CN204789874U - Distribution network small current neutral grounding sys tem earth fault route selection device - Google Patents
Distribution network small current neutral grounding sys tem earth fault route selection device Download PDFInfo
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- CN204789874U CN204789874U CN201520544387.7U CN201520544387U CN204789874U CN 204789874 U CN204789874 U CN 204789874U CN 201520544387 U CN201520544387 U CN 201520544387U CN 204789874 U CN204789874 U CN 204789874U
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Abstract
The utility model relates to a distribution network provides distribution network small current neutral grounding sys tem earth fault route selection device, whole device by: drive signal receiving terminal, voltage sample unit, current sample unit, comprehensive criterion unit, signal synchronization judge that unit, low frequency signals source, low frequency signals excitation unit, signal pour into return circuit, warning route selection unit into, realized the route selection function of distribution network small current neutral grounding sys tem trouble, through the trouble characteristic route selection to zero sequence voltage signal, zero sequence current signal, confirmed fault line, plus one set of drive signal judges through the integrated information of PT secondary coupling method, improved the rate of accuracy of small current neutral grounding sys tem earth fault route selection, solve the problem of single -phase earth fault erroneous judgement.
Description
Technical field
The utility model relates to the fault detect of a kind of power industry small electric current grounding system of distribution network, particularly for the device of the small current neutral grounding system earth fault line selection of power distribution network.
Background technology
In the power distribution network of China's electric system, be widely used small current neutral grounding mode.Neutral point as 10KV-66KV power distribution network adopts non-effective earthing mode, includes isolated neutral and neutral by arc extinction coil grounding two kinds, and object is can automatic distinguishing electric arc recover to insulate when power distribution network generation singlephase earth fault.When there is permanent earth fault, in order to prevent healthy phases voltage from raising, causing trouble expands, and must determine faulty line as early as possible and exit power supply as soon as possible.Power industry is perplexed, not good solution, one of " worry " of becoming power distribution automation for this earth fault line selection problem.Particularly 6-10kV grid parts adopts isolated neutral mode, and indivedual area is the urban electrical network employing low resistance grounding mode such as sea, Beijing, Guangzhou as above.In China, at least within long period of time, neutral point adopts small current neutral grounding mode to be still a kind of typical, competitive earthing mode, will be in the highest flight.
The probability of small current neutral grounding system generation singlephase earth fault is the highest, and many data show: singlephase earth fault accounts for 80% of low current neutral grounding system fault.When there is singlephase earth fault, because current in the fault point is less, and do not affect the normal power supply of load, general permission continues to run 1-2h.But along with increasing of feeder line, capacitance current becomes large, and may cause a lot of harm to power transmission and transforming equipment and user, long-play easily makes failure propagation become or multipoint earthing short circuit at 2; The single-phase superpotential that metallic earthing causes may burn the voltage transformer (VT) of bus; Arc grounding also may cause total system superpotential, and the superpotential of generation may puncture line insulator, and lightning arrester causes phase fault, destroys safe operation; Ground current also may cause personal injury accidents.Therefore should find faulty line rapidly when ensureing uninterrupted power supply and fix a breakdown as far as possible in actual motion.But single-phase grounded malfunction in grounded system of low current route selection technology is powered safely and reliably for power distribution network and realized the integrated automation of transformation stations etc. important and far-reaching meaning, and Ye Shi State Grid Corporation of China development priority direction from now on.
There is a large amount of wrong report problems in existing various low-current ground fault line selection devices.The present invention proposes aggregation of data disconnected according to method; Based on the comprehensive criterion of residual voltage method, current method and pumping signal method, by the fault characteristic route selection to residual voltage signal, zero sequence current signal, determine faulty line, additional a set of pumping signal is judged by the integrated information of PT bis-coupled methods, the accuracy rate of low current neutral grounding system fault route selecting is improved greatly, solves the problem that singlephase earth fault accurately judges.Its advantage is as follows.
1. do not need zero sequential potential transformer is installed, realize fault location function.
2. distributed frame, wiring is simple, extendibility good, transformer station increase feeder line not device without any impact.
Select faulty line not by the impact of system outlet method, earth fault mode.
