CN105738758A - Small current grounding line selecting device application system - Google Patents
Small current grounding line selecting device application system Download PDFInfo
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- CN105738758A CN105738758A CN201410758200.3A CN201410758200A CN105738758A CN 105738758 A CN105738758 A CN 105738758A CN 201410758200 A CN201410758200 A CN 201410758200A CN 105738758 A CN105738758 A CN 105738758A
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Abstract
The invention belongs to the technical field of electric power and especially relates to a small current grounding line selecting device application system. The wavelet packet algorithm is adopted, wherein in the wavelet packet algorithm, related signals are resolved into a high frequency part and a low frequency part, and the more resolving points are during the resolving process, the higher resolution of the frequency domain is, and the lower resolution of corresponding time domain resolution is, and therefore, the line selecting precision and accuracy are increased. Real-time network linking between a transformer substation monitor host and a transformer substation telecontrol information management host is realized through improvement of a novel small current grounding line selecting system. When a single-phase earth fault occurs in the small current grounding line selecting system, an application background monitor system can perform remote real-time monitor management to the on-site single-phase earth fault. In real operations of the devices, non-crash earth fault line selecting is realized. For single-phase earth faults in a small current grounding system, the line selecting precision and accuracy are increased substantially.
Description
Technical field
The invention belongs to technical field of electric power, particularly relate to a kind of Small Electric Current Earthing And Routing Device application system.
Background technology
Small current neutral grounding system occurs that the probability of singlephase earth fault is relatively larger, the impact that this meeting is certain on the properly functioning generation of power distribution network, therefore in conjunction with the current situation of Single-phase Earth-fault Selection in Distribution Systems technology, Small Electric Current Earthing And Routing Device being improved and updates, the safe and stable operation for Urban Low-voltage Distribution net has positive effect.In order to anti-locking system is subject to more serious damage in running, after there is singlephase earth fault in small current neutral grounding system, carry out earth fault line selection fast and accurately to be very important, but the detection effectiveness of some conventional at present line-selected earthing devices is generally relatively low, in order to ensure the safe and stable operation of distribution network, it is necessary on existing basis, line-selected earthing device being improved and researching and developing.
Summary of the invention
The present invention provides a kind of Small Electric Current Earthing And Routing Device application system, the problem generally relatively low to solve the detection effectiveness that proposes in above-mentioned background technology.
Technical problem solved by the invention realizes by the following technical solutions: the present invention provides a kind of Small Electric Current Earthing And Routing Device application system, it is characterized in that: employing is Wavelet Packet Algorithm, in Wavelet Packet Algorithm, relevant signal is decomposed, being broken down into as high frequency and two parts of low frequency, in the process of decomposition, the quantity of its decomposition point is more many, and the resolution of frequency domain is more high, the resolution of corresponding time domain is more low, and then realizes the raising of route selection precision and accuracy.
nullThe described decomposition that zero-sequence current in each circuit is carried out wavelet packet，For it is carried out four layers of decomposition，The essence of this isolation is that the zero-sequence current in circuit is decomposed into 16 frequency sub-band，And the developed width value arranging each frequency range is 125 hertz，The maximum frequency sub-band of energy is selected again according to energy spectrum function，Namely this is the most significant characteristic spectra of fault transient feature，On the other hand，If there is the near zero-crossing point in phase voltage in the singlephase earth fault in small current neutral grounding system，The feature of the transient zero-sequence current in circuit mainly depends on the value of transient inductance electric current in main line，At this moment in transient characterisitics, the component value freely shaken of capacitance current is 0，Its frequency values is generally in the scope of 0-50 hertz，Line related is carried out four layers of decomposition by application wavelet packet，What after decomposition, energy was maximum is first frequency sub-band，Again each circuit is implemented single reconstruct in this frequency range afterwards，If the signal after reconstruct is partial to the side of time shaft，The zero-sequence current of the faulty line in system so has the value of substantial amounts of DC component，According to relevant analysis result，Just can quickly find out faulty line.
The invention have the benefit that the Curve guide impeller by novel Little Current Ground Connection System, it is achieved the real-time interconnection of supervisory control of substation main frame and transformer station's telecontrol information management main frame.When occurring singlephase earth fault in small current neutral grounding system, on-the-spot singlephase earth fault is carried out remote real-time monitoring management by application background monitoring system.This equipment is in actual motion, it is achieved that without the earth fault line selection die.For the singlephase earth fault occurred in small current neutral grounding system, route selection precision and accuracy are obviously improved.
Accompanying drawing explanation
Fig. 1 is principles of the invention schematic diagram.
