KR20000029814A - Sf6 gas-insulated switch installation for electricity distribution supply networks - Google Patents

Abstract

PURPOSE: An Electricity distribution supply networks is provided on which power-circuit breaker is installed. Power circuit breaker has the feature that keeps insulation-distance for protecting cable part or fuse compound part of load-breaker switch or transformer. CONSTITUTION: An SF6 gas-isolated switch installation for several switchboard sections,each with a three-pole separating switch and an earthing device. A switchboard section is equipped with a separating switch designed as a transformer switch. The switch installation has for the support of mobile switch contacts and the connection of cables and/or cutouts appropriate lead-through in the housing walls and switch shafts mounted on said walls, as well as omnibus bars for the fixed contact of phases L1, L2 and L3, and individual phase quenching devices directly connected to the omnibus bars(9). Blow-out coils(13, 13a) are introduced according to an arrangement which when in off position meets the requirements for a dis connected section, with a contact arrangement corresponding to the remaining load-break switches for the three phases of the switch designed as a transformer switch

Description

SF6 Gas-Insulated Switch Installation for Electricity Distribution Supply Networks

An SF6 gas-insulated switchgear assembly for a power distribution network having a power circuit breaker (power isolating switch) with an insulating distance to protect the load-breaking switch cable portion and the load-breaking switch / fuse combination or transformer. .

Switchgear assemblies of this kind are known. In the power distribution base station, an intermediate voltage switchgear assembly with three switchboard sections has been commonly used, two of which are connected to surround the main cable, and the other switchboard section has a high voltage for the output transformer feeder. Fuses or power isolation switches are installed.

SF6 gas-insulated load-break switch placement is known from DE-OS 38 20 489, where the load-break switch is arranged in a sealed housing filled with sulfur hexafluoride (SF6) and for each phase And a quenching device consisting of a fixed and mobile contact piece, a ground contact, and a deion plate, wherein the fixed contact piece of the same phase is a bus-bar. Fixed directly to the bus, the dissipating devices are arranged adjacent to each other directly on the bus-bar.

In order to make the switchgear assembly of this kind very small and easy to assemble, in the new development stage, which was the subject of DE 40 11 397 C2, the essential parts of the load-break switch are combined to form a pre-assembled module. Is initially inserted into the open housing and connected to the open housing. In the switchgear assembly, the ground contact belonging to the grounding device is fixed to the switch shaft and can be assembled in a simpler manner.

The purpose of the arc dissipation device disposed on the phase of a load-disconnect switch or power isolating switch is as a result of the heat of the joules when the circuit is interrupted by the opening of the contact and the vaporization of the final metal bridge to ensure the switching capability of the switch. It is to quickly extinguish the arc that occurs and appears on it. In the case of alternating current, the object is to efficiently reduce the charge carriers in a short time between zero current and the rise of the return voltage.

In addition to the decay device consisting of deionized plates, other decay devices for electrical switchgear, such as decay coils, are known, in which the forming arc is rectified and, as a result of the current passing through the coil, eventually rotates the arc, Create a magnetic field to destroy. EP 0 012 522 therefore describes an electrical switchgear with a dissipation coil on the stationary contact. The subject matter of EP 0 021 577, EP 0 058 007 and EP 0 313 106 B1 is also an electrical switchgear with a quenching coil, such as an arc quenching device.

In the SF6 switchgear assembly mentioned at the outset, the load-blocking switch of the switchboard section is optionally coupled with a fuse assembly with a high voltage fuse with striker pins as a hermetic seal, the load-breaking switch having a tripping connection. An accumulation-energy mechanism is provided having a tripping store that is operable using a striker pin of one of the fuses through a tripping linkage. Desired options regarding the interaction of the load-break switch with the fuses are open. In addition, with respect to the breaking capacity (level of the nominal fuse current) and the associated insulation distance conditions, restrictions are imposed on the deionization plate used as the quenching device.

It is an object of the present invention to provide an SF6 gas-insulated switchgear assembly according to the preamble of claim 1, which has an increased breaking capability while leaving the entire space for switch placement intact.

