CN102565646A  Lightningwave surgevoltage type test device for dry sleeve and frequency band analysis method thereof  Google Patents
Lightningwave surgevoltage type test device for dry sleeve and frequency band analysis method thereof Download PDFInfo
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 CN102565646A CN102565646A CN2012100149248A CN201210014924A CN102565646A CN 102565646 A CN102565646 A CN 102565646A CN 2012100149248 A CN2012100149248 A CN 2012100149248A CN 201210014924 A CN201210014924 A CN 201210014924A CN 102565646 A CN102565646 A CN 102565646A
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 sleeve pipe
 sleeve
 sequence
 lightning
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 238000004458 analytical methods Methods 0.000 title claims abstract description 23
 238000009413 insulation Methods 0.000 claims abstract description 17
 230000015556 catabolic process Effects 0.000 claims abstract description 14
 239000010410 layers Substances 0.000 claims abstract description 12
 239000003990 capacitor Substances 0.000 claims abstract description 11
 238000005070 sampling Methods 0.000 claims description 7
 238000010606 normalization Methods 0.000 claims description 6
 230000000903 blocking Effects 0.000 claims description 5
 230000000875 corresponding Effects 0.000 claims description 5
 238000001228 spectrum Methods 0.000 claims description 5
 241000212893 Chelon labrosus Species 0.000 claims description 3
 230000003247 decreasing Effects 0.000 claims description 2
 238000004321 preservation Methods 0.000 claims description 2
 230000003595 spectral Effects 0.000 claims description 2
 238000000034 methods Methods 0.000 abstract description 6
 238000005516 engineering processes Methods 0.000 abstract description 5
 238000010586 diagrams Methods 0.000 description 4
 238000006243 chemical reactions Methods 0.000 description 3
 230000000694 effects Effects 0.000 description 3
 230000002950 deficient Effects 0.000 description 2
 239000011810 insulating materials Substances 0.000 description 2
 230000035939 shock Effects 0.000 description 2
 241000893018 Armeria Species 0.000 description 1
 230000002349 favourable Effects 0.000 description 1
 238000004519 manufacturing process Methods 0.000 description 1
 230000000630 rising Effects 0.000 description 1
 238000004088 simulation Methods 0.000 description 1
 238000010183 spectrum analysis Methods 0.000 description 1
Abstract
Description
Technical field
The invention belongs to large scale electrical power unit insulation state monitoring technology, relate to signal processing technology, particularly dry sleeve lightning wave impulse voltage pattern test unit and frequency range analysis method thereof.
Background technology
Insulating material all can only keep its insulation characterisitic once in certain electric field intensity, and when electric field intensity surpassed certain limit, insulating material just can lose insulation characterisitic moment, and entire equipment is destroyed.Therefore, dielectric strength is the most basic insulation characterisitic parameter.No matter in the production of electric product, still in use, all to often do the type approval test of dielectric strength.
Various highvoltage electrical equipments are in operation, and will suffer atmospheric overvoltage unavoidably.In order to check dry sleeve to bear this superpotential ability, need carry out the dielectric test [1] of surge voltage to it.In the dielectric test under the surge voltage, the surge voltage waveform of employing is the maximum surge voltage waveform of probability of occurrence in the simulation actual motion, and this is the various reference waveforms of stipulating out according to a large amount of results that survey statistics.According to GB/T16927.11997 " the highvoltage test part: ordinary test requires " regulation; General wave head time T 1 is 1.2 ± 30% μ s; Wave rear time T 2 is 50 ± 2% μ s, the shock wave peak value is no more than ± and 3%, the overbump oscillation amplitude that produces on the peak value is less than 5% of peak value.In general, can use formula (1) to represent that lightning wave is in t voltage U constantly:
Wherein: t _{1}=T _{2}/ ln 2, t _{2}=T _{1}/ 3.25, T1, T2 are respectively wave head time and wave rear time, and A is the shock wave amplitude.
Usually, dry sleeve can be regarded the series connection of a plurality of resistance capacitance parallelconnection structures as, shown in accompanying drawing 1.In the real work, the engineering staff is through the relevant voltage waveform of observation sleeve pipe under surge voltage on the voltage divider that is connected in parallel on sleeve pipe insulation core both sides, and the variation of measurement sleeve pipe capacitance before and after test is to confirm the puncture number of plies.But in fact, this method has two defectives: 1) the sleeve pipe number of plies is more and puncture the number of plies when few, before and after the test variation of capacitance of bushing value all very not obvious, make that the engineering staff is difficult to discover; 2) in lightning wave type approval test process, no matter whether whether sleeve pipe punctures its response wave shape is not had significant change, and promptly this method is not directly perceived.
