DE10047032A1 - Medium voltage isolating blade-diverter used in electrical switching devices comprises a circuit breaker integrated between isolating blades - Google Patents

Abstract

The isolating blade-diverter comprises a circuit breaker integrated between isolating blades (5). The circuit breaker is in the form of commutation path connected in series with a vacuum switching chamber.

Description

The invention relates to a medium-voltage switch disconnector switch according to the preamble of claim 1.

A medium-voltage switch disconnector is an electrical switching device, that can carry and switch off the nominal current of an electrical network, and at the one air gap defined by regulations is maintained in the off state have to be. In contrast to isolators, where a circuit is not live a switch disconnector must be able to lead and extinguish an arc, its output by the nominal voltage or the nominal current to be switched is defined.

A load-break switch in the medium-voltage range can be used, for example, as a so-called Compression switch disconnector can be carried out, in which a blowing Arc gap during the switching process with a, during the Switching process generated, compressed air volume is generated. Or with others Common designs, the arc is made in a narrow gap gas-giving insulating material - mainly plastic - pulled and so through the Increased pressure and hardening of the isolating section in the zero current crossing deleted.

Both versions - regardless of whether as a push switch or as Knife disconnector developed - is peculiar that they have a more or less large Have air or gas emissions, which on the one hand the separation distance between the Phases impaired, which must be limited by design effort, on the other hand, depending on the direction of gas discharge, switch parts in the course of the multitude of Dirt on circuits and reduce dielectric strength.

The object of the invention is to develop a load disconnector in which the constructive design a clean, fast separation of the separating arc without ejection, minimal disconnect contact wear and high switching frequency all of this is achieved with cheap, small dimensions.  

In a first embodiment, two fixed contact pieces ( 1 ) ( 2 ) are connected to a base frame ( 4 ) at medium-voltage insulators ( 3 ) at a shock-proof distance. The arrangement of these contact pieces ( 1 ) ( 2 ) was chosen so that due to the elevated position of the one ( 2 ), the pair of separating knives ( 5 ) connecting the two contact pieces in the ON position in the OFF position only one, in comparison to common designs , reduced switch height can arise (Figure ( 1 )).

The necessary contact pressure of the pair of isolating knives ( 5 ) on the contact pieces ( 1 ) ( 2 ) is here instead of the usual plate spring sets or spring arrangements by means of simple, inexpensive tension springs ( 6 ) without bent eyelets, in the outer turns by inserted sheet metal pieces, e.g. B. leaf springs ( 7 ), which additionally includes a flat spring line (Figure ( 2 )).

In a further embodiment, an associated extinguishing device ( 8 ) is arranged between the pairs of contact blades ( 5 ) in an axially extendable and pivotable manner. In cooperation with the catch / locking hook ( 9 ) inside the contact piece ( 1 ) placed below, when the disconnecting knife pair ( 5 ) is switched off, the swiveling extinguishing device ( 8 ) is forced to elongate against an increasing spring restoring force (claim 3; 4).

The extinguishing device ( 8 ) consists of a rigid front part, the disengagement piece ( 10 ), which engages with the catch / latching hook ( 9 ) when it is switched on, and the backward pivoting mechanism ( 14 ) in the rear part. The insulation housing of the extinguishing device ( 8 ) is firmly connected to a guide pin ( 11 ) which is guided over a pair of cams ( 12 ) and thus controls the switching process. The opening pair of isolating knives ( 5 ), which takes the extinguishing device ( 8 ) with it via an internal pivot point ( 13 ), opens, controlled by means of the cam disc ( 12 ), after a sufficiently large, structurally defined separation distance between isolating knife ( 5 ) and contact piece ( 1 ) the vacuum switching path and switches off the load current. The separation path inside the switched V-chamber is kept open in the interaction between the catch / latching hook ( 9 ) and the cam disc ( 12 ), which ensures that a voltage-proof separation path remains inside the V-chamber during the further OFF switching movement (Claim 6 and 7 Fig. 3a, 3b, 3c).

Only shortly before reaching the OFF position does the release piece ( 10 ) come out of the catch / locking hook ( 9 ). Now the swivel device ( 14 ) is able to turn back the extinguishing device ( 8 ) between the pair of separating knives ( 5 ) (claim 7 Fig. 4).

The load disconnector vacuum interrupter ( 15 ), placed in the rear part of the extinguishing device ( 8 ), is completely enclosed by an insulating housing ( 16 ) (e.g. molded plastic part), which protects the chamber from external influences, the axial guidance, the precisely limited switching stroke of the chamber as well as the contact pressure of the chamber by means of a compression spring ( 17 ) together with addition ( 18 ) of a possible erosion inside the chamber. In another embodiment, in order to increase the outer insulating distance of the vacuum chamber, this can be completely encapsulated in the insulating housing with a curable dielectric ( 19 ) (e.g. curable silicone compound) in order to ensure safe use for higher voltage levels (e.g. 24 kV) ensure with the same dimensions (claims 5 and 6; Figure ( 5 )).

