EP2545574B1 - Electric medium-high and high voltage circuit breaker having return upon closure and insertion device with closing resistor - Google Patents

Description

Field of the invention

The invention relates to the field of electrical equipment of high and very high voltages, including switches and / or circuit breakers using the insertion of one or more resistors, during current closing operations.

Prior art and problem

In high and very high voltage interruption and interruption devices, it is known to use one or more resistors, connected in parallel with the return chamber of the assembly, to limit overvoltage phenomena during reclosing. on the airlines. Thus, the various mechanisms provide for the insertion of said resistor or resistors just before closing the main contacts to ensure the passage of the main stream.

Many devices have been designed. However, they lead to some disadvantages which are, among other things, a blow of manufacturing too high to because of a lot of milling and the use of an unlocking system with a neutral position.

However, with reference to the figure 1 by the patent application in France, published under the number 2 450 501, there is known a device for inserting a resistance to the closing of a current interruption device comprising a breaking chamber, a movable main contact 15, the insertion contacts 12 and 13 of the resistor being arranged in the breaking chamber of the apparatus with a displacement along a path parallel to that of the moving main contact 15. In this device, the closing resistor is in alignment with the chamber disposed in the interrupting chamber and is not visible in the drawings, one of the contacts ensuring the insertion of the closing resistor is attached to one of the main break contacts and is disposed of sliding way with respect to one of the main break contacts. Temporary elastic connection means are used between the movable resistance contact and its support element so that the movable resistance contact can take two defined positions. These temporary elastic connection means are composed of several balls 19, placed in holes and each pushed by a spring 18 towards the inner wall of the movable resistance contact 12, which comprises two series of notches 20 and 21 corresponding to the two positions of the means of temporary elastic connection.

This system is relatively complicated mechanically.

On the other hand, there are toric and flexible helical springs serving as temporary mechanical connection means. The patent document WO 2004/031595 A2 describes such a spring.

Summary of the invention

• une tige de commande, et
• un contact mobile solidarisable temporairement avec la tige de commande.

The object of the invention is to overcome the disadvantages of the systems mentioned above. For this purpose, a first object of the invention is a medium or high voltage electrical switch, equipped with a mechanical device comprising:

• a control rod, and
• a movable contact temporarily secured to the control rod.

According to the invention, this electrical switch has a flexible toroidal coil spring placed in a groove of the control rod and an energy accumulation system bearing on the movable rod which is intended to be loaded up to a certain value. determined for which the flexible toroidal coil spring deforms under the force and allows the removal of the movable contact.

• deux contacts d'insertion de résistance, un mobile et un fixe ;
• la tige de commande (bielle d'entrée de mouvement), directement liée à la chambre de coupure et solidarisée temporairement avec le contact mobile d'insertion de résistance ;
• un porte-contact du contact mobile d'insertion de résistance pouvant faire transiter le courant circulant dans la résistance ;
• au moins un ressort de rappel constituant le système d'accumulation d'énergie, qui permet de faire revenir à sa position initiale le contact mobile d'insertion de résistance et qui est placé entre le porte-contact qui est tubulaire, et le contact mobile d'insertion de résistance qui est également tubulaire et solidaire de la tige de commande, le au moins un ressort de rappel pouvant servir de conducteur vis-à-vis de la résistance ;
• une bande de guidage entre le contact mobile d'insertion et son porte-contact ; et
• un élément élastique de liaison temporaire entre le contact mobile d'insertion de résistance et la tige de commande pour solidariser ces deux pièces temporairement.

A second object of the invention is a device for inserting a resistor that can be used in an electrical switch, during a closing operation of the switch, the insertion of the resistor to be made parallel to the movement of the chamber. switching off the switch, the device comprising:

• two resistance insertion contacts, a mobile and a fixed;
• the control rod (movement input link), directly linked to the breaking chamber and temporarily secured to the movable resistance insertion contact;
• a contact carrier of the movable resistance insertion contact capable of passing the current flowing in the resistor;
• at least one return spring constituting the energy accumulation system, which makes it possible to return to its initial position the movable resistance insertion contact and which is placed between the contact carrier which is tubular, and the moving contact resistor insertion which is also tubular and integral with the control rod, the at least one return spring being able to serve as a conductor vis-à-vis the resistance;
• a guide strip between the movable insertion contact and its contact holder; and
• an elastic member for temporary connection between the movable resistance insertion contact and the control rod for securing these two parts temporarily.

