CN101162838A  Low current neutral grounding system fault route selecting method by wavelet package decompose and correlation analysis  Google Patents
Low current neutral grounding system fault route selecting method by wavelet package decompose and correlation analysis Download PDFInfo
 Publication number
 CN101162838A CN101162838A CNA2007100664040A CN200710066404A CN101162838A CN 101162838 A CN101162838 A CN 101162838A CN A2007100664040 A CNA2007100664040 A CN A2007100664040A CN 200710066404 A CN200710066404 A CN 200710066404A CN 101162838 A CN101162838 A CN 101162838A
 Authority
 CN
 China
 Prior art keywords
 fault
 current
 circuit
 zero
 transient
 Prior art date
Links
 238000010219 correlation analysis Methods 0.000 title claims description 10
 230000001264 neutralization Effects 0.000 title description 11
 230000001052 transient Effects 0.000 claims abstract description 66
 238000000354 decomposition reaction Methods 0.000 claims abstract description 32
 238000000034 method Methods 0.000 claims abstract description 11
 239000011159 matrix material Substances 0.000 claims description 9
 230000000875 corresponding Effects 0.000 claims description 7
 238000004458 analytical method Methods 0.000 abstract description 23
 238000002592 echocardiography Methods 0.000 description 7
 230000001939 inductive effect Effects 0.000 description 5
 238000005070 sampling Methods 0.000 description 5
 230000035945 sensitivity Effects 0.000 description 3
 230000001629 suppression Effects 0.000 description 3
 239000012141 concentrate Substances 0.000 description 2
 230000000694 effects Effects 0.000 description 2
 238000005516 engineering process Methods 0.000 description 2
 230000011218 segmentation Effects 0.000 description 2
 238000001228 spectrum Methods 0.000 description 2
 230000002123 temporal effect Effects 0.000 description 2
 230000001131 transforming Effects 0.000 description 2
 241000252206 Cypriniformes Species 0.000 description 1
 229910002056 binary alloy Inorganic materials 0.000 description 1
 239000003990 capacitor Substances 0.000 description 1
 238000006243 chemical reaction Methods 0.000 description 1
 230000000295 complement Effects 0.000 description 1
 230000021615 conjugation Effects 0.000 description 1
 238000005314 correlation function Methods 0.000 description 1
 230000002950 deficient Effects 0.000 description 1
 230000001066 destructive Effects 0.000 description 1
 238000001514 detection method Methods 0.000 description 1
 230000018109 developmental process Effects 0.000 description 1
 238000001914 filtration Methods 0.000 description 1
 230000004807 localization Effects 0.000 description 1
 239000000203 mixture Substances 0.000 description 1
 238000004451 qualitative analysis Methods 0.000 description 1
 238000010187 selection method Methods 0.000 description 1
 238000006467 substitution reaction Methods 0.000 description 1
Abstract
The present invention relates to a small current grounding system fault line selecting method by wavelet package decomposition and relevant analysis, belonging to the power system relay protection technical field. The method comprises: starting the fault line selecting device and recording wave to acquire transient zeroorder current on each of the feeder lines when bus zeroorder voltage transient value exceeds limit; calculating energy on each of frequency bands of the transient zeroorder current after wavelet package decomposition, summing the energy of transient zeroorder current on all the lines according to frequency bands and selecting the frequency bands with the maximum and secondary value of energy and values as the characteristic frequency bands, applying relevant analysis method to line transient zeroorder current on the selected characteristic frequency bands in order; and finally determining fault point integrating the relevant analysis results of two frequency bands. The method uses wavelet package decomposition and relevant analysis, thereby effectively using information (amplitude and phase) contained in fault transient process and reflecting differences between fault line and nonfault line to maximum degree. Principle analysis and simulations demonstrate that the method has precise and reliable line selection.
Description
Technical field:
The present invention relates to a kind of low current neutral grounding system fault route selecting method that utilizes WAVELET PACKET DECOMPOSITION and correlation analysis, belong to the relay protection of power system technical field.
Background technology:
A large amount of research has been done by China aspect lowcurrent ground fault line selection in recent years, has obtained certain achievement, but the problem of route selection accurately and reliably still is not well solved.Can not detect the development that earth fault has not only hindered power distribution automation rapidly and accurately, and safety, the stable operation of electrical network is had threat.
During small current neutral grounding system generation single phase ground fault, total system all residual voltage will occur, flow through in the electric current of fault point and contain the higher transient state amount of amplitude, fainter steadystate quantity after the relative fault, fault signature can fully be extracted and delineate to the transient state amount more, therefore uses the transient state amount will help to improve route selection sensitivity and reliability
^{[1]}
Wavelet packet analysis provides a kind of meticulousr analytical method for signal on the multiresolution analysis basis, frequency band is divided at many levels, therefore can not have the HFS of segmentation to do further decomposition to multiresolution analysis, can extract the transient state amount after the fault more accurately and efficiently.Mostly research in the past is route selection on a frequency band
^{[28]}Because the frequency content and the size of transient state amount are subjected to influence of various factors such as network parameter, fault moment, the frequency distribution of different circuit transient state amounts is always not in full accord yet.The characteristic spectra concentrated is always consistent because the complexity of transient process, each circuit transient current distribute, therefore only route selection under a frequency band, and its result is also unreliable, and should route selection on multiband
^{[911]}Document [911] route selection on the basis of multiband, but all only utilized the amplitude or the polarity of transient current, only utilized the part transient information, can not distinguish faulty line and nonfault line to greatest extent.
List of references:
[1]Chaari?O，Meunier?M，Brouaye?F?Wavelets：A?New?Tool?for?the?Resonant?GroundedPower?Distribution?Systems?Relaying[J].IEEE?Trans.On?Power?Delivery.1996，11(3).
[2] Yu Xiaorong, Liao Peijin, Peng Shutao etc. the application [J] of wavelet analysis in low current neutral grounding system fault route selecting. Power System and its Automation journal .2003,15 (4): 2426.
[3] Jia Qingquan, Xiao Peng, Yang Yihan etc. the small echo selection method [J] of low current neutral grounding electric network singlephase earth fault. relay .2001,29 (3): 58.
[4] neat Zheng, Yang Yihan, Lin Rong etc. based on the singlephase grounded malfunction in grounded system of low current route selection research [J] of wavelet transformation and Wiener filtering technology. electric power network technique .2004,28 (13): 2326.
