EP2294592B1 - Load interrupter comprising an arc extinguishing device - Google Patents

Description

The invention relates to a switch disconnector for gas-insulated switchgear with an arc quenching device comprising an extinguishing coil formed by a winding support and a winding with an electrically conductive arc running surface.

It is known to equip the switch-disconnectors of gas-insulated switchgear with extinguishing coils in order to keep the arcing occurring during switching between the fixed contact and the movable contact as small as possible and to delete quickly.

The JP 10228846A describes an arc extinguishing coil comprising a winding and a coil core and an arc leading to a fixed contact of the switchgear extending. The arc generated when opening the movable contact of the switchgear is moved over the arc guiding element to the arc extinguishing coil. A through the commutated to a race switching arc current flows through the extinguishing coil and builds up a magnetic field, so that the arc root, due to the Lorentz force rotates on the race and the switching arc due to the rotational speed and cooling by the located in the switchgear gas in Current zero crossing is cleared.

One from the EP 1064663 B1 known, based on the same principle arc quenching device for a gas-insulated switch disconnector has a coil carrying a winding body of a conductive plastic and a field control electrode and an outgoing from the winding, reaching close to the fixed contact, shiny metallic guide element whose end to a certain minimum distance the mobile contact moving past it and the foot point of the fixed contact has. When the movable contact passes the end of the baffle, the fixed contact base of the arc is taken over by the baffle and a current is conducted into the winding so that the base of the arc due to the magnetic field makes a rotating movement on the metallically bare last winding and in the current zero crossing goes out.

The JP08167354A describes a switch-disconnector with an arc-quenching device according to the preamble of claim 1.

The invention has for its object to provide an arc extinguishing coil, which is inexpensive and compact and has a high and reliable fire fighting capacity.

According to the invention the object is achieved with a trained according to the features of claim 1 arc quenching device for switch disconnector. Further features and advantageous embodiments of the invention are the subject of the dependent claims.

An important feature combination of positioned near a fixed contact of the circuit breaker arc quenching device is that its ironless executed quench coil is assigned on the side of the arc root, a metallic race with raised outer edges, and the quenching coil on the winding support and an outer and inner shells of non-conductive material is arranged insulated to the outside, and the two ends of the winding are connected to the one fixed contact and the other to the raceway.

With the thus formed arc quenching device, which can be arranged close to the fixed contact, a parallel to the surface of the race aligned and focused on this area magnetic field is generated directly with the resulting upon separation of the switch contacts switching arc, so that the base of the without additional guide immediately on the exposed part of the race commuting arc a fast and controlled, that is, executes rotational movement limited to the annular arc running surface while being well cooled and rapidly extinguished. The inner jacket of the ironless quenching coil also forms a gas circulation opening, so that the existing gas in the switchgear circulate on the quenching coil and can provide for improved cooling of the arc. Damage to the fixed contact and the moving contact due to the thermal effect of the arc is excluded as well as a burning of the arc on the race. The live parts of the quenching coil are covered by the plastic sheath (outer sheath, inner sheath, winding carrier) to the outside so that re-ignitions are prevented by hot plasma arc. Equally excluded is a pre-ignition of the arc when closing the switch, so that the extinguishing coil can not be destroyed when switched on after a short circuit due to the resulting very high current. The arc quenching device is also simple and compact.

According to a further feature of the invention, in each case an inwardly directed annular collar is integrally formed on the lower edge of the inner shell and the outer shell, on which the raceway and resting on this extinguishing coil are supported. The two collars end at liberation of an annular gap at a distance from each other. The annular gap defines a geometrically defined arc running surface of the centrally arranged above this race. The arc running surface is dimensioned in the diameter so that a short-circuiting of the arc is excluded on its career. The arranged in the winding support winding of the quenching coil is - isolated by a circumferential ridge of the winding carrier - just above the arc running surface and over the annular gap. As a result, a maximum transverse magnetic field acts on the arc base point on a narrow trajectory, so that its particularly high rotational speed is ensured.

In the upper region of the quenching device, which is opposite the raceway, it is insulated from the outside by the fact that a cover plate extending to the outer jacket and to the inner jacket is integrally formed on the winding carrier. The cover plate is held by locking elements on the inner and outer sheath, so that the extinguishing coil is fixed in total between the inner and outer shells in a simple way.

According to another important feature of the invention, the raceway has a U-shaped cross-sectional profile, i. at the inner and outer edge raised legs which bear against the inner and outer sheath. This results in a very good electrical control to adjacent live parts and the ground potential and thus a compact and inexpensive construction. The U-shaped design of the raceway and thereby achieved electrical control allows the small distance to the fixed contact and thus possible without additional guide elements fast commutation of the arc arc quenching device, despite the small distance without the risk of re-ignition of the already deleted arc from moving contact on the fixed contact. On the raised inner leg of the guide ring can also advantageously one end of the winding of the quenching coil - be fixed conductively - for example by means of tab or welded joint.

In a further embodiment of the invention, the arc quenching device is attached by means of attached to the outer jacket mounting straps on the fixed contact. The second end of the winding is held by a contact element on one of the fastening tabs and so galvanically connected to the fixed contact.

