CN104779576B - Selective leakage protection method and system by composite signal method - Google Patents
Selective leakage protection method and system by composite signal method Download PDFInfo
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- CN104779576B CN104779576B CN201510188901.2A CN201510188901A CN104779576B CN 104779576 B CN104779576 B CN 104779576B CN 201510188901 A CN201510188901 A CN 201510188901A CN 104779576 B CN104779576 B CN 104779576B
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Abstract
The invention discloses a selective leakage protection method and a system by a composite signal method, wherein the method comprises the steps of injecting an additional detection direct current signal while a main line is powered on with alternating current, and a low-voltage protector of a main switch always detects the insulation condition of the whole power supply line through the additional detection direct current signal; when the low-voltage protector of the main switch detects that insulation is reduced to be lower than a threshold value, the low-voltage protector of the main switch injects additional alternating current generated by an alternating current generator into a power supply line from a main line through a signal injection control component, wherein the phase current direction of the additional alternating current is different from the phase voltage of the power supply alternating current; when the power direction type leakage protector in the branch switch of one branch line detects the zero sequence current of the additional alternating current, the fact that the current leakage exists in the branch line is judged, and the branch line is immediately cut off. The invention can ensure that the branch switch correctly selects the grounding leakage circuit to achieve the aim of selective leakage protection.
Description
Technical field
The invention belongs to colliery power supply technique field, more particularly to a kind of selective earth leakage protection method and system.
Background technology
In underground coal mine low-voltage explosion-proof feeding switch, it is desirable to selective earth leakage protection must be installed, it is therefore an objective to when one
When branch road leaks electricity, the selective leakage of the feeding switch (hereinafter referred to as switch-dividing) of the branch road starts, the tripping branch road, and
Electric power system is set to recover normal, it is ensured that the safety of electric power system.However, often because the selective earth leakage protection of switch-dividing does not have
, there is feeding switch tripping or malfunction, installed in feeding switch (hereinafter referred to as master switch) malfunction of wire inlet loop etc. in selectivity
Situation, the normal production in colliery is had a strong impact on.
The earth leakage protective of underground low voltage feeder system is realized at present：
Direct current signal is added in master switch, master switch measures the caused insulation against ground in systems of additional direct current signal always
Resistance, when the resistance is less than a certain resistance value, the earth leakage protective start-up study tripping operation of master switch, wait switch-dividing cut-out ground connection
Duplexure, make insulation recovery.If branch switch can not selected not cutting off and leaked electricity in master switch delay time
Duplexure, total switch-dividing just trips, and cuts off the power supply of whole low-pressure system.
The selective earth leakage protection of switch-dividing uses zero sequence power direction earth leakage protective.Its principle is leaked in system
When electric, residual voltage and zero-sequence current will be produced, in principle, bus, non-electric leakage are pointed in the zero-sequence current direction of loop of electric leakage
Circuit is pointed in power loop direction, judges whether oneself is loop of electric leakage with this, reaches the purpose of selective earth leakage protection.It is real
On border, underground coal mine low-pressure system is isolated neutral system, and the leakage current of low-pressure system is exactly all cables and set
Standby capacitance current over the ground.Because low-pressure system cable is thinner, cable length is shorter, and the direct-to-ground capacitance of whole low-pressure system is very
Small, particularly at single phase to ground via resistance (namely insulation reduces), capacity current is smaller, and switch-dividing is had no idea correctly fixed
Amount determines the direction of zero-sequence current, thus, often there is malfunction or tripping, also result in the malfunction of master switch.
The content of the invention
The technical problems to be solved by the invention are to provide a kind of composite signal method selective earth leakage protection method, this method
Enable to switch-dividing correctly to select earth leakage circuit, reach the purpose of selective earth leakage protection, to overcome existing skill
The defects of art is present.
In order to solve the above technical problems, the present invention adopts the following technical scheme that：
A kind of composite signal method selective earth leakage protection method, using in the supply line in colliery, the supply line wraps
The multiple separated time roads for including main line and being connected with main line, master switch is provided with main line, is provided with separated time road and separates
Close, there is low voltage protection device for electrophonic in master switch, there is power direction type earth leakage protective device in switch-dividing, it is characterised in that：In main line
Additional detected direct current signal is injected in road while leading to supply and AC electricity, and the low voltage protection device for electrophonic of master switch passes through the additional detected direct current
Signal detects the insulation status of whole supply line always；When the low voltage protection device for electrophonic of the master switch, to detect that insulation is reduced to low
When threshold value, the low voltage protection device for electrophonic of the master switch will be added by control signal injection device caused by ac generator to be handed over
Flow electric current to inject in supply line from main line, each phase current direction of the additional alternating current is different from the supply and AC
Each phase voltage of electricity；When the power direction type earth leakage protective device in the switch-dividing of a separated time road therein detected it is described attached
When adding the zero-sequence current of alternating current, then judge that this separated time road has electric leakage, cut off this separated time road immediately.