The drive arrangements, irrespective of whether the spring drive (20 or the memory drive) were basically arranged in the inside of the base frame ( 4 ), so that its outer surfaces are free of drive arrangements and also - similarly as described at the beginning - a small size, this time in the This was achieved because the selector shaft (21 is guided partially concentrically in the tensioning shaft (22 and thus represents an inexpensive solution since one shaft was saved (claim 8 - Figures ( 6 a) and ( 6 b)).

Claims (8)

1. Medium voltage switch disconnector with one between the Isolating knives integrated load switching device, which in the form of a Series with a vacuum interrupter switched commutation path is pronounced. The vacuum chamber switches to a defined switch the load current safely and cleanly without ejection. 2. Medium voltage switch disconnector with a fixed contact piece, which in a medium voltage insulator on a base frame is attached to an elevated position, at which a contact pressure loaded Pair of separating knives is pivotally mounted; characterized in that a another fixed contact piece in a significantly lowered position over a Medium voltage isolator with a voltage level corresponding to the Distance to the former contact piece is attached to the base frame. The at different distances from the flange surface of the bottom frame-mounted contact pieces allow one - compared to the Competition - lower total height of the switch in the OFF position, what in turn allows a small installation depth of panels.   3. Medium voltage switch disconnector switch according to claim 1, characterized characterized in that the contact pressure of the separating knife pair, which in switched on state connects the fixed contact pieces by integrated Tension springs without eyelets by leaf springs between the two outermost Windings transfer their tensile force to the pair of disconnect knives is generated. In contrast to the commonly used disc spring sets on the Outside of the knife, which is the width of the knife Couple can enlarge with the tension springs without eyelets, which only consist of resilient coils, a flatter, cheaper contact pressure course be ensured. 4. Medium-voltage isolating switch disconnector according to claims 1 and 2, characterized in that a load switching device is pivotally mounted between the pair of isolating knives, which ensures the commutation and interruption of the breaking current via a sensible, path-dependent mechanism.
Medium-voltage disconnector switch-disconnector according to previous claims, characterized in that there is a catching device for the vacuum circuit-breaker device in the interior of the lower-lying contact piece, which is designed as a switch-on contact, the design of which makes it impossible to release it before reaching a voltage-proof isolating plug ,
Medium-voltage isolating switch disconnector according to the preceding claims, characterized in that the vacuum interrupter is shockproof and protected from external influences, is mounted in a plastic insulation housing, which on the one hand ensures the necessary contact pressure of the vacuum interrupter, but on the other hand also the switching stroke of the vacuum switch chamber limited to protect them. 5. Medium-voltage switch disconnector switch according to claim 4 thereby characterized in that the vacuum load switching chamber in the plastic insulation housing in its entire fixed length by an injected, so cured dielectric (e.g. curable silicone mass) their insulation stretch far beyond the length specified by the porcelain insulator length has increased and so for higher voltage levels (here 24 kV) at the same Overall length can be used.   6. Medium voltage switch disconnector switch, according to claim 4 and 5, characterized in that the insulation housing of the V-chamber firmly with a guide pin is connected, which, guided via a with the Disconnect knife connected pair of cams, a sufficiently large, constructively defined separation distance between the switching off Disconnector pair and the contact piece until the start of the interruption the current commutated to the quenching device through the vacuum Switch chamber ensures. 7. Medium-voltage disconnector switch-disconnector according to the preceding claims, characterized in that the cam disk control ensures that the isolating path inside the switched V-chamber is kept open during the switching process according to a predetermined, defined path. On the other hand, the cam disc control ensures that after the switching process has been completed and a voltage-proof isolating distance has been reached, the disengagement piece from the catch hook inside the lower-lying contact piece is actuated, which causes the extinguishing device to become free from the contact piece, and this, in turn, causes the extinguishing device mentioned to pivot back with the still opened V-chamber separating distance between the pair of isolating knives by means of a mechanism on the insulation housing.
Only after swiveling the extinguishing device (with V-camera) almost between the pair of isolating knives, shortly before it reaches the OFF position, does the cam disc control allow the V-chamber to close, and the load-break switch is ready to be switched on again. 8. Medium voltage disconnector switch disconnector according to previous type say characterized in that the mechanical drives - whether so jump or spreader drive - through a special training of Switching shaft, which is partially guided in the tensioning shaft, always with all parts such as levers, coil springs and jack systems inside the Base frame except for the necessary, above tension drive shafts for load disconnectors and, if applicable, earth electrodes are free of drive mechanisms.