Both the load-breaker switch and the power isolating switch are designed to meet the insulation distance conditions and to have the required dielectric strength depending on the nominal voltage. Similarly, the switches are designed to ensure their switching capability by controlling and extinguishing the arc via the shortest path.

This object is achieved with an SF6 gas-insulated switchgear assembly having the features of the preamble of claim 1. The switchgear assembly of the previously defined type has several switchboard sections with three pole load-breaking switches and a grounding device, wherein one switchboard section has a load designed as a transformer switch having a phase coupled with a fuse. A cutoff switch may be provided, or it may have a power isolation switch, wherein the fixed contacts of phases L1, L2 and L3 are rigidly connected to the bus-bars on which the individual phase extinguishing devices are arranged; According to the present invention, the vanishing device for phases L1, L2, and L3 of a switch designed as a transformer switch with a switching contact arrangement corresponding to the remaining switches is a vanishing coil, and the vanishing device for phases of the residual breaking switch is known as Likewise, it is characterized in that the decay chamber having a deionized plate.

In the space conditions provided for switches having quenching chambers and corresponding switch contact arrangements, the coil axis makes an obtuse angle on the fixed contact side with the switch contact in the open position, and the free end of the switch contact in the open position Located in the region of the axis, at least the coil radius corresponds to the distance between the switch contact in the open position and the fixed contact, the coil edge region on the fixed contact side being at least from the free end of the fixed contact and the switch contact moving past it. If the quench coil is arranged and designed to be a distance, the insulation distance condition is met in the case of a power isolation switch, and means are provided to ensure the switching performance.

In the case of a load-break switch, the coil axis is at a right angle or an obtuse angle on the stationary contact side such that the coil contact has a switch contact in the open position, and each extinguished coil extends into the immediate vicinity of the stationary contact, assuming the base of the arc, When the quenching coil is designed and arranged to have a deflector disposed tangentially in the movement path of the free end, an insulation distance condition is satisfied and a means for ensuring switching capability is provided. The deflector plays an important role in ensuring the switching capability of the load-break switch. It transfers arc formation along the deflector into the coil between the contact blade and the contact. The arc remains very short because of the short distance, but quickly and reliably reaches the internal path of the vanishing coil. The purpose of the deflector is therefore to allow a smaller vanishing coil to be placed away from the bus-bar contact in the case of a load-breaking switch than in the case of a power isolating switch, with the arrangement causing the arc to reverse in the vanishing coil.

The placement of the quenching coil on the transformer switch increases the breaking performance of the switchgear assembly at a given invariant installation site, so that more accurate requirements or the short circuit current blocking required by the load-breaking switch / fuse combination are provided. Indicates significant technological progress.

The stationary contacts and vanishing coils for each phase L1, L2 and L3 may be conveniently placed on a common cross arm connected to the bus-bars for each phase, in which the movable switch contacts are mounted on the stationary contacts. And is rotatably disposed to pivot into a ground position from and beyond a closed position provided parallel to the cross arm.

The dissipation coil may be arranged such that the coil axis is at an obtuse angle of preferably 165 ° to 175 °, or at right angles to the switch contact in the open position such that the coil axis is on the side facing the switch contact in the open position toward the fixed contact. do. By the latter dissipation coil arrangement, the stationary contact is positioned in the center of the dissipation coil and the deflector is directed into the coil.

In order to avoid increased arc erosion at the edge of the contact, caused by high breaking current (power isolating switch), the arc of the arc-resistant material of the free end of the movable switch contact and the contacting edge of the fixed contact is larger than the respective contact material Caps and arc erosion strips and caps may be provided.

In conclusion, in order to facilitate the assembly process and reduce the space required in the assembly switchgear assembly, the quenching coil and quenching chamber are connected to the module, which is inserted into the housing which is initially open from the rear. The module may also consist of a bus-bar, a fixed contact fixed to the bus-bar by a cross arm, an insulating support for the cross arm and holding devices for placement on the housing. Three ground contacts belonging to the grounding device are fixed to the switch shaft.

The invention is described below with reference to the embodiments. The contents of related drawings are as follows.