[5] Wu Ling, Sun Ying. the application [J] of continuous wavelet transform in the singlephase grounded malfunction in grounded system of low current route selection. relay .2003,31 (11): 2024.
[6] Song Hongyun, Lv Yanping, Xia Yunfei. the research [J] of 2 singlephase earth fault line selections of small current neutral grounding system. relay .2005,33 (10), 3135.
[7] Su Zhantao, Lv Yanping. a kind of low current neutral grounding electric network singlephase earth fault route selection new method [J] based on wavelet packet analysis. electric power network technique .2004,28 (12); 3033.
[8] lift a sail Pan Zhencun, Zhang Huifen etc. based on the small current earthing wireselecting new criterion [J] of zerosequence current transient state maximum. Automation of Electric Systems .2006,30 (4): 4548.
[9] Wang Yaonan, Huo Bailin, Wang Hui etc. based on the new criterion [J] of the low current neutral grounding system fault route selecting of wavelet packet. Proceedings of the CSEE .2004,20 (6): 5658.
[10] Pan Lu, Lv Yanping is in virtue. based on the low current neutral grounding system fault route selecting [J] of phasefrequency characteristic and multiband analysis. and Automation of Electric Systems .2007,31 (4): 7679.
[11] Dai Jianfeng, Zhang Yanxia. study [J] based on the self adaptation distribution network fault line selection that multifrequency is analyzed. Proceedings of the CSEE .2003,23 (5): 4447.
[12] to shine year Cao Meiyue. electric power system resonance grounding [M]. Beijing: China Electric Power Publishing House, 2000.
[13] Cui Jintai (U.S.). wavelet analysis introduction [M]. Xi'an: publishing house of Xi'an Communications University, 1995
[14] Jia Qingquan, Xiao Peng, Yang Yihan. etc. the small echo selection method [J] of low current neutral grounding electric network singlephase earth fault. relay, 2001,29 (3): 58.
[15] Hu Changhua, Zhang Junbo, Xia Jun etc. based on the Design ﹠ Analysis of System [M] of MATLAB. Xi'an: publishing house of Xian Electronics Science and Technology University, 1999.
[16] hair roc, Sun Yaming, Zhang Zhaoning etc. the application [J] of wavelet packet in the onephase earthing failure in electric distribution network route selection. electric power network technique, 2000,24 (6): 913.
[17] Wu Xiangqi. signal, system and signal processing [M]. Beijing: Electronic Industry Press .2000.
[18] Xue Yongrui, Xu Bingyin, low current grounding transient state direction protection principle researchs [J] such as Feng Zuren. Proceedings of the CSEE, 2003.23 (7): 5156.
Summary of the invention
In order to overcome the deficiency of existing low current neutral grounding system fault route selecting method, the present invention proposes a kind of singlephase ground fault line selecting method of smallelectric current grounding system that utilizes WAVELET PACKET DECOMPOSITION and correlation analysis.
Technical scheme of the present invention is as follows: a kind of method of utilizing WAVELET PACKET DECOMPOSITION that low current grounding is carried out route selection, carry out failure line selection by online measuring device, and it is characterized in that realizing through following process:
A, with bus residual voltage instantaneous value u
_{n}(t) greater than K
_{u}U
_{n}As the entry condition of fault, wherein K
_{u}Value is 0.15, U
_{n}Be the bus rated voltage, note each feeder line zerosequence current of 1 cycle in fault front and back by line selection apparatus;
B, employing db10 wavelet packet are done 4 layers of decomposition to each feeder line transient zerosequence current, and the route selection frequency bandwidth is 125Hz;
C, be calculated as follows each transient zerosequence current, press frequency band again the energy of all circuit transient zerosequence currents on each frequency band is sued for peace at the energy that removes on (4,0) outer each frequency band:
ω in the formula
_{k} ^{(j)}(n) be WAVELET PACKET DECOMPOSITION (j, the k) coefficient under the subband, with the frequency band at the maximum of energy and value and second largest value place as feature band;
D, successively on the feature band of step C to fault after each bar circuit zero sequence current temporary state component waveformwavelet coefficient carries out correlation analysis, ask for the coefficient correlation between the circuit, form correlation matrix M
_{1}, M
_{2}, ask for the integrated correlation coefficient ρ (j) of every circuit according to correlation matrix with respect to All other routes, j=1,2 ..., n, and with the mean value of the coefficient correlation that defines this circuit and the All other routes integrated correlation coefficient as this circuit:
Integrated correlation coefficient is found the solution by the following method: ask earlier M respectively
_{1}, M
_{2}The mean value of the every row element of matrix obtains ρ
_{1}, ρ
_{2}, use ρ again
_{1}, ρ
_{2}Average after the corresponding element addition and obtain integrated correlation coefficient ρ;
The integrated correlation coefficient ρ of E, each bar circuit of comparison, when the difference Δ ρ of minimax integrated correlation coefficient greater than threshold values ρ
_{Set}The time, then the circuit of Zui Xiao integrated correlation coefficient correspondence is faulty line; When the difference Δ ρ of minimax integrated correlation coefficient less than threshold values ρ
_{Set}The time, then decisionmaking system generation busbar grounding fault, wherein threshold values ρ
_{Set}Be 0.5.
Theory analysis of the present invention is as follows:
1, single phase ground fault analysis
From the transient process of singlephase earthing, the transient state amount of earth current is bigger a lot of times than steadystate quantity, the time very short (12 cycle) that false voltage and fault current transient process continue, but contain abundant one of transient characteristic quantity.
System with neutral by arc extinction coil grounding is an example below, the transient process of analysis of failure.At instant of failure, both there had been power frequency component in the transient state earth current that flows through the fault point, also had higherorder of oscillation component.The transient state earth current that flows through the fault point be by fault relatively capacitance discharges electric current, nonfault relatively the charging current of electric capacity and the transient state inductive current of arc suppression coil are formed by stacking
^{[12]}The transient state earth current distributes and sees Fig. 1.
The expression formula of transient state earth current is:
In the formula: I
_{Cm}Be electric capacity stable state amplitude; ω
_{f}Angular frequency for transient state free component oscillating component; τ
_{C}Time constant for capacitor loop; I
_{Lm}Steadystate value for inductive current; τ
_{L}Time constant for inductor loop.