Fig. 1

eine Seitenansicht eines in einer gasisolierten Schaltanlage angeordneten Lastrennschalters mit dessen Kontaktsystem zugeordneter Lichtbogenlöscheinrichtung;

Fig. 2

eine perspektivische Ansicht der Lichtbogenlöscheinrichtung;

Fig. 3

eine Draufsicht der Lichtbogenlöscheinrichtung;

Fig. 4

eine Schnittansicht der Lichtbogenlöscheinrichtung längs der Linie I-I in Fig. 3;

Fig. 5

eine Einzelheit "X" der Lichtbogenlöscheinrichtung nach Fig. 4; und

Fig. 6

eine Explosionsdarstellung der Lichtbogenlöscheinrichtung.

An embodiment of the invention will be explained in more detail with reference to the drawing. Show it:

Fig. 1

a side view of a arranged in a gas-insulated switchgear circuit breaker with the Contact system associated with arc quenching device;

Fig. 2

a perspective view of the arc quenching device;

Fig. 3

a plan view of the arc quenching device;

Fig. 4

a sectional view of the arc quenching device along the line II in Fig. 3 ;

Fig. 5

a detail "X" of the arc quenching device according to Fig. 4 ; and

Fig. 6

an exploded view of the arc quenching device.

Fig. 1 shows the arranged within a gas-filled switchgear contact system of a circuit breaker 1, which has a fixed contact 2, a pivotable by means of a switching shaft 3 moving contact 4 and a grounding contact 5. The moving contact 4 is on the switching shaft 3 and the fixed contact 2 is held on a support 6. With the fixed contact 2 is an arc quenching device 7, which is arranged close to the contact point between the fixed and the moving contact, galvanically connected, so that when pivoting the moving contact 4 in the in Fig. 1 shown opened position quickly formed arc - and without additional guide elements - commutate the arc quenching device 7 and can be deleted reliably. As the drawing shows, the arc facing lower level of the arc quenching device 7 is arranged at a certain angle to the contact point, which - relative to the horizontal - preferably can be between 0 and 60 °.

The core of the arc quenching device 7 is an extinguishing coil 8, which in the present embodiment consists of a two-layer, arranged on an annular winding support 10 Winding 9 consists of copper enameled wire. The winding support 10 comprises a circumferential web 11 with a wide cover plate 12 which struts away from its upper edge and a narrow leg 13 which struts away from its lower edge to one side and consists of a nonconductive plastic, preferably a UV-resistant thermoset or thermosetting plastic. The quenching coil 8 rests with the encircling leg 13 on or in a raceway 14 with a U-shaped cross section, which consists of an electrically conductive metallic material, such as brass, copper, aluminum or bronze. An attached at an inner end 15 of the winding 9 tab 16 is placed on the inner circumferential raised edge 14 a of the race 14, so that the race 14 is electrically connected to the winding 9. Another type of electrical contacting, for example by a welded connection, is conceivable. The other, outer end 17 of the winding 9 is connected via a contact element 18, which may be, for example, a contact spring, a ring cable lug or an eyelet formed on the end of the winding, with a fastening tab 19 provided for fixing the arc quenching device 7 on the fixed contact 2 and thus with connected to the fixed contact 2. In fact, the connection of the arc quenching device 7 with the fixed contact 2 by means of two parallel spaced, formed on an outer shell 20 mounting tabs 19. The outer jacket 20 surrounds the outer peripheral surface of the quenching coil 8 including the raceway 14, which is bent on a lower, inwardly Ring collar 21 of the outer shell 20 is supported and the outer edge 14 b rests against the inner surface of the outer shell 20. The inner peripheral surface of the quenching coil 8 is covered with an inner shell 22 which has a lower, outwardly bent annular collar 23 on which the raceway 14 also rests. The winding support 10 with the winding 9 (quenching coil 8) is held on the opposite side of the race 14 by locking elements 24 which are formed on the inner surface of the outer shell 20 and on the outer surface of the inner shell 22. However, the two bent collars 21, 23 terminate at a distance from each other, so that at the - the contact point between the fixed and moving contact facing - lower side of the arc quenching device 7, an annular gap 27 and a limited by this bilateral annular arc running surface 25 for the arc root, which is located directly under the winding 9 of the quenching coil 8, remains free.

An emerging when opening the circuit breaker 1 arc can quickly and directly, that is, without special Kommutierungsmittel, on the close to the fixed and moving contact 2, 4 lying raceway 14 commute, so that the fixed contact can not be damaged by the arc and the arc the predetermined annular arc surface 25 can rotate immediately and controlled. In addition, since the annular arc running surface 25 runs directly under the winding 9, the transverse magnetic field generated by this when impressing a current through the arc with maximum strength on the arc root, so that it reaches a high rotational speed and can not burn into the arc surface 25 as well as intensively cooled and can be quickly extinguished.

