CN204167872U - Underground coal mine electrical network selective earth leakage protection checkout gear - Google Patents
Underground coal mine electrical network selective earth leakage protection checkout gear Download PDFInfo
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- CN204167872U CN204167872U CN201420715126.2U CN201420715126U CN204167872U CN 204167872 U CN204167872 U CN 204167872U CN 201420715126 U CN201420715126 U CN 201420715126U CN 204167872 U CN204167872 U CN 204167872U
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- 238000002955 isolation Methods 0.000 claims abstract description 10
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- 238000001514 detection method Methods 0.000 claims description 11
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Abstract
Underground coal mine electrical network selective earth leakage protection checkout gear, makes supply line pass through to realize selectively turning off the circuit that electric leakage occurs, and does not cut off whole supply network, realize the optimization of power supply.Comprise sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter, the optical coupling isolation circuit that are connected on the artificial neutral point of three-phase reactor L; Obtain end D at residual voltage and be serially connected with 50HZ band pass filter, phase shift treatment circuit and shaping isolator A; Be enclosed within zero sequence current mutual inductor CT in a triple line output after sampling resistor R2, amplifying circuit A, low pass filter through amplifying circuit B, shaping isolator B and shaping isolator A output through phase place phase with after exports, access the pulse width measurement circuit of processing unit; Another output of low pass filtered filter, through rectification circuit, linear optical coupling buffer circuit, accesses another A/D thief hatch of processing unit.
Description
Technical field
The utility model relates to a kind of underground coal mine electrical network selective earth leakage protection checkout gear.
Background technology
Underground coal mine bad environments, dust is large, and humidity is high, and containing flammable explosive gas, proposes very harsh requirement to the power supply safety of underground low-tension network.Because electric leakage accounts for about 70% of the total failare of underground power supply system, not only cause the person to get an electric shock, and gas, coal-dust explosion may be caused, even make electric detonator ahead detonate.The widely used earth leakage protective device of current China underground electric network adopts single principle to form mostly, there is action non-selectivity, or easily produces misoperation, and what have needs enough zero-sequence currents and just can make many defects such as protection act.As realized earth leakage protective device, action non-selectivity by detecting additional DC source; Realize earth leakage protective device by detecting residual voltage size, action resistance value is unstable, when electrical network three phase isolated resistance symmetry declines, relay fail, and when single-phase earth leakage action non-selectivity; Realize earth leakage protective device by detecting zero-sequence current size, although action is selective when single-phase earth leakage, action resistance value is unstable, when grid branch is less, easily produces misoperation.; Earth leakage protective device is realized by measuring zero-sequence current direction, zero-sequence current size and Orientation different differentiation fault branch and the non-faulting branch road of fault branch and non-faulting branch road can be utilized, reach the object of selective protection, but it is unstable also to there is action resistance value, and needs enough zero-sequence currents and just can make protection act; By the earth leakage protective device that homopolar power real component method realizes; the zero sequence active power direction of failure judgement, non-faulting branch road and size is utilized to realize route selection of leaking electricity; but when electric power system structure is very little, zero-sequence current is also very little, will cause the decline of protective device sensitivity.
The utility model proposes a kind of selective earth leakage protection checkout gear; be exactly when electrical network generation leak current fault; selectively can judge fault branch; concurrent signal or the disengagement failure branch road power supply of being out of order; it can ensure only to excise leak current fault branch road, reduces fault outage scope, is convenient to find leak current fault; shorten electric leakage interruption duration, improve the reliability of power supply.Specific implementation carries out examination and analysb by the zero-sequence current of the circuit that leaks electricity, counter-measure is studied to the analysis of its characteristic, and transmitted the electric leakage detection of zero-sequence current, process and amplifying by chip microcontroller, and executive termination order makes electric leakage portion ends power.。
Utility model content
The utility model object is to provide and a kind ofly detects the underground coal mine electrical network selective earth leakage protection checkout gear combined based on additional direct current source and drain electro-detection and zero sequence power direction type selective leakage; supply line is made to pass through to realize selectively turning off the circuit that electric leakage occurs; and do not cut off whole supply network, realize the optimization of power supply.
