州供电公司 | High-frequency fault positioning method and system for single-end adaptive correction of power transmission line |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Weidman et al. | The Fine Structure of Lightning Return-Stroke Wave Forms 6 | |
| Mach et al. | Photoelectric return‐stroke velocity and peak current estimates in natural and triggered lightning | |
| CN108120901A (en) | A kind of cable fault localization method and device | |
| CN109917232A (en) | A kind of fault distance-finding method and system of Automatic Optimal ranging parameters | |
| CN204989471U (en) | Multiple target pulsed laser distancer | |
| CN103217626A (en) | Single-ended traveling wave fault location method using positive and negative wave head time sequence intervals | |
| CN108445477B (en) | High-precision distance measurement method for airport surface foreign matter detection radar | |
| JP2020079724A (en) | Lightning current waveform estimation method and lightning current waveform estimation device | |
| CN100394205C (en) | Method for promoting testing reliability of cable obstacle | |
| CN103018749B (en) | Device and method for pulse laser ranging | |
| CN103163428B (en) | A kind of method improving Single Terminal Traveling Wave Fault Location reliability | |
| CN111044848B (en) | Cable fault high-precision positioning method based on characteristic parameter adjustment wave speed | |
| CN202798620U (en) | Laser pulse-type generation circuit | |
| CN111416543B (en) | Square wave pulse power supply for positioning cable intermediate joint | |
| Romero et al. | A statistical analysis on the risetime of lightning current pulses in negative upward flashes measured at Säntis tower | |
| CN103486987B (en) | A kind of method utilizing curve to improve ultrasonic thickness measurement precision | |
| CN110320398B (en) | Testing system and measuring method for effective impact length of tower grounding electrode | |
| CN107272011A (en) | Time point discrimination method, time point discriminator circuit system and LDMS | |
| Watanabe et al. | Current and electric field changes associated with the initial stage of upward lightning | |
| CN103457580B (en) | A kind of laser pulsed generative circuit | |
| CN105137291A (en) | Pulse optimization method used for increasing ranging accuracy of cable faults and pulse generating circuit | |
| CN111880010A (en) | Method for detecting impact effective length of grounding electrode of power transmission line tower | |
| CN201984161U (en) | Laser detection circuit based on time-varying thresholds | |
| CN104457545B (en) | The whether isometric system and method detected of each cable in a kind of group to cable | |
| CN110261834B (en) | Method for improving quality of hybrid radar signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190621 |