Summary of the invention
Defective or deficiency to abovementioned prior art exists the objective of the invention is to, and a kind of simple and effective method really is provided, and confirm whether punchthrough takes place and puncture the number of plies at lightning wave type approval test middle sleeve.
For realizing abovementioned purpose, the present invention adopts following technical scheme:
Dry sleeve lightning wave impulse voltage pattern test unit; Comprise the sleeve pipe main capacitance fuse and the extra capacitor that stand lightning wave type approval test and series connection each other as a whole; The two ends of said extra capacitor are connected with oscillograph; Data collecting card is gathered oscillographic signal and is transferred to computing machine, adopts Fourier analysis judgement in shortterm to puncture the time of origin and the sleeve pipe puncture number of plies.
3 times of the capacitance that the said capacitance that adds electric capacity is sleeve pipe insulation core main capacitance at least;
Said data collecting card is the multichannel digital capture card of picking rate more than 1GS/s.
The frequency range analysis method of dry sleeve lightning wave impulse voltage type approval test at first utilizes data collecting card to oscillographic waveform u _{2}(t) sample, and with sampled result u _{2}(n) be transferred to computing machine and preserving, computing machine is to sampled result u then _{2}(n) use a plurality of rectangular window function g _{i}(n) carry out intercepting and handle, obtain a series of sequences Then, to sequence Carry out carrying out the normalization processing after the FFT, obtain sequence The numerical frequency amplitude response Through with the comparison of consecutive point amplitude response just can obtain sleeve pipe at a time the section whether puncture.
As the preferred embodiments of the present invention, to sampled result u _{2}(n) use a plurality of rectangular window function g _{i}(n) carry out intercepting and handle after, carry out intercepting once more and handle, promptly remove In null value, keep nonzero value;
As the preferred embodiments of the present invention, the length of the secondary intercepting sequence that obtains is N _{i}=n _{I+1}n _{i}+ 1;
As the preferred embodiments of the present invention, said Wherein, [n _{i}, n _{I+1}] be window g _{i}(n) block the interval;
As the preferred embodiments of the present invention, said
Compared with prior art; Dry sleeve lightning wave impulse voltage pattern test unit of the present invention and frequency range analysis method thereof have the following advantages at least: the present invention utilizes the extra capacitor ground connection of connecting with sleeve pipe main capacitance fuse; Stand the lightning wave type approval test as a whole, and utilize in shortterm Fourier analysis to puncture the number of plies and estimate puncturing time of origin and sleeve pipe exactly, so; Can not receive the interference of factors such as stray capacitance, judged result is comparatively accurate.
Description of drawings
Fig. 1 is a dry sleeve capacitanceresistance parallelseries structural representation in the background technology;
Fig. 2 is the lightning wave type approval test circuit diagram that the present invention proposes;
Fig. 3 is voltage u under Fig. 2 hookup _{2}(t) variation synoptic diagram comprises under the normal condition and punctures u when taking place _{2}(t) waveform;
Fig. 4 is that the present invention is to u _{2}(t) sampled result is carried out the process flow diagram of Fourier analysis in shortterm;
Fig. 5 is u _{2}Frequency domain distortion synoptic diagram a) is under the normal condition wherein Amplitude response is when b) puncturing generation for wavefront Amplitude response is to puncture when taking place behind the ripple c) Amplitude response (for ecbatic more clearly, only provide and close on the distortional point place);
Fig. 6 is the frequency domain amplitude response of rectangular window of the present invention;
Fig. 7 is a test findings of the present invention; Wherein, Concern between the distorted position in the ratio e of breakdown layer capacitance value of sleeve pipe and sleeve pipe insulation core total capacitance value and frequency domain when a) puncturing generation, concern between the ratio e of breakdown layer capacitance value of sleeve pipe and sleeve pipe insulation core total capacitance value and the distortion degree E when b) puncturing generation for wavefront for wavefront; C), d) be that E concerns between ratio e and the distortion degree of the breakdown layer capacitance value of sleeve pipe and sleeve pipe insulation core total capacitance value when puncturing generation behind the ripple for concerning between the distorted position in the ratio e that punctures the breakdown layer capacitance value of sleeve pipe and sleeve pipe insulation core total capacitance value when taking place behind the ripple and frequency domain.