Technical solution of the present utility model is:
A kind of underground coal mine grid power leakage protection checkout gear, its special character is: comprise sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter, the optical coupling isolation circuit that are connected on the artificial neutral point of three-phase reactor L, described sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter and optical coupling isolation circuit additional DC source method detection of electrical leakage unit in series, exports zero-sequence voltage samples signal and accesses the A/D thief hatch of processing unit; Sampling resistor R1 on the artificial neutral point being connected on described three-phase reactor L and the node of earth resistance R3 are connected to earth resistance R4 by electric capacity C1 and draw residual voltage and obtain end D, obtain end D be serially connected with 50HZ band pass filter, phase shift treatment circuit and shaping isolator A at residual voltage; Be enclosed within zero sequence current mutual inductor CT in a triple line output after being connected on sampling resistor R2, the amplifying circuit A of zero sequence current mutual inductor CT secondary side, low pass filter through amplifying circuit B, shaping isolator B and shaping isolator A output through phase place phase with after exports, access the pulse width measurement circuit of processing unit; Another output of low pass filtered filter, through rectification circuit, linear optical coupling buffer circuit, accesses another A/D thief hatch of processing unit; Described zero sequence current mutual inductor is current transformer with single-turn cored structure.
The beneficial effects of the utility model are: the earth leakage protective of master switch branch road is based on additional direct current source and drain electro-detection principle, and the earth leakage protective of switch-dividing branch road is based on zero sequence power direction type detection of electrical leakage principle.The earth leakage protective device that this selective earth leakage protection combines makes supply line realize selectively turning off the circuit that electric leakage occurs by detecting zero sequence current signal, and does not cut off whole supply network, realizes the optimization of power supply.This earth leakage protective checkout gear; there is respond and good selectivity power down function fast; effectively fault branch can be excised when breaking down; ensure non-leak current fault branch road normal power supply; reduce the power failure range caused because of fault; reduce the impact between each power load; greatly improve the safety and reliability of underground power supply system; both personal electric shock injures and deaths and leakage current actuation gas coal dust had effectively been prevented; economic loss can be dropped to again minimum, to downhole safety and production, there is higher using value and far-reaching influence.
Accompanying drawing explanation
Fig. 1 is this underground coal mine grid power leakage protection structure of the detecting device figure.
Embodiment
As shown in Figure 1, a kind of underground coal mine grid power leakage protection checkout gear, comprise sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter, the optical coupling isolation circuit that are connected on the artificial neutral point of three-phase reactor L, described 50Hz non active band exclusion filter, drive circuit, low pass filter and optical coupling isolation circuit additional DC source method detection of electrical leakage unit in series, exports zero-sequence voltage samples signal and accesses the A/D thief hatch of processing unit; Sampling resistor R1 on the artificial neutral point being connected on described three-phase reactor L and the node of earth resistance R3 are connected to earth resistance R4 by electric capacity C1 and draw residual voltage and obtain end D, obtain end D be serially connected with 50HZ band pass filter, phase shift treatment circuit and shaping isolator A at residual voltage; Be enclosed within zero sequence current mutual inductor CT in a triple line output after being connected on sampling resistor R2, the amplifying circuit A of zero sequence current mutual inductor CT secondary side, low pass filter through amplifying circuit B, square wave reshaper B and shaping isolator A output through phase place phase with after exports, access the pulse width measurement circuit of processing unit; Another output of low pass filtered filter, through rectification circuit, linear optical coupling buffer circuit, accesses another A/D thief hatch of processing unit; Described zero sequence current mutual inductor is current transformer with single-turn cored structure.
Described 50Hz non active band exclusion filter adopts double T filter, and direct current can be allowed to pass through, simultaneously again by the alternating voltage interference attenuation of fundamental frequency to minimum.
Described low pass filter is multiple feedback type low pass filter, electrical network is produced clutter component by equipment interference such as frequency converters possibly in actual motion, also the reliability of leakage detection apparatus leak detection will be affected, multiple feedback type low pass filter is added in sampling resistor R2 rear class, direct current can be reached through, the effect of elimination clutter component.
In order to ensure the accuracy of measurement result, circuit-under-test and test circuit are isolated on electrically, the electric leakage signal is after filtering coupled to external processing unit by linear optical coupling buffer circuit.Adopt HCRN200 photoelectrical coupler in the present embodiment, it is a kind of high linearity analog photoelectricity coupler, has the very high linearity and sensitivity, can transmit voltage signal accurately in detection system.
Residual voltage is obtained by sampling resistor R1 on the artificial neutral point of three-phase reactor L, after algorithm, then through phase shift, shaping, light-coupled isolation and zero sequence current signal phase and after send into the pulse width measurement circuit of processing unit.Zero-sequence current is obtained by sampling resistor R2 by the additional dc power supply method detection of electrical leakage information of being inserted in zero sequence current mutual inductor sampling in triple line, and the voltage signal of acquisition is divided into two-way after amplification, filtering conditioning; Lead up to amplification, shaping, isolation and residual voltage pulse signal through phase place phase with after send into the pulse width measurement circuit of processing unit; Leading up to rectification, linear optical coupling isolation in addition sends into another A/D Sampling Interface of processing unit.
