CN106443432B - Circuit-breaker status detection method based on morphology identification - Google Patents
Circuit-breaker status detection method based on morphology identification Download PDFInfo
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- 238000001514 detection method Methods 0.000 title claims abstract description 21
- 238000000034 method Methods 0.000 claims abstract description 11
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- 230000000877 morphologic effect Effects 0.000 claims abstract description 5
- 238000001914 filtration Methods 0.000 claims description 12
- 230000007246 mechanism Effects 0.000 claims description 11
- 230000004913 activation Effects 0.000 claims description 5
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- 230000007547 defect Effects 0.000 description 4
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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
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
- G01R31/3277—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
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Abstract
The invention discloses a kind of circuit-breaker status detection methods based on morphology identification, it is characterized in that acquiring the current signal of circuit-breaker switching on-off under nominal situation first, current signal is filtered using Multi-structure elements parallel composition morphological filter, square net is drawn in signal plane and covers full signal；The grid number that calculated current signal is covered within certain time；Choosing first grid number rapid drawdown moment is point/combined floodgate Startup time, the last one grid number rapid drawdown moment is point/it closes a floodgate finish time, and it is divided into point/feed motion the time between the two；The feature of the current signal of practical breaker is compared with the current signal feature of circuit-breaker switching on-off under nominal situation, and then judges failure.The method of the present invention is efficiently, accurately.
Description
Technical field
The present invention relates to status of electric power detection methods, more particularly, to a kind of breaker shape based on morphology identification
State detection method.
Background technique
With the expansion of city size and the growth of electricity consumption, power grid is more and more huger, the distribution that unit personnel is administered
Net number of devices sharply increases, and therefore, improves operation of power networks efficiency and field labor productivity, carries out the inspection of grid equipment state
It repairs, transformation grid equipment operation and management mode is extremely urgent.
Power network switch equipment is the most huge grid equipment of quantity, and breaker is most complicated, most important switchgear, quilt
It is widely used in power plant, substation, switchyard and in electric line.The safe and stable operation of breaker not only can be limited effectively
Short circuit current has weight to the security and stability for improving entire electric system to reduce the electrocaloric effect of fault current generation
Want meaning.
Due to breaker self-characteristic, with the increase of action frequency, probability of malfunction is also dramatically increased.Wherein, 60%-
70% breaker defect or failure is as caused by breaker mechanism defect, comprising: mechanism bite, grease solidification, spring are old
Change, Slow-disconnecting and slow-connecting, link transmission axle fracture, mechanism tripping etc..
Currently used fault detection method includes Infrared Detection Method and Partial Discharge Detection method, although can be preferably
Realize breaker on-line monitoring, but correlation technique is diagnosed only for electro-contact defect and insulating element defect, and to disconnected
Road device mechanism-trouble not can be carried out effective detection still.
In the current signal of circuit-breaker switching on-off control loop comprising circuit-breaker switching on-off process various time-parameters,
The information such as mechanism action parameter and coil electric parameter, but circuit breaker current signal detection technique in the prior art be according to
Manually, the situation of change of current waveform is observed, this makes the analysis for wave character have stronger subjectivity, especially
When minor change occurs there are noise jamming or certain features, characteristic signal is not easy to identify, easily state is caused to judge by accident.
Summary of the invention
The present invention is to provide a kind of breaker based on morphology identification to avoid above-mentioned deficiency of the prior art
Condition detection method identifies its divide-shut brake moment for the divide-shut brake current signal of breaker, and to normally with spy when failure
Sign compares, to carry out efficient, accurate detection to circuit-breaker status.