Summary of the invention
The utility model is carried as small electric current grounding system of distribution network ground fault line selection device, it is characterized in that, include: pumping signal receiving end, voltage sampling unit, current sampling unit, comprehensive criterion unit, the synchronous identifying unit of signal, low frequency signal source, low frequency signal exciting unit, signal injection loop, warning route selection unit.Pumping signal receiving end connects with comprehensive criterion unit; Voltage sampling unit connects with comprehensive criterion unit; Current sampling unit connects with comprehensive criterion unit; Comprehensive criterion unit identifying unit synchronous with signal connects; The synchronous identifying unit of signal connects with low frequency signal source; Low frequency signal source connects with low frequency signal exciting unit; Low frequency signal exciting unit connects with signal injection loop; Signal injection loop identifying unit synchronous with signal connects; The synchronous identifying unit of signal connects with warning route selection unit.These three unit of pumping signal receiving end, voltage sampling unit, current sampling unit monitor data and are transferred to comprehensive criterion unit; The data that comprehensive criterion unit is returned according to each unit collection carry out criterion, relevant data transfer to the synchronous identifying unit of signal; The synchronous identifying unit of signal simultaneously the Signal transmissions after judging to low frequency signal source; Low frequency signal source self also injects a signal, the signal of synchronous for signal identifying unit transmission is transferred to low frequency signal exciting unit together simultaneously; Low frequency signal exciting unit makes signal more stable, reduces interference, then Signal transmissions to signal injection loop; Signal injection loop Signal transmissions to the synchronous identifying unit of signal; The data of various information and quantity of state judge by the synchronous identifying unit of signal, judge abnormal information and the route selection of fault, again the route selection of the information of exception and fault is transferred to warning route selection unit, warning route selection unit carries out warning to abnormal information and exports, and carries out route selection to the line-to-ground fault of fault.
In order to allow above-mentioned feature and advantage of the present utility model become apparent, below especially exemplified by embodiment, and accompanying drawing is coordinated to be described in detail below.
Accompanying drawing explanation
Fig. 1 is the structural representation of the utility model device.
Embodiment
embodiment:as shown in Figure 1, the structural representation of the utility model device, the utility model is for transformer station's distribution runs the device providing low current neutral grounding system fault route selecting to locate, and includes: pumping signal receiving end (1), voltage sampling unit (2), current sampling unit (3), comprehensive criterion unit (4), the synchronous identifying unit of signal (5), low frequency signal source (6), low frequency signal exciting unit (7), signal injection loop (8), warning route selection unit (9).Pumping signal receiving end (1) connects with comprehensive criterion unit (4); Voltage sampling unit (2) connects with comprehensive criterion unit (4); Current sampling unit (3) connects with comprehensive criterion unit (4); Comprehensive criterion unit (4) identifying unit (5) synchronous with signal connects; The synchronous identifying unit of signal (5) connects with low frequency signal source (6); Low frequency signal source (6) connects with low frequency signal exciting unit (7); Low frequency signal exciting unit (7) connects with signal injection loop (8); Signal injection loop (8) identifying unit (5) synchronous with signal connects; The synchronous identifying unit of signal (5) connects with warning route selection unit (9).These three unit of pumping signal receiving end (1), voltage sampling unit (2), current sampling unit (3) monitor data and are transferred to comprehensive criterion unit (4); The data that comprehensive criterion unit (4) is returned according to each unit collection carry out criterion, relevant data transfer to the synchronous identifying unit of signal (5); The synchronous identifying unit of signal (5) simultaneously the Signal transmissions after judging to low frequency signal source (6); Low frequency signal source (6) self also injects a signal, the signal that synchronous for signal identifying unit (5) is transmitted is transferred to low frequency signal exciting unit (7) together simultaneously; Low frequency signal exciting unit (7) makes signal more stable, reduces interference, then Signal transmissions to signal injection loop (8); Signal injection loop (8) Signal transmissions to the synchronous identifying unit of signal (5); The data of various information and quantity of state judge by the synchronous identifying unit of signal (5), judge abnormal information and the route selection of fault, again the route selection of the information of exception and fault is transferred to warning route selection unit (9), warning route selection unit (9) carries out warning to abnormal information and exports, and carries out route selection to the circuit of fault.
Pumping signal receiving end (1) collects the pumping signal of each branch road of each output of power distribution network, mainly completes the receiving port of input signal.Employing collects at the current transducer signal of each original outlet simultaneously to be believed by low frequency
Number exciting unit (7) is injected into the signal of power distribution network.Pumping signal receiving end (1) is by swashing of collecting
The signal of encouraging the receiving port of signal voltage and current signal is delivered to comprehensive criterion unit (4) and is comprehensively sentenced
Disconnected.Receiving end mainly adopts model to be the transmitter of DT101, and DA company of the U.S. produces.
Voltage sampling unit (2) adopts resistor voltage divider network, by sending A/D to carry out voltage sample effect again after a voltage follower.The resistor voltage divider network of voltage sampling unit is from PT bis-output terminal samplings, the output voltage of voltage sampling unit (2) is 0-5V, voltage sampling unit (2) can judge the voltage status of A, B, C three-phase, not right if any a phase voltage, can be judged as that signal gives comprehensive criterion unit (4) when phase voltage abnormal failure.
Current sampling unit (3) have employed RMS conversion chip AD736.The electric current that main circuit exports converts voltage to and is sent to signal synthesis criterion unit (4), single-chip microcomputer again according to deviate change control amount and
Realize the function such as over-voltage over-current protection, breakdown judge.Current sampling unit (3) collects each branch-path
Zero sequence current signal and phase current signal, send to comprehensive criterion unit (4) as the foundation of comprehensive descision.