1 is a plan view of an SF6 gas-insulated switchgear assembly (load-blocking switch) according to the present invention.

2 is a rear view of the switchgear assembly (power isolation switch).

3 is a phase diagram of the load-break switch in conjunction with a fuse.

4 is a diagram of another embodiment showing the phase of a load-disconnect switch coupled with a fuse.

5 shows another stationary and switch contact embodiment in the case of a power isolated switch.

According to FIG. 1, the gas-insulated switchgear assembly consists of an airtight housing 1 having three switchboard parts I, II and III therein, each of which comprises a three-pole load-break switch and A grounding device is provided. The switchboard part I accommodates a load-blocking switch designed as a transformer switch, and phases L1, L2 and L3 of the load-blocking switch are coupled with a fuse (not shown) through a feed-through. do.

The load-breaking switch has a contact blade 3 as a movable switch contact, which is in the form of a double blade. With respect to phase L2, each of the contact blades 3 is hung in a respective transport pipe 2, and for phases L1 and L3, a special contact is connected to the associated transport pipe 2 by bearing pieces (not shown). A blade insulating support is used. The conveying pipe 2 is located at the front face 4 of the housing 1. The contact blade 3 is operated via a switch shaft 5 mounted to the wall of the housing 1, the switch shaft 5 being connected to the contact blade 3 via a lever 6 and a connecting rod 7. Is connected to. The ground contact 8 is directly connected to the switch shaft 5.

The contact blade 3 can occupy three positions. In the closed state, each contact blade 3 is in contact with a fixed contact 10 which is firmly connected to the bus-bar 9. The closed state is shown in the switchboard section III. In the open state, each contact blade 3 is moved to a height between the stationary contact 10 and the ground contact 8. This switching state is shown in the switchboard section II. In the grounded state, each contact blade 3 is in contact with the ground contact 8, which is shown in the switchboard section I.

Three bus-bars 9 are arranged in the housing 1 in which the fixed contacts 10 of each of phases L1, L2 and L3 of the load-break switch are arranged. In addition, dissipating devices are arranged on the bus-bar 9 for each phase L1, L2, and L3, among which dissipating devices for the phase of the unfused fused load-breaking switches of the switchboard parts II, III. Is the decay chamber 12 provided with the deionization plate, and the decay device for the phase of the load-disconnect switch coupled with the fuses of the switchboard part I is the decay coil 13a. These quenching coils 13a and fixed contacts 10 are arranged on cross arms 14 connected to the respective bus-bars 9, and in the open position the contact blades 3 are aligned parallel to this cross arms. have. The quenching coil 13a is arrange | positioned on the side toward the fixed contact part 10 so that coil axis A may make obtuse angle (alpha) of about 165 degrees with switch contact part 3 in an open position (refer FIG. 2).

The quenching coil 13a and the quenching chamber 12 are disposed on the bus bar 9, the cross arm 14, whereby the fixed contact 10, the cross arm 14, which is firmly connected to the bus bar 9. Combined with an insulating support (15), a bracing device (16) and a strut (18) for placement on the housing (1), through the rear face (19) before the housing is hermetically sealed. Form a module that can be inserted into.

Each quenching coil 13a has a deflector 17 in the immediate vicinity of each stationary contact 10, which deflector 17 is electrically connected to the end of the coil winding and has a contact blade 3 width and contact. It is arrange | positioned in the tangential direction to the movement path of the free end of the blade 3.

2 shows three bus-bars 9 and quenching coils 13 arranged thereon by a portion 9a of the bus-bars. The dissipation coil is rigidly arranged on the cross arm 14 which loads the stationary contact 10, which in turn is placed on the housing by the insulating support 15, the brace device 16 and the support 18. Supported. It is evident that the switchboard section I (power-isolated switch) does not take up more installation space in the housing 1 than the switchboard sections II, III.

3 shows an enlarged arrangement of the quenching coil 13a for one phase. The quenching coil 13a is supported on the bracket 20, which is electrically connected to the beginning of the winding of the quenching coil 13a and the cross arm 14, in this way a bus-bar ( 9) is electrically connected.