From (1) formula as can be seen, the transient state amount of earth current equals the transient DC component sum of the transient state free component and the inductive current of capacitance current, and both amplitudes not only can not be cancelled out each other, and can also superpose, and the transient current amplitude can be bigger.Approach maximum during moment when fault occurs in phase voltage, the transient state capacitance current is more a lot of greatly than transient state inductive current, and the frequency of transient state is also very high, and the electric current that at this moment flows through arc suppression coil is very little, and is inoperative to transient state.So at the initial stage of fault, inductive current and capacitance current can not compensate mutually, the characteristic of its transient state earth current mainly is that the characteristic by the transient state capacitance current is determined.
Isolated neutral system is not because there is arc suppression coil, so its transient state earth current is exactly the transient state capacitance current.Therefore, no matter be that resonant earthed system or the isolated neutral system transient current can utilize fault the time comes route selection.
Analysis chart 1 can be drawn a conclusion:
(1) zerosequence current appears in faulty line and nonfault line, and the nonfault line zerosequence current equals the capacitive earth current of this circuit itself, and the faulty line zerosequence current is the summation of total system nonfault line capacitive earth current.
(2) the leading residual voltage of nonfault line zerosequence current is 90 °; 90 ° of faulty line zerosequence current hysteresis residual voltages, promptly fault and nonfault zerosequence current differ 180 °.
According to above analysis, the amplitude and the polarity that can fully utilize transient zerosequence current realize route selection.
During singlephase earthing, the zerosequence current of faulty line and certain nonfault line distributes and sees Fig. 2.
2, WAVELET PACKET DECOMPOSITION
2.1 the proposition of wavelet packet
The just global feature of signal of Fourier transform reflection, therefore be mainly used in the analysis of stationary signal, for the transient state nonstationary signal, it can't demarcate time location that changes and the violent degree that changes, and promptly Fourier transform is not demarcated and tolerance power the local distortion of signal.Multiresolution analysis can carry out effective timefrequency to signal and decompose, but owing to its yardstick changes by binary system, so relatively poor in its frequency resolution of high band, and relatively poor in its time resolution of lowfrequency range.Wavelet packet analysis can provide a kind of meticulousr analytical method for signal, frequency band is divided at many levels, therefore can there be the HFS of segmentation to do further to decompose to multiresolution analysis, and can be according to the feature of analyzed signal, select frequency band adaptively, make it to be complementary with signal spectrum, thus when having improvedfrequency resolution, have using value widely.
2.2 the definition of wavelet packet
With yardstick subspace V
_{j}With wavelets Subspace W
_{j}, with a new subspace U
_{j} ^{n}The unified sign, definition subspace U
_{j} ^{n}It is function U
_{n}(t) closure space, and U
_{j} ^{2n}It is function U
_{2n}(t) closure space, and make U
_{n}(t) satisfy following two yardstick equations
^{[13]}
G (k) is the high pass filter coefficient in the formula (2); H (k) is a lowpass filter coefficients; G (k)=(1)
^{k}H (1k), promptly two coefficients have orthogonality relation.Sequence { U by formula (1) structure
_{n}(t) } (n ∈ Z wherein
_{+}) be called by basic function U
_{o}(t)=the definite Orthogonal Wavelet Packet of Ф (t).
2.3 the decomposition of wavelet packet
By formula (2) as can be known, to n ∈ Z arbitrarily
_{+}(nonnegative integer) has
The various decomposition of wavelets Subspace are as follows like this
Corresponding to W
_{j}, the j frequency range just be broken down into 2
^{k}Individual frequency subband, thus its localization property strengthened, overcome the deficiency of orthogonal wavelet transformation.The WAVELET PACKET DECOMPOSITION tree as shown in Figure 2.
2.4 choosing of wavelet function
Compare with the standard Fourier transform, used wavelet function has not uniqueness in the wavelet analysis, i.e. the selection of wavelet function has diversity.Analyze same problem with different wavelet basiss and can produce different effects, do not select wavelet function, adopt qualitative analysis in the reality in conjunction with experiment way relatively so have an acceptable principle at present.The little wave system of dbN is to use more wavelet function on the engineering
^{[14]}, the characteristics of this little wave system are energy nondestructive and complimentary
^{[11]}, and along with the increase of sequence number N, the time domain bearing length is elongated, the temporal locality variation; Filter length is elongated; The vanishing moment exponent number increases; Regularity increases, and the frequency domain locality improves.It is not very strict that the application of this paper requires temporal locality, the frequency domain locality is then had relatively high expectations, to prevent frequency alias.By adopting multiple small echo to carry out repeatedly emulation experiment relatively, basis experience in the past determines to select for use the db10 small echo again.
Fault transient state current from zero sequence current mutual inductor or the acquisition of zerosequence current pass filter is carried out WAVELET PACKET DECOMPOSITION, its essence is and allow signal pass through the conjugation orthogonal filter group of one group high low pass combination, constantly division of signal is on different frequency ranges, the every effect of bank of filters once, sampling interval doubles, and number of data points then reduces by half
^{[15]}For similar frequency bands, what of the number of coefficient of wavelet decomposition are relevant with the filter length of used small echo, and filter length is long more, and then number is many more, and the sensitivity of route selection criterion is corresponding high more.But can not pursue the length of filter simply,, reduce the reliability of criterion because for the more and more serious distribution network system of Harmonic Interference, the increase of the number of coefficient of wavelet decomposition also may be introduced more disturbing factor.This also is an one of the main reasons of selecting the db10 small echo.
2.5 the WAVELET PACKET DECOMPOSITION number of plies
Consider that the freerunning frequency of transient state capacitance current generally concentrates on 3001500Hz
^{[12]}, getting sample frequency in the emulation is 4000Hz, sampled data window length is got each 1 week of short circuit front and back: when carrying out WAVELET PACKET DECOMPOSITION, what choose is the db10 small echo; Consider that the frequency bandwidth that finally is used for failure line selection should select suitably, if meticulous, then the corresponding sampling number of frequency band is very few, will reduce the reliability of failure line selection; If wide, then information content increases, and will be unfavorable for further signal analysis
^{[16]}, the comprehensive pros and cons of this two aspect, the route selection frequency bandwidth is decided to be 125Hz, according to two fens characteristics of frequency of wavelet packet, decomposes the number of plies and should be 4 layers.
Adopt the db10 wavelet packet that the circuit transient zerosequence current is done 4 layers of decomposition, remove the lowest band (4,0) at power frequency place after, the frequency band that energy is bigger has comprised the principal character of transient state capacitance current
^{[18]}Can get rid of the influence of power frequency amount and other nonfeature bands after the WAVELET PACKET DECOMPOSITION.
