CN102590703B  Singlephase grounding failure route selection method of resonance grounding system based on zerosequence transient charge  Google Patents
Singlephase grounding failure route selection method of resonance grounding system based on zerosequence transient charge Download PDFInfo
 Publication number
 CN102590703B CN102590703B CN201210036898.9A CN201210036898A CN102590703B CN 102590703 B CN102590703 B CN 102590703B CN 201210036898 A CN201210036898 A CN 201210036898A CN 102590703 B CN102590703 B CN 102590703B
 Authority
 CN
 China
 Prior art keywords
 zero
 feeder line
 zero sequence
 transient
 sequence transient
 Prior art date
Links
 230000001052 transient Effects 0.000 title claims abstract description 91
 238000010187 selection method Methods 0.000 title claims abstract description 11
 230000000875 corresponding Effects 0.000 claims abstract description 10
 238000001914 filtration Methods 0.000 claims abstract description 4
 238000005070 sampling Methods 0.000 claims description 11
 238000000034 methods Methods 0.000 abstract description 5
 230000035945 sensitivity Effects 0.000 abstract description 2
 238000003745 diagnosis Methods 0.000 abstract 1
 238000007519 figuring Methods 0.000 abstract 1
 239000003990 capacitor Substances 0.000 description 5
 230000001629 suppression Effects 0.000 description 4
 238000004458 analytical methods Methods 0.000 description 2
 230000005540 biological transmission Effects 0.000 description 2
 230000000694 effects Effects 0.000 description 2
 230000001131 transforming Effects 0.000 description 2
 238000009825 accumulation Methods 0.000 description 1
 230000001186 cumulative Effects 0.000 description 1
 238000005516 engineering processes Methods 0.000 description 1
 230000014759 maintenance of location Effects 0.000 description 1
 230000001264 neutralization Effects 0.000 description 1
 238000004088 simulation Methods 0.000 description 1
Abstract
Description
Technical field
The present invention relates to a kind of resonant earthed system fault line selection method for singlephasetoground fault based on zero sequence transient charge in electric system.
Background technology
At present, adopt the resonant earthed system of arc suppression coil due to after circuit generation singlephase earth fault, fault current is subject to the compensation of arc suppression coil and diminishes, so can selfextinguish ground arc; Simultaneously resonant earthed system is due to still retention wire voltage threephase symmetrical after singlephase earth fault, does not affect the power supply capacity to load, therefore allows charging operation 12 hour.But along with the development of power distribution network, bus feeder line increases and the use of cable in circuit year by year, short circuit capacitance electric current is increased, longplay easily produces multipoint earth faults, so fault feeder must be judged rapidly and accurately within limited working time, for the accurate location of further fault and failture evacuation provide foundation.
For the failure line selection of power distribution network resonant earthed system, although power frequency amount energy is large but be subject to the compensation of arc suppression coil, fundametal compoment amplitude and direction all can produce larger change, based on this reason, the transient produced after analysis of failure, realizes being that the selection method of criterion progressively becomes research and practical focus with transient information.But high resistance earthing fault is the difficult point of route selection in power distribution network always, because stake resistance is excessive, after fault, the amplitude of transient is very little, causes extreme difficulties to route selection accurate after resonant earthed system fault.
Summary of the invention
The object of the invention is the weak point overcoming existing power distribution network resonant earthed system failure line selection, a kind of resonant earthed system fault line selection method for singlephasetoground fault based on zero sequence transient charge is proposed, the route selection of this selection method is highly sensitive, speed fast, accurately can locate provide foundation more accurately and reliably with failture evacuation for further fault.
The present invention is for solving its technical matters, and the technical scheme adopted is a kind of resonant earthed system fault line selection method for singlephasetoground fault based on zero sequence transient charge, the steps include:
A, the threephase current signal gathering power distribution network each bar feeder line bus end and threephase voltage signal, after choosing singlephase earth fault, first semiperiod of each bar feeder line or the sampled data of holocyclic threephase current signal and threephase voltage signal are as the input quantity of route selection element;
B, decoupling zero is carried out to the input quantity of the route selection element chosen, obtain zerosequence current component and the zero sequence voltage component of each bar feeder line respectively;