4 shows another quenching coil for the switchgear assembly in which the quenching coil 13a is arranged on the bracket 21 such that the coil axis A is at right angle β with the contact blade 13a in the open position, the quenching coil 13a ) Surrounds the stationary contact 10. Again the vanishing coil 13a is electrically connected to the end of the coil winding in the immediate vicinity of each stationary contact 10 and has a width of the contact blade 3 and tangentially to the movement path of the free end of the contact blade. The deflector 17 arrange | positioned is provided.

In the embodiment of the switchgear assembly for the high breaking current according to the invention, in order to increase the arc erosion resistance, a cap 22 is provided at the free end of the contact blade 3 and an arc erosion strip 23 at the fixed contact 10. ) May be installed. The material of the cap 22 and the arc erosion strip 23 is more arc-resistant than the base material of each contact 3 or 10 (FIG. 5).

Claims (6)

A hermetic housing for several switchboard sections, each of the several switchboard sections having a three-pole load-break switch and a grounding device, wherein one of the several switchboard sections is designed as a transformer switch and coupled with a fuse. A load-break switch having a phase is installed, or the one switchboard portion has an airtight housing for the several switchboard portions with a power isolating switch, supports movable switch contacts in the longitudinal wall of the housing and Or a transfer shaft suitable for connecting fuses, a switch shaft mounted on said longitudinal wall, a bus bar for fixed contacts of phases L1, L2 and L3 and an individual phase extinguisher directly connected to said bus-bar. The dissipation device of the load-breaker switch, which is not used as a transformer switch, has a deionization plate. In the insulated switchgear assembly, - the extinction chamber installed in the tree, the power distribution network SF6 gas The vanishing device for phases L1, L2 and L3 of the switch designed as a transformer switch with a switch contact arrangement corresponding to the residual switches is a vanishing coil 13; 13a in an arrangement which satisfies the insulation distance condition in the open state, and switching Has the means to ensure abilities, The extinction coil 13 for the power isolation switch, The coil axis A of the coil forms an obtuse angle α on the fixed contact portion side with the switch contact portion 3 in the open position, and the free end of the switch contact portion 3 lies within the region of the coil axis A. And wherein the coil radius corresponds at least to the distance between the switch contact 3 and the fixed contact 10, On the fixed contact side, the coil edge region is designed to be arranged at a minimum distance from the free end of the fixed contact 10 and the switch contact 3, The quenching coil 13a for the load-breaking switch, The coil axis A of the quenching coil forms a right angle or an obtuse angle β; α on the fixed contact portion side with the switch contact portion 3 in the open position, Each of the vanishing coils 13a extends inwardly near the fixed contact portion 10 assuming the base point of the arc and is disposed tangentially to the movement path of the free end of the switch contact portion 3 ( 17) switchgear assembly characterized in that the arrangement is designed to have. In claim 1, The fixed contact 10 and the extinction coils 13 and 13a for each phase L1, L2 and L3 are arranged on a cross arm 14 connected to the respective bus-bar 9 and connected to the cross arm. Switchgear assembly characterized in that the movable switch contacts (3) in parallel open position are aligned. The method of claim 2, The obtuse angle (α) is an opening and closing device assembly, characterized in that 165 ° to 175 °. The method of claim 2, The vanishing coil (13a) is designed and arranged such that the vanishing coil surrounds the fixed contact (10) and the deflector (17) is directed into the coil. The method of claim 1, The free end of the movable switch contact 3 is provided with a cap 22, and the fixed contact 10 is provided with an arc erosion strip made of a material that is more arc-resistant than the respective contact material on the contact blocking edge. Switchgear assembly characterized in that the. The method of claim 1, The quenching coil 13; 13a and the quenching chamber 12 are connected to a module insertable into the housing 1 which is initially open at the rear face 19, the module being a bus-bar 9, cross Bracing device for placement on the fixed contact 10, the insulating support 15 for the cross arm 14, and the housing 1, fixed on the bus-bar 9 by an arm 14) 16), The three earthing contacts (8) belonging to the earthing device are fixed to the switch shaft (5).