2.6 determining of feature band
Adopt the db10 wavelet packet that the circuit transient zerosequence current is done 4 layers of decomposition, remove the lowest band (4,0) at power frequency place after, the frequency band that energy is bigger has comprised the principal character of transient state capacitance current
^{[18]}Therefore, press frequency band with the summation of the energy of all circuit transient zerosequence currents, energy and the bigger inevitable concentrated expression of frequency band the constitutive relations between each circuit.Calculate each circuit transient zerosequence current at the energy that removes on (4,0) outer each frequency band by (5) formula, and calculate the energy and the value of all circuit transient zerosequence currents on each frequency band by frequency band, selecting the energy and the maximum of value and the frequency band at second largest value place is feature band.
ω in the formula (5)
_{k} ^{(j)}(n) be WAVELET PACKET DECOMPOSITION (j, k) coefficient under the subband.
Faulty line and certain nonfault line zerosequence current, the coefficient of wavelet decomposition on two feature bands is shown in Fig. 4,5.
3, correlation analysis
Correlation function is the very important numerical characteristic that timefrequency is described the random signal statistical nature.Deterministic signal can be regarded as stably and has the special case of ergodic random signal, thereby its basic conception and definition (stationary random process) equally also are suitable for deterministic signal and do correlation analysis
^{[17]}The physical meaning that its inherence is arranged from the theory of correlation analysis, establishing x (t) and y (t) is the real signal waveform of 2 finite energies.For studying the difference between them, weigh it at difference similarity degree constantly, introduce
ε＝x(t)λy(t+τ) (6)
ε is a constant in the formula (6).
According to the mean square error minimum criteria, get ε
^{2}Time average W weigh similitude between the two, then have
Order
$\frac{\mathrm{dW}}{\mathrm{dt}}=0,$ Try to achieve best λ
_{Opt}Make two waveforms the most similar, and with its substitution formula (7), the W that obtains minimum is
ρ in the formula (8)
_{Xy}The expression formula of the discrete sampling sequence of respective signal x (t) and y (t) in certain data window is
By formula (9) as can be known, ρ is big more, and W is more little, and two waveforms are similar more.When ρ=1, then W=0 illustrates that x (t) is similar fully with y (t).ρ is defined as coefficient correlation for this reason.Formula (9) has been represented the dependency relation that x (t), y (t) waveform are sampled in certain data window intersync, combined reaction the comprehensive phase relation and the amplitude information of each frequency component in 2 signals, and be not the simple phase relation of singlefrequency, effectively overcome the defective that the single information that only relies on faultsignal is come detection failure.
4, route selection criterion
According to above 3 point analysis, to the transient zerosequence current of WAVELET PACKET DECOMPOSITION, carry out correlation analysis after, can form the route selection criterion:
1), ρ
_{Max}ρ
_{Min}＞ρ
_{Set}, j=1,2 ..., n, ρ
_{Min}Corresponding feeder line is fault feeder (ρ
_{Set}Get 0.5);
2), ρ
_{Max}ρ
_{Min}＜ρ
_{Set}, j=1,2 ..., n judges busbar fault (ρ
_{Set}Get 0.5).
The present invention compared with prior art has following advantage:
1), usually, when near phase voltage is crossed null value single phase ground fault taking place, the fault transient state current amplitude is very little, causes the route selection difficulty, and the present invention can overcome the little influence of fault transient state current under the situation of glitch angle effectively, realizes correct route selection.
2), the present invention has stronger arc resistant grounded capacity; Be subjected to the influence of neutral point operational mode less; The freerunning frequency of transient state capacitance current generally concentrates on 3001500Hz
^{[12]}, adopt 12 A/D to record ripple with the 4kHz sample frequency, be enough to meet the demands.
3), the present invention when the shortterm fault, can overcome of the influence of sound long line to earthing capacitance current; Very strong noise resisting ability is arranged; Also correctly route selection during high resistance ground.
4), the present invention utilizes WAVELET PACKET DECOMPOSITION; removed the influence of power frequency amount and other nonfeature bands; and utilize relevant function method; can effectively utilize the information (amplitude, phase place) that comprises in the fault transient process more; reflect the difference of faulty line and nonfault line to greatest extent, improve protection nargin.Simultaneously, the situation that causes fault signature to be fallen into oblivion because of interference and measure error can not appear in the route selection on two frequency bands of this method, can improve the sensitivity and the reliability of failure line selection.
Description of drawings:
Fig. 1 singlephasetoground current distributes.
Fig. 2 circuit zerosequence current.
Fig. 3 wavelet packet binary tree.
The coefficient of wavelet decomposition of Fig. 4 circuit zerosequence current on first feature band.
The coefficient of wavelet decomposition of Fig. 5 circuit zerosequence current on second feature band.
Fig. 6 failure line selection algorithm flow chart.
Embodiment:
During small current neutral grounding system generation single phase ground fault, utilize abovementioned principle can realize perfect failure line selection.The specific implementation flow process as shown in Figure 6.
Specific implementation step of the present invention is as follows:
1. as bus residual voltage instantaneous value u
_{n}(t) greater than K
_{u}U
_{n}, fault line selection device starts immediately, notes each feeder line zerosequence current, wherein K of 1 cycle in fault front and back
_{u}General value is 0.15, U
_{n}Expression bus rated voltage;
2. with the db10 small echo each feeder line zerosequence current is carried out four layers of wavelet decomposition.
3. after removing the lowest band (4,0) at power frequency place, the frequency band that energy is bigger has comprised the principal character of transient state capacitance current
^{[18]}Therefore, press frequency band with the summation of the energy of all circuit transient zerosequence currents, energy and the bigger inevitable concentrated expression of frequency band the constitutive relations between each circuit.Calculate each circuit transient zerosequence current at the energy that removes on (4,0) outer each frequency band by (5) formula, and calculate the energy and the value of all circuit transient zerosequence currents on each frequency band by frequency band, selecting the energy and the maximum of value and the frequency band at second largest value place is feature band.
ω in the formula (5)
_{k} ^{(j)}(n) be WAVELET PACKET DECOMPOSITION (j, k) coefficient under the subband.
