CN201887537U

CN201887537U - Arc extinguishing cabinet

Info

Publication number: CN201887537U
Application number: CN2010206204781U
Authority: CN
Inventors: 方彧
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-24
Filing date: 2010-11-24
Publication date: 2011-06-29
Anticipated expiration: 2020-11-24

Abstract

The utility model relates to an arc extinguishing cabinet, which comprises a microcomputer controller. A chip of a single chip microcomputer is arranged in microcomputer controller; an input end of the microcomputer controller is connected with an outlet end of a voltage transformer; an output end of the single chip microcomputer is connected with a contact of a high-voltage vacuum contactor; an outlet end of the high-voltage vacuum contactor is grounded by the aid of a reactor; inlet ends of the voltage transformer and the high-voltage vacuum contactor are connected with a three-phase power line; and the input end of the microcomputer controller receives low-voltage signals transmitted by the voltage transformer and outputs control signals to the high-voltage vacuum contactor. The arc extinguishing cabinet distinguishes fault properties by the aid of the microcomputer controller and gives instructions to ground and transfer a fault phase, and enables current flowing through a fault point to cross zero by the aid of the reactor, thereby achieving the purposes of extinguishing arc and protecting a system and electric equipment.

Description

A kind of arc extinction cabinet

Technical field

The utility model relates to the electric arc cancellation element in the electric power system, especially a kind of arc extinction cabinet.

Background technology

Both at home and abroad to the supply power mode of 3～35KV medium voltage network, adopt neutral point mostly at present through low resistance grounding mode and neutral by arc extinction coil grounding mode.When resistive ground, make the fault point produce certain voltage hazardous area, in case people or livestock are strayed into this voltage hazardous area, will cause unexpected injury, in addition, be struck by lightning if any continuity, then trip phenomenon can occur, cause the power supply of electric power system unreliability, flowing water operation enterprise is badly damaged; At the arc grounding phenomenon, generally adopt at present the mode of grounding through arc, but the extensive use in electric power system along with development of science and technology and electronic technology, bring serious challenge for traditional extinguishing arc mode, its reason is: the grounding through arc mode is easy to generate series resonance, and cause resonance overvoltage and illusory grounding phenomenon, amplified the transformer high-voltage side to low-pressure side mutual inductance transmission overvoltage phenomenon, make a lot of apparatus insulated major tests that face, cause little electric current line selection apparatus route selection difficulty.

At present, arc extinction cabinet in the internal configurations configuration aspects only with the direct ground connection of the earth terminal of high-pressure vacuum contactor, ground connection is shifted only according to realizing less than resistance under the cabinet of fault point resistance in the fault point, but resistance can not accomplish that trend is zero under the cabinet, and the capacity current that also just can not fully the fault point be flow through shifts, therefore, in the prior art, because remaining electric arc, heat still might be gathered in the fault point, and hidden danger is existed.

The utility model content

The purpose of this utility model is in order to provide a kind of current in the fault point that makes to become zero or the arc extinction cabinet of zero passage.

For achieving the above object, a kind of arc extinction cabinet that the utility model provides, be provided with the microcomputerized controller of singlechip chip in comprising, the input of microcomputerized controller links to each other with the leading-out terminal of voltage transformer, the output of microcomputerized controller links to each other with the contact of high-pressure vacuum contactor, the leading-out terminal of high-pressure vacuum contactor is by reactor L ground connection, voltage transformer, the inlet wire termination three-phase power line of high-pressure vacuum contactor, the input of microcomputerized controller receives the low voltage signal that voltage transformer sends, output control signals to high-pressure vacuum contactor, described high-pressure vacuum contactor comprises three single-phase contactors, the contact of three single-phase contactors links to each other with the output of microcomputerized controller respectively, passes through reactor L ground connection after the leading-out terminal parallel connection of three single-phase contactors.

The utility model is distinguished the fault attribute of fault phase by microcomputerized controller, and sends instruction fault phase ground connection is shifted, and utilizes reactor to make to flow through the electric current of fault point to become zero or zero passage, to reach the purpose of extinguish arcs, protection system and power consumption equipment.

Description of drawings

Fig. 1 is a systematic schematic diagram of the present utility model;

Fig. 2 is a structure chart of the present utility model;

Fig. 3 is the fundamental diagram that the arc extinction cabinet of reactor is not installed;

Fig. 4 is the equivalent circuit diagram of Fig. 3;

Fig. 5 is the fundamental diagram that the arc extinction cabinet of reactor is installed;

Fig. 6 is the equivalent circuit diagram of Fig. 5.

