EP2728602B1 - Electrical high voltage circuit breaker and method for opening same - Google Patents

Description

The invention is in the field of gas-insulated high-voltage switchgear (GIS) and in particular relates to a load disconnector, also called "on-load disconnector", with a movable first contact element and a fixed second contact element.

High-voltage switchgears are understood to be switchgears which are configured for nominal voltages of 1 kV or higher, in particular of 75 kV or higher.

For load disconnectors two load cases are distinguished, namely the so-called "bus-charging" operation and the so-called "bus transfer" operation. While "bus-charging" focuses on the interruption of capacitive currents, the "bus-transfer" is aimed at disconnection situations in case of switching cases in which a change from a first busbar to a second busbar is to be carried out in rated operation. Disconnectors, in particular load disconnectors, are used both in the case of "bus transfer" switching operations as well as "bus-charging" switching operations. For the following disclosure is the "bus transfer" case in the foreground.

If, for example, the busbar is changed in gas-insulated (GIS) switchgear with a double busbar, induced voltages and equalizing currents occur in nominal mode (nominal operation), which require a certain cut-off line of the (load) disconnector. In nominal operation occur at a given nominal voltage and a given rated current due to a so-called dome field when opening the load breaker due to the impedances of the current loop formed between the two busbars not negligible compensation currents.

When opening the (load) disconnector, an arc is created between the moving contact and the fixed contact. Depending on the switching situation, transient overvoltages (VFTs) with a very high frequency in the order of magnitude of MHz, which can be detrimental to the connected switchgear equipment, also occur. The faster a load breaker works, the less arc ignition occurs. Therefore, a with high speed movable movable arcing contact sought to contact or dekontaktieren a fixed arcing contact. Immediately after the connection of these arcing contacts, the continuous current contacts (rated current contacts) of the movable isolator contact and the stationary isolator contact can be approximated without ignition of arcs and therefore wear-free and electrically connected to each other.

In the case of a load disconnector, the respective disconnecting switches used for disconnecting or connecting the busbars must be able to switch repeatedly reliably and without wear, depending on the requirements of the switchgear even in the presence of these induced voltages and equalizing currents. In gas-insulated switchgear, these induced voltages are usually not more than 20 volts. The currents are estimated at a maximum of 80% of the nominal current. In special cases, in which the busbars or panels are more widely spaced or removed and / or depending on the configuration and number of dome fields, the current loops - and accordingly also the induced voltages - can be greater than generally common for switch disconnectors. This induced voltage in nominal operation can increase, for example, in the case of gas-insulated switchgear panels combined with an outdoor system, depending on the switchgear, for example up to 300 V. There is therefore a need for a switch-disconnector which switches reliably and wear-free even under increased requirements.

For this purpose, high-voltage load disconnectors are known, which have a fixed contact and a separator tube as a movable contact. In these circuit breakers, a follow-up contact is integrated in the fixed contact, which is able to carry an arc. When the switch is opened, an arc may form between the separator tube and the follower contact. The fact that such disconnectors are designed to carry an arc enables them to be separated under a certain load, for example at a voltage of 20 V and a current of 1600 A. Such disconnectors are quite sufficient for many situations. However, situations also arise in which a rapid, reliable and low-wear separation is desired even under higher load.

From the DE 60030032 T2 is a gas-insulated high voltage circuit breaker with fast moving contact known. The circuit breaker has a fixed contact and a movable contact. Within the movable contact is a piston, the is actuated by an actuating rod. Between respective ends of the movable contact and the piston two springs are arranged. Further, two locking systems are provided to fix the movable contact in an axial direction with respect to the piston. Thereby, the movable contact can be moved independently of the actuating rod and the piston.

Next is from the EP 0 066 533 a gas-insulated electrical high-voltage circuit breaker known, this comprises a first contact group with a guide element and along a separation axis movably arranged first contact element comprising a first nominal conductor contact element and a first arc contact and a drive system for moving the first contact element along the separation axis relative to a second contact group for opening and closing the isolator, wherein the second contact group comprises a second nominal conductor contact element and a second arc contact, and wherein, upon opening the isolator, the first contact element after opening a nominal current path within a first position range of the first contact element relative to the guide member and the separation axis in an opening direction is further movable, while the holding means is held on the counter-holding means, that the first arc contact is maintained at the second arc contact, w During the return system is biased and establishes a biasing force, and wherein the return system is unlatched at the transition of the first contact element in an adjoining the first position range the second position range, so that the second contact group from the first contact group is electrically disconnected.