Embodiment
The present invention proposes to utilize the extra capacitor ground connection of connecting with sleeve pipe main capacitance fuse, stands the lightning wave type approval test as a whole.The capacitance of extra capacitor is much larger than the capacitance of sleeve pipe main capacitance fuse; In process of the test, bear most voltages like this by capacitance of bushing; Assurance adds electric capacity can be not breakdown in process of the test; In general, adding capacitor C 2 capacitances should be more than 3 times of sleeve pipe insulation core main capacitance C1 value at least.Using oscillograph observation to add capacitor C 2 voltage u _{2}(t) it is carried out uniform sampling waveform the time, and sampled signal is transferred to terminal carry out Fourier analysis in shortterm, system architecture is shown in accompanying drawing 2.
How will combine Fig. 2 to Fig. 7 specifically to introduce this method below uses oscillograph to observe u _{2}(t) the puncture time of origin and the sleeve pipe puncture number of plies are estimated in waveform and analysis:
1) this method needs the oscillograph actual sample rate to be at least 50Mhz, and bandwidth is at least 200Mhz, and adjustment oscillograph triggering mode triggers for the single rising edge.Choose suitable channel oscilloscope and measure u through the voltage divider shown in the accompanying drawing 2 _{2}(t) waveform.Evidence, when puncturing generation, the sudden change shown in accompanying drawing 4 takes place with display waveform in oscillograph;
2) the Usage data collection card is to u _{2}(t) in 01ms, sample, and with sampled result u _{2}(n) transfer in the computing machine and preservation, this method recommends to use the multichannel digital capture card of picking rate more than 1GS/s;
3) to u _{2}(n) use a plurality of rectangular window function g _{i}(n) carry out truncation, obtain a series of sequences Wherein:
[n _{i}, n _{I+1}] be window g _{i}(n) block the interval;
Wherein, 3 points below the selection of window function must be satisfied: each g _{i}(n) blocking burst length between can be different but block interval zero lap; Each g _{i}(n) blocking interval position (for example: g distributes by number order _{1}(n) block interval be [1,1000], g _{2}(n) block interval be [1001,2000]); All g _{i}(n) block burst length sum and sequence u _{2}(n) length is consistent.
The number of windows and each the window g that need _{i}(n) block interval concrete length and choose by actual conditions, in general: sampled point is many more, and the window that needs is many more; g _{i}(n) blocking interval minimum length must not be less than 1000, otherwise the error of followup work is bigger.
4) in order to practice thrift the calculator memory space and to improve the conversion speed in the followup work, need be to blocking sequence Carry out truncation once more: remove In null value, only keep nonzero value, obtain secondary and block sequence Its length is N _{i}=n _{I+1}n _{i}+ 1, promptly satisfy:
Wherein: n _{i}With n _{I+1}Referring to step I i) middle rectangular window g _{i}(n) definition;
5) to the sequence after the secondary intercepting Carry out carrying out the normalization processing behind the fast Fourier transform (FFT), obtain The numerical frequency amplitude response (owing to carried out the normalization processing, Maximal value is no more than 1), wherein Be secondary intercepting sequence At the discrete digital Frequency point (k=1,2, the spectrum value of 3...N) locating can be known secondary intercepting sequence by the Nyquist sampling theorem The discrete digital frequencies omega _{k}Corresponding to the period Interior continuous voltage signal u _{2}(t) analog frequency value does (k=1,2,3...N), f wherein _{s}Be step I) in SF;
6) under the normal condition, secondary blocks sequence Amplitude response With frequencies omega _{k}Monotone decreasing; But work as sleeve pipe in the period When interior generation punctured, this period, pairing secondary blocked sequence The frequency amplitude response Can produce the distortion shown in accompanying drawing 5, distortion place spectral magnitude is all bigger than adjacent spectra amplitude.
Use the consecutive point relative method to judge that each amplitude response that is obtained by step 5) does not distort, can know whether whether sleeve pipe puncture in the period ;
7) definition u (n) for to the standard lightning wave in 01ms set by step 1) in the sequence that obtains after sampling of sampling rate, and is for to u (n) set by step 3) sequence of stages once more that obtains after handling with step 4). ? for FFT and normalized to obtain the corresponding amplitude response?
When distortion takes place at the frequencies omega place in definite amplitude response , definition distortion degree
The breakdown layer capacitance value of definition sleeve pipe is e with the ratio of sleeve pipe insulation core total capacitance value, can be got between E value size and the e by a large amount of test findings statistics to concern roughly shown in accompanying drawing 6;
Known when the sleeve structure design, when promptly each layer capacitance of sleeve pipe and insulation core total capacitance are known, just can estimate that through the E value sleeve pipe punctures the number of plies in type approval test.
Can learn by step 6) and step 7) whether sleeve pipe punctures, puncture the roughly estimation that belongs to the period constantly and puncture the number of plies.