The present invention adopts the following technical scheme that in order to solve the technical problem
The present invention is based on the characteristics of circuit-breaker status detection method of morphology identification to be: breaking under acquisition nominal situation first
The current signal of road device divide-shut brake is filtered current signal using Multi-structure elements parallel composition morphological filter, is believing
Square net is drawn in number plane and covers full signal；The grid number that calculated current signal is covered within certain time；Choosing
Taking first grid number rapid drawdown moment is to divide/combined floodgate Startup time, the last one grid number rapid drawdown moment is at the end of dividing/closing a floodgate
Carve, between the two every be point/the feed motion time；By breaker under the feature of the current signal of practical breaker and nominal situation
The current signal feature of divide-shut brake is compared, and then judges failure.
It is to carry out as follows the present invention is based on the characteristics of circuit-breaker status detection method of morphology identification:
Step 1, with f0It for sample frequency, is sampled for one section of circuit-breaker switching on-off current signal x (t), obtains n
Sampled point；The current signal x (t) is filtered using self adapting morphology junction filter, obtains the electricity through filtering
It flows signal z (t)；
Step 2, in the signal plane through the current signal z (t) filtered using δ as side length draw square net,
The current signal z (t) through filtering, δ=1/f is completely covered in the grid0；
Step 3 calculates current signal z (t) all moment corresponding grid number N through filteringδ(i) are as follows:
Nδ(i)=| xi-xi+1|/δ, in which:
xiThe value of z (t), x are corresponded to for ith sample pointi+1Correspond to the value of z (t) for i+1 sampled point, i=1,2 ...
n；δ=1/f0；And by Nδ(i) maximum value is denoted as m；
Step 4, according to Nδ(i) breaker point/combined floodgate Startup time T is calculated1, finish time T2With actuation time T；
Step 5 divides/switching current signal history data according to breaker, calculates practical point/combined floodgate Startup time T1', it is real
Border finish time T2' and actual act time T ', and according to point/the discrepancy delta T of combined floodgate Startup time1=| T1-T1′|/T1With it is dynamic
Make the discrepancy delta T=of time | T-T ' |/T judges circuit-breaker status:
If Δ T1>=50%, being judged as the activation member of breaker, there are jam faults；
If Δ T >=50%, it is judged as that the main actuating mechanism of breaker loosens or fatigue, mechanism bite and biography there are spring
Dynamic component lubricates inadequate failure.
The present invention is based on the characteristics of circuit-breaker status detection method of morphology identification to lie also in: to electricity in the step 1
It is to carry out as follows that stream signal x (t), which is filtered:
Current signal x (t) is expressed as one-dimensional discrete sequence f (s) by step 1.1；
Step 1.2 calculates structural element gjAre as follows: gj=Hj sin(τπ/Lj)；Wherein, HjFor gjElevational dimension, LjFor gj
Length dimension, τ=0,1 ..., Lj, j=1,2 ..., k, k are the number of structural element；And have:
K=3, H1=1, H2=3, H3=5, L1=3, L2=5, L3=7
Step 1.3 calculates form open-close OC filter OCgjWith close-open (CO) filter COgjIt is respectively as follows:
Wherein,For modified opening operator symbol, accorded with for form closed operation；
Step 1.4 calculates form open-close OC maximal filter ΨOC[f (s)]: and CO minimum filters are closed-opened to form
ΨCO[f (s)] is respectively as follows: ΨOC[f (s)]=max (OCgj), ΨCO[f (s)]=min (COgj),
Then the current signal z (t) through filtering is indicated are as follows:
The present invention is based on morphology identification circuit-breaker status detection method the characteristics of to lie also in: in the step 4 to point/
Combined floodgate Startup time, finish time and actuation time are to carry out according to the following procedure:
Step 4.1 enables p=1, calculates N=Nδ(p+1)-Nδ(p), if N > m/3, the numerical value of p at this time is put into set P
In；
If step 4.2, p < n-1, by p plus 1, step 4.1 is executed again；It is no to then follow the steps 4.3；
Step 4.3, by maximum value p in set Pmax, minimum value pminWhen being respectively defined as point/close a floodgate to start at the time of corresponding
Carve T1, point/close a floodgate finish time T2, then divide/feed motion time T be T=T2-T1。
Compared with the prior art, the invention has the advantages that:
1, the present invention uses morphology discrimination method, can effectively filter out to the noise in signal, introduces grid number
Concept can accurately identify the disturbance and distortion situation of signal part, so as to effectively extract the electricity under each operating condition of breaker
Wave character is flowed, the accuracy of detection is substantially increased.