50Hz power frequency component in C, filtering each bar feeder line zerosequence current and residual voltage, obtain corresponding zero sequence transient current and zero sequence transient voltage, and obtain in first selected semiperiod or time in complete period the zero sequence transient charge amount be accumulated on feeder line according to the zero sequence transient current of each bar feeder line;
D, set up the corresponding relation of each bar feeder line zero sequence transient charge amount and zero sequence transient voltage, calculate the transient zerosequence voltage of each bar feeder line and the related coefficient of zero sequence transient charge amount, the minimum feeder line of related coefficient is judged to be fault feeder.
Compared with prior art, the invention has the beneficial effects as follows:
One, the relativeness that the transient charge amount that the present invention passes through to accumulate in half or oneperiod changes at distribution and each feeder line transient voltage of each feeder line, because the transient information amount utilized is accumulation, improve the recognition capability to feeble signal, overcome the shortcoming that high resistance earthing fault causes transient current information too small, solve the transient state electric parameters problem that extremely faint caused route selection is inaccurate in high resistance ground situation, improve sensitivity and the accuracy of the route selection of resonant earthed system high resistance ground.
Two, there is singlephase earth fault in resonant earthed system and can produce two transient state processes simultaneously.One is that faulted phase voltage reduces suddenly and the discharge capacity electric current caused, and another is that nonfaulted phase voltage raises suddenly the charging capacitor electric current caused.Discharge capacity electric current flows to trouble spot by bus, directly forms flow cycle through fault phase line mutualground capacitor and ground, and then charging capacitor electric current then forms path through healthy phases line mutualground capacitor and ground by transformer.The present invention is by the total charge dosage asking for two transient state charge and discharge process and accumulate in first semiperiod or the complete period distribution relation with corresponding transient voltage, investigate the correlation coefficient value of different both feeder lines, this correlation coefficient value more close to 1, reflect this feeder line load stabilization, disturb little; This correlation coefficient value contrary is more less than 1, illustrates that its load there occurs sudden change or receives interference; Therefore, the feeder line that after breaking down, correlation coefficient value is minimum can be judged to be faulty line.It is without the direction of Direct Recognition transient current and size, and route selection criterion is simple, facilitates executeinplace.
Three, the discharge and recharge transient state process that when the transient charge amount owing to accumulating is resonant earthed system generation singlephase earth fault, self produces is formed, and not by the impact of system neutral degree of compensation, also makes its route selection accurately, reliably; And only need the threephase electricity flow and the voltage that gather each bar feeder line of bus bar side, and not high to equipment requirement, equally, improve the reliability of method.
Four, when the present invention only needs to gather singlephase earthing, the transient of capacitor charge and discharge process, is generally between hundreds of to a few KHz, so sample frequency scope is at 10kHz ~ 20kHz, to sample devices without particular/special requirement, and convenient enforcement.
In abovementioned C step, the specific practice obtaining the zero sequence transient charge amount be accumulated on feeder line in first selected semiperiod or time in complete period according to the zero sequence transient current of each bar feeder line is;
By following discrete integration formula draw occur singlephase fault begin ith sampling interval time in the quantity of electric charge accumulated
In formula, be the zero sequence transient current that ith sampling interval of nth feeder line gathers, Δ t is the time of sampling interval; When or during i=T/ Δ t, T is the cycle of threephase electricity, the quantity of electric charge calculated be in first semiperiod or time in complete period the zero sequence transient charge amount be accumulated on nth feeder line
Adopt the zero sequence transient charge amount that can calculate each bar feeder line in this way easily and fast and accumulate within access time.
Below in conjunction with embodiment, the present invention is described in further detail.
Accompanying drawing explanation
The realistic model topological structure of the emulation experiment of Fig. 1 embodiment of the present invention.