Against this background, therefore, the electrical Hochspannungstrenner according to claim 1 and a method according to claim 13 is proposed. Further advantageous aspects are evident from the dependent claims, the following description and the figures.

A first aspect of the invention comprises a high voltage electrical disconnector. The high-voltage separator comprises a first contact group with a guide element and a first contact element which is movable along a separation axis. The first contact element itself comprises a first nominal conductor contact element and a first arc contact. In the first arc contact a along the separation axis movably arranged, third arc contact is arranged. The first contact element includes a return system for retrieving the third arc contact in an opening direction. In this case, the first arc contact via the return system is operatively connected to the third arc contact such that the first arc contact is movable relative to the third arc contact. The high voltage circuit breaker further includes a drive system for moving the first contact element along the separation axis relative to a second contact group to open and close the isolator. The second contact group comprises a second nominal conductor contact element and a second arc contact. The second arc contact element has a holding means for cooperating with a counter-holding means of the third arc contact. In a consideration in which the separator is initially closed, it will be understood that the third arc contact is initially in mechanical and electrical contact with the second arc contact. At the same time, the third arc contact is in electrical connection with the first arc contact. When the high-voltage disconnector is opened, the first contact element is displaced in the opening direction along a separation axis through a first position region of the first contact element relative to the separation axis. Within the first position range, the second arc contact element holds the third arc contact initially back, so that the third arc contact is displaced relative to the first contact element against a spring force of the return system and the electrical contact between the second arc contact element and third arc contact is interrupted. As the drive advances, the first contact element is displaced into a second position region of the first contact element which adjoins the first position region. When entering this second position range, a maximum holding force of the holding means is deliberately exceeded. In other words, their holding force at that time is less than a return force of the return system, for example in the form of a return spring. When the holding force of the holding means dissolves, the third arc contact detaches from the second arc contact and is led away from the second arc contact instantaneously in the opening direction by the return system, so that the second arc contact (ie, the second contact group) during operation of the high-voltage disconnector is quickly and reliably electrically separated from the third arc contact (ie the first contact group) in time.

In addition to the high voltage disconnector, this document discloses a method of opening a high voltage electrical disconnector.

The term 'sticking' is not interpreted narrowly in the following, but in the sense of 'holding' or 'holding on', and includes any phenomenon in which two elements maintain a fixed position against a force acting on them, which is a release of the sticking / Holds. This can be done for example by mechanical means, such as a latching mechanism with appropriately selected, complementary geometry, such as in the form of a mechanical resistance, the object of larger diameter, but which is at least partially deformable, undergoes passage through an opening with a smaller diameter. Furthermore, magnetic adhesion may also be liable.

An advantage of the separators according to embodiments of this invention is that when separating the two contact groups quickly a high relative speed between the contact elements can be achieved as soon as the Abbrandstrompfad is interrupted electrically when opening. This promotes rapid quenching of a developing arc. As a result, larger loads can be achieved with the separator in rated operation, for example, power from 500 to 1500 kW or more, repeatedly switch quickly, reliably and with low wear.

• Figur 1 zeigt einen Hochspannungstrenner gemäss Ausführungsformen in geöffnetem Zustand;
• Figur 2 zeigt den Hochspannungstrenner aus Figur 1 in geschlossenem Zustand;
• Figur 3 zeigt den Hochspannungstrenner aus Figur 1 während einer Anfangs-Phase des Trennens;
• Figur 4 zeigt den Hochspannungstrenner aus Figur 1 während einer mittleren Phase des Trennens;
• Figur 5 zeigt den Hochspannungstrenner aus Figur 1 während einer Endphase des Trennens.
• Figur 6 zeigt ein Trenner-Modul einer Hochspannungs-Schaltanlage (GIS) mit einem Trenner gemäss Ausführungsformen.