Detailed description of the invention
Once small current neutral grounding system occurs singlephase earth fault, the current temporary state component of its ground capacity can show significant increase, relative to its steady-state value, several times even tens times can be increased, in the design process of line selection apparatus, in order to effectively promote the accuracy rate of its failure line selection, in actual application, the characteristic component in its transient signal should be made full use of, and apply translation and the expansion performance of wavelet function, making it produce variable time frequency window, this ensure that in actual application, carries out the extraction of characteristic component from transient signal.There is certain difference in the short-circuit protection of the single-phase earthing snap action of the protection act of single-phase grounded malfunction in grounded system of low current line selection apparatus and neutral-point solid ground electrical network, it is in actual running, allow for there is certain deferred action, this guarantees the application of small echo, in order to in practical application, the feasibility of the program is verified, in this research, the program has been carried out l-G simulation test by application electromagnetic transient state procedure, practice result explanation, the method has applies effect preferably, and sensitivity and reliability are that comparison is high in actual applications for they.The failure line selection of peak value and near zero-crossing point is crossed in phase voltage, in this line selection apparatus, apply comparative feature frequency band reconstruct after current instantaneous value symbol and realize comprehensively, the failure line selection of intelligence, on the basis of the program, the TS4430 type Small Electric Current Earthing And Routing Device researched and developed, in the process of time frequency analysis, application is Wavelet Packet Algorithm, in Wavelet Packet Algorithm, relevant signal can be decomposed, it is broken down into as high frequency and two parts of low frequency, in the process decomposed, the quantity of its decomposition point is more many, the resolution of frequency domain is more high, the resolution of corresponding time domain is more low.nullIf the singlephase earth fault in small current neutral grounding system occurs in voltage peaks，The transient characterisitics of the zero-sequence current in each circuit depend primarily on transient state capacitance current in circuit，If the value of capacitance current is more than the inductive current in transient characterisitics，So freely the shaking in the scope that frequency values is generally in 300-1500 hertz of transient state capacitance current，So in the development process of actual line selection apparatus，The value of its sample frequency can be chosen as 4000 hertz，And the zero-sequence current in each circuit is carried out the decomposition of wavelet packet，It is typically chosen and it is carried out four layers of decomposition，The essence of this isolation is that the zero-sequence current in circuit is decomposed into 16 frequency sub-band，And the developed width value arranging each frequency range is 125 hertz，The maximum frequency sub-band of energy is selected again according to energy spectrum function，Namely this is the most significant characteristic spectra of fault transient feature.On the other hand, if there is the near zero-crossing point in phase voltage in the singlephase earth fault in small current neutral grounding system, the feature of the transient zero-sequence current in circuit mainly depends on the value of transient inductance electric current in main line, at this moment in transient characterisitics, the component value freely shaken of capacitance current is 0, its frequency values is generally in the scope of 0-50 hertz, line related is carried out four layers of decomposition by application wavelet packet, what after decomposition, energy was maximum is first frequency sub-band, again each circuit is implemented single reconstruct in this frequency range afterwards, if the signal after reconstruct is partial to the side of time shaft, the zero-sequence current of the faulty line in system so has the value of substantial amounts of DC component, according to relevant analysis result, just can quickly find out faulty line.
Utilize technical solutions according to the invention, or those skilled in the art is under the inspiration of technical solution of the present invention, design similar technical scheme, and reach above-mentioned technique effect, all fall into protection scope of the present invention.
Claims (2)
1. a Small Electric Current Earthing And Routing Device application system, it is characterized in that: employing is Wavelet Packet Algorithm, in Wavelet Packet Algorithm, relevant signal is decomposed, being broken down into as high frequency and two parts of low frequency, in the process of decomposition, the quantity of its decomposition point is more many, and the resolution of frequency domain is more high, the resolution of corresponding time domain is more low, and then realizes the raising of route selection precision and accuracy.
null2. a kind of Small Electric Current Earthing And Routing Device application system according to claim 1，It is characterized in that: the described decomposition that zero-sequence current in each circuit is carried out wavelet packet，For it is carried out four layers of decomposition，The essence of this isolation is that the zero-sequence current in circuit is decomposed into 16 frequency sub-band，And the developed width value arranging each frequency range is 125 hertz，The maximum frequency sub-band of energy is selected again according to energy spectrum function，Namely this is the most significant characteristic spectra of fault transient feature，On the other hand，If there is the near zero-crossing point in phase voltage in the singlephase earth fault in small current neutral grounding system，The feature of the transient zero-sequence current in circuit mainly depends on the value of transient inductance electric current in main line，At this moment in transient characterisitics, the component value freely shaken of capacitance current is 0，Its frequency values is generally in the scope of 0-50 hertz，Line related is carried out four layers of decomposition by application wavelet packet，What after decomposition, energy was maximum is first frequency sub-band，Again each circuit is implemented single reconstruct in this frequency range afterwards，If the signal after reconstruct is partial to the side of time shaft，The zero-sequence current of the faulty line in system so has the value of substantial amounts of DC component，According to relevant analysis result，Just can quickly find out faulty line.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410758200.3A CN105738758A (en) | 2014-12-11 | 2014-12-11 | Small current grounding line selecting device application system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201410758200.3A CN105738758A (en) | 2014-12-11 | 2014-12-11 | Small current grounding line selecting device application system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111077413A (en) * | 2020-01-21 | 2020-04-28 | 山东大学 | Three-phase transient current-based small current grounding system fault phase selection and line selection method |
| CN116073345A (en) * | 2023-04-06 | 2023-05-05 | 安徽凯民电力技术有限公司 | Intelligent comprehensive grounding management system |
-
2014
- 2014-12-11 CN CN201410758200.3A patent/CN105738758A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111077413A (en) * | 2020-01-21 | 2020-04-28 | 山东大学 | Three-phase transient current-based small current grounding system fault phase selection and line selection method |
| CN116073345A (en) * | 2023-04-06 | 2023-05-05 | 安徽凯民电力技术有限公司 | Intelligent comprehensive grounding management system |
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Application publication date: 20160706 |
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| WD01 | Invention patent application deemed withdrawn after publication |