The zero sequence transient charge amount of feeder line 14 and the relation of zero sequence transient voltage in the emulation experiment of Fig. 2 embodiment of the present invention.
Embodiment
Embodiment
A kind of embodiment of the present invention is, a kind of resonant earthed system fault line selection method for singlephasetoground fault based on zero sequence transient charge, the steps include:
A, the threephase current signal gathering power distribution network each bar feeder line bus end and threephase voltage signal, after choosing singlephase fault, first semiperiod (i.e. 10ms) of each bar feeder line or the threephase current signal in complete period (20ms) and the sampled data of threephase voltage signal are as the input quantity of route selection element.
B, decoupling zero is carried out to the input quantity of the route selection element chosen, obtain zerosequence current component and the zero sequence voltage component of each bar feeder line respectively.
During decoupling zero, various existing decoupling zero can be adopted to carry out, as symmetrical component transformation can be adopted to carry out, specific as follows:
In formula (1), I _{a}, I _{b}, I _{c}be respectively A, B, C phase current that each bar feeder line obtains in the measurement of bus place; I _{0}for zerosequence current; I _{1}for forwardorder current; I _{2}for negativesequence current.
In formula (2), U _{a}, U _{b}, U _{c}be respectively A, B, C phase voltage that each bar feeder line obtains in the measurement of bus place; U _{0}for residual voltage; U _{1}for positive sequence voltage; U _{2}for negative sequence voltage.
In formula (1) and (2), α is twiddle factor, and its expression formula is:
By above symmetrical component transformation, the asymmetric currentvoltage information after generation singlephase earth fault is transformed into three symmetrical order components, the feeder line zerosequence current component I wherein obtained _{0}, zero sequence voltage component U _{0}be the information that nextstep operation needs.
50Hz power frequency component in C, filtering each bar feeder line zerosequence current and residual voltage, obtain corresponding zero sequence transient current and zero sequence transient voltage, and obtain in first selected semiperiod or time in complete period the zero sequence transient charge amount be accumulated on feeder line according to the zero sequence transient current of each bar feeder line.
In this example, the specific practice obtaining the zero sequence transient charge amount be accumulated on feeder line in first selected semiperiod or time in complete period according to the zero sequence transient current of each bar feeder line is;
By following discrete integration formula draw occur singlephase fault begin ith sampling interval time in the quantity of electric charge accumulated
In formula, be the zero sequence transient current that ith sampling interval of nth feeder line gathers, Δ t is the time of sampling interval; When or during i=T/ Δ t, T is the cycle (20ms) of threephase electricity, the quantity of electric charge calculated be in first semiperiod or time in complete period the zero sequence transient charge amount be accumulated on nth feeder line
D, set up the corresponding relation of each bar feeder line zero sequence transient charge amount and zero sequence transient voltage, calculate the transient zerosequence voltage of each bar feeder line and the related coefficient of zero sequence transient charge amount, the minimum feeder line of related coefficient is judged to be fault feeder.
The computing formula of the transient zerosequence voltage of each bar feeder line and the related coefficient of zero sequence transient charge amount is:
In formula, ρ _{n}represent the zero sequence transient voltage amount of nth feeder line and the related coefficient of zero sequence transient charge amount, represent the zero sequence transient voltage amount of nth feeder line and the covariance of zero sequence transient charge amount, represent the variance of the zero sequence transient voltage amount of nth feeder line, represent the variance of the zero sequence transient charge amount of nth feeder line.
Emulation experiment:
For checking the inventive method has carried out emulation experiment to above method, the simulation experiment result shows that its route selection is highly sensitive, and route selection speed is fast, and route selection accurately and reliably.