Successively on two feature bands to fault after the waveform (wavelet coefficient) of each bar circuit zero sequence current temporary state component carry out correlation analysis in twos, ask for the coefficient correlation in twos between the circuit, form correlation matrix M
_{1}, M
_{2}, ask for every circuit relatively and the integrated correlation coefficient ρ (j) of All other routes according to the pairwise correlation coefficient matrix, j=1,2 ..., n.(mean value of coefficient correlation that defines this circuit and All other routes is as the integrated correlation coefficient of this circuit)
Integrated correlation coefficient is found the solution by the following method: ask earlier M respectively
_{1}, M
_{2}The mean value of the every row element of matrix obtains ρ
_{1}, ρ
_{2}, use ρ
_{1}, ρ
_{2}Average after the corresponding element addition and obtain integrated correlation coefficient ρ.
5. the integrated correlation coefficient ρ of each bar circuit relatively, when the difference Δ ρ of minimax integrated correlation coefficient greater than a threshold values ρ
_{Set}(ρ
_{Set}Get 0.5) time, the circuit of minimum integrated correlation coefficient correspondence is faulty line.When the difference Δ ρ of minimax integrated correlation coefficient less than a threshold values ρ
_{Set}(ρ
_{Set}Get 0.5) time, decisionmaking system generation busbar grounding fault then.
Claims (1)
1. a method of utilizing WAVELET PACKET DECOMPOSITION that low current grounding is carried out route selection is carried out failure line selection by online measuring device, it is characterized in that realizing through following process:
A, with bus residual voltage instantaneous value u
_{n}(t) greater than K
_{u}U
_{n}As the entry condition of fault, wherein K
_{u}Value is 0.15, U
_{n}Be the bus rated voltage, note each feeder line zerosequence current of 1 cycle in fault front and back by line selection apparatus;
B, employing db10 wavelet packet are done 4 layers of decomposition to each feeder line transient zerosequence current, and the route selection frequency bandwidth is 125Hz;
C, be calculated as follows each transient zerosequence current, press frequency band again the energy of all circuit transient zerosequence currents on each frequency band is sued for peace at the energy that removes on (4,0) outer each frequency band:
ω in the formula
_{k} ^{(j)}(n) be WAVELET PACKET DECOMPOSITION (j, the k) coefficient under the subband, with the frequency band at the maximum of energy and value and second largest value place as feature band;
D, successively on the feature band of step C to fault after each bar circuit zero sequence current temporary state component waveformwavelet coefficient carries out correlation analysis, ask for the coefficient correlation between the circuit, form correlation matrix M
_{1}, M
_{2}, ask for the integrated correlation coefficient ρ (j) of every circuit according to correlation matrix with respect to All other routes, j=1,2 ..., n, and with the mean value of the coefficient correlation that defines this circuit and the All other routes integrated correlation coefficient as this circuit:
Integrated correlation coefficient is found the solution by the following method: ask earlier M respectively
_{1}, M
_{2}The mean value of the every row element of matrix obtains ρ
_{1}, ρ
_{2}, use ρ again
_{1}, ρ
_{2}Average after the corresponding element addition and obtain integrated correlation coefficient ρ;
The integrated correlation coefficient ρ of E, each bar circuit of comparison, when the difference Δ ρ of minimax integrated correlation coefficient greater than threshold values ρ
_{Set}The time, then the circuit of Zui Xiao integrated correlation coefficient correspondence is faulty line; When the difference Δ ρ of minimax integrated correlation coefficient less than threshold values ρ
_{Set}The time, then decisionmaking system generation busbar grounding fault, wherein threshold values ρ
_{Set}Be 0.5.
Priority Applications (1)
Application Number  Priority Date  Filing Date  Title 

CNB2007100664040A CN100546144C (en)  20071129  20071129  A kind of low current neutral grounding system fault route selecting method that utilizes WAVELET PACKET DECOMPOSITION and correlation analysis 
Applications Claiming Priority (1)
Application Number  Priority Date  Filing Date  Title 

CNB2007100664040A CN100546144C (en)  20071129  20071129  A kind of low current neutral grounding system fault route selecting method that utilizes WAVELET PACKET DECOMPOSITION and correlation analysis 
Publications (2)
Publication Number  Publication Date 

CN101162838A true CN101162838A (en)  20080416 
CN100546144C CN100546144C (en)  20090930 
Family
ID=39297700
Family Applications (1)
Application Number  Title  Priority Date  Filing Date 

CNB2007100664040A CN100546144C (en)  20071129  20071129  A kind of low current neutral grounding system fault route selecting method that utilizes WAVELET PACKET DECOMPOSITION and correlation analysis 
Country Status (1)
Country  Link 

CN (1)  CN100546144C (en) 
Cited By (48)
Publication number  Priority date  Publication date  Assignee  Title 

CN101587159B (en) *  20090622  20110126  昆明理工大学  Power distribution network outgoing feeder fault route selecting method by S transform amplitude detection 
CN102305898A (en) *  20110518  20120104  昆明理工大学  Method for selecting fault phase of alternating current transmission line by using transient energy 
CN102654553A (en) *  20120507  20120905  河南省电力公司南阳供电公司  Method for line selection and positioning 
CN102680854A (en) *  20120508  20120919  山东康威通信技术股份有限公司  Online monitoring method for covert faults and joint process defects of power cable 
CN102866326A (en) *  20120906  20130109  国家电网公司  Distribution network fault line selection method based on zero sequence current variable quantity waveform correlation coefficient matrix 
CN102944814A (en) *  20121128  20130227  福建省电力有限公司  Power distribution network singlephase earth fault locating method based on transient state 
CN103018627A (en) *  20121025  20130403  福建省电力有限公司  Adaptive fault type fault line detection method for noneffectively earthed system 
CN103018630A (en) *  20121128  20130403  福建省电力有限公司  Singlephase earth fault transient line selection method of distribution network 
CN103163430A (en) *  20130329  20130619  昆明理工大学  Resonant grounding system fault line selection method by combining complex wavelets with ANN (artificial neural network) 
CN103197202A (en) *  20130329  20130710  昆明理工大学  Distribution network fault line selection method based on wavelet coefficient correlation analysis in threephase breaking current component characteristic frequency band 
CN103197203A (en) *  20130329  20130710  昆明理工大学  Fault line selection method based on time domain waveform correlation analysis of threephase current breaking variable 