In addition, the invention will be explained with reference to exemplary embodiments illustrated in figures, from which further advantages and modifications result. These show, in each case in a schematic lateral cross-sectional view:

• FIG. 1 shows a high-voltage disconnector according to embodiments in the open state;
• FIG. 2 shows the high voltage disconnector FIG. 1 in closed condition;
• FIG. 3 shows the high voltage disconnector FIG. 1 during an initial phase of separation;
• FIG. 4 shows the high voltage disconnector FIG. 1 during a middle phase of separation;
• FIG. 5 shows the high voltage disconnector FIG. 1 during a final phase of the separation.
• FIG. 6 shows a disconnector module of a high voltage switchgear (GIS) with a separator according to embodiments.

FIG. 1 shows a high-voltage load disconnector 1 - in the following simplifying only high-voltage disconnector 1 or simply called disconnector 1 - according to embodiments of the invention in the open state. It comprises a first contact group 66 with a typically stationary guide element 88 and a first contact element 22 movably mounted along a separation axis 8. This first contact element 22 comprises a first nominal conductor contact element 20 and a first arc contact 25. The first arc contact 25 is permanently electrically connected to the guide member 88 via at least one third contact 87. In the embodiment shown, the third contact 87 is a sliding contact. In the first arc contact 25, a third arc contact 40 is movably arranged along the separator axis 8. The first contact group 66 further includes a return system 80, which serves to retrieve the third arc contact 40 in an opening direction 7. In this case, the first arc contact 25 and the first nominal conductor contact element 20 are operatively connected via the return system 80 to the third arc contact 40 such that the first arc contact 25 is movable relative to the third arc contact 40. A drive system 30, typically comprising a spindle which is rotatably mounted on the nominal conductor contact element 20 by means of a driver, the first nominal conductor contact element 20 during rotation during operation of the separator 1 in a longitudinal movement about the separator axis 8. The drive system 30 is used to move the first contact element 22nd and the associated first nominal conductor contact element 20 along the disconnector axis 8 relative to a fixed second contact group 55 in order to be able to open and close the disconnector 1. The second contact group 55 is designed here as a fixed contact. The second contact group 55 comprises a second nominal conductor contact element 90 and a second arc contact 60. The second arc contact 60 has on a side facing the first contact group 66 holding means 71 for interacting with a counter-holding means 41 of the third arc contact 40 first contact group 66. The guide element 88 of the first contact group 66 is stationarily arranged in the isolator 1 and electrically isolated by means of an insulating gas connected to a housing. The housing is a housing of a high-voltage switchgear.

According to embodiments described below with reference to the FIGS. 1 to 5 When opening the disconnector 1 during operation of the disconnector 1, the first contact element 22 is further movable or displaceable in an opening direction 7 after opening a nominal current path 5 within a first position region 44 of the first contact element 22 relative to the guide element 88 and to the separation axis 8 , During the opening of the separator 1, the holding means 71 remains held on the counter-holding means 41 in a holding phase, so that the third arc contact 40 remains held on the second arc contact 60, while the return system 80 is pretensioned and a prestressing force is established. When the first contact element 22 is transferred to a second position region 46 adjoining the first position region 44, the prestressing force exerted by the return system 80 is greater than a structurally predefinable holding force of the holding means 71 acting on the counterpart means 41 in the direction of the separation axis 8 a subsequent separation phase of the third arc contact 40 of the return system 80 in the opening direction 7 retrieved and thereby accelerated. In this way, the second contact group 55 is electrically separable from the first contact group 66.

As part of the drive system 30, a motor or a hand crank is provided (not shown). An attached to the movable first contact element 20 driver cooperates with a spindle such that rotation of the spindle about the axis 8 of Separator is converted into a longitudinal movement of the movable first contact element 20 along the axis 8 of the separator.

The FIG. 2 shows the separator 1 from FIG. 1 in the closed state. The first contact element 22 has been moved by the drive system 30 in the direction of the second contact group 55 (in the FIG. 2 to the right) that the first nominal conductor contact element 20 has entered the gap between the second nominal conductor contact element 90 and the second arc contact 60 of the second contact group 55. During this entrance, the first arc contact 25 was pressed against the stationary second arc contact 60 of the second contact group 55. The first nominal conductor contact element 20 was then further moved by the drive system 30, whereby the first arc contact 25 remained stationary against the tension of the spring 24, which is supported at its other end against the first nominal conductor contact element 20 and thus relative to moved further moved first nominal conductor contact element 20. When the disconnector is closed, as in FIG. 2 shown, the spring 24 tensioned and the first arc contact 25 relative to the first nominal conductor contact element 20 in the opening direction 7 moves. During closing, a portion of the third arc contact 40 enters a correspondingly shaped cavity 72 in the second contact group 55, wherein the counter-holding means 41 is partially compressed in the illustrated embodiment by the holding means 71 of the second contact group 55, so that its diameter is reduced.