In conjunction with an actual motion line parameter circuit value, to build electric pressure be the single supply 4 feeder line resonant earthed system of 35kV is empirical model, and circuit is the overhead transmission line model of frequency dependence.Its topology as shown in Figure 1.Correlation parameter is: the length of feeder line 1 is 30km, and the length of feeder line 2 is 19km, and the length of feeder line 3 is 10km, and feeder line 4 length is 6km.The positive and negative sequence impedance Z of overhead transmission line _{1}=Z _{2}=0.25542+j0.37294 Ω/km, positive and negative sequence admittance Y _{1}=Y _{2}=j3.0803 × 10 ^{6}s/km, zero sequence impedance Z _{0}=0.51664+j1.48516 Ω/km, zero sequence admittance Y _{0}=j1.47574326 × 10 ^{6}s/km, Arc Suppression Coil Compensation Degree is set to overcompensation 10%, and signal pickup assembly is installed in the data acquisition that each bar feeder line bus end carries out threephase fault electric current and threephase fault voltage.
Data sampling rate is 20kHz, and data window length gets 414 points and oneperiod, supposes that feeder line 1 A phase earth fault occurs, transition resistance R=2000 Ω at t=0.3243s distance bus l=18km place.Then can calculate: the zero sequence transient charge amount that feeder line 14 accumulates in oneperiod, the correlation coefficient value ρ of corresponding zero sequence transient charge amount and zero sequence transient voltage _{1}=0.1084, ρ _{2}=0.9992, ρ _{3}=0.9986, ρ _{4}=0.9951.According to criterion, ρ _{1}minimum, therefore feeder line 1 is fault feeder.Fig. 2 is, the zero sequence transient charge amount of feeder line 14 at each hours cumulative of oneperiod and the relation curve of zero sequence transient voltage, the curve of lineal layout of leveling off in Fig. 2 is feeder line 2, the relation curve of 3,4, and the curve of random distribution is fault feeder curve, also feeder line 2 is described, 3, on 4, zero sequence transient charge amount and zero sequence transient voltage are the positively related relation of highly linear, and on feeder line 1, zero sequence transient charge amount and zero sequence transient voltage do not have obvious correlationship.
The route selection result of the inventive method under the operating mode of different faults Distance geometry different faults stake resistance is given with following table 1 and table 2.
Table 1 for feeder line 1 different distance place occur A phase earth fault time (time of failure is 0.3243s, transition resistance R=2800 Ω) route selection results contrast:
Table 1
√: represent protection route selection result and actual to arrange fault feeder result consistent
Table 2 is the comparison of feeder line 1 (time of failure for 0.3243s, fault distance l=15km) route selection result when there is A phase earth fault with different grounding resistance.
Table 2
√: represent protection route selection result and actual to arrange fault feeder result consistent
The route selection result of table 1 and table 2 shows, under the working condition of various fault distance and fault ground resistance, the zero sequence transient charge amount of fault feeder and the degree of correlation of zero sequence transient voltage are all starkly lower than healthy feeder line.Its route selection result accurately and be easy to operating personnel and read, confirms that this inventive method has very high dependable with function.
More than test and do not consider noise effect, for the adaptability of checking the present invention in practical engineering application, to the threephase current collected and voltage signal superposition white Gaussian noise, simulate the signal disturbing that may occur in actual applications, to verify the route selection fiduciary level of the present invention under low signaltonoise ratio.
Singlephase earth fault is there is in feeder line 1 apart from bus 20km place, data sampling rate is 20kHz, (t=0.3243s) 414 sampled points (oneperiod) after data window length gets fault, table 3 is the route selection results contrast of the inventive method in unlike signal signal to noise ratio (S/N ratio) (Signaltonoise ratio, SNR) situation.
Table 3
√: represent protection route selection result and actual to arrange fault feeder result consistent
Add Gauss's noise experiment result to show: input signal signal to noise ratio (S/N ratio) all correctly can complete failure line selection from 10dB to 70dB.But can find that signal to noise ratio (S/N ratio) is when more than 40dB, the zero sequence transient charge amount of healthy feeder line and the related coefficient of zero sequence transient voltage, all more than 0.95, illustrate that the zero sequence transient charge amount distribution of healthy feeder line and zero sequence transient voltage change linear degree high.Along with the reduction of signal to noise ratio (S/N ratio), noise affects greatly electric parameters effective information, and the correlation coefficient value that the charge amount distribution of fault feeder and healthy feeder line is corresponding with it also produces larger change.But fault feeder correlation coefficient value is starkly lower than healthy feeder line all the time.The analysis of comprehensive above fault condition, illustrates that route selection of the present invention is highly sensitive, and antijamming capability is strong, can adapt to onthespot practical application.
Claims (2)
Priority Applications (1)
Application Number  Priority Date  Filing Date  Title 

