WO2011018426A1

WO2011018426A1 - Cutoff chamber for medium- or high-voltage circuit breaker with reduced controlling power

Info

Publication number: WO2011018426A1
Application number: PCT/EP2010/061535
Authority: WO
Inventors: Denis Dufournet; Michel Perret; Dan Lucius Penache
Original assignee: Areva T&D Sas
Priority date: 2009-08-14
Filing date: 2010-08-09
Publication date: 2011-02-17
Also published as: FR2949170A1; EP2465127A1; JP2013502030A; JP5615362B2; CN102484015A; FR2949170B1

Abstract

The invention relates to a novel cutoff chamber (1) with reduced controlling power.

Description

BREAKER CHAMBER FOR A MEDIUM OR HIGH VOLTAGE CIRCUIT BREAKER WITH REDUCED HANDLING ENERGY

DESCRIPTION TECHNICAL FIELD

The invention relates to a breaking chamber for use in a medium or high voltage circuit breaker typically in the range of 7.2 kV to 800 kV.

An interesting particular application is the use in an alternator circuit breaker.

PRIOR ART

In this particular application in which it is necessary to be able to cut a high short circuit current, typically 63 kA or more, the design must be provided so that the opening and closing maneuvers of the three-pole circuit breaker can be performed only by means of actuation of a spring latching mechanism control which is located outside the interrupting chambers.

However, the mass and dimensions (volumes) required for the parts through which the short-circuit current increases with the value of the latter.

The maneuvering energy required to move them to cut off the short-circuit current accordingly increases to the point where it is no longer possible to use low-speed controls energy with external spring coupling to the cutoff chambers that are standard.

To solve this problem, various alternative solutions to an oversizing of the external controls have been proposed.

Thus, patent FR 2 435 118 discloses a solution which consists in integrating a coil spring 20 inside the interrupting chamber, which is compressed during a closing operation by the external control and whose function is to compress the gas arc blowing present in a blowing volume during an opening maneuver. Referring to the embodiment of Figures 5 and 6 of this patent, the coil spring 20 bearing against the blow piston 15 formed integrally and around an arc contact 18 is compressed during the closing maneuver by the other arc contact 21 connected to the control. During an opening maneuver the coil spring 20 expands and thus compresses the gas present in the blast volume 30. During the high current cut, the pressure in this volume 30 is further increased by the heating of the gases. from the arc energy 25.

The main disadvantage of this solution is that the piston 15 is pushed in the opposite direction (to the left in FIGS. 5 and 6) when the pressure is increased by the arc energy. The blowing volume 30 is then increased, which tends to lower the pressure of the blowing gas during the cut. A Another disadvantage is that the arc blow is limited to single blow through the nozzle 27b.

This same patent FR 2 435 118 proposes in its embodiment of FIGS. 36 and 37 means which in theory are able to overcome the main drawback: these means consist of latches 43 arranged at the edge of the blast volume 30 and actuated by leaf springs 44 which are provided to be housed in grooves 45 formed in the piston 15 and thus lock in translation in the detent position of the spring 20 having compressed the gas. In practice, it turns out that these mechanical means 43, 44, 45 for locking in translation of the piston can not be effective in recent blow-off chambers in which the pressure variations are too high (up to 60 bar and more). In other words, the mechanical translation locking means 43, 44, 45 can not actually block the piston 15 when breaking high short circuit currents.

Patent EP 0 441 292 discloses a solution similar to the previous one and which furthermore consists, according to the short-circuit operation illustrated in FIGS. 3 and 4, of producing a double blow-out flow from the volumes V1 and V4 in parallel towards the contact d 4A and through the nozzle 16. However, the volume Vl increases during the breaking of high currents and consequently the overpressure generated for the cut is reduced. Another disadvantage is that the two arcing contacts 4A, 7A may repel each other when breaking short-circuit currents. high circuit if the force of the spring 13 is not sufficient. In addition, the blows in parallel from each other respectively volumes V1, V4 tend to be mutually disrupted. In other words, this solution can not be applied for high short-circuit currents (> 25kA).

WO 2006/066420 discloses another solution which consists in cooling the arc which occurs between the arcing contacts 4 and 5 by blowing gas generated from the volume 24, as shown schematically in FIG. 1 of this patent. The increase in pressure in the volume 24 is achieved by the compressed gas from the volume 27 through the channel 29 and simultaneously by the heating of the gases caused by the energy of the arc.

A disadvantage of this solution is that the volume 27 is arranged on an outer diameter of the volume 24. This outer diameter is wide and tends to increase the diameter of the insulators 3, 3c.