2, the present invention effectively filters current signal using Multi-structure elements parallel composition morphological filter, so as to
Enough influences for avoiding noise and other interference to greatest extent to analysis result.
3, the present invention divides current signal space using grid, and signal institute grid coverage number can be retouched preferably
Current waveform variation is stated, to more accurately extract relevant feature parameters.
4, the present invention defines threshold value using maximum mesh number, can with the situation of change of rational judgment grid number, thus according to
The grid number acute variation moment more accurately determines and divides/close a floodgate starting and finish time.
5, breakdown judge standard is provided in the present invention, the High Voltage Circuit Breaker Condition can be quantitatively evaluated, to obtain
More accurate the High Voltage Circuit Breaker Condition.
Detailed description of the invention
Fig. 1 is the method for the present invention flow chart；
Specific embodiment
Circuit-breaker status detection method based on morphology identification in the present embodiment is: open circuit under acquisition nominal situation first
The current signal of device divide-shut brake is filtered current signal using Multi-structure elements parallel composition morphological filter, in signal
Square net is drawn in plane and covers full signal；The grid number that calculated current signal is covered within certain time；It chooses
First grid number rapid drawdown moment is to divide/combined floodgate Startup time, the last one grid number rapid drawdown moment is at the end of dividing/closing a floodgate
Carve, between the two every be point/the feed motion time；By breaker under the feature of the current signal of practical breaker and nominal situation
The current signal feature of divide-shut brake is compared, and then judges failure.
It is to carry out as follows referring to Fig. 1, in specific implementation:
Step 1, with f0It for sample frequency, is sampled for one section of circuit-breaker switching on-off current signal x (t), obtains n
Sampled point；Current signal x (t) is filtered using self adapting morphology junction filter, obtains the electric current letter through filtering
Number z (t)；In addition, f0=10000Hz, n=10000.
Step 2, in the signal plane through the current signal z (t) filtered using δ as side length draw square net,
The current signal z (t) through filtering, δ=1/f is completely covered in the grid0。
Step 3 calculates current signal z (t) all moment corresponding grid number N through filteringδ(i) are as follows:
Nδ(i)=| xi-xi+1|/δ, in which:
xiThe value of z (t), x are corresponded to for ith sample pointi+1Correspond to the value of z (t) for i+1 sampled point, i=1,2 ...
n；δ=1/f0；And by Nδ(i) maximum value is denoted as m, herein, δ=0.0001.
Step 4, according to Nδ(i) breaker point/combined floodgate Startup time T is calculated1, finish time T2With actuation time T.
Step 5 divides/switching current signal history data according to breaker, calculates practical point/combined floodgate Startup time T1', it is real
Border finish time T2' and actual act time T ', and according to point/the discrepancy delta T1=of combined floodgate Startup time | T1-T1′|/T1With it is dynamic
Make the discrepancy delta T=of time | T-T ' |/T judges circuit-breaker status:
If Δ T1>=50%, being judged as the activation member of breaker, there are jam faults；
If Δ T >=50%, it is judged as that the main actuating mechanism of breaker loosens or fatigue, mechanism bite and biography there are spring
Dynamic component lubricates inadequate failure.
