Electrical tripout device integrating a circuit breaker and an isolator

A current-interrupter device (1) comprising a circuit breaker (2) including a first stationary conductive support (4) carrying both a stationary arcing contact (14) and a movable arcing contact (16), and also carrying a movable permanent contact (17), the movable arcing contact (16) and the movable permanent contact (17) being electrically connected to the first stationary support (4), and a disconnector (3) including a second stationary conductive support (6) carrying a disconnector contact (18), and wherein:

TECHNICAL FIELD

The invention relates to interrupting electrical current in an installation of the medium- or high-voltage type.

STATE OF THE PRIOR ART

An electrical installation of the high- or medium-voltage type typically comprises two types of switchgear: circuit breakers and disconnectors.

A disconnector includes a single set of contacts comprising a stationary disconnector contact and a movable disconnector contact, through which current flows when the disconnector is closed.

When the disconnector is open, the disconnector contacts are separated by a distance enabling the disconnector to present a certain strength, i.e. a determined dielectric strength.

A circuit breaker includes a set of permanent contacts mounted in parallel with a set of arcing contacts. The arcing contacts are in an enclosure containing a dielectric gas such as SF6promoting the extinction of an electric arc that forms between said arcing contacts when the circuit breaker opens.

Since the arcing contacts cannot pass a rated current for too long, they are used only during a stage in which the circuit breaker is being operated. In normal operation, when the circuit breaker is closed, the permanent contacts are thus closed so that the rated current passes mainly via the permanent contacts. During the opening operation, the permanent contacts are opened before opening of the arcing contacts.

A circuit breaker and a disconnector are generally used in series in order to combine the characteristics and advantages of each kind of equipment: the breaking power of the circuit breaker and the dielectric strength of the disconnector.

The object of the invention is to propose a new arrangement of this type of equipment.

SUMMARY OF THE INVENTION

The invention provides a current-interrupter device comprising a circuit breaker including a first stationary conductive support carrying both a stationary arcing contact and a movable arcing contact that is movable between a closed position and an open position, and also carrying a movable permanent contact that is movable between a closed position and an open position, the movable arcing contact and the movable permanent contact being electrically connected to the first stationary support, and a disconnector including a second stationary conductive support carrying a disconnector contact that is movable between a closed position and an open position, and wherein:the movable disconnector contact is in contact with the stationary arcing contact when it is closed;the movable disconnector contact is spaced apart from the stationary arcing contact when it is open;the movable disconnector contact and the movable permanent contact are connected to each other when they are both in the closed position; andthe movable disconnector contact and the movable permanent contact are spaced apart from one another when one or the other is open.

With this arrangement, the current-interrupter device jointly constitutes a circuit breaker and a disconnector, thereby presenting a reduced number of components so as to offer two functions in one. The permanent movable contact also acts as a stationary contact of the disconnector, and in analogous manner, the movable disconnector contact also acts as a stationary permanent contact.

The invention also provides a device as described above, wherein the movable arcing contact and the movable permanent contact are dynamically linked together in order to move together in such a manner that when the movable disconnector contact is closed, during a movement of the movable arcing contact and of the movable permanent contact from the closed position to the open position, the movable permanent contact is disconnected from the movable disconnector contact before the movable arcing contact disconnects from the stationary arcing contact.

The invention also provides a device as described above, wherein the movable arcing contact and the movable permanent contact are dynamically linked together by forming a single movable unit.

The invention also provides a device as described above, wherein the permanent movable contact has a hollow body of revolution surrounding the stationary arcing contact and the movable arcing contact while being slidably mounted relative to the first stationary support that carries it.

The invention also provides a device as described above, wherein the movable disconnector contact has a body of revolution and is slidably mounted relative to the second movable support by including a tubular portion for connection to the permanent movable contact and a central pin for connection to the stationary arcing contact.

The invention also provides a device as described above, wherein firstly the components of the circuit breaker and secondly the components of the disconnector are spaced apart when all of the contacts are open by a distance that allows a screen to be inserted between the circuit breaker and the disconnector.

The invention also provides a device as described above, fitted with a screen that is inserted into the gap separating the components of the circuit breaker and the components of the disconnector when the contacts are open.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

As can be seen inFIG. 1, the current-interrupter device1of the invention has a body of revolution about an axis AX that corresponds to its longitudinal axis. It includes a portion forming an electrical circuit breaker, given reference2and situated in the left-hand portion of the figures, and a part forming an electrical disconnector, given reference3and situated in the right-hand portion of the figures.

This device includes a first stationary support4, situated on the same side as the circuit breaker part, and a second stationary support6, situated on the same side as the disconnector part. When the current-interrupter device1is in place while being interposed between two segments of a conductive line, the stationary supports4and6are electrically connected to respective segments of the line.