The nominal current path 5 leads, in the closed state of the isolator 1, from the guide element 88 via first contacts 89, which are designed here as sliding contacts, via the first nominal conductor contact element 20 to the second nominal contact element 90 of the second contact group 55 via the second contacts 56 enter. Theoretically, the current path could also lead from the guide element 88 via the first contacts 89, the first nominal conductor contact element 20, via the third contact 87 on to the first arc contact 25 and from there to the second arc contact 60. In practice, however, the ohmic resistance greater and the distance of such a current path longer than on the Nominalstrompfad 5, so that in the closed state of the separator 1 de facto no current through the arc contact system 25, 60 flows.

The FIG. 3 shows the separator 1 in an initial phase of the separation. By rotating the spindle of the drive 30 with the spindle-nut combination, the first contact element 22 has moved so far in the opening direction 7, that the nominal current path 5 between the first nominal conductor contact element 20 and the second nominal conductor contact element 90 (as in FIG. 1 shown) is electrically interrupted. In the in FIG. 3 Therefore, when the nominal current path 5 is opened, the current path 5b now leads from the first contact group 66 from the guide element 88 over the first contacts 89 to the first nominal conductor contact element 20 and from there via the third contact 87 via the first arc contact 25 Holding means 71 of the second arc contact 60 of the second contact group 55. Between the third arc contact 40 and the central opening of the first arc contact 25, an annular gap is arranged, wherein in the operation of the separator 1 and insulating gas is located. Since the electrical resistance due to the gas-filled gap between the third arc contact 40 and the central opening of the first arc contact 25 is higher than between the first arc contact 25 and the holding means 71 of the second arc contact 60, the current path leads 5b directly from the first arc contact 25 to the holding means 71 of the second arc contact 60, without going over the third arc contact 40.

In FIG. 4 is the separator 1 even further than in FIG. 3 open. Shortly after the in FIG. 3 As shown in FIG. 1, by moving the first contact element 22 further in the opening direction 7, the electrical contact between the first arc contact 25 and the second nominal conductor contact element 90 has been disconnected FIG. 4 the current path 5c between the first contact group 66 and the second contact group 55 now leads exclusively via the third arc contact 40. Since the annular gap between the third arc contact 40 and the central opening of the first arc contact 25 forms a high electrical resistance electrically, the current path 5c now leads via an alternative negative-resistance route. This in FIG. 4 shown alternative route of the current path 5c leads at still open Nominalstrompfad 5 of the first contact group 66 from the guide element 88 her forth first still via the first contacts 89 to the first nominal conductor contact element 20. In contrast to the basis FIG. 3 described current path 5b leads the alternative route according to FIG. 4 from the first nominal conductor contact element 20, however, no longer via the third contact 87 to the first arc contact 25, but via a support flange 85 of the first nominal conductor contact element 20 via the return system 80 to the third arc contact 40. From the third Arc contact 40 leads the current path 5c via the holding means 71 finally to the second arc contact 60 of the second contact group 55th

This just mentioned alternative route of the current path 5c already exists in the in FIG. 3 However, since the current path 5b, which seen from the guide member 88 forth via the first contacts 89 to the first nominal conductor contact element 20 and from there via the third contact 87 via the first arc contact 25 on to the second arc contact 60 , shorter in terms of length and overall lower impedance than the alternative route of the current path 5c from the guide element 88 via the first contacts 89 to the first nominal conductor contact element 20 and from there via the support flange 85 of the first nominal conductor contact element 20 via the return system 80 to the third Arc contact 40 to the second arc contact 60, the current flows in FIG. 3 shown state of the separator 1 de facto via the current path 5b and not on the alternative route of the current path 5c.