CN201210036898.9A CN102590703B (en)  20120218  20120218  Singlephase grounding failure route selection method of resonance grounding system based on zerosequence transient charge 
Applications Claiming Priority (1)
Application Number  Priority Date  Filing Date  Title 

CN201210036898.9A CN102590703B (en)  20120218  20120218  Singlephase grounding failure route selection method of resonance grounding system based on zerosequence transient charge 
Publications (2)
Publication Number  Publication Date 

CN102590703A CN102590703A (en)  20120718 
CN102590703B true CN102590703B (en)  20150520 
Family
ID=46479624
Family Applications (1)
Application Number  Title  Priority Date  Filing Date 

CN201210036898.9A CN102590703B (en)  20120218  20120218  Singlephase grounding failure route selection method of resonance grounding system based on zerosequence transient charge 
Country Status (1)
Country  Link 

CN (1)  CN102590703B (en) 
Families Citing this family (9)
Publication number  Priority date  Publication date  Assignee  Title 

CN102944806B (en) *  20121120  20141105  中国石油大学(华东)  Zero sequence current polarity comparisonbased resonant earthed system line selection method 
CN103207352B (en) *  20130313  20150902  福建省电力有限公司  Route selection impedance magnitude characteristic is utilized to realize wire selection method for power distribution network single phase earthing failure 
WO2014154164A1 (en) *  20130329  20141002  北京映翰通网络技术股份有限公司  Method and system for detecting and locating singlephase ground fault on low current grounded powerdistribution network 
CN103323747B (en) *  20130627  20160810  国家电网公司  A kind of fault line selection method for singlephasetoground fault of small current neutral grounding system 
CN103675605B (en) *  20131211  20160309  湖南大学  A kind of power distribution network earth fault line selection method based on the correlation analysis of faultsignal transient state 
CN104617566B (en) *  20150123  20170912  昆明理工大学  A kind of small current neutral grounding system singlephase fault based on the positive and negative area sum of residual voltage starts method 
CN105044550A (en) *  20150428  20151111  国家电网公司  Distribution network line fault positioning method based on fault current discharge path 
CN106896294A (en) *  20170327  20170627  国家电网公司  Noneffectively earthed system faultline selecting method based on transient state discharge capacity 
CN108132417A (en) *  20171124  20180608  国网北京市电力公司  Method for locating singlephase ground fault and device 
Family Cites Families (3)
Publication number  Priority date  Publication date  Assignee  Title 

JP2008113508A (en) *  20061031  20080515  Chugoku Electric Power Co Inc:The  Protective relay device and electric power system protecting method 
JP5208684B2 (en) *  20081110  20130612  中国電力株式会社  Ground fault protection relay system 
CN101478149A (en) *  20090116  20090708  西安交通大学  Wire selection method for power distribution network single phase earthing failure based on transient signal 

2012
 20120218 CN CN201210036898.9A patent/CN102590703B/en active IP Right Grant
Also Published As
Publication number  Publication date 

CN102590703A (en)  20120718 
Similar Documents
Publication  Publication Date  Title 

AU2011313840B2 (en)  Apparatus and method for fault detection and location determination  
CN103344875B (en)  Classification line selection method for singlephase earth fault of resonance earthing system  
CN104155582B (en)  Distribution line fault section location method based on Full wave shape information  
Pradhan et al.  Fault direction estimation in radial distribution system using phase change in sequence current  
Suonan et al.  A novel faultlocation method for HVDC transmission lines  
Li et al.  Traveling wavebased protection scheme for inverterdominated microgrid using mathematical morphology  
CN100546143C (en)  A kind of low current grounding detects the device and method with the location  
CN101545943B (en)  Method for fault line selection of cablewire mixed line of electric distribution network by using wavelet energy relative entropy  
CN101242097B (en)  Failure line selection method of small current ground system by using simulation after zero mode current measure  
Suonan et al.  Distance protection for HVDC transmission lines considering frequencydependent parameters  
CN103293443B (en)  A kind of distribution network overhead line Earth design method  
Saha et al.  Fault location on power networks  
CN102928704B (en)  Intelligent diagnosis method for corrosion failure point of transformer substation grounding grid  
CN100335912C (en)  Small Current earthing line selecting method based on model parametric recognition  
CN102495336B (en)  Distributed singlephase earth fault ranging system and ranging method thereof  
CN103245883B (en)  A kind of distribution network fault line selection method based on transient zerosequence current timefrequency characteristics vector  
CN101551432B (en)  Power distribution network fault positioning method  
CN102967799B (en)  Comprehensive fault distance measuring method for electric power system  
CN100386637C (en)  Fault line selection method for singlephasetoground fault in small ground current distribution network  
CN101719663B (en)  Grounding line selection method, grounding line selection device and application system based on active component of zero sequence current  
CN1333503C (en)  Protection and fault positioning method for generator stator winding singlephase earthing  
CN103675605B (en)  A kind of power distribution network earth fault line selection method based on the correlation analysis of faultsignal transient state  
CN101188354B (en)  Test simulation method for failure line selection of small current ground system  
US20150073735A1 (en)  Method for adaptive fault location in power system networks  
CN104198884B (en)  Differential principle based largescale power grid intelligent trouble diagnosis method 
Legal Events
Date  Code  Title  Description 

C06  Publication  
PB01  Publication  
C10  Entry into substantive examination  
SE01  Entry into force of request for substantive examination  
C14  Grant of patent or utility model  
GR01  Patent grant 