CN207663964U - A kind of intelligent air switch that can detect DC earthing - Google Patents
A kind of intelligent air switch that can detect DC earthing Download PDFInfo
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- CN207663964U CN207663964U CN201721897575.3U CN201721897575U CN207663964U CN 207663964 U CN207663964 U CN 207663964U CN 201721897575 U CN201721897575 U CN 201721897575U CN 207663964 U CN207663964 U CN 207663964U
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Abstract
The utility model discloses a kind of intelligent air switches that can detect DC earthing, include the positive electrode current I of acquisition air switch1xThe first Hall sensor, acquire electric current air switch cathodal current I2xThe second Hall sensor, calculate positive electrode current I1xWith cathodal current I2xComputing element is calculated gained difference and definite value I by the computing element of differencexCarry out logic decision element, control element and the signal lamp L being connected on control element of logic comparison.The utility model can be accurate to each branch to the detection of DC earthing, have convenience, improve DC earthing detection efficiency；The problem of traditional open line method processing DC earthing, can increase uncertainty, time and effort consuming, and transforming plant primary equipment may be caused to have a power failure, and the utility model intelligent measurement has prevented hidden danger；The deferred action element of the utility model setting, the case where ensureing the reliability of detection, branch can be accurately detected；The utility model detects rapidly and efficiently, time saving and energy saving.
Description
Technical field
The utility model is related to a kind of intelligent air switches that can detect DC earthing.
Background technology
Straight-flow system provides power supply for transformer substation communication device, protective device, monitoring system, be substation secondary device and
The guarantee of power of automatic device normal operation.But in During Process of Long-term Operation can due to the change of environment, the variation of weather,
The problem of aging of cable and connector, equipment itself etc., the element insulatings for keeping certain insulation weak reduce, or even insulation is broken
It is bad, cause DC earthing.In DC earthing, it is two points ground fault to endanger larger, and two points ground fault, possible structure occur for straight-flow system
At ground short circuit, relay protection, signal, automatic device malfunction or miss operation is caused, or main fuse is caused to fuse, protected
Shield and automatic device lose power supply.
The harm of direct current two points ground fault is described in detail by taking Fig. 1 as an example：（1）Cause protection and automatic device malfunction.Such as Fig. 1
It is shown, when DC earthing is happened at A, B at 2, by electric current relay KA1, KA2 contact short circuit, and start KM, KM is closed contact
It closes and trips；A, when C two points ground faults the contacts short circuit KM and trip；A, 2 points of D, whens ground connection such as 2 points of D, F, equally can all cause to fill
Set malfunction.
（2）Cause relay protection, automatic device miss operation.Such as Fig. 1, if ground connection is happened at B, E at 2 points, 2 points of D, E or
C, 2 points of E, tripping coil and protective relay coil are grounded a short circuit and akinesia, cause switch failure.
（3）It causes short circuit that main fuse is made to fuse, protection and automatic device, control loop is made to lose power supply.Such as Fig. 1,
When earth point is happened at B, E and C, E at 2 points, when protection act, not only switch failure, and cause fuse failure, while having burning
The possibility of bad relay contact.
In view of DC earthing may caused by serious consequence just needed once DC earthing occurs in substation's normal operation
It to handle as early as possible.It is a complex problem to search DC earthing at the scene.The method for searching DC ground fault at present
Mainly have following two：
（1）Draw loop method.This is a kind of conventional method that DC ground fault is looked into electric system.So-called " retracting road ", just
It is the DC power supply for cutting off the circuit, power off time should be less than 3 seconds.It is general first from signal circuit, lighting loop, then operate back
Road, protective loop etc..This kind of method, since electrical secondary system becomes increasingly complex, most plant stand is due in construction or enlarging
The variety of problems left makes signal circuit and control loop and the protective loop stringent differentiation of neither one, and more
Some improper closed loops are also formed, has inevitably enlarged and has retracted the difficulty that earth fault is searched on road.It is connect just because of circuit
There is uncertainty in line, often during retracting road, it occur frequently that artificial trip accident, adds the big of Microcomputer Protection
Amount application, Microcomputer Protection since the operation characteristic of computer does not allow arbitrarily to power off yet, retract road may cause control loop and
Protective loop major accident occurs.
（2）DC earthing line selection apparatus monitoring method.This is a kind of device of on-line monitoring straight-flow system insulation against ground situation.
The advantages of device is to monitor on-line, reports DC system earth fault at any time, and shows that earth-return circuit is numbered.The disadvantage is that
The device can only monitor the specific earth-return circuit or branch of DC loop ground connection, when carrying several sub- branches under the branch, again
It needs to do further judgement by open line method.The limitation of its technical monitored installation number, it is difficult to which earth fault is reduced
The range small to one.And the device must carry out construction and installation, and it is very inconvenient to the transformation of old system.Such device is also universal
It is not high that there are accuracy of detection, and anti-distribution capacity interference is poor, reports more problem by mistake.
Utility model content
The purpose of this utility model is to provide a kind of intelligent air switch that is easy to operate, can detecting DC earthing.
To achieve the goals above, the technical solution that the utility model is taken is as follows：
A kind of intelligent air switch that can detect DC earthing, includes the positive electrode current I of acquisition air switch1xFirst
Hall sensor, the cathodal current I for acquiring electric current air switch2xThe second Hall sensor, calculate positive electrode current I1xWith cathode
Electric current I2xComputing element is calculated gained difference and definite value I by the computing element of differencexCarry out the logic decision member of logic comparison
Part receives the signal lamp L that logic judgment component logic compares the control element of signal and is connected on control element.
Further include that the delay being arranged between control element and signal lamp L is moved as a further improvement of the utility model,
Make element.
The deferred action element switchs for landing operation as a further improvement of the utility model,；When generation direct current
When ground connection, earth current I1x-I2xNot less than definite value IxAnd duration t up to 5s or more when, i.e. I1x-I2x≥IxAnd t >=5s
When, landing operation switch connection, signal lamp L sends out lamp and closes alarm；Work as I1x-I2x＜ IxOr when t ＜ 5s, landing operation switch does not connect
Logical, signal lamp L will not send out light warning.
Further include the low-voltage being arranged between control element and signal lamp L as a further improvement of the utility model,
Element.
The lower voltage components are ground connection AND gate circuit as a further improvement of the utility model,；
When spill current I1x-I2x and voltage-to-ground u changes simultaneously, the first situation：As earth current I1x-I2x
Not less than definite value IxAnd when voltage-to-ground u reductions, i.e. I1x-I2x≥IxAnd u<When 30V, by being grounded AND gate circuit trigger signal lamp
L, signal lamp L send out light warning；The second situation：Work as I1x-I2x＜ IxOr when u >=30V, will not trigger signal lamp L, signal lamp
L does not send out light warning.
The computing element, logic decision element and control element are integrated as a further improvement of the utility model, sets
It sets on singlechip chip plate, singlechip chip plate model MC68332ACFC20IJ66AQQFP0S21.
Compared with prior art, having the beneficial effect that acquired by the utility model：
The utility model can be accurate to each branch to the detection of DC earthing, further be looked into without using open line method
It looks for, has convenience, improve DC earthing detection efficiency；The problem of traditional open line method processing DC earthing, can increase not really
It is qualitative, time and effort consuming, and transforming plant primary equipment may be caused to have a power failure, the utility model intelligent measurement has prevented open line method
Existing hidden danger；The deferred action element of the utility model setting, ensures the reliability of detection, can be accurately detected the feelings of branch
Condition；The utility model detects rapidly and efficiently, time saving and energy saving.
Description of the drawings
Attached drawing 1 is DC system grounding schematic diagram；
Attached drawing 2 is DC earthing current direction schematic diagram；
Attached drawing 3 is that the utility model detects DC earthing schematic diagram；
Attached drawing 4 is the utility model DC earthing delayed alarm schematic diagram；
Attached drawing 5 is the utility model DC earthing voltage blocking schematic diagram.
Specific implementation mode
Further details of narration is carried out to the utility model below in conjunction with attached drawing.
As illustrated in the accompanying drawings from 1 to 3, a kind of intelligent air switch that can detect DC earthing, includes the anode of acquisition air switch
Electric current I1xThe first Hall sensor, acquire electric current air switch cathodal current I2xThe second Hall sensor, calculate just
Electrode current I1xWith cathodal current I2xComputing element is calculated gained difference and definite value I by the computing element of differencexCarry out logic comparison
Logic decision element, receive logic judgment component logic and compare the control element of signal and the letter that is connected on control element
Signal lamp L.It is straight-flow system under normal circumstances when be not grounded, due to interfered by outside and running environment influence,
Also there can be the difference stream of very little between air switch anode and cathode.And after being grounded, the difference stream between anode and cathode
Meeting bigger, in order to distinguish the bigger difference stream generated after normal interference electric current and ground connection, so needing one threshold of setting
Value IxAs comparison other, it is less than threshold value IxIt is then normal operating condition, intelligent air switch will not alert, and be more than threshold
Value IxIt is then that earth fault has occurred, intelligent air switch will alarm.In this way it is also ensured that intelligence, which is spaced apart, gives full play to it
It was found that the reliability and correctness of DC earthing.Threshold value IxNumberical range be 30-50mA.As shown in Fig. 4, this practicality is new
Type has the function of DC earthing delayed alarm original, and deferred action element is arranged between control element and signal lamp L.The delay
Action element switchs for landing operation；When DC earthing occurs, earth current I1x-I2xNot less than definite value IxAnd duration t
When up to 5s or more, i.e. I1x-I2x≥IxAnd when t >=5s, landing operation switch connection, signal lamp L sends out lamp and closes alarm；Work as I1x-
I2x＜ IxOr when t ＜ 5s, landing operation switch is disconnected, and signal lamp L will not send out light warning.As shown in Fig. 5, this practicality
It is novel to have the function of DC earthing voltage blocking, lower voltage components are set between control element and signal lamp L.The low-voltage
Element is ground connection AND gate circuit；In spill current I1x-I2xAnd voltage-to-ground u is simultaneously when changing, the first situation：Work as ground connection
Electric current I1x-I2xNot less than definite value IxAnd when voltage-to-ground u reductions, i.e. I1x-I2x≥IxAnd u<When 30V, by being grounded AND gate circuit
Trigger signal lamp L, signal lamp L send out light warning；The second situation：Work as I1x-I2x＜ IxIt, will not trigger signal or when u >=30V
Lamp L, signal lamp L do not send out light warning.The computing element, logic decision element and control element are integrally disposed in microcontroller
On chip board, singlechip chip plate model MC68332ACFC20IJ66AQQFP0S21.
The utility model can be accurate to each branch to the detection of DC earthing, further be looked into without using open line method
It looks for, has convenience, improve DC earthing detection efficiency；The problem of traditional open line method processing DC earthing, can increase not really
It is qualitative, time and effort consuming, and transforming plant primary equipment may be caused to have a power failure, the utility model intelligent measurement has prevented open line method
Existing hidden danger；The deferred action element of the utility model setting, ensures the reliability of detection, can be accurately detected the feelings of branch
Condition；The utility model detects rapidly and efficiently, time saving and energy saving.
Embodiment described above is only the preferred embodiment of the utility model, and the not feasible implementation of the utility model
It is exhaustive.For persons skilled in the art, it is made under the premise of without departing substantially from the utility model principle and spirit
Any obvious change gone out, should all be contemplated as falling within the claims of the utility model.
Claims (6)
1. a kind of intelligent air switch that can detect DC earthing, it is characterised in that：Positive electrode current including acquiring air switch
I1xThe first Hall sensor, acquire electric current air switch cathodal current I2xThe second Hall sensor, calculate anode electricity
Flow I1xWith cathodal current I2xComputing element is calculated gained difference and definite value I by the computing element of differencexCarry out patrolling for logic comparison
It collects decision element, receive the signal lamp that logic judgment component logic compares the control element of signal and is connected on control element
L。
2. a kind of intelligent air switch that can detect DC earthing according to claim 1, it is characterised in that：Further include setting
Set the deferred action element between control element and signal lamp L.
3. a kind of intelligent air switch that can detect DC earthing according to claim 2, it is characterised in that：The delay
Action element switchs for landing operation；When DC earthing occurs, earth current I1x-I2xNot less than definite value IxAnd duration t
When up to 5s or more, i.e. I1x-I2x≥IxAnd when t >=5s, landing operation switch connection, signal lamp L sends out lamp and closes alarm；Work as I1x-
I2x＜ IxOr when t ＜ 5s, landing operation switch is disconnected, and signal lamp L will not send out light warning.
4. a kind of intelligent air switch that can detect DC earthing according to claim 1, it is characterised in that：Further include setting
Set the lower voltage components between control element and signal lamp L.
5. a kind of intelligent air switch that can detect DC earthing according to claim 4, it is characterised in that：The low electricity
It is ground connection AND gate circuit to press element；In spill current I1x-I2xAnd voltage-to-ground u is simultaneously when changing, the first situation：When connecing
Earth-current I1x-I2xNot less than definite value IxAnd when voltage-to-ground u reductions, i.e. I1x-I2x≥IxAnd u<When 30V, pass through ground connection and door electricity
Road trigger signal lamp L, signal lamp L send out light warning；The second situation：Work as I1x-I2x＜ IxOr when u >=30V, letter will not be triggered
Signal lamp L, signal lamp L do not send out light warning.
6. a kind of intelligent air switch that can detect DC earthing according to claim 1, it is characterised in that：The calculating
Element, logic decision element and control element are integrally disposed on singlechip chip plate, singlechip chip plate model
MC68332ACFC20IJ66AQQFP0S21。
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| Application Number | Priority Date | Filing Date | Title |
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| CN201721897575.3U CN207663964U (en) | 2017-12-29 | 2017-12-29 | A kind of intelligent air switch that can detect DC earthing |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201721897575.3U CN207663964U (en) | 2017-12-29 | 2017-12-29 | A kind of intelligent air switch that can detect DC earthing |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108109862A (en) * | 2017-12-29 | 2018-06-01 | 国家电网公司 | A kind of intelligent air switch that can detect DC earthing |
| CN110672984A (en) * | 2019-11-22 | 2020-01-10 | 国网四川省电力公司检修公司 | Portable direct current system ground fault detection device |
| CN110672985A (en) * | 2019-11-22 | 2020-01-10 | 国网四川省电力公司检修公司 | Non-adjacent feeder line monitoring module of transformer substation and use method |
-
2017
- 2017-12-29 CN CN201721897575.3U patent/CN207663964U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108109862A (en) * | 2017-12-29 | 2018-06-01 | 国家电网公司 | A kind of intelligent air switch that can detect DC earthing |
| CN110672984A (en) * | 2019-11-22 | 2020-01-10 | 国网四川省电力公司检修公司 | Portable direct current system ground fault detection device |
| CN110672985A (en) * | 2019-11-22 | 2020-01-10 | 国网四川省电力公司检修公司 | Non-adjacent feeder line monitoring module of transformer substation and use method |
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