Another disadvantage of this solution is that the blowing piston 28 and the arc contact 4 must be moved by the same mechanism by means of a complex linkage because of the different races to be performed for each moving part and that the linkage must have completed compression in the volume 27 when the arc is established between the arc contacts 4 and 5.

It is known from patent GB 1570035, very old, a circuit breaker breaking chamber comprising rods 41 fixed on an arc blowing piston 37 and a sliding cup 30 around a movable arcing contact 14 in temporary support. against the rods, the displacement of the movable arcing contact 14 by the operating member allowing the simultaneous movement of the blowing piston under the action of a spring 38 to the complete compression of a compression volume 40.

The breaking chamber according to this document GB 1570035 is not adapted to the performance required for recent high-voltage circuit breakers from 7.2 kV to 800 kV. Indeed, in the disclosed breaking chamber 1 'heating blowing gases occurs by generating, prior to the cutting of the final arc 28, an initial arc 27 within the same blowing volume 6, 26. This leads to a significant deterioration of the dielectric properties of the gas contained in this volume 6, 26 and therefore implies an unsuitability for recent high-voltage circuit breakers.

The object of the invention is thus to provide a breaking chamber for high or medium voltage circuit breakers typically in the range of 7.2 kV to 800 kV which does not have the disadvantages of the prior art and which requires a low energy maneuver , especially in case of high short-circuit current failure (> 63kA). SUMMARY OF THE INVENTION To this end, the object of the invention is a current breaking chamber for a medium or high voltage circuit breaker extending along a longitudinal axis and comprising: a pair of arcing contacts, one of which is fixed and the other is movable along the longitudinal axis (XX ') under the action of a maneuvering rod to separate from one another during a power failure ; the travel in translation of the movable contact being sufficiently high to achieve the power failure whatever value and to obtain the dielectric strength of the circuit breaker,

an arc-blowing nozzle integral with the fixed-arc contact,

- A blowing chamber whose volume V2 is fixed and which opens inside the blowing nozzle to bring the blowing gas to the arc formed between the contacts during a cut,

a compression chamber, substantially arranged behind the blowing chamber parallel to the longitudinal axis, and whose volume Vl varies and opens into the blowing chamber under the action of a piston,

a helical spring fixed at one of its ends directly to the piston and at the other of its ends to a fixed part,

temporary mechanical connection means between the piston and the movable arcing contact for compressing the spring bearing against the piston during a closing maneuver of the contacts and to obtain a stroke of the movable arcing contact greater than the stroke of the spring which performs the complete compression of the volume Vl, said complete compression of the gas in the volume Vl being moreover performed approximately as soon as the arcing contacts are separated,

wherein the blowing chamber opens into the blast nozzle through a blast channel for supplying the blast gas to the area outside the blast chamber where the single arc formed between the arc contacts occurs during a blast. cut.

Otherwise defined, the invention therefore consists essentially in combination with:

define a fixed blowing volume and a fixed blast nozzle in order to reduce the moving mass of the breaking chamber and thereby the kinetic energy,

generating a pressure increase in the blowing volume mainly by heating the gases in high currents, and having a pressure increase by the compression volume for the cuts in small currents,

- producing a compression of the gases, until approximately that the arcing contacts are separated, and only by a coil spring which pushes the piston and thus reduces the compression volume, the pressure increase being then transmitted to the volume of blowing through the opening of a valve. The spring is also arranged just behind the piston and is compressed during a closing operation by being pushed by the temporary mechanical connection means. The energy required for the compression of the gas is thus minimized because of the proximity of the spring to the compression volume, obtaining a simple way of moving the piston and the movable arcing contact with their respective necessary strokes, the stroke of the movable arcing contact being equal to the compression stroke of the piston plus an additional stroke to obtain a sufficient distance between the arcing contacts in the open position (high enough to achieve the power failure regardless of value and to obtain the dielectric strength of the circuit breaker),

defining a dual flow flow geometry on an area outside the blowing volume where the single arc formed between the arcing contacts occurs during a break,

have the possibility to use a circuit breaker external control command that provides just the energy needed to close the contacts and to maneuver the movable arcing contact when opening.

Compared to the breaking chamber according to GB 1570035 cited in the preamble, the breaking chamber according to the invention is perfectly suited to the performance required in modern high-voltage circuit breakers, typically from 7.2kV to 80OkV.

In comparison with the breaking chambers according to the documents FR 2 435 118 and EP 0 441 292 mentioned in the preamble, the breaking chamber according to the invention has:

a blown volume V2 that is not increased with the large increases in pressure during the high power outages, a blow-molding chamber with a standard shape such as that used in modern high-voltage circuit breakers, and which opens with a small diameter channel on the zone where the arc occurs,

a double flow of blowing gas on

1 bow.