Comprehensive criterion unit (4) receives simultaneously, the pumping signal of pumping signal receiving end (1), voltage sampling unit (2) phase voltage, residual voltage signal, the phase current of current sampling unit (3).Comprehensively sentence
According to unit (4) according to phase voltage, residual voltage, phase current, zero-sequence current and excitation signal voltage, electricity
Stream signal, comprehensive criterion unit (4) is further according to the synchronizing signal of the synchronous identifying unit of signal (5)
Judge pumping signal, the signal sent by low frequency signal exciting unit (7) exactly, other letters asynchronous
Number will to be removed by antimony, and effectively can improve the precision of judgement, greatly improve the accuracy of earth fault line selection.
It is synchronous that the synchronous identifying unit of signal (5) mainly completes low frequency signal, makes nonsynchronous signal carry out comprehensive criterion, effectively improves the accuracy of criterion and improve antijamming capability.
Low frequency signal source (6) provides a low frequency signal, through computing, amplifies.Low frequency signal source comprises internal signal oscillator, signal shaping, signal amplifying part are divided, and be 12V by generation amplitude, frequency is 1Hz
Synchronous square wave low frequency signal deliver to low frequency signal exciting unit (7).Signal oscillator is by chip 18741
Complete, signal shaping amplification is completed by CM324.
The signal that low frequency signal exciting unit (7) is brought by low frequency signal source (6) is by producing the pumping signal of 100mA, 100V after this exciting unit.Mainly completing chip model is LM444.
The low frequency signal of low frequency signal exciting unit (7) is carried out isolated variable and connects with the mutual inductor of secondary by signal injection loop (8), carries out available protecting and isolation, achieves injection and the safety problem of pumping signal,
Transformer primarily of infusion circuit completes.
Warning route selection unit (9) is made up of dry contact, relay and pilot lamp, has been mainly used to warning; Warning route selection unit is reported to the police to each outlet line of power distribution network, and its warning is sended over by comprehensive criterion unit (4), and occur that the signal of earth fauit loops carries out warning and exports, the actuating of relay, refers to
Show that lamp is bright.The relay exported of reporting to the police is two groups of dry contacts, selects DT1240 relay, Shanghai radio
Eight factories produce, 24 Power supplies, and pilot lamp is common luminous φ 5 light emitting diode, and lamp is bright for reporting to the police.
Claims (1)
1. small electric current grounding system of distribution network ground fault line selection device, it is characterized in that, include: pumping signal receiving end, voltage sampling unit, current sampling unit, comprehensive criterion unit, the synchronous identifying unit of signal, low frequency signal source, low frequency signal exciting unit, signal injection loop, warning route selection unit; Pumping signal receiving end connects with comprehensive criterion unit; Voltage sampling unit connects with comprehensive criterion unit; Current sampling unit connects with comprehensive criterion unit; Comprehensive criterion unit identifying unit synchronous with signal connects; The synchronous identifying unit of signal connects with low frequency signal source; Low frequency signal source connects with low frequency signal exciting unit; Low frequency signal exciting unit connects with signal injection loop; Signal injection loop identifying unit synchronous with signal connects; The synchronous identifying unit of signal connects with warning route selection unit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520544387.7U CN204789874U (en) | 2015-07-27 | 2015-07-27 | Distribution network small current neutral grounding sys tem earth fault route selection device |
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| CN201520544387.7U CN204789874U (en) | 2015-07-27 | 2015-07-27 | Distribution network small current neutral grounding sys tem earth fault route selection device |
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| CN204789874U true CN204789874U (en) | 2015-11-18 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105301448A (en) * | 2015-11-19 | 2016-02-03 | 天津大学 | Time synchronization method among small-current grounding devices of coal mine system |
| CN106066444A (en) * | 2016-06-14 | 2016-11-02 | 北京鼎科远图科技有限公司 | Ground fault detection device and method based on capacitance partial pressure and big data analysis |
-
2015
- 2015-07-27 CN CN201520544387.7U patent/CN204789874U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105301448A (en) * | 2015-11-19 | 2016-02-03 | 天津大学 | Time synchronization method among small-current grounding devices of coal mine system |
| CN106066444A (en) * | 2016-06-14 | 2016-11-02 | 北京鼎科远图科技有限公司 | Ground fault detection device and method based on capacitance partial pressure and big data analysis |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 325800 Cangnan Industrial Park, Wenzhou, Zhejiang, 06 blocks through two road. Patentee after: Zhejiang Branch electronic Limited by Share Ltd Address before: 325800 Wenzhou, Zhejiang:Cangnan Industrial Park through two road 06 massif Patentee before: ZHEJIANG KE CHANG ELECTRONIC CO., LTD. |
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| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151118 Termination date: 20200727 |