Between the states in FIG. 3 and in FIG. 4 That is, during the movement of the first contact element 22 in the opening direction 7 through a first position region 44 of the first contact element 22 (exemplarily defined as the position of the end 21 of the first nominal conductor contact element 20 relative to the first position region 44), this becomes the third arc Contact 40 held by the second arc contact 60. The first position region 44 is thus defined as a holding region of the third arc contact 40. In this case, the third arc contact 40 shifts in the operation of the separator 1 relative to the first contact element 22 against a spring force of the return system 80 in the direction of the second contact group 55. By the shift in this embodiment designed as a tension spring coil spring 81 is stretched. In FIG. 4 the spring 81 is already in fully tensioned, that is shown in the elongated in the direction of the separator axis, stretched state. In the figures, the distances of the spring coils could not be faithfully reproduced. In FIG. 4 For example, the end 21 of the first nominal conductor contact element 20 is positioned on a boundary between the first position region 44 (holding region) and a second position region 46, representative of the first contact element 22. The second position area 46 is also called the release area below.

When the first contact element 22 is moved further in the opening direction 7 by the drive system 30, the following occurs: When the first contact element 22 moves from the second position region 46 (release region) to the first position region 44 (holding region), the biasing force of the return system 80 becomes greater As a force acting in the direction of the separation axis 8, structurally defined holding force of the holding means 71 on the counter-holding means 41 of the third arc contact 40. As a result, the third arc contact 40 is accelerated by the return system 80 in the opening direction 7, or retrieved, so that the current path 5c is broken by the dissolution of the electrical connection between the third arc-contact 40 and the second arc-contact 60 quasi-sudden, after which the second contact group 55 of the first contact group 66 is temporally fast, reliable and completely electrically separable. The position area 46 is thus defined as the release area of the third arc contact 40. This return operation is in Fig. 5 shown, wherein the third arc-contact 40 is shown in the acceleration phase, ie shortly after the spring force of the spring 81 has exceeded the holding force between the holding means 71 and the counter-holding means 41.

In embodiments, the first contact group 66 and the second contact group 55 are electrically connected to each other when the disconnector is closed and separated by an isolating distance when the disconnector is open, which corresponds to the sum of the position ranges 44 and 46. According to exemplary embodiments, the first arc contact 25, the third arc contact 40 and the second arc contact 60 each comprise a consumable contact element in order to carry an arc forming between the elements during operation of the isolator 1 and the isolator 1 against excessive wear To protect burnup.

Like in FIG. 2 can be seen, is stowed in the closed circuit state of the third arc contact 40 typically in a cavity 72 in the second contact group 55. The holding means 71 of the second contact group 55 is typically arranged wholly or partly in the cavity 72. Once the separation is initiated, the third arc contact 40 is moved in the opening direction and pushes, as in FIG. 3 represented, from the direction of the interior of the cavity 72 to the holding means 71 of the second contact group 55, from which it is held during the further opening movement (until the solution and acceleration by spring 81, as described above) or adheres to this. In this case, in exemplary embodiments, the third arc contact 40 typically arranged as a slidable piston in the nominal conductor contact element 20. The arc contact 40 is preferably designed as a tubular body, seen in the direction of the separation axis 8, has an annular cross-section. The tubular body may have recesses or windows in its lateral surface in order to reduce its overall mass balance. The above-mentioned features are used for mass or weight alleviation of the third arc contact 40. At a given strength of the spring 81 of the return system 80, which is limited by constructive limitations in their size / strength, by the mass reduction, the acceleration of the third arc contact. Contact 40 can be improved, whereby a higher separation speed can be achieved. Thus, if the third arc contact 40 is sleeve-shaped or at least partially hollow, this is advantageous because of the reduction in mass, since less force is needed to accelerate the third arc contact 40 when opening the separator than for a heavier third arc-contact. As a result, the return system 80 may be made weaker and thus more compact than a heavier third arc contact.

The return spring 81 is typically disposed between a first end 21 of the nominal conductor contact element 20 and a first end 42 of the third arc contact 40 in embodiments with respect to the separator axis 8. Here, the interaction of the structural elements of the spring 81, the strength of the interaction or "held his" of the holding means 71 with the counter-holding means 41, and the mass of the third arc contact 40 is designed so that after releasing the held connection during the opening movement the third arcing contact 40 is accelerated by the spring to a speed of at least 1 m / s relative to the second arcing contact 60. Preferably, the speed is more than 2 m / s, more preferably more than 4 m / s, so that the arc duration is as small as possible. The counterpart 41 may, as in the FIGS. 1 to 5 sketched to be executed in the form of a collet-like executed end with at least one radially resilient contact tongue.

