The invention relates to electrical protection devices such as contactors, circuit breakers, switches and high-voltage quick disconnects, and in particular to vacuum bulbs used on high-voltage networks for such switches. The use of vacuum bulbs allows high voltages to be maintained whilst having low contact resistance in the closed state.
Document JPH0992100 describes a high-voltage DC vacuum bulb.
Document JPH08222092 describes a vacuum bulb actuated by electromagnetic repulsion.
A vacuum bulb typically has a fixed and a mobile electrode, with contact between the electrodes taking place within a chamber with vacuum sealing. For a circuit breaker, the movement of the mobile electrode is made possible by the use of a circuit breaker drive comprising an opening coil, a closing coil and a mobile plate placed between these coils. The mobile electrode is connected to the mobile plate by a generally insulating rod.
To operate the circuit breaker, a capacitive assembly is discharged into the corresponding coil. The current peak that runs through the coil then generates an electromagnetic pulse that generates eddy currents, known as Foucault's currents, in the mobile plate, whose electromagnetic field opposes that of the coil. The mobile plate is then said to be “induced”. This creates a repulsive force between the energised coil and the armature, allowing the mobile plate and the connected mobile electrode to move.
The reaction force on the opening coil and its support induces harmful vibrations during the opening. When in use, the reaction force on the opening coil and its support may deform or displace them in the frame reference of the supporting frame. As a result, the air gap between the opening coil and the armature surface can become uneven on the armature surface. In particular, the air gap can increase during the lifetime of the circuit breaker. And, since a small air gap optimises the efficiency of the electromechanical conversion, the opening of the circuit breaker may become increasingly slower over time. In addition, in order to increase the breaking capacity, it is necessary to increase the stroke of the mobile plate as well as the force exerted to perform the opening.
Furthermore, a similar problem is encountered when implementing the closing of a contactor.
The invention aims to overcome one or more of these drawbacks. The invention thus relates to a vacuum bulb switch with inductive control as defined in the appended claims.
The invention also relates to variants of the dependent claims. A person skilled in the art will appreciate that each of the features of the dependent claims and the description can be combined independently with the above features, without constituting an intermediate generalisation.
Further features and advantages of the invention will be clear from the following description, which is indicative and not restrictive, with reference to the attached drawings, in which:
The invention applies to an electrical safety switch, the main function of which is either disconnection, for example for a circuit breaker, or connection, for example for an earthing device.
The vacuum bulb 11 has:
The line current is supplied and removed by electrical connections 1112 and 1114 connected to electrodes 1111 and 1113 respectively.
The circuit breaker 1 comprises an actuator 12 which is integral with the mobile electrode 1113. The actuator 12 allows the mobile electrode 1113 to be operated to open or close the switch 111 of the circuit breaker 1. The actuator 12 is slidably mounted in the vertical orientation parallel to the A axis. The actuator 12 comprises an armature 122.
The circuit breaker 1 also comprises:
The opening control-element is configured to simultaneously induce an opening current in the armature 122 and a current in the armature 222, so as to separate the electrodes 1111 and 1113 and so as to move the actuators 12 and 22 in opposite directions along the vertical orientation parallel to the A axis. To minimise the stresses on the frame created by the reaction forces, the two axes along which the movements of the actuators 12 and 22 take place are merged. The control-element thus makes it possible to open the circuit breaker 1 in a reduced time and to compensate for the reaction forces of the armature 122 on the coil 131 by the reaction forces of the armature 222 on the coil 131, as will be explained in detail below. Thus, compressive forces of the same magnitude are only applied to this coil 131, which reduces the size of its attachment to the frame 10. As a result of the compensation of these forces, the coil 131 undergoes less deformation and the air gap between this coil 131 and the armature 122 varies little over the lifetime of the circuit breaker 1. In this way, a fast opening time of the circuit breaker 1 can be guaranteed, even after a large number of opening and closing operations. The vibrations generated when circuit breaker 1 is opened are also reduced.
Advantageously, the mobile mass integral with the actuator 22 is at least equal to half the mobile mass integral with the actuator 12, preferably equal to the mass of this actuator 12, in order to obtain optimal compensation of the reaction forces on the coil 131. The mobile mass integral with an actuator includes its mass and that of its mobile electrode.