CN103245883A (en) *  20130427  20130814  昆明理工大学  Power distribution network fault circuit selection method based on transient zerosequence current timefrequency characteristic vectors 
CN103267927A (en) *  20130427  20130828  昆明理工大学  Small current grounding system fault line selection method using power frequency component wavelet coefficients to carry out linear fitting detection 
CN103364684A (en) *  20130712  20131023  桐乡市供电局  Fault line selection method based on wavelet analysis 
CN103941153A (en) *  20140403  20140723  昆明理工大学  Multioutgoingline radiation network fault distance measuring method for kNN algorithm based on waveform similarity 
CN103941152A (en) *  20140403  20140723  昆明理工大学  Cable hybrid line fault distance measuring method for kNN algorithm based on waveform similarity 
CN104020394A (en) *  20140430  20140903  河北工程大学  Network technology based lowcurrent line selection method of power supply system 
CN104122484A (en) *  20140610  20141029  昆明理工大学  Distribution network fault line selection method based on correlation analysis of zero modal current wavelet coefficients 
CN104237731A (en) *  20140925  20141224  福州大学  Singlephase earth fault line selection method on basis of EEMD (ensemble empirical mode decomposition) and energy method for resonance earthed power distribution network 
CN104393580A (en) *  20141105  20150304  昆明理工大学  Tconnection power grid transient state quantity unit protection method utilizing voltage and current abrupt change quantity wavelet coefficient correlation analysis 
CN104614638A (en) *  20141224  20150513  国家电网公司  Grounding line selection method for small current system 
CN104655980A (en) *  20141105  20150527  云南电网公司楚雄供电局  Method for quickly identifying short trouble of adjacent lines with different voltage grades based on db4 wavelet decomposition 
CN104898021A (en) *  20150525  20150909  昆明理工大学  Fault line selecting method based on kmeans cluster analysis for power distribution network 
CN105226616A (en) *  20150922  20160106  昆明理工大学  A kind of bus bar protecting method based on row wave height frequency component coefficient correlation 
CN105258940A (en) *  20151130  20160120  上海无线电设备研究所  Standardized multiwavelet and multiwavelet packet transformation method for mechanical failure quantitative extraction 
CN105259480A (en) *  20151127  20160120  国家电网公司  Dispatching end small current singlephase grounding wire selection method and system 
CN105486978A (en) *  20151201  20160413  江苏省电力公司淮安供电公司  Singlephase short circuit fault line selection method 
CN105929297A (en) *  20160428  20160907  长沙理工大学  Ground fault line selection method based on highfrequency component correlation 
CN106324432A (en) *  20160830  20170111  南京南瑞继保电气有限公司  Singlephase grounding line selection method for smallcurrent grounding system 
CN106872859A (en) *  20170426  20170620  山东钢铁集团日照有限公司  A kind of small current earthing wireselecting method 
CN106896294A (en) *  20170327  20170627  国家电网公司  Noneffectively earthed system faultline selecting method based on transient state discharge capacity 
CN106940411A (en) *  20170421  20170711  国网江苏省电力公司宿迁供电公司  A kind of singlephase ground fault line selecting method of smallelectric current grounding system 
CN106990324A (en) *  20170406  20170728  北京四方继保自动化股份有限公司  A kind of distribution net work earthing fault detects localization method 
CN107153149A (en) *  20170511  20170912  西安交通大学  Power distribution network singlephase disconnection fault recognition method based on negative sequence voltage current characteristic 
CN107181460A (en) *  20160309  20170919  上海英孚特电子技术有限公司  A kind of photovoltaic system method for detecting arc 
CN107526006A (en) *  20170811  20171229  国网湖南省电力公司  A kind of small current system singlephase earth fault localization method 
CN108645634A (en) *  20180806  20181012  深圳市晟达机械设计有限公司  A kind of rail vehicle troubleshooter 
CN109085455A (en) *  20171226  20181225  贵州电网有限责任公司  A kind of determination method for distribution line high resistance earthing fault 
CN109188200A (en) *  20180831  20190111  华中科技大学  A kind of power distribution network transient fault selection method for ground fault transfer control 
CN109188193A (en) *  20180726  20190111  昆明理工大学  A kind of distribution network fault line selection method based on feature band convergence Min Shi distance 
CN109375060A (en) *  20181112  20190222  上海金智晟东电力科技有限公司  A kind of distribution network failure waveform similarity calculation method 
CN109375011A (en) *  20181015  20190222  上海电力学院  A kind of detection method of novel microgrid failure 
CN109507531A (en) *  20181121  20190322  杭州电力设备制造有限公司  A kind of power distribution network singlephase grounding selecting method, system, device and readable storage medium storing program for executing 
CN109541395A (en) *  20181123  20190329  三峡大学  Distribution Section Location based on Hausdorff under a kind of feature band 
CN109596945A (en) *  20190118  20190409  广东电网有限责任公司  A kind of New Criterion of Faulty Line Detection for Distribution based on related coefficient vector similarity degree 
CN110118912A (en) *  20190423  20190813  武汉理工大学  It is a kind of that wire selection method for power distribution network single phase earthing failure is grounded through arc suppression coil device based on grey correlation analysis 
CN110221176A (en) *  20190628  20190910  昆明理工大学  A kind of microcapacitance sensor fault detection method based on juxtaposition differential transformation 
CN110488152A (en) *  20190927  20191122  国网河南省电力公司电力科学研究院  A kind of distribution network fault line selection method based on Adaptive Neurofuzzy Inference 
Family Cites Families (1)
Publication number  Priority date  Publication date  Assignee  Title 

CN100335912C (en) *  20040303  20070905  西安交通大学  Small Current earthing line selecting method based on model parametric recognition 

2007
 20071129 CN CNB2007100664040A patent/CN100546144C/en not_active IP Right Cessation
Cited By (71)
Publication number  Priority date  Publication date  Assignee  Title 

CN101587159B (en) *  20090622  20110126  昆明理工大学  Power distribution network outgoing feeder fault route selecting method by S transform amplitude detection 
CN102305898B (en) *  20110518  20130403  昆明理工大学  Method for selecting fault phase of alternating current transmission line by using transient energy 
CN102305898A (en) *  20110518  20120104  昆明理工大学  Method for selecting fault phase of alternating current transmission line by using transient energy 
CN102654553A (en) *  20120507  20120905  河南省电力公司南阳供电公司  Method for line selection and positioning 
CN102680854A (en) *  20120508  20120919  山东康威通信技术股份有限公司  Online monitoring method for covert faults and joint process defects of power cable 
CN102680854B (en) *  20120508  20140820  山东康威通信技术股份有限公司  Online monitoring method for covert faults and joint process defects of power cable 