By comparison with a breaking chamber according to the patent WO 2006/066420 mentioned in the preamble, the breaking chamber according to the invention has:

a smaller diameter of the active parts of the arrangement of the compression chamber behind that of blowing,

a simpler mechanism for moving the piston and the movable arcing contact,

- greater efficiency due to the proximity of the spring with the compression volume,

a shape of the blowing chamber and a channel shape connecting the blowing chamber to the standard arc zone, as usually used in high-voltage circuit breakers. This makes it possible to have an optimal mixture between hot and cold gases in the blowing volume.

According to a first embodiment, the temporary mechanical connection means are arranged outside the blow and compression chambers with respect to the longitudinal axis.

An advantageous variant of the temporary mechanical connection means consists of a tube fixed to the piston and of diameter substantially equal to the permanent contact itself fixed to the moving arcing contact, said tube being in abutment against the end of the contact mobile permanent until complete compression of the volume Vl.

According to a second embodiment, the temporary mechanical connection means are arranged inside the blow and compression chambers with respect to the longitudinal axis.

According to an advantageous variant, the fixed arc contact has a generally tubular shape, the temporary mechanical connection means being arranged inside the fixed arc tube. This variant is advantageous because it makes it possible to obtain a more compact chamber with respect to a chamber according to the other variant with the temporary connection means consisting of a tube of substantially equal to the permanent contact.

According to this advantageous variant, the temporary mechanical connection means comprise a tube fixed to the piston and of smaller diameter than the fixed contact, said tube being in abutment against the end of the movable arc contact until the complete compression of the volume Vl. Here we assign a new temporary support function to the movable arcing contact, which simplifies the realization compared to the other variant with the temporary connection means consisting of a tube substantially equal to the permanent contact.

The invention relates to a high or medium voltage circuit breaker, comprising, for a pole, one or more breaking chambers described above. BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and characteristics of the invention will emerge more clearly on reading the detailed description given with reference to the following figures:

- Figures 1 to 4 show a first embodiment of a breaking chamber according to the invention for longitudinal sectional view and in different positions from the closure of the contacts to the extreme opening of the contacts and the cut made,

FIG. 5 is a cross-sectional view of the interrupting chamber according to FIGS. 1 to 4,

- Figures 6 and 7 show a second embodiment of a breaking chamber according to the invention for longitudinal section and respectively in the closed position of the contacts and the extreme opening of the contacts and the cut made.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The current interrupting chamber 1 for a medium or high voltage circuit breaker according to the invention extends along a longitudinal axis (XX ') and firstly comprises an insulating envelope 10 and a pair of permanent contacts 2, 3 of which one is fixed 3 and the other 2 is movable along the longitudinal axis (XX ') under the action of a not shown operating rod.

It also comprises a pair of arcing contacts 4, 5 of which one is fixed and secured. the permanent fixed contact 3 and the other 5 is movable along the longitudinal axis (XX ') and integral with the permanent movable contact 2. The arc contacts 4, 5 are provided to separate each other during a power failure . The travel in translation of the movable contact 5 is sufficiently high to achieve the power failure regardless of value and to obtain the dielectric strength of the circuit breaker.

There is further provided an arc-blowing nozzle 6 integral with the fixed-arc contact 4.

A blowing chamber 7 delimited by a fixed part 70 and the arc-blowing nozzle 6 defines a fixed volume V2 and which opens inside the blast nozzle 6 by a blowing duct 700 of reduced diameter to bring the blowing gas in the zone Z outside the chamber I ₁ where the arc formed between the arcing contacts occurs during a break.

A compression chamber 8 defines a volume Vl that varies and opens into the blowing chamber 7 under the action of a piston 9. The compression chambers 8 and blowing 7 are substantially arranged one behind the other parallel to the longitudinal axis XX '.

A helical spring 11 is fixed at one of its ends 110 directly to the piston and at the other of its ends 111 to a fixed part 12.

The interrupting chamber 1 further comprises temporary mechanical connection means 13 between the piston 9 and the movable arcing contact 4 to compress the spring 11 against the piston during a closing operation of the contacts 4, 5 and to obtain a stroke of the movable arcing contact 5 greater than the stroke of the spring 11 which performs the complete compression of the volume Vl. Furthermore, the complete compression of the gas in the Volume Vl is approximately made as soon as the arcing contacts 4, 5 are separated (FIG. 2).

The first embodiment provides that the spring 11 is compressed by temporary connection means arranged outside the rooms of the chamber (Figures 1, 2, 3, 4 and 5). As illustrated, these means 13 consist of a tube 130 fixed to the piston 9 by pins 131.