The additional alternating current is industrial frequency AC electric current.
The industrial frequency AC electric current is only injected into two nonisulated reduction phases of supply line.
The industrial-frequency alternating current stream distinguishes two nonisulated 90 ° of two-phase voltages for reducing phase of advanced supply line.
In addition, the present invention also provides a kind of composite signal method selective earth leakage protection system, including located at the total of main line
Switch and the switch-dividing located at separated time road, there is low voltage protection device for electrophonic in the master switch, there is power direction in the switch-dividing
Type earth leakage protective device, it is characterised in that：Additional D.C. resistance detection part, signal injection control unit are additionally provided with the master switch
Part, AC signal generator, the additional D.C. resistance detection part is arranged on main line and is connected with low voltage protection device for electrophonic, low
Pressure protector is connected to signal injection control unit part, AC signal generator one end ground connection, and the other end is also connected to the letter
Number injection control unit part, the signal injection control unit part are connected to main line.
Using above-mentioned technical proposal, the present invention adds an additional exchange letter on the basis of master switch adds direct current
Number, assist switch-dividing correctly to select ground path with this, reach the purpose of selective earth leakage protection, overcome existing
There is the defects of switch-dividing malfunction or tripping existing for technology and master switch malfunction.
Brief description of the drawings
The present invention is described in detail with reference to the accompanying drawings and detailed description：
Fig. 1 is the structural representation of supply line；
Fig. 2 is the structural representation of master switch.
Embodiment
As shown in figure 1, in the supply line in colliery, including main line and a plurality of separated time road being connected with main line, main line
Master switch 100 is provided with road, is provided with switch-dividing 200 in separated time road.There is power direction type earth leakage protective in switch-dividing 200
Device.
As shown in Fig. 2 master switch 100 includes additional D.C. resistance detection part 101, low voltage protection device for electrophonic 102, signal injection
Control unit 103, AC signal generator 104.Wherein, add D.C. resistance detection part 101 be arranged on main line and with
Low voltage protection device for electrophonic 101 connects, and low voltage protection device for electrophonic 102 is connected to signal injection control unit part 103.AC signal generator 104
Ground connection, its three-phase export the AC signal input for being wired to signal injection control unit part 103, AC signal generator
104 three-phase output electric wire is connected respectively on the three-phase wire of main line again.
The working method of the composite signal method selective earth leakage protection system is：
Additional detected direct current signal is injected while main line leads to supply and AC electricity, the low voltage protection device for electrophonic of master switch passes through
The additional detected direct current signal detects the insulation status of whole supply line always；When the low voltage protection device for electrophonic of master switch detects absolutely
When edge falls below threshold value, low voltage protection device for electrophonic control signal injection device (upper seamount source company production, the model of master switch
For SY3606) two nonisulated reduction phases of the alternating current from main line injection supply line will be added caused by ac generator
In, it is industrial frequency AC electric current to add alternating current.Each phase current direction of additional alternating current is different from supply and AC electricity
Each phase voltage, the industrial-frequency alternating current stream distinguishes two nonisulated 90 ° of two-phase voltages for reducing phases of advanced supply line.When wherein
A separated time road switch-dividing in power direction type earth leakage protective device detect the zero-sequence current of the additional alternating current
During more than threshold value, then judge that this separated time road has leak current fault, cut off this separated time road immediately.
Pending fault eliminates, after insulation recovery, master switch revocation AC signal injection.
The present invention adds an additional AC signal on the basis of master switch adds direct current, separated to assist with this
Pass can correctly select ground path, reach the purpose of selective earth leakage protection, overcome and separated existing for prior art
The defects of closing malfunction or tripping and master switch malfunction.
It is described above, only it is presently preferred embodiments of the present invention, any formal limitation, Ren Hesuo not is made to the present invention
Have usually intellectual in category technical field, if not departing from scope of the claims proposed by the invention, utilize
The local equivalent embodiment for changing or modifying made by disclosed technology contents, and without departing from the skill of the present invention
Art feature, in the range of still belonging to the technology of the present invention feature.