The high separation speed achieved in this way can, in embodiments, be constructive during or at the end of the opening or separating movement, that is, when the third arc contact 40 is in its rest position in the disconnected state (see FIG. 1 ), are braked to prevent damage to the retrieval system 80 and / or the third arc contact 40, for example. This can be in the return 80 a gas-tight housing 2 may be provided. This damping element serves to decelerate the speed of the third arc contact 40 again after acceleration by the return system 80; otherwise - depending on the concrete constructive interpretation - at the end of the movement even a rebound of the third arc contact 40 could take place counter to the opening direction 7, which could cause an unwanted, new arcing (re-arcing). In the present embodiment of the Hochspannungsstrenners forms the inner volume of the sleeve-shaped part of the return system 80 a piston chamber 83, while a flange 84 at the first end 42 of the third arc contact 40 forms a piston which is slidably arranged in the piston chamber 83 slidably. In the direction of the drive 30 directed support flange 85 of the first nominal conductor contact element 20, a small opening 86 is arranged. This opening 86 forms by its geometric configuration with respect to length, size and shape a valve of the piston chamber 83. When the third arc contact 40 is moved with its piston 84 in the direction of the drive 30 when opening the Hochspannungsstrenners, the gas in the piston chamber 83 is compressed and can only escape targeted and predefinable via the opening 86, so that in operation of the high-voltage circuit breaker 1 by simple means a damping effect can be realized.

In embodiments, the third arc contact 40 and / or the second arc contact 60 may comprise a magnet, such as a permanent magnet. By the magnet, the defined holding force / adhesive force between the holding means 71 and the counter-holding means 41 can be defined, which can be carried out alternatively or in addition to the mechanical solution shown in the figures.

In the illustrated high voltage diverter, the conductivity and geometry of the first arcing contact 25 and the third arcing contact 40 are designed so that when the isolator is opened in operation, it is placed in a state between FIGS. 3 and 4 , an arc has its first foot point first on the first arcing contact 25, and that root point commutes subsequent to the third arcing contact 40, while its other foot point remains at the second arcing contact (60).

In exemplary embodiments, the nominal conductor contact element 90 is arranged in the radial direction relative to the separation axis 8 outside the second arc contact 60. According to a general aspect of the invention, those in the figures are in cross-section shown elements formed generally rotationally symmetrical to the separator axis 8. In particular, the first contact element 22 with its components and the second contact group 55 are arranged substantially rotationally symmetrical to the separator axis 8.

In alternative embodiments, the third arc contact 40 may include a cavity along the separation axis 8 (such as instead of the counter-holding means 41 of FIGS FIGS. 1 to 5 ) in order to accommodate a portion of the second arc contact 60 in the closed state of the separator 1 can. In this embodiment, the return system can then be accommodated correspondingly in the second arc contact. This variant provides a mechanical alternative for the holding means 41 and 71 to prevent the third arc contact 40 from being held by the second arc contact 60 during the holding phase (such as in FIG FIG. 4 shown).

Return to Illustrated Embodiment of Separator 1. One advantage of the substantially pin-shaped third arc contact 40 as compared to the separator of FIG DE 60030032 T2 is that the return system 80 can be arranged radially around the pin-shaped third arc-contact 40, while the return system radially within the sleeve-shaped arc-contact of the separator according to the DE 60030032 T2 is arranged and thus must have a minimum radial size that is significantly higher than that of a third arc contact 40 according to the present disclosure. Because of this minimal size-related mass of the sleeve-shaped arc contact of the separator according to the DE 60030032 T2 For example, the force required to move the arcing contact is greater than in one embodiment of a third arcing contact 40 according to the present disclosure. The greater the required force, the larger and less compact a disconnector can be realized. As the trend towards the miniaturization of gas-insulated switchgear and therefore its components continues, it is important that the load-breaker is dimensionally as small and compact as possible.

If required, additional resistance and / or impedance elements can also be integrated in the third arc contact 40. Resistance elements are advantageous because they cause a reduction in current when opening the contact groups, which current reduction results in that the burnup of the arc contact can be kept lower than in a comparable separator without resistance elements. Impedance elements can be used to smooth VFT voltage spikes.