Zero sequence current mutual inductor is current transformer with single-turn cored structure.When measuring zero-sequence current, allow three-phase conducting wire together through zero sequence current mutual inductor, utilize zero sequence current mutual inductor to detect three-phase current phasor and.Under circuit and the normal situation of electric equipment, the vector of each phase current equals zero, and therefore when electrical network normally runs, the secondary side winding no signal of zero sequence current mutual inductor exports.When there is leak current fault, the vector of each phase current is non-vanishing, and fault current makes to produce magnetic flux in the annular core of zero sequence current mutual inductor, and the secondary side of zero sequence current mutual inductor just can induce zero-sequence current.
This device improves and detects based on the earth leakage protective in zero-sequence current direction merely, for the earth-free feature of transformer neutral point, adopts the electric leakage unit based on additional direct current source protection principle at the main branch road of electrical network; And adopting the electric leakage unit based on zero sequence power direction protection philosophy in the branch path of electrical network, selective earth leakage protection is realized by processing unit.Also solve because field condition is different and cause earth leakage protective device cannot the problem of action.
Claims (1)
1. a underground coal mine electrical network selective earth leakage protection checkout gear, it is characterized in that: comprise sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter, the optical coupling isolation circuit that are connected on the artificial neutral point of three-phase reactor L, described sampling resistor R1,50Hz non active band exclusion filter, drive circuit, low pass filter and optical coupling isolation circuit additional DC source method detection of electrical leakage unit in series, exports zero-sequence voltage samples signal and accesses the A/D thief hatch of processing unit; Sampling resistor R1 on the artificial neutral point being connected on described three-phase reactor L and the node of earth resistance R3 are connected to earth resistance R4 by electric capacity C1 and draw residual voltage and obtain end D, obtain end D be serially connected with 50HZ band pass filter, phase shift treatment circuit and shaping isolator A at residual voltage; Be enclosed within zero sequence current mutual inductor CT in a triple line output after being connected on sampling resistor R2, the amplifying circuit A of zero sequence current mutual inductor CT secondary side, low pass filter through amplifying circuit B, shaping isolator B and shaping isolator A output through phase place phase with after exports, access the pulse width measurement circuit of processing unit; Another output of low pass filtered filter, through rectification circuit, linear optical coupling buffer circuit, accesses another A/D thief hatch of processing unit; Described zero sequence current mutual inductor is current transformer with single-turn cored structure.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201420715126.2U CN204167872U (en) | 2014-11-25 | 2014-11-25 | Underground coal mine electrical network selective earth leakage protection checkout gear |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201420715126.2U CN204167872U (en) | 2014-11-25 | 2014-11-25 | Underground coal mine electrical network selective earth leakage protection checkout gear |
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| CN204167872U true CN204167872U (en) | 2015-02-18 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104753026A (en) * | 2015-03-18 | 2015-07-01 | 胡妍 | Electricity leakage protecting system for preventing symmetric electricity leakage |
| CN104934925A (en) * | 2015-06-01 | 2015-09-23 | 沈阳基辅新能源科技发展有限公司 | Selective electric leakage protection system for low-voltage power grid of underground coal mine |
| CN107359587A (en) * | 2017-08-04 | 2017-11-17 | 江苏师范大学 | The non-reliability earthed system self-adaption route selection leakage protection system of three-phase and method |
| CN111465863A (en) * | 2017-12-12 | 2020-07-28 | Ad电力株式会社 | Three-phase four-wire type zero-phase inverter device for live insulation resistance measurement and live insulation resistance measurement device |
-
2014
- 2014-11-25 CN CN201420715126.2U patent/CN204167872U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104753026A (en) * | 2015-03-18 | 2015-07-01 | 胡妍 | Electricity leakage protecting system for preventing symmetric electricity leakage |
| CN104934925A (en) * | 2015-06-01 | 2015-09-23 | 沈阳基辅新能源科技发展有限公司 | Selective electric leakage protection system for low-voltage power grid of underground coal mine |
| CN107359587A (en) * | 2017-08-04 | 2017-11-17 | 江苏师范大学 | The non-reliability earthed system self-adaption route selection leakage protection system of three-phase and method |
| CN107359587B (en) * | 2017-08-04 | 2019-04-30 | 江苏师范大学 | Adaptive line selection leakage protection system and method for three-phase unreliable grounding system |
| CN111465863A (en) * | 2017-12-12 | 2020-07-28 | Ad电力株式会社 | Three-phase four-wire type zero-phase inverter device for live insulation resistance measurement and live insulation resistance measurement device |
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Granted publication date: 20150218 Termination date: 20151125 |