Embodiment

A kind of arc extinction cabinet, be provided with the microcomputerized controller 10 of singlechip chip in comprising, the input of microcomputerized controller 10 links to each other with the leading-out terminal of voltage transformer 20, the end of incoming cables of voltage transformer 20 links to each other with three high-tension fuses 30 respectively, the earth terminal ground connection of voltage transformer 20, three high-tension fuses 30 connect three-phase power line by high voltage isolator K1, K2, K3 respectively; High-pressure vacuum contactor 40 comprises three single-phase contactors, and the contact of three single-phase contactors links to each other with the output of microcomputerized controller 10 respectively, passes through reactor L ground connection after the leading-out terminal parallel connection of three single-phase contactors; The three pairs of high-voltage and current-limitation fuses 50, high energy absorber 60 are in parallel in twos, and the end after the parallel connection links to each other with the end of incoming cables of three single-phase contactors respectively, the other end after the parallel connection connects three-phase power line by high voltage isolator K1, K2, K3 respectively, the heat that produces when as shown in Figure 1, high energy absorber 60 is used to absorb high-voltage and current-limitation fuse 50 fusing.

In conjunction with Fig. 1,2; the end of first, second and third zinc oxide valve plate R1, R2, R3 connects three-phase power line by three high voltage isolator K1, K2, K3 respectively; by the 4th zinc oxide valve plate R4 ground connection, first, second, third and fourth zinc oxide valve plate R1, R2, R3, R4 form three phase combined over-voltage protector 80 after the other end parallel connection of first, second and third zinc oxide valve plate R1, R2, R3.

In conjunction with Fig. 2, be provided with microcomputerized controller 10 in the housing 90, three-phase power line connects the end of incoming cables of high voltage isolator K through wall bushing 70, the leading-out terminal of high voltage isolator K divide three the tunnel respectively with high energy absorber 60, the end of incoming cables of high-voltage and current-limitation fuse 50 and high-tension fuse 30 links to each other, connect the end of incoming cables of high-pressure vacuum contactor 40 after high energy absorber 60 and high-voltage and current-limitation fuse 50 are in parallel, high-pressure vacuum contactor 40 adopts three single-phase contactors, connect the end of incoming cables of reactor L after the leading-out terminal parallel connection of three single-phase contactors, the end of incoming cables of the outlet termination reactor L of high-pressure vacuum contactor 40, the leading-out terminal ground connection of reactor L, the leading-out terminal of high-tension fuse 30 is connected with the end of incoming cables of voltage transformer 20, the leading-out terminal ground connection of voltage transformer 20.

Also be provided with three phase combined over-voltage protector 80 in the described housing 90, its end of incoming cables links to each other with the leading-out terminal of high voltage isolator K, its leading-out terminal ground connection.Three phase combined over-voltage protector 80 is used to protect power consumption equipment.

The striker mechanism 51 of described high-voltage and current-limitation fuse 50 is made by insulating material, and the top of striker mechanism 51 is provided with three sensitive switches, and three sensitive switches are overlapped on the striker 511 by insulating rod respectively.When high-voltage and current-limitation fuse 50 fusing, insulating rod is gone up on striker 511 tops, drives the sensitive switch action, and sends the fusing signal, and the low voltage signal that microcomputerized controller 10 sends according to voltage transformer 20 is monitored the situation of operation of power networks in real time.Variation according to three-phase voltage and open delta voltage; if single phase ground fault has taken place in system; microcomputerized controller 10 is at first distinguished fault attribute; and send command adapted thereto; if microcomputerized controller 10 is by distinguishing that the intermittent arc grounding fault has taken place A mutually in the system of drawing; microcomputerized controller 10 sends action command so; order A phase high-pressure vacuum contactor 40 closures make fault that the ground connection transfer action take place mutually, the effect of performance reactor L; make the current over-zero that flows through the fault point; extinguish arcs, thus reach the purpose of protection system and power consumption equipment, after fault is eliminated; microcomputerized controller 10 resets, and continues the situation of monitoring operation of power networks in real time.

Below in conjunction with Fig. 3,4,5,6, the operation principle of reactor L in the utility model is further described:

In conjunction with Fig. 3, in being installed, arc extinction cabinet and cabinet do not install in the neutral point insulation electric power system of reactor L, if single-phase earthing has taken place mutually for certain, under the effect of cabinet inner control mechanism, the fault of vacuum contactor 40 in the cabinet is dropped into mutually, with the earth current transfer ground connection of fault point.Its extinguishing arc ability can only be by means of the advantage of earth resistance under the cabinet less than the fault point, play a good shunting action, although ground connection is handled through artificial under the cabinet, fault point earth resistance than random ground connection is little a lot, earth resistance is zero under the cabinet but still can't make, can not hundred-percent short circuit fault point, the fault point just still stream relatively capacitance current is arranged.Rephrase the statement:

∵R1＞＞R2 ∴I2＞＞I1

∵R2≠0 ∴I1≠0

So just may make electric arc remaining or make the fault point still gather heat, cause hidden danger to continue to enlarge.In Fig. 3, I _CABe A capacitance current relatively, I _CBBe B capacitance current relatively, R1 is the natural grounding resistance of branch point, and R2 is an artificial earth resistance under the cabinet, and I1 is the short dot branch current of flowing through, and I2 is the arc extinction cabinet branch current of flowing through.