If necessary, the third arc contact 40 can be freely rotatably arranged in the circumferential direction.

Embodiments also include gas-insulated switchgear comprising one or more separators according to described embodiments, such as in FIG. 6 shown schematically and in part. A separator module 100 for a GIS comprises a separator 1 according to described embodiments in a gas-tight metal housing 106. The first contact group 66 and the second contact group 55 are each connected to one or more nominal conductors 103, 104, 105. On the side of the second contact group 55, the nominal conductor 104 is connected to the housing 106 of the isolator module 100 with an insulator 102. A gas-tight passage 110 (shown only schematically) for the drive 30 is provided in a wall of the module 100.

The invention has been explained by way of example with reference to a gas-insulated separator. However, it is also suitable for other disconnectors for high and medium voltage applications, especially substations, e.g. for vacuum circuit breaker, self-blower circuit breaker, etc.

Claims (16)

1. Electrical high-voltage disconnector (1), comprising

   - a first contact group (66) comprising a guide element (88) and a first contact element (22), which is arranged movably along a disconnection axis (8) and comprises a first nominal conductor contact element (20) and a first arc contact (25);

   - a third arc contact (40) which is arranged movably along the disconnection axis (8) in the first arc contact (25),

   - a retracting system (80) for retracting the third arc contact (40) in an opening direction (7), wherein the first arc contact (25) is operatively connected to the third arc contact (40) via the retracting system (80) in such a way that the first arc contact (25) is movable in the direction of the disconnection axis (8) relative to the third arc contact (40);

   - a drive system (30) for moving the first contact element (22) along the disconnection axis (8) relative to a second contact group (55) in order to open and to close the disconnector (1), wherein the second contact group (55) comprises a second nominal conductor contact element (90) and a second arc contact (60);

   - wherein the second arc contact (60) has a holding means (71) for interacting with a mating holding means (41) of the third arc contact (40); and

   - wherein, during opening of the disconnector once a nominal current path (5) has opened, the first contact element (22) is capable of moving further relative to the guide element (88) and to the disconnection axis (8) in an opening direction (7) within a first position region (44) of the first contact element (22), while the holding means (71) is held on the mating holding means (41) in such a way that the third arc contact (40) remains held on the second arc contact (60), while the retracting system (80) is prestressed and builds up a prestressing force, and

   - wherein, when the first contact element (22) passes over to a second position region (46) adjoining the first position region (44), the prestressing force of the restoring system (80) is higher than a predefinable holding force of the holding means (71) on the mating holding means (41), which holding force acts in the direction of the disconnection axis (8), with the result that the third arc contact (40) is retracted by the retracting system (80) in the opening direction (7), with the result that the second contact group (55) is electrically disconnected from the first contact group (66).
2. Electrical high-voltage disconnector (1) according to Claim 1, wherein the third arc contact (40) is arranged as a piston capable of performing a sliding movement in the nominal conductor contact element (20).
3. Electrical high-voltage disconnector (1) according to either of the preceding claims, wherein the third arc contact (40) is in the form of a tubular body, which preferably has cut-outs or windows, wherein the tubular body, when viewed in the direction of the disconnection axis (8), preferably has a cross section in the form of a circular ring.
4. Electrical high-voltage disconnector (1) according to either of the preceding claims, wherein the retracting system (80) comprises a return spring (81).
5. Electrical high-voltage disconnector (1) according to Claim 4, wherein the return spring (81) is arranged, in relation to the longitudinal axis (8), between a first end (21) of the nominal conductor contact element (20) and a first end (42) of the third arc contact (40).
6. Electrical high-voltage disconnector (1) according to one of the preceding claims, wherein the second arc contact (60) comprises a cavity (72) along the disconnection axis (8), which cavity is designed to accommodate a section of the third arc contact (40) in the closed state of the disconnector (1).
7. Electrical high-voltage disconnector (1) according to Claim 6, wherein the holding means (71) is arranged in the cavity (72).
8. Electrical high-voltage disconnector (1) according to one of Claims 4 to 7, wherein the strength of the return spring (81) which can be held back by interaction of the holding means (71) and the mating holding means (41), and the mass of the third arc contact (40) are configured in such a way that, once the held connection is released during the opening movement, the third arc contact (40) is accelerated by the spring to a speed of at least 1 m/s relative to the second arc contact (60).
9. Electrical high-voltage disconnector (1) according to one of the preceding claims, further having a gas-tight housing (2), wherein the retracting system (80) has a damping element arranged within an internal volume of the housing (2) in order to decelerate the speed of the third arc contact (40) once acceleration has taken place by means of the retracting system (80).
10. Electrical high-voltage disconnector (1) according to one of the preceding claims, wherein the third arc contact (40) and the second arc contact (60) are designed in such a way that, during restoring of the first contact element (22), the third arc contact (40) is held in the first position region (44) releasably by the second arc contact (60),
    preferably by means of a mechanical engagement one inside the other owing to a system comprising a holding means (71) in the form of a protrusion on the second arc contact (60) and at least one mating holding means (41) on the third arc contact (40), in the form of a collet-like end with at least one radially sprung contact tongue.
11. Electrical high-voltage disconnector (1) according to one of the preceding claims, wherein the conductivity and geometry of the first arc contact (25) and the third arc contact (40) are configured in such a way that, during opening of the disconnector during operation, an arc has its root initially on the first arc contact (25), and this root then commutates to the third arc contact (40) as the opening process continues, while its other root remains on the second arc contact (60).
12. Electrical high-voltage disconnector (1) according to one of the preceding claims, wherein the nominal conductor contact element (90) is arranged outside the second arc contact (60) in the radial direction relative to the disconnection axis (8).
13. Method for opening an electrical high-voltage disconnector (1), said high-voltage disconnector comprising:

    - a first contact group (66) comprising a guide element (88) and a first contact element (22), which is arranged movably along a disconnection axis (8) and comprises a first nominal conductor contact element (20) and a first arc contact (25);

    - a third arc contact (40) which is arranged movably along the disconnection axis (8) in the first arc contact (25),

    - a retracting system (80) for retracting the third arc contact (40) in an opening direction (7), wherein the first arc contact (25) is operatively connected to the third arc contact (40) via the retracting system (80) in such a way that the first arc contact (25) is movable in the direction of the disconnection axis (8) relative to the third arc contact (40);

    - a drive system (30) for moving the first contact element (22) along the disconnection axis (8) relative to a second contact group (55) in order to open and to close the disconnector (1), wherein the second contact group (55) comprises a second nominal conductor contact element (90) and a second arc contact (60);

    - wherein the second arc contact (60) has a holding means (71) for interacting with a mating holding means (41) of the third arc contact (40); and

    wherein the disconnector (1) is first closed, so that the third arc contact (40) is in contact with the second arc contact (60) and at the same time said second arc contact is electrically connected to the first arc contact (25), and wherein, for opening of the disconnector, the following steps are implemented:

    - moving the first contact element (22) in the opening direction (7) along a disconnection axis through a first position region (44) of the first contact element (22) relative to the disconnection axis, wherein, within the first position region, the second arc contact (60) holds the third arc contact (40) and, in the process, the third arc contact (40) is shifted counter to a spring force of the retracting system (80) in relation to the first contact element (22), and

    - exceeding a holding force and releasing the third arc contact (40) from the second arc contact (60) in a second position region (46), adjoining the first position region (44), of the first contact element (22), and

    - retracting the third arc contact (40) by means of the retracting system (80) in the opening direction (7), with the result that the second arc contact (60) is electrically disconnected from the first contact element (22).
14. Method according to Claim 13, wherein, once the held connection has been released, a previously produced arc between the first arc contact (25) and the second arc contact (60) commutates from the first arc contact (25) in a disconnection phase to the third arc contact (40), while the third arc contact (40) is retracted.
15. Method according to Claim 13 or 14, wherein the strength of the return spring (81) which can be held back by interaction of the holding means (71) and the mating holding means (41), and the mass of the third arc contact (40) are configured in such a way that, once the held connection is released during the opening movement, the third arc contact (40) is accelerated by the spring to a speed of at least 1 m/s relative to the second arc contact (60).
16. Disconnector module (100) for a gas-insulated switchgear assembly, comprising:

    - a disconnector according to one of Claims 1 to 12,

    - a metal housing (106),

    - at least two nominal conductors (103, 104, 105),

    - an insulator (102),

    wherein the first contact group (66) and the second contact group (55) of the disconnector (1) are each connected to one or more nominal conductors (103, 104, 105).

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