According to the invention, the elastic connecting element between the movable resistance insertion contact and the control rod consists of the spring of the flexible toroidal helical type placed in a notch of the control rod (or the movable contact of insertion of resistance) and a groove of the control rod (or movable contact), and the device comprises one or more return springs.

Preferably, it comprises an intermediate contact for effecting the passage of the insertion current of the resistor between one end of the movable resistance insertion contact and the contact carrier.

In a preferred embodiment, at least a portion of the insertion resistor is placed around the control rod.

List of Figures

• figure 1, déjà décrite, un dispositif d'insertion de résistance selon l'art antérieur ;
• figure 2, l'interrupteur selon l'invention avec un dispositif d'insertion de résistance selon l'invention dans une première position avant la fermeture de l'interrupteur électrique dans une première position ;
• figure 3, en coupe, le même interrupteur selon l'invention dans une deuxième position de fermeture de l'interrupteur, et
• figure 4, en coupe, le même interrupteur dans une troisième position de fermeture de l'interrupteur.

The invention and its various features will be better understood from the description which follows of an embodiment of the invention and which is accompanied by four figures respectively representing:

• figure 1 , already described, a resistance insertion device according to the prior art;
• figure 2 , the switch according to the invention with a resistance insertion device according to the invention in a first position before closing the electric switch in a first position;
• figure 3 in section, the same switch according to the invention in a second closed position of the switch, and
• figure 4 in section, the same switch in a third position of closing the switch.

Detailed description of an embodiment of the invention

The first intended use of the switch according to the invention is provided for a resistance insertion device according to the invention can be used in parallel with the switch-off chamber of the switch on which the assembly is installed. It is recalled that the goal is to insert resistors for a time ranging from four milliseconds to fifteen milliseconds in order to dissipate some of the energy that may cause overvoltages during closing operations under long voltage lines.

The resistance insertion device according to the invention makes it possible, in the resistance insertion contact, to return to the open position before the main contacts of the switch or circuit breaker have the time to close and reopen during the first time. a closing / opening operation. This is intended not to interfere with the switch or the circuit breaker, during the opening operation, in particular to maintain the recovery voltage during the cut. For this reason, the contacts of the resistor insertion device must be at a sufficient distance to allow to obtain certain recovery voltage, when opening the main contacts of the switch. or circuit breaker on which is installed the device according to the invention.

With reference to the figure 2 , the insertion device according to the invention has a control rod 1, or movement input link, which is directly related to the travel of the main breaking chamber of the switch or circuit breaker, the races of those may be different. This control rod 1 is temporarily secured to a movable resistance insertion contact 2 whose end 2A is provided to come into contact with the end 6A of a fixed contact insertion resistance 6. All these elements are, in the embodiment described here, a shape of revolution about a common axis 10, which may preferably be parallel to the axis of the direction of movement of the main contacts of the switch or circuit breaker, to which the insertion device according to the invention.

In this embodiment, a contact carrier 3 makes it possible to maintain the assembly and to make the current flow, if necessary, for example if the control rod 1 is made of insulating material and the resistor itself, which is not not shown in this figure is placed around it. In this case, an intermediate contact 5 placed between the end of a contact carrier 3 and the movable contact for resistance insertion 2 is used. Finally, and most importantly, the contact carrier 3 serves as a guide for the moving contact of resistance insertion 2. As such, the movable resistance insertion contact 2 comprises a shoulder 9 itself carrying a band 7 to guide its movements in the contact carrier 3. This contact carrier 3 is integral with the movable resistance insertion contact 2 and the control rod 1.

One or more return springs 4 are placed in the cylindrical space formed between the inner face of the contact carrier 3 and the outer face of the movable resistor insertion contact 2. The return springs 4 can serve as drivers for -vis resistance to insert.

With reference to the figure 3 , the movable resistance insertion contact 2 and the control rod 1 have moved to the right until the end 2A of the movable insertion contact 2 penetrates inside the end 6A and the fixed resistance insertion contact to establish the electrical contact between them and make the resistance operational. As a result, the springs 4 have been compressed.