The second embodiment provides that the spring 11 is compressed by temporary connection means arranged inside the chamber 1. (Figures 6 and 7). As illustrated, these means 13 consist of a tube 132 attached to the piston 9 and of smaller diameter than the fixed contact 4, said tube 132 being in abutment against the end of the movable arc contact 5 until the complete compression of the volume Vl.

The operation of the breaking chambers 1 will now be explained in more detail.

When closing the contacts, the moving part 2 pushes the tube 130 and thus the piston 9 which is connected thereto by the axes 131 (see for example Figure 5) and compresses the spring 11. A valve 14 implanted in an opening 90 in the piston 9 avoids having a pressure drop in the volume Vl (Figure 1).

When opening, the spring 11 pushes the piston 9 and the tube 130 which is bound (towards the right in Figure 2), the part integrating the arc contact 5 and permanent 2 is also pushed and at the same time moved in translation by the not shown actuating rod. The dimensioning is such that the tube 130 and the part 2, 5 remain in contact C until the position in FIG. 2 is reached. The permanent contact 2 is separated from the permanent contact 3 in this position. During this phase, the gas is compressed in V1, the overpressure opens the valve 15 between the volumes V1 and V2, so that the volume V2 is precompressed and before the energy of the arc has heated the gas in V2.

Then, the arc contact 4 remains fixed while the arc contact 5 is moved by the not shown operating rod (Figures 3 and 4). After the separation of the arcing contacts 4, 5 has taken place, the arc is stretched, the energy of the arc heats the gas in the volume V2 and increases the pressure in this volume V2. At zero current, the overpressure in the chamber 7 produces a blow through the blast channel 700 which cools the arc in the zone Z outside the chamber 7 and consequently, the arc is interrupted.

In the embodiment of FIG. 6, the spring 11 is compressed when the piston 9 is pushed to the left by the moving arc contact 5 via the insulating tube 132.

FIG. 7 shows the breaking chamber 1 according to the second embodiment, in the fully open position.

Claims

1. A circuit breaking chamber (1) for a medium or high voltage circuit breaker extending along a longitudinal axis (XX ') and comprising:

a pair of arcing contacts of which one (4) is fixed and the other (5) is movable along the longitudinal axis (XX ') under the action of a maneuvering rod to separate each other during a power failure; the travel in translation of the movable contact being sufficiently high to achieve the power failure whatever value and to obtain the dielectric strength of the circuit breaker,

an arc-blowing nozzle (6) integral with the fixed-arc contact,

- A blowing chamber (7) whose volume V2 is frozen and which opens into the blowing nozzle,

- a compression chamber (8), arranged substantially behind the blowing chamber parallel to the longitudinal axis XX 'and whose volume Vl varies and opens into the blowing chamber under the action of a piston (9),

a helical spring (11) fixed at one of its ends (110) directly to the piston (9) and at the other of its ends (111) to a fixed part (12),

- Temporary mechanical connection means (13, 130, 131, 132) between the piston (9) and the movable arcing contact (5) for compressing the spring (11) directly attached to the piston during a closing operation of the contacts and to obtain a stroke of the movable arcing contact greater than the stroke of the spring which carries out the complete compression of the volume Vl, said complete compression of the gas in the volume Vl being moreover approximately that the arcing contacts are separated,

wherein the blowing chamber opens into the blowing nozzle through a blast duct (700) for supplying blast gas to the zone Z outside the blow chamber where the single arc formed between the arc contacts occurs. during a break.

2. Cutoff chamber (1) according to claim 1, wherein the temporary mechanical connection means are arranged outside the blow and compression chambers with respect to the longitudinal axis (XX ').

3. Cutoff chamber (1) according to claim 2, wherein the temporary mechanical connection means comprise a tube (130) attached to the piston and of diameter substantially equal to the permanent contact itself fixed to the moving arc contact, said tube being pressed against the end of the movable permanent contact (2) until complete compression of the volume Vl.

4. Cutoff chamber (1) according to claim 1, wherein the temporary mechanical connection means are arranged inside the blow and compression chambers with respect to the longitudinal axis (XX ').

5. Cutoff chamber (1) according to claim 4, wherein the fixed arc contact (4) has a generally tubular shape, the temporary mechanical connection means being arranged inside the fixed arc tube.

6. Cutoff chamber (1) according to claim 5, wherein the temporary mechanical connection means comprise a tube (132) attached to the piston (9) and of smaller diameter than the fixed contact, said tube being in abutment against the end from the moving arc contact to the complete compression of the volume Vl.

7. High or medium voltage circuit breaker upper, comprising, for a pole, one or more breaking chambers (1) according to any one of the preceding claims.