The actuator 12 here has a rod 121. The rod 121 may have a dielectric material element 1210 to eliminate any risk of arcing between a control zone of the circuit breaker 1 and the mobile electrode 1113. The rod 121 also has one or more arms 1211, advantageously made of conductive material. The element 1210 is interposed between the arm 1211 and the electrode 1113. The armature 122 is integral with the arm 1211. The dielectric element 1210 of the rod 121 is advantageously tubular in shape.
The armature 122 advantageously takes the form of a plate located between a planar coil 132 and the (here also planar) coil 131. The planar coil 132 belongs to a closing control-element of the circuit breaker 1. The planar coil 132 is the closing coil. The coil 132 is therefore positioned opposite the armature 122 of the actuator 12, on the opposite side to the armature 222.
The armature 122 here has a lower conducting surface 1221 facing the coil 132 and an upper conducting surface 1222 facing the coil 131. The surfaces 1221 and 1222 may be formed in one piece in a solid plate or may be mounted on a plate-like support of a different material. The surfaces 1221 and 1222 are perpendicular to the A axis. Advantageously, the surfaces 1221 and 1222 are metallic. The material of the armature 122 may be selected for its high conductivity to density ratio; the armature material 122 may thus advantageously be aluminium. Advantageously, the arm(s) 1211 are coated with the same metallic material as the surfaces 1221 and 1222 or are formed from the same metallic material as the surfaces 1221 and 1222. A metal part of the arms 1211 is thus encircled by the coil 131, in order to promote centering of the actuator 12. Advantageously, the armature surfaces 1221 and 1222 (as well as the coil 131) are axisymmetrical with respect to the A axis, so that force torques are compensated on the different elements of the armature 122.
A planar coil 133 is placed opposite the coil 132 symmetrically with respect to the coil 131.
The coils 131, 132 and 133 are attached to the frame 10 and are traversed in the vertical orientation parallel to the A axis by the rod 121 of the actuator 12.
The actuator 22 also passes through the coils 131, 132 and 133 in the vertical orientation parallel to the A axis.
The actuator 22 also has a rod 221, advantageously tubular in shape, symmetrical to the rod 121 in the vertical orientation parallel to the A axis. The rod 221 also has one or more arms 2211, passing through the coils 131, 132 and 133 and the armature 122 in the vertical orientation.
The armature 222 here has an upper conducting surface 2221 facing the coil 133 and a lower conducting surface 2222 facing the coil 131. The surfaces 2221 and 2222 may be formed in one piece in a solid plate or may be mounted on a support. The surfaces 2221 and 2222 are perpendicular to the A axis. The surfaces 2221 and 2222 are metallic. The material of the armature 222 may be selected for its high conductivity to density ratio; the armature material 222 may thus advantageously be aluminium. The arm(s) 2211 are advantageously covered with the same metallic material as the surfaces 2221 and 2222. A metal part of the arms 2211 is thus encircled by the coil 131, in order to promote centering of the actuator 22. The armature 222 is integral with the arm 2211.
The actuator 12 passes through the armature 222 between the coils 131 and 133. The actuator 22 passes through the armature 122 between the coils 131 and 132. Advantageously, the actuators 12 and 22 have strictly similar tubular shapes. The actuators 12 and 22 are also advantageously made of the same material.
This configuration allows the actuators 12 and 22 to guide each other in sliding in the orientation parallel to the A axis perpendicular to the surfaces 1221, 1222, 2221 and 2222.
The armature 122 is advantageously disc-shaped.
The rod 121 advantageously has three arms 1211 extending in the orientation parallel to the A axis perpendicularly to the surface 1222 and to the surface 1221 (not visible in
The armature 122 is pierced with orifices 123, in which the arms 2211 of the rod 221 of the actuator 22(not shown) slide. There are advantageously as many orifices 123 as there are arms 1211 of the rod 121 and the former are symmetrically distributed around the centre Z of the armature 122.
According to an example of an embodiment of the invention, the coil 131 is connected to a capacitor or capacitive assembly (not shown) configured to generate an opening current in the coil 131. The opening-current peak thus flows through the coil 131 which then generates an electromagnetic pulse which generates induced eddy currents in the armature 122 and in the armature 222 whose electromagnetic field opposes that of the coil 131. Mechanical repulsive forces B, C and D then occur between the energised coil 131 and the armatures 122 and 222.