In fact, step 3), 4), 5) in work be Fourier analysis in shortterm.Different with the Fourier analysis on the common meaning, Fourier analysis is in shortterm only carried out spectrum analysis to the content of signal in a certain period, can be expressed as the Fourier analysis in shortterm of continuous analog signal:
Wherein, g (t) is window function, is removing the t=u part, and g (t) amplitude decays rapidly, is playing the effect of intercept signal f (t) in the t=u nearby content in the Fourier analysis in shortterm.According to the uncertainty principle of Heisenburg, signal is carried out after the Fourier transform signal time domain width cs _{t}And frequency domain width cs _{ω}Between satisfy:
σ _{t}*σ _{ω}＝k≥0.5
That is, after signal time domain width was by brachymemma, its frequency domain width can extend, and this for the research sleeve pipe u in this instantaneous process takes place to puncture _{2}(t) variation of frequency spectrum is very favourable.
Select the reason of rectangular window to mainly contain 2 points: 1) the rectangular window pattern is comparatively simple, uses rectangular window to carry out that Fourier analysis is comparatively convenient in shortterm; 2) the Gibbs effect brought of rectangular window can be ignored herein; In general; Because the response of the frequency domain amplitude of rectangular window is the sinc function; Shown in accompanying drawing 6; So the use rectangular window carries out the distortion that the FFT conversion might cause discrete signal cutoff frequency place after cutting the discrete signal that obtains of sampling again; But it is high by the lightning wave cutoff frequency; Puncture is far away apart from cutoff frequency to the range of influence of ; And amplitude is very little near cutoff frequency; The distortion that the Gibbs effect is brought can be ignored basically; So can affirm distortion be caused fully by puncturing, with to use rectangular window to block sampled signal irrelevant.
Generally speaking, to puncture the number of plies many more when wavefront, and the distortional point frequency amplitude is big more, and the distortion degree is also big more; The rule that punctures behind the ripple is then just opposite.This conclusion is seen and can be helped the engineering staff to make corresponding judgement according to analysis result.
The above is merely one embodiment of the present invention; It or not whole or unique embodiment; The conversion of any equivalence that those of ordinary skills take technical scheme of the present invention through reading instructions of the present invention is claim of the present invention and contains.
Claims (10)
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Citations (7)
Publication number  Priority date  Publication date  Assignee  Title 

US5305235A (en) *  19910710  19940419  Mitsubishi Denki Kabushiki Kaisha  Monitoring diagnosis device for electrical appliance 
CN2844932Y (en) *  20051107  20061206  珠海泰坦科技股份有限公司  System for monitoring external insulation of transformer 
CN201273890Y (en) *  20080728  20090715  青海电力科学试验研究院  Moving type field impact pressure durable test apparatus for 750kV voltage stage GIS equipment 
CN101893654A (en) *  20100625  20101124  国网电力科学研究院  Method and system for measuring transient overvoltage of high voltage power network through distribution capacitance method 
CN101944719A (en) *  20100820  20110112  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  Detection system and detection method of capacitance sleeve pipe and current transformer 
CN102103183A (en) *  20101201  20110622  西安交通大学  Partial discharge measurement device under impulse voltage on site and signal processing method thereof 
CN102262203A (en) *  20110425  20111130  南京智达电气有限公司  Device for monitoring insulating state of capacitor sleeve online and method thereof 

2012
 20120116 CN CN2012100149248A patent/CN102565646A/en not_active IP Right Cessation
Patent Citations (7)
Publication number  Priority date  Publication date  Assignee  Title 

US5305235A (en) *  19910710  19940419  Mitsubishi Denki Kabushiki Kaisha  Monitoring diagnosis device for electrical appliance 
CN2844932Y (en) *  20051107  20061206  珠海泰坦科技股份有限公司  System for monitoring external insulation of transformer 
CN201273890Y (en) *  20080728  20090715  青海电力科学试验研究院  Moving type field impact pressure durable test apparatus for 750kV voltage stage GIS equipment 
CN101893654A (en) *  20100625  20101124  国网电力科学研究院  Method and system for measuring transient overvoltage of high voltage power network through distribution capacitance method 
CN101944719A (en) *  20100820  20110112  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  Detection system and detection method of capacitance sleeve pipe and current transformer 
CN102103183A (en) *  20101201  20110622  西安交通大学  Partial discharge measurement device under impulse voltage on site and signal processing method thereof 
CN102262203A (en) *  20110425  20111130  南京智达电气有限公司  Device for monitoring insulating state of capacitor sleeve online and method thereof 
NonPatent Citations (1)
Title 

杨长龙 等: "500kV变压器段间试验模型的雷电冲击试验", 《黑龙江电力技术》 * 
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