The stationary support4comprises a tubular portion7having its end closed by a flat end wall8that carries a base plate9on its inside face, which base plate carries an arc-control shell11, the base plate and the shell thus being surrounded by the tubular portion7.

This shell11defines a leaktight enclosure containing a dielectric gas such as SF6, and it contains a movable arcing contact and a stationary arcing contact, which are the contacts between which an electric arc may be formed during a stage of opening the circuit breaker.

The shell11comprises a cylinder12having one of its ends carried by the base plate9and its other end closed by a shell end wall13that carries the stationary arcing contact14on its inside face, i.e. its face that is directed towards the inside of the shell.

This stationary arcing contact14is a rectilinear pin extending in the cylinder12towards the base plate9, and presents a convex free end that is situated substantially half way along the cylinder12.

The movable arcing contact, which is given reference16, is carried by the base plate9while being movable in translation along the axis AX inside the shell and while being electrically connected to the stationary support4. It comprises both a tubular portion having an end that surrounds the stationary arcing contact14in order to establish electrical contact in the closed position as inFIG. 1, and also a nozzle surrounding said tubular portion.

In the closed position as inFIG. 1, the movable arcing contact16is thus deployed inside the shell so as to surround the stationary arcing contact14by gripping it in order to be in electrical contact therewith. In contrast, in the open position as inFIG. 2, this movable arcing contact16is retracted so as to be remote from the stationary arcing contact14.

During opening of the circuit breaker, the movable arcing contact16is moved in translation so as to pass from its closed position in which it is deployed, to its open position in which it is retracted. When the arcing contacts14and16separate during this movement, an electric arc is established between them, and in particular as a result of the presence of SF6insulating gas, said arc disappears before the end of the opening movement.

When the circuit breaker is closed again, its arcing contacts are brought closer together until they establish electrical contact when the movable arcing contact16reaches its closed position.

In service, the entire rated current does not pass in the arcing contacts, since it would damage them in the long term. The circuit breaker thus includes a movable contact referred to as a “permanent” contact, and via which most of the line current passes when the circuit breaker is closed and is not being operated.

In this example, the movable permanent contact, which is given reference17, has the shape of tube that slides inside the tubular portion7of the stationary support4in order to be movable in translation between a closed position and an open position.

In the closed position corresponding toFIG. 1, the movable permanent contact17is deployed in order to be in electrical contact with another contact given reference18. In the open position corresponding toFIG. 2, the movable permanent contact17is retracted in the tubular portion7in order to be spaced apart from the other contact18.

The movable permanent contact17is electrically connected to the tubular portion7in which it slides by means of a sliding contact19that is carried by the inside face of the tubular portion7in the end region of said tubular portion7. The movable permanent contact17is thus electrically connected to the stationary support4whatever the position it occupies.

In addition, the movable permanent contact17and the movable arcing contact16are linked together dynamically by mechanical elements that are not shown, and in this example they form a single movable unit.

In order to open the circuit breaker, when this unit is moved from its closed position to its open position, the movable permanent contact is disconnected from the contact18before the movable arcing contact16disconnects from the stationary arcing contact14. The arc thus cannot be formed at the permanent contact, but only at the arcing contacts.

In the example shown in the figures, this order of disconnection is ensured by a suitable choice of lengths and positions for the movable permanent contact17relative to the contact18, and for the movable arcing contact16relative to the stationary arcing contact14. More concretely, when the unit is in the closed position, the insertion length of the stationary arcing contact14inside the movable arcing contact16is longer than the insertion length of the movable permanent contact inside the contact18.

Another possibility may consist in providing for the movable arcing contact16and the movable permanent contact17to be movable independently of each other, and for them to be operated one after the other by means of a control system or operating procedure for the device.

The other contact, given reference18, in fact constitutes the movable disconnector contact of the device, and it is slidably mounted in the second stationary support6of the device so that the device is also movable in translation along the axis AX.

This second stationary support6thus comprises, just like the first, a tubular portion21having an end that is closed by a flat end wall22. The movable contact of the disconnector18comprises a tubular body23that is slidably mounted inside the tubular portion21of the stationary support6. A sliding contact24mounted on the inside face of the tubular portion21, in the region of its end, ensures continual electrical contact between the stationary support6and the movable disconnector contact18.

In the same manner, in the region of its end that is close to the movable permanent contact17, i.e. the end extending towards the first stationary support4, the tubular body23carries a sliding contact26on its inside face.

This movable disconnector contact18is movable in translation between an open position corresponding to the position ofFIG. 3and a closed position corresponding to the position that it occupies inFIGS. 1 and 2.