The circular shape of the race 14 with the raised edges 14a, 14b causes a very good electrical control to adjacent live components and the ground potential, so that on the one hand a compact, cost-effective design is possible and on the other hand - despite the small distance to the fixed contact - a reignition of the Arc is excluded from moving contact on the fixed contact. In addition, a good contact between the winding 9 and the race 14 and thus an intense effect of the magnetic field generated by the winding 9 is achieved on the arc with the given shape of the race 14 via the contact element 18.

The inner jacket 22 and the outer jacket 20 with the attachment tabs 19 formed thereon and the winding carrier 10 are made of a non-conductive plastic and cover all live parts of the quenching coil 8 completely off, so that caused by emerging plasma of the arc Neuentzündungen are excluded. The large, central gas circulation opening 26 generated by the inner shell 22 also ensures good circulation of the gas surrounding the switch-disconnector, so that the rotating arc constantly comes into contact with new, cool gas and its extinguishing behavior due to the extracted energy is further improved.

When switching on the switch-disconnector with the above-described design of the arc quenching device 7 and a pre-ignition of the arc from the moving contact to the quenching coil, that is, before the closing of the circuit via the moving contact and the fixed contact, prevented, so that the arc quenching device when switched to a short circuit can not be destroyed by the effective high current.

LIST OF REFERENCE NUMBERS

1

Switch disconnectors

2

Fixed contact (busbar contact)

3

shift shaft

4

Moving contact (switch blade)

5

ground contact

6

supporters

7

Arc quenching device

8th

cancellation coil

9

winding

10

winding support

11

Circumferential bridge v. 10

12

Cover plate v. 10

13

Lower thigh v. 10

14

race

14a

inner raised edge

14b

outer raised edge

15

inner end v. 9

16

tabs

17

outer end v. 9

18

contact element

19

Fastening strap v. 20

20

outer sheath

21

Ring collar v. 20

22

inner sheath

23

Ring collar v. 22

24

locking elements

25

Arc tread

26

Gas circulation opening

27

annular gap

Claims (11)

1. Switch disconnector for gas-insulated switchgear assemblies having an arc quenching device (7) which comprises a quenching coil (8) which is formed by a winding (9), is arranged on a stationary contact (2) and has an electrically conductive arcing surface (25), wherein the quenching coil (8), which has no iron, is covered on the side facing the arc foot point on the stationary contact (2) with a circular arcing ring (14), which has raised edges, wherein the winding (9) is connected to the arcing ring (14) at one end and to the stationary contact (2) at the other end,
   characterized in that the quenching coil (8) is shielded on the outside via a winding former (10) of the quenching coil (8) and an inner and an outer casing (20, 22) composed of nonconductive material.
2. Switch disconnector according to Claim 1, characterized in that
   the outer casing (20) and the inner casing (22), which bounds a gas circulation opening (26) formed in the arc quenching device (7), each have an annular collar (21, 23), which are bent inward from their lower edge and end at a distance from one another leaving an annular gap (27) free, wherein the arcing ring (14) is supported with the quenching coil (8) centrally over the annular gap (27) on the two annular collars (21, 23) and the annular gap (27) bounds an annular arcing surface (25), and the winding (9) runs directly above the annular gap (27) or the arcing surface (25).
3. Switch disconnector according to Claim 1 or 2,
   characterized in that
   the arcing ring (14) has a U-shaped cross-sectional profile, on whose web the quenching coil (8) rests and whose circumferential raised edges (14a, 14b) are supported on the inner casing (22) and the outer casing (20).
4. Switch disconnector according to Claim 3,
   characterized in that
   the annular winding former (10) has a circumferential lower limb (13) which is bent at one end and is supported on the arcing ring (14), and a circumferential cover plate (12) which extends to the inner casing (22) and to the outer casing (20), such that the live parts of the arc quenching device (7) are covered on the outside, except for the annular arcing surface (25).
5. Switch disconnector according to Claim 4,
   characterized in that
   the quenching coil (8) is fixed by means of latching elements (24) which are provided on the inner casing (22) and on the outer casing (20) and engage over the cover plate (12).
6. Switch disconnector according to one of the preceding claims,
   characterized in that
   one end (17) of the winding (9) is held via a contact element (18) on one of two attachment lugs (19), which are integrally formed on the outer casing (20) and are attached to the stationary contact (2) and is thus galvanically connected to the stationary contact (2) of the switch disconnector, while the other end (15) of the winding (9) is connected to the arcing ring (14) via a welded joint or a flat plug (16).
7. Switch disconnector according to Claim 6,
   characterized in that
   the contact element (18) is a contact spring, an annular cable shoe or an eye which is integrally formed on the winding (9).
8. Switch disconnector according to Claim 1,
   characterized in that
   the winding (9) is formed from one or more layers of wound, lacquered copper wire.
9. Switch disconnector according to Claim 1
   characterized in that
   the arcing ring (14) is composed of an electrically conductive metal.
10. Switch disconnector according to Claim 9,
    characterized in that
    the arcing ring (14) is composed of brass, copper, aluminum or bronze.
11. Switch disconnector according to Claim 1
    characterized in that
    the arcing surface (25) is arranged at an angle of preferably between 90 and 120° with respect to the vertical longitudinal axis of the stationary contact (2).

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