CN102866326A (en) *  20120906  20130109  国家电网公司  Distribution network fault line selection method based on zero sequence current variable quantity waveform correlation coefficient matrix 
CN102866326B (en) *  20120906  20150826  国家电网公司  Based on the distribution network fault line selection of zero sequence current variable quantity waveform correlation coefficient matrix 
CN103018627A (en) *  20121025  20130403  福建省电力有限公司  Adaptive fault type fault line detection method for noneffectively earthed system 
CN103018627B (en) *  20121025  20141231  福建省电力有限公司  Adaptive fault type fault line detection method for noneffectively earthed system 
CN102944814A (en) *  20121128  20130227  福建省电力有限公司  Power distribution network singlephase earth fault locating method based on transient state 
CN103018630A (en) *  20121128  20130403  福建省电力有限公司  Singlephase earth fault transient line selection method of distribution network 
CN103163430A (en) *  20130329  20130619  昆明理工大学  Resonant grounding system fault line selection method by combining complex wavelets with ANN (artificial neural network) 
CN103197203A (en) *  20130329  20130710  昆明理工大学  Fault line selection method based on time domain waveform correlation analysis of threephase current breaking variable 
CN103197202B (en) *  20130329  20150722  昆明理工大学  Distribution network fault line selection method based on wavelet coefficient correlation analysis in threephase breaking current component characteristic frequency band 
CN103197202A (en) *  20130329  20130710  昆明理工大学  Distribution network fault line selection method based on wavelet coefficient correlation analysis in threephase breaking current component characteristic frequency band 
CN103267927A (en) *  20130427  20130828  昆明理工大学  Small current grounding system fault line selection method using power frequency component wavelet coefficients to carry out linear fitting detection 
CN103245883B (en) *  20130427  20151202  昆明理工大学  A kind of distribution network fault line selection method based on transient zerosequence current timefrequency characteristics vector 
CN103267927B (en) *  20130427  20160113  昆明理工大学  A kind of low current neutral grounding system fault route selecting method utilizing power frequency component wavelet coefficient fitting a straight line to detect 
CN103245883A (en) *  20130427  20130814  昆明理工大学  Power distribution network fault circuit selection method based on transient zerosequence current timefrequency characteristic vectors 
CN103364684A (en) *  20130712  20131023  桐乡市供电局  Fault line selection method based on wavelet analysis 
CN103364684B (en) *  20130712  20150708  国家电网公司  Fault line selection method based on wavelet analysis 
CN103941153B (en) *  20140403  20161012  昆明理工大学  A kind of outgoing lines radiation network fault distancefinding method of kNN algorithm based on waveform similarity 
CN103941153A (en) *  20140403  20140723  昆明理工大学  Multioutgoingline radiation network fault distance measuring method for kNN algorithm based on waveform similarity 
CN103941152B (en) *  20140403  20160914  昆明理工大学  A kind of cable mixed line fault distancefinding method of kNN algorithm based on waveform similarity 
CN103941152A (en) *  20140403  20140723  昆明理工大学  Cable hybrid line fault distance measuring method for kNN algorithm based on waveform similarity 
CN104020394A (en) *  20140430  20140903  河北工程大学  Network technology based lowcurrent line selection method of power supply system 
CN104122484B (en) *  20140610  20170201  昆明理工大学  Distribution network fault line selection method based on correlation analysis of zero modal current wavelet coefficients 
CN104122484A (en) *  20140610  20141029  昆明理工大学  Distribution network fault line selection method based on correlation analysis of zero modal current wavelet coefficients 
CN104237731A (en) *  20140925  20141224  福州大学  Singlephase earth fault line selection method on basis of EEMD (ensemble empirical mode decomposition) and energy method for resonance earthed power distribution network 
CN104237731B (en) *  20140925  20170118  福州大学  Singlephase earth fault line selection method on basis of EEMD (ensemble empirical mode decomposition) and energy method for resonance earthed power distribution network 
CN104393580A (en) *  20141105  20150304  昆明理工大学  Tconnection power grid transient state quantity unit protection method utilizing voltage and current abrupt change quantity wavelet coefficient correlation analysis 
CN104393580B (en) *  20141105  20170613  昆明理工大学  A kind of T of utilization voltage x current Sudden Changing Rate wavelet coefficient correlation analysis gets access to grid transient cell protection method 
CN104655980A (en) *  20141105  20150527  云南电网公司楚雄供电局  Method for quickly identifying short trouble of adjacent lines with different voltage grades based on db4 wavelet decomposition 
CN104614638A (en) *  20141224  20150513  国家电网公司  Grounding line selection method for small current system 
CN104898021B (en) *  20150525  20180306  昆明理工大学  A kind of distribution network fault line selection method based on k means cluster analyses 
CN104898021A (en) *  20150525  20150909  昆明理工大学  Fault line selecting method based on kmeans cluster analysis for power distribution network 
CN105226616B (en) *  20150922  20180424  昆明理工大学  A kind of bus bar protecting method based on traveling wave high fdrequency component related coefficient 
CN105226616A (en) *  20150922  20160106  昆明理工大学  A kind of bus bar protecting method based on row wave height frequency component coefficient correlation 
CN105259480A (en) *  20151127  20160120  国家电网公司  Dispatching end small current singlephase grounding wire selection method and system 
CN105258940A (en) *  20151130  20160120  上海无线电设备研究所  Standardized multiwavelet and multiwavelet packet transformation method for mechanical failure quantitative extraction 
CN105258940B (en) *  20151130  20180209  上海无线电设备研究所  The standardization m ultiwavelet that mechanical breakdown is quantitatively extracted and multiwavelet packets transform method 
CN105486978A (en) *  20151201  20160413  江苏省电力公司淮安供电公司  Singlephase short circuit fault line selection method 
CN107181460B (en) *  20160309  20181214  上海英孚特电子技术有限公司  A kind of photovoltaic system method for detecting arc 
CN107181460A (en) *  20160309  20170919  上海英孚特电子技术有限公司  A kind of photovoltaic system method for detecting arc 
CN105929297A (en) *  20160428  20160907  长沙理工大学  Ground fault line selection method based on highfrequency component correlation 
CN106324432A (en) *  20160830  20170111  南京南瑞继保电气有限公司  Singlephase grounding line selection method for smallcurrent grounding system 
CN106896294A (en) *  20170327  20170627  国家电网公司  Noneffectively earthed system faultline selecting method based on transient state discharge capacity 