The temporary connection means between the control rod 1 and the movable resistance insertion contact 2 consist of a groove 1A, made on the outer surface of the control rod 1, of a helical coil spring 8 which is flexible and a notch 2B, made on the inner surface of the movable resistance insertion contact 2.

Once the compression of the return springs 4 has reached a certain value, the latter offers a resistance such that it pushes, via a shoulder 9, the movable resistance insertion contact 2 towards its position. initial, the flexible toric coil spring 8 deforming under the pressure of the force. As a result, it leaves the notch 2B of the movable resistance insertion contact 2 and allows the latter to move back to its initial position.

The figure 4 shows the recoil position of the movable resistance contact 2. On the other hand, the control rod has slightly continued its translational movement along the axis 10, keeping the flexible coil spring 8 in its notch 1A.

When opening the switch or circuit breaker, the interrupting chamber drives the control rod 1 in the opposite direction, that is to say it returns to the position of the figure 1 , the flexible coil spring 8 finding the notch 2B of the movable resistance insertion contact 2.

It is also possible to provoke the detachment of the movable insertion contact 2 and of the control rod 1 by the impact of the electrical contacts, namely the ends 2A of the movable insertion contact 2 and 6A of the fixed resistance insertion contact 6 In this case, the inertia of the resistance insertion mobile contact 2 causes it to enter the fixed resistor insertion contact 6 and restart in the other direction, under the effect of the return springs 4.

Another shock can be deliberately provoked in another way.

Finally, a second type of spring may be added to the return springs 4, but having a different stiffness to cause a sudden increase in end-of-stroke forces.

It can be seen that this system is relatively simple, while making it possible to achieve the going and the return of the movable resistance insertion contact.

It avoids the use of retractable moving parts, whether the fixed resistance insertion contact or the resistance insertion mobile contact.

The flexible toroidal coil spring 8 used in the switch according to the invention is a known spring. This type of spring is of the type of the one marketed, inter alia, by the company BAL SEAL ENGINEERING.

Claims (4)

1. A medium- or high-voltage electric switch provided with a mechanical device comprising:

   · a control rod (1); and

   · a movable resistance-insertion contact (2) that is able to be secured temporarily to the control rod (1);
   the switch being characterized in that it has a flexible toroidal helical spring (8) placed in a groove of the control rod and an energy accumulation system (4) pressing against the movable resistance-insertion contact, which system is intended to be loaded until it reaches a certain value at which the flexible toroidal helical spring (8) deforms under the force and enables the movable contact to be withdrawn.
2. A resistance-insertion device comprising:

   · two resistance-insertion contacts: one movable (2) and one stationary (6);

   · the control rod (1) directly connected to the arc-control device and temporarily secured to the movable resistance-insertion contact (2);

   · a contact carrier (3) for carrying the movable resistance-insertion contact (2) and suitable for conveying the current flowing in the resistance;

   · at least one return spring (4) constituting the energy accumulation system that enables the movable resistance-insertion contact (2) to return to its initial position and that is placed between the contact carrier (3), which is tubular, and the movable resistance-insertion contact (2), which is also tubular and secured to the control rod (1), the at least one return spring (4) being suitable for use as a conductor associated with the resistance;

   · a guide strip (7) between the movable resistance-insertion contact (2) and the contact carrier (3); and

   · a resilient element for temporarily connecting the movable resistance-insertion contact (2) to the control rod (1) so as to secure these two parts together temporarily;
   characterized in that the resilient element for connection between the movable resistance-insertion contact (2) and the control rod (1) is constituted by a flexible toroidal helical spring (8) that is placed either inside a notch (2B) of the movable resistance-insertion contact (2) and a groove (1A) of the control rod (1) or in a notch of the control rod (1) and a groove of the movable contact (2), and in that it includes one or more return springs (4).
3. A device according to claim 2, characterized in that it includes an intermediate contact (5) for enabling the insertion current to pass between the end (2a) of the movable resistance-insertion contact (2) and the contact carrier (3).
4. A device according to claim 2, characterized in that a portion or all of the resistance that is to be inserted is placed about the control rod (1).

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