Being filtered in step 1 to current signal x (t) in the present embodiment is to carry out as follows:
Current signal x (t) is expressed as one-dimensional discrete sequence f (s) by step 1.1；
Step 1.2 calculates structural element gjAre as follows: gj=Hj sin(τπ/Lj)；Wherein, HjFor gjElevational dimension, LjFor gj
Length dimension, τ=0,1 ..., Lj, j=1,2 ..., k, k are the number of structural element；And have:
K=3, H1=1, H2=3, H3=5, L1=3, L2=5, L3=7
Step 1.3 calculates form open-close OC filter OCgjWith close-open (CO) filter COgjIt is respectively as follows:
Wherein,For modified opening operator symbol, accorded with for form closed operation；
Step 1.4 calculates form open-close OC maximal filter ΨOC[f (s)]: and CO minimum filters are closed-opened to form
ΨCO[f (s)] is respectively as follows: ΨOC[f (s)]=max (OCgj), ΨCO[f (s)]=min (COgj),
Then the current signal z (t) through filtering is indicated are as follows:
In the present embodiment step 4 to point/combined floodgate Startup time, finish time and actuation time be to carry out according to the following procedure:
4.1, p=1 is enabled, N=N is calculatedδ(p+1)-Nδ(p), if N > m/3, the numerical value of p at this time is put into set P；
If 4.2, p < n-1, by p plus 1, step 4.1 is executed again；It is no to then follow the steps 4.3；
4.3, by maximum value p in set Pmax, minimum value pmin/ combined floodgate Startup time is respectively defined as point at the time of corresponding
T1, point/close a floodgate finish time T2, then divide/feed motion time T be T=T2-T1。
Running a certain breaker is detected by the method for the present invention, obtains following parameter:
T1=50ms, T2=72ms, T=22ms.
T1'=108ms, T2'=129ms, T '=21ms.
ΔT1=116%, Δ T=4.5%
Judge according to this: the breaker activation member is there are serious jam faults, while main actuating mechanism operational excellence, leads to
Practical maintenance is crossed, it is found that serious jam faults occurs in the breaker activation member roller bearing, to demonstrate the effective of this method
Property and accuracy.
Claims (2)
1. a kind of circuit-breaker status detection method based on morphology identification, it is characterized in that: acquiring open circuit under nominal situation first
The current signal of device divide-shut brake is filtered current signal using Multi-structure elements parallel composition morphological filter, in signal
Square net is drawn in plane and covers full signal；The grid number that calculated current signal is covered within certain time；It chooses
First grid number rapid drawdown moment is to divide/combined floodgate Startup time, the last one grid number rapid drawdown moment is at the end of dividing/closing a floodgate
Carve, between the two every be point/the feed motion time；By breaker under the feature of the current signal of practical breaker and nominal situation
The current signal feature of divide-shut brake is compared, and then judges failure；The circuit-breaker status detection based on morphology identification
Method is to carry out as follows:
Step 1, with f0It for sample frequency, is sampled for one section of circuit-breaker switching on-off current signal x (t), obtains n sampling
Point；The current signal x (t) is filtered using self adapting morphology junction filter, obtains the electric current letter through filtering
Number z (t)；
Step 2, in the signal plane through the current signal z (t) filtered using δ as side length draw square net, it is described
The current signal z (t) through filtering, δ=1/f is completely covered in grid0；
Step 3 calculates current signal z (t) all moment corresponding grid number N through filteringδ(i) are as follows:
Nδ(i)=| xi-xi+1|/δ, in which:
xiThe value of z (t), x are corresponded to for ith sample pointi+1The value of z (t), i=1,2 ... n are corresponded to for i+1 sampled point；δ=
1/f0；And by Nδ(i) maximum value is denoted as m；
Step 4, according to the following procedure according to Nδ(i) breaker point/combined floodgate Startup time T is calculated1, finish time T2And actuation time
T；
Step 4.1 enables p=1, calculates N=Nδ(p+1)-Nδ(p), if N > m/3, the numerical value of p at this time is put into set P；
If step 4.2, p < n-1, by p plus 1, step 4.1 is executed again；It is no to then follow the steps 4.3；
Step 4.3, by maximum value p in set Pmax, minimum value pmin/ combined floodgate Startup time T is respectively defined as point at the time of corresponding1、
Point/close a floodgate finish time T2, then divide/feed motion time T be T=T2-T1；
Step 5 divides/switching current signal history data according to breaker, calculates practical point/combined floodgate Startup time T1', practical knot
Beam moment T2' and actual act time T ', and according to point/the discrepancy delta T of combined floodgate Startup time1=| T1-T1′|/T1When with movement
Between discrepancy delta T=| T-T ' |/T judges circuit-breaker status:
If Δ T1>=50%, being judged as the activation member of breaker, there are jam faults；
If Δ T >=50%, it is judged as that the main actuating mechanism of breaker loosens or fatigue, mechanism bite and driving section there are spring
Part lubricates inadequate failure.