Claims (3)
1. a kind of composite signal method selective earth leakage protection method, using in the supply line in colliery, the supply line includes
Main line and the multiple separated time road being connected with main line, master switch is provided with main line, is provided with switch-dividing in separated time road,
There is low voltage protection device for electrophonic in master switch, there is power direction type earth leakage protective device in switch-dividing, it is characterised in that：Lead in main line
Additional detected direct current signal is injected while supply and AC electricity, the low voltage protection device for electrophonic of master switch passes through the additional detected direct current signal
The insulation status of whole supply line is detected always；When the low voltage protection device for electrophonic of the master switch detects that insulation falls below door
During threshold value, the low voltage protection device for electrophonic control signal injection control unit part of the master switch will add alternating current caused by ac generator
Stream is injected in supply line from main line, and the additional alternating current is industrial frequency AC electric current；The additional alternating current it is each
Phase current direction is different from each phase voltage of supply and AC electricity；Power side in the switch-dividing of a separated time road therein
When detecting the zero-sequence current of the additional alternating current to type earth leakage protective device, then judge that this separated time road has electric leakage,
This separated time road is cut off immediately.
2. composite signal method selective earth leakage protection method according to claim 1, it is characterised in that：The industrial frequency AC
Electric current is only injected into two nonisulated reduction phases of supply line.
3. composite signal method selective earth leakage protection method according to claim 2, it is characterised in that：The industrial frequency AC
Electric current distinguishes two nonisulated 90 ° of two-phase voltages for reducing phase of advanced supply line.
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| CN201510188901.2A CN104779576B (en) | 2015-04-20 | 2015-04-20 | Selective leakage protection method and system by composite signal method |
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| CN201510188901.2A CN104779576B (en) | 2015-04-20 | 2015-04-20 | Selective leakage protection method and system by composite signal method |
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| CN104779576B true CN104779576B (en) | 2017-12-22 |
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| FR3071351B1 (en) * | 2017-09-18 | 2019-08-30 | Airbus Operations (S.A.S.) | ELECTRICAL CONNECTION COMPRISING AN ELECTRICAL PROTECTION SYSTEM |
| KR102083600B1 (en) * | 2018-11-19 | 2020-03-02 | 엘에스산전 주식회사 | Elcb(earth leakage circuit breaker) and control method for the elcb |
| CN112653075A (en) * | 2020-12-15 | 2021-04-13 | 刘景福 | Shunt leakage detection system and implementation method thereof |
| CN115951114B (en) * | 2023-01-17 | 2023-06-23 | 上海山源电子科技股份有限公司 | Current signal identification method in power supply monitoring system |
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| CN101382577B (en) * | 2008-10-24 | 2010-12-01 | 华北电力大学 | Single-phase ground fault location device for distribution network |
| CN101562322B (en) * | 2009-03-24 | 2010-06-23 | 煤炭科学研究总院沈阳研究院 | Network power supply graded latch-selective power-off control system under coal mine well |
| CN102035172A (en) * | 2010-12-21 | 2011-04-27 | 山西晋城无烟煤矿业集团有限责任公司 | Injection leakage protection method |
| CN203289073U (en) * | 2013-06-24 | 2013-11-13 | 上海山源电子电气科技发展有限公司 | Electric leakage protection system for mine power distribution network |
| CN103311883A (en) * | 2013-06-24 | 2013-09-18 | 上海山源电子电气科技发展有限公司 | Leakage protection system and method for mine power distribution network |
| CN203445594U (en) * | 2013-09-06 | 2014-02-19 | 天津华宁电子有限公司 | Novel explosion-proof type low-voltage selective electric leakage protector used for mining |
| CN204517354U (en) * | 2015-04-20 | 2015-07-29 | 上海山源电子科技股份有限公司 | Selective leakage protection system by composite signal method |
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Address after: Room 209, 2nd Floor, Building 3, No. 588 Caolong Road, Songjiang District, Shanghai, 2016 Patentee after: Shanghai Sany Electronic Technology Co.,Ltd. Country or region after: China Address before: 201612 room 505, building 23, No. 518, Xinzhuan Road, Songjiang high tech park, Caohejing Development Zone, Songjiang District, Shanghai Patentee before: Shanghai Sany Electronic Technology Co.,Ltd. Country or region before: China |
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