CN106990324B (en) *  20170406  20200602  北京四方继保自动化股份有限公司  Power distribution network ground fault detection and positioning method 
CN106990324A (en) *  20170406  20170728  北京四方继保自动化股份有限公司  A kind of distribution net work earthing fault detects localization method 
CN106940411A (en) *  20170421  20170711  国网江苏省电力公司宿迁供电公司  A kind of singlephase ground fault line selecting method of smallelectric current grounding system 
CN106940411B (en) *  20170421  20190531  国网江苏省电力公司宿迁供电公司  A kind of singlephase ground fault line selecting method of smallelectric current grounding system 
CN106872859A (en) *  20170426  20170620  山东钢铁集团日照有限公司  A kind of small current earthing wireselecting method 
CN107153149B (en) *  20170511  20190611  西安交通大学  Power distribution network singlephase disconnection fault recognition method based on negative sequence voltage current characteristic 
CN107153149A (en) *  20170511  20170912  西安交通大学  Power distribution network singlephase disconnection fault recognition method based on negative sequence voltage current characteristic 
CN107526006A (en) *  20170811  20171229  国网湖南省电力公司  A kind of small current system singlephase earth fault localization method 
CN109085455A (en) *  20171226  20181225  贵州电网有限责任公司  A kind of determination method for distribution line high resistance earthing fault 
CN109188193A (en) *  20180726  20190111  昆明理工大学  A kind of distribution network fault line selection method based on feature band convergence Min Shi distance 
CN109188193B (en) *  20180726  20200925  昆明理工大学  Power distribution network fault line selection method based on characteristic frequency band convergence Min's distance 
CN108645634A (en) *  20180806  20181012  深圳市晟达机械设计有限公司  A kind of rail vehicle troubleshooter 
CN109188200A (en) *  20180831  20190111  华中科技大学  A kind of power distribution network transient fault selection method for ground fault transfer control 
CN109375011A (en) *  20181015  20190222  上海电力学院  A kind of detection method of novel microgrid failure 
CN109375060B (en) *  20181112  20201113  上海金智晟东电力科技有限公司  Method for calculating fault waveform similarity of power distribution network 
CN109375060A (en) *  20181112  20190222  上海金智晟东电力科技有限公司  A kind of distribution network failure waveform similarity calculation method 
CN109507531A (en) *  20181121  20190322  杭州电力设备制造有限公司  A kind of power distribution network singlephase grounding selecting method, system, device and readable storage medium storing program for executing 
CN109541395B (en) *  20181123  20201124  三峡大学  Distribution network section positioning method based on Hausdorff under characteristic frequency band 
CN109541395A (en) *  20181123  20190329  三峡大学  Distribution Section Location based on Hausdorff under a kind of feature band 
CN109596945A (en) *  20190118  20190409  广东电网有限责任公司  A kind of New Criterion of Faulty Line Detection for Distribution based on related coefficient vector similarity degree 
CN110118912A (en) *  20190423  20190813  武汉理工大学  It is a kind of that wire selection method for power distribution network single phase earthing failure is grounded through arc suppression coil device based on grey correlation analysis 
CN110221176A (en) *  20190628  20190910  昆明理工大学  A kind of microcapacitance sensor fault detection method based on juxtaposition differential transformation 
CN110488152A (en) *  20190927  20191122  国网河南省电力公司电力科学研究院  A kind of distribution network fault line selection method based on Adaptive Neurofuzzy Inference 
Also Published As
Publication number  Publication date 

CN100546144C (en)  20090930 
Similar Documents
Publication  Publication Date  Title 

Chaari et al.  Wavelets: A new tool for the resonant grounded power distribution systems relaying  
Judd et al.  Partial discharge monitoring of power transformers using UHF sensors. Part I: sensors and signal interpretation  
Ray et al.  Support vector machine based fault classification and location of a long transmission line  
El Safty et al.  Applying wavelet entropy principle in fault classification  
Mohanty et al.  A cumulative sumbased fault detector for power system relaying application  
Morsi et al.  A new perspective for the IEEE standard 14592000 via stationary wavelet transform in the presence of nonstationary power quality disturbance  
Samantaray et al.  High impedance fault detection in power distribution networks using time–frequency transform and probabilistic neural network  
Livani et al.  A fault classification and localization method for threeterminal circuits using machine learning  
Li et al.  Fault detection and classification in medium voltage DC shipboard power systems with wavelets and artificial neural networks  
Cui et al.  Hilberttransformbased transient/intermittent earth fault detection in noneffectively grounded distribution systems  
Swetapadma et al.  All shunt fault location including crosscountry and evolving faults in transmission lines without fault type classification  
Zhang et al.  Transmission line boundary protection using wavelet transform and neural network  
EP0873583B1 (en)  Digital current differential system  
Livani et al.  A singleended fault location method for segmented HVDC transmission line  
Macedo et al.  Proposition of an interharmonicbased methodology for highimpedance fault detection in distribution systems  
Michalik et al.  Highimpedance fault detection in distribution networks with use of waveletbased algorithm  
US7865321B2 (en)  Arcing event detection  
Chen et al.  Detection of high impedance faults using current transformers for sensing and identification based on features extracted using wavelet transform  
CN100530884C (en)  Selfadaption route selection method for singlephase ground fault of power distribution network based on transient zero sequence current  
US8680873B2 (en)  Method and apparatus for fault identification in a power tansmission line  
Song et al.  Second generation wavelet transform for data denoising in PD measurement  
CN103245883B (en)  A kind of distribution network fault line selection method based on transient zerosequence current timefrequency characteristics vector  
Gilany et al.  Travelingwavebased faultlocation scheme for multiendaged underground cable system  
Ahmadimanesh et al.  Transientbased faultlocation method for multiterminal lines employing Stransform  
Gu et al.  Bridge the gap: signal processing for power quality applications 
Legal Events
Date  Code  Title  Description 

PB01  Publication  
C06  Publication  
SE01  Entry into force of request for substantive examination  
C10  Entry into substantive examination  
GR01  Patent grant  
C14  Grant of patent or utility model  
CF01  Termination of patent right due to nonpayment of annual fee 
Granted publication date: 20090930 Termination date: 20111129 

C17  Cessation of patent right 