2. the circuit-breaker status detection method according to claim 1 based on morphology identification, characterized in that the step
Be filtered in 1 to current signal x (t) is to carry out as follows:
Current signal x (t) is expressed as one-dimensional discrete sequence f (s) by step 1.1；
Step 1.2 calculates structural element gjAre as follows: gj=Hjsin(τπ/Lj)；Wherein, HjFor gjElevational dimension, LjFor gjLength
Scale, τ=0,1 ..., Lj, j=1,2 ..., k, k are the number of structural element；And have:
K=3, H1=1, H2=3, H3=5, L1=3, L2=5, L3=7
Step 1.3 calculates form open-close OC filter OCgjWith close-open (CO) filter COgjIt is respectively as follows:
Wherein,For modified opening operator symbol, accorded with for form closed operation；
Step 1.4 calculates form open-close OC maximal filter ΨOCCO minimum filters Ψ is closed-opened to [f (s)] and formCO[f
(s)] it is respectively as follows: ΨOC[f (s)]=max (OCgj), ΨCO[f (s)]=min (COgj),
Then the current signal z (t) through filtering is indicated are as follows:
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| CN110991295B (en) * | 2019-11-26 | 2022-05-06 | 电子科技大学 | Self-adaptive fault diagnosis method based on one-dimensional convolutional neural network |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130026690A (en) * | 2011-09-06 | 2013-03-14 | 한국전력공사 | Measurement device with multi-function for operation confirm of earth leakage breaker |
| CN104267343A (en) * | 2014-10-17 | 2015-01-07 | 广东电网有限责任公司佛山供电局 | Method and device for diagnosing failure state of circuit breaker |
| CN104714076A (en) * | 2015-03-24 | 2015-06-17 | 清华大学 | Method and device for smoothing current signals |
| CN105866669A (en) * | 2016-05-19 | 2016-08-17 | 华南理工大学 | Circuit breaker breaking-closing control loop fault diagnosis method |
| CN106019131A (en) * | 2016-05-18 | 2016-10-12 | 四川大学 | State comprehensive evaluation method for high-voltage circuit breaker operating mechanism based on switching-on and switching-off coil currents |
-
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20130026690A (en) * | 2011-09-06 | 2013-03-14 | 한국전력공사 | Measurement device with multi-function for operation confirm of earth leakage breaker |
| CN104267343A (en) * | 2014-10-17 | 2015-01-07 | 广东电网有限责任公司佛山供电局 | Method and device for diagnosing failure state of circuit breaker |
| CN104714076A (en) * | 2015-03-24 | 2015-06-17 | 清华大学 | Method and device for smoothing current signals |
| CN106019131A (en) * | 2016-05-18 | 2016-10-12 | 四川大学 | State comprehensive evaluation method for high-voltage circuit breaker operating mechanism based on switching-on and switching-off coil currents |
| CN105866669A (en) * | 2016-05-19 | 2016-08-17 | 华南理工大学 | Circuit breaker breaking-closing control loop fault diagnosis method |
Non-Patent Citations (1)
| Title |
|---|
| 基于网格曲线频率特性识别励磁涌流;马静 等;《电力自动化设备》;20080731;第29-36页 * |
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