Forces B and C occur in orientations perpendicular to surfaces 1221 and 1222 respectively. Forces B and C are used to give the actuator 12 sufficient acceleration in the orientation parallel to the A axis to move the actuator 12 in that orientation, in an opening direction. In a similar fashion, the actuator 22 is simultaneously moved in an opposite direction to the actuator 12.
When the arms 1211 and 2211 are made of conductive material, the force D appears in an orientation perpendicular to the A axis. The force D is used to generate a magnetic centering of the actuator 12 and the actuator 22 with respect to the A axis.
In an example of an embodiment of the invention, the coils 132 and 133 are connected to a capacitor or capacitive assembly (not shown) configured to generate a closing current in the coils 132 and 133. The closing-current peak thus flows through the coils 132 and 133, which then generate an electromagnetic pulse that generates induced eddy currents in the armature 122 and in the armature 222 respectively, whose electromagnetic field opposes that of the coils 132 and 133 respectively.
Mechanical repulsive forces then occur between the coil 132 and the armature 122, in an orientation perpendicular to the surface 1221. These forces allow the actuator 12 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 12 in that orientation, in a direction to close the switch 111.
In a similar operation, equivalent mechanical forces also occur between the coil 133 and the armature 222 in an orientation perpendicular to the surface 2221. These forces allow the actuator 22 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 22 in that orientation, in a direction opposite to that of the actuator 12.
The vacuum bulb 21 has:
The line current is supplied and removed by electrical connections 2112 and 2114 connected to electrodes 2113 and 2111 respectively.
The mobile electrode 2113 is made integral with a member 2210 of the actuator rod 221 of the actuator 22. The element 2210 is made of a dielectric material in order to eliminate any risk of arcing between a control zone of the circuit breaker 1 and the mobile electrode 2113. The dielectric element 2210 is advantageously tubular in shape.
According to this example of an embodiment of the invention, just the generation of an opening current in the coil 131 suffices to give the actuators 12 and 22 sufficient acceleration to open both the switch 111 and the switch 211, while preserving the balance of the forces exerted on the coil 131. If the actuators 12 and 22 are identical and the switches 111 and 211 are identical, the forces on the coil 131 are perfectly balanced. The forces of gravity may be considered negligible compared to the forces exerted on the actuators 12 and 22 by the coil 131 during opening.
According to an alternative embodiment of the invention, the switches 111 and 211 may be electrically connected in series, thereby increasing the breaking capacity of the opening control of the circuit thus formed. Such a double cut-off can also be achieved in a relatively small space, with the switches 111 and 211 fixed to the same body and the actuators 12 and 22 nested.
According to another embodiment of the invention, the switches 111 and 211 may each be connected to an independent current circuit or to two circuits connected in parallel, thereby enabling simultaneous opening of these two current circuits.
A parallel connection allows the double current to be conducted in the closed state, thus avoiding excessive heating.
When the switches 111 and 211 are connected in series or parallel, it is advantageous to connect their mobile electrodes 1113 and 2113 together, so that the thickness of the dielectric elements 1210 and 2210 can be minimised or eliminated.
In an example of an embodiment of the invention, the coils 132 and 133 are connected to a capacitor or capacitive assembly (not shown) configured to generate a closing current in the coils 132 and 133. As in the previous embodiment, mechanical repulsive forces then occur between the coil 132 and the armature 122, in an orientation perpendicular to the surface 1221. These forces allow the actuator 12 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 12 in that orientation, in a direction to close the switch 111.
In a similar operation, equivalent mechanical forces also occur between the coil 133 and the armature 222 in an orientation perpendicular to the surface 2221. These forces allow the actuator 22 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 22 in that orientation, in a direction to close the switch 211, which direction is opposite to that of the actuator 12.
The circuit breaker 1 comprises here:
In the configuration described in
The armature 123 is located between the coils 134 and 136. The armature 124 is located between the coil 135 and the bulb 21. The armature 223 is located between the coils 134 and 135. The armature 224 is located