When it is in its open position, the movable disconnector contact18is retracted into the tubular portion21in order to be spaced apart from the movable permanent contact17, regardless of whether it is closed or open. When in its closed position, the movable disconnector contact18is deployed so as to come into contact with the movable permanent contact17if it is closed, i.e. deployed as inFIG. 1.

Thus, and as can be seen inFIG. 1, when the movable permanent contact17is in its deployed closed position, if the movable disconnector contact18is also in its deployed closed position, it surrounds the movable permanent contact17so as to be in electrical contact with it via the sliding contact26.

In this situation, the device is completely closed, and the rated current passes successively through the stationary support4, the movable permanent contact17, the movable disconnector contact18, and the second stationary support6.

In addition to its tubular body23, the disconnector contact18comprises a plane middle wall27that extends along a plane that is normal to the axis AX, that closes the tubular body23, and that carries a central contact pin28.

This contact pin28extends along the axis of revolution AX towards the arc-control shell11, i.e. away from the second stationary support6.

In addition to this contact pin28, the shell end wall13carries a tubular contact member29on its outside face in which the contact pin28comes to engage when the movable disconnector contact18is in its closed position as inFIG. 1orFIG. 2. Under these conditions, the stationary arcing contact14of the circuit breaker is electrically connected to the second stationary support6, by means of the shell end wall13, the contact member29, and the movable disconnector contact18.

As will be understood, in normal operation, the current-interrupter device of the invention is entirely closed, as inFIG. 1. Opening it then consists initially in operating the movable unit including the movable permanent contact17and the movable arcing contact16, to move from its closed position to its open position, namely from left to right in the figures.

In a first stage, the movable permanent contact17disconnects from the movable disconnector contact18. At this point, the entire current passes via the arcing contacts14and16, and via the central pin28of the movable disconnector contact18in order to reach the stationary support6.

As this movement continues, the movable arcing contact16moves away from the stationary arcing contact14, and that causes an electric arc to form between these two elements. The arc is then extinguished as the movable arcing contact16continues to move away, and this movement ends when it reaches its maximum opening position, as inFIG. 2.

At this stage, the current is interrupted because the movable permanent contact17and the disconnector contact18are spaced apart from each other and the movable arcing contact16and the stationary arcing contact14are also spaced apart from each other.

To end electrical opening of the device, it is still advisable to operate the movable disconnector contact18until it reaches its open position in order to space it as far apart as possible from the part forming the circuit breaker so as to ensure maximum breaking strength, which corresponds to the situation inFIG. 3.

As can be seen inFIG. 3, in the fully open situation of the device, the various components of the circuit breaker part of the device and the various components of the disconnector part of the device are all spaced apart from one another, by at least a minimum distance given reference D inFIG. 4.

There thus remains a gap between these two parts, of length D along the direction AX, thereby leaving a gap that is sufficient for inserting a screen making it possible to increase dielectric strength even further. This thus makes it possible to carry out human intervention on one of the parts of the device, while the other part can be left live.

For this reason,FIG. 4shows the incorporation of a current-interrupter device of the invention in an enclosure comprising a casing31having its top portion closed by two half-roofs32and33which respectively cover the part2forming a circuit breaker and the part3forming a disconnector.

These two half-roofs may be opened independently of each other, and they are spaced apart from each other along the axis AX by a slot of narrow width allowing an electric screen34to be inserted before opening one or the other of the roofs. This slot makes it possible to insert the screen, but it is sufficiently narrow to prevent a technician from passing an arm or a leg.

An intervention on the circuit breaker part of the device thus consists in ensuring the circuit breaker part is dead, and inserting the electric screen34between the two half-roofs, while leaving the disconnector part live. The half-roof32covering the circuit breaker part can then be opened in order to make it possible for an operator to intervene on the circuit breaker without risk of electrocution.

In concrete terms, the screen that is inserted along the circuit breaker part ensures that, during an intervention by an operator, a sufficient distance, namely at the distance D, is maintained between all the components of the circuit breaker part and all the components of the disconnector part.

The invention thus provides the following advantages: in the event of damage to the controls of the circuit breaker part, the disconnector-forming part remains operational and may be operated independently of the other part.

Although the device of the invention unites a circuit breaker and a disconnector, it thus enables them to be operated independently. It is thus possible to perform operating tests risk on the circuit breaker part without risk, simply by leaving the disconnector part open, e.g. before the system is commissioned.

By means of the gap being established between the circuit breaker part and the disconnector part when the device is open, it is possible to insert a screen in order to intervene on one of the parts of the device without having to ensure the other part is dead.