In conjunction with Fig. 4, series connection inserts the reactor L with certain inductance value in the down conductor of arc extinction cabinet, when single-phase earthing, the arc extinction cabinet that promptly ought be connected to reactor L is connected moment with fault phase and ground violent, under the inductance effect of reactor L, of short duration being obstructed of electric current initial value by arc extinction cabinet is close to zero, but just has one to shove by reactor L after moment.Under this effect of shoving,, I2 is uprushed just like there being a forward electromotive force to be applied in the arc extinction cabinet branch road.For the D point, according to Kirchhoff's first law as can be known, I1 must have an anticlimax.

In addition, the single-phase short circuit current to earth after the arc extinction cabinet input generally is not easy to remain stable, and its amplitude often has the fluctuation of improper alternation.As long as when its electric current become little in, inductive nature decision does not allow electric current to suddenly change within it, so reactor L just stops electric current to diminish, this just means, the reactor L of this moment is at parallel branch---fault point branch road contention electric current with it.

As seen, change because system is three-phase sine-wave, single phase ground fault point electric current does not have the natural zero-crossing point, under the effect of the arc extinction cabinet that reactor L is not installed, though current in the fault point greatly reduces, can not turn to null value.Have only after the arc extinction cabinet that installs reactor L additional drops into, just have the chance of zero or zero passage,, and then make arc extinction cabinet intelligent more promptly without artificial just blow-out voluntarily of processing, recovery insulation to current in the fault point.

In sum, core of the present utility model is reactor L is installed in arc extinction cabinet, makes the current over-zero that flows through the fault point, to reach extinguish arcs, the purpose of protection system and power consumption equipment.

Claims

1. arc extinction cabinet, it is characterized in that: the microcomputerized controller (10) that is provided with singlechip chip in comprising, the input of microcomputerized controller (10) links to each other with the leading-out terminal of voltage transformer (20), the output of microcomputerized controller (10) links to each other with the contact of high-pressure vacuum contactor (40), the leading-out terminal of high-pressure vacuum contactor (40) is by reactor L ground connection, voltage transformer (20), the inlet wire termination three-phase power line of high-pressure vacuum contactor (40), the input of microcomputerized controller (10) receives the low voltage signal that voltage transformer (20) sends, output control signals to high-pressure vacuum contactor (40), described high-pressure vacuum contactor (40) comprises three single-phase contactors, the contact of three single-phase contactors links to each other with the output of microcomputerized controller (10) respectively, passes through reactor L ground connection after the leading-out terminal parallel connection of three single-phase contactors.

2. arc extinction cabinet according to claim 1, it is characterized in that: the end of incoming cables of described voltage transformer (20) links to each other with three high-tension fuses (30) respectively, and three high-tension fuses (30) connect three-phase power line by high voltage isolator K1, K2, K3 respectively.

3. arc extinction cabinet according to claim 1, it is characterized in that: the end of first, second and third zinc oxide valve plate R1, R2, R3 connects three-phase power line by high voltage isolator K1, K2, K3 respectively, passes through the 4th zinc oxide valve plate R4 ground connection after the other end parallel connection of first, second and third zinc oxide valve plate R1, R2, R3.

4. arc extinction cabinet according to claim 1, it is characterized in that: three pairs of high-voltage and current-limitation fuses (50), high energy absorber (60) are in parallel in twos, and the end after the parallel connection links to each other with the end of incoming cables of three single-phase contactors respectively, and the other end after the parallel connection connects three-phase power line by high voltage isolator K1, K2, K3 respectively.

5. arc extinction cabinet according to claim 1, it is characterized in that: comprise housing (90), be provided with microcomputerized controller (10) in the housing (90), three-phase power line connects the end of incoming cables of high voltage isolator K through wall bushing (70), the leading-out terminal of high voltage isolator K divides three the tunnel to absorb (60) with high energy respectively, the end of incoming cables of high-voltage and current-limitation fuse (50) and high-tension fuse (30) links to each other, high energy absorber (60) and the end of incoming cables that connects high-pressure vacuum contactor (40) after high-voltage and current-limitation fuse (50) is in parallel, the end of incoming cables of the outlet termination reactor L of high-pressure vacuum contactor (40), the leading-out terminal ground connection of reactor L, the leading-out terminal of high-tension fuse (30) is connected with the end of incoming cables of voltage transformer (20), the leading-out terminal ground connection of voltage transformer (20).

6. arc extinction cabinet according to claim 5; it is characterized in that: also be provided with three phase combined over-voltage protector (80) in the described housing (90); its end of incoming cables links to each other with the leading-out terminal of high voltage isolator K; its leading-out terminal ground connection; described high-voltage and current-limitation fuse (50) comprises striker mechanism (51); striker mechanism (51) is an insulating material, and its top is provided with three sensitive switches, and three sensitive switches are overlapped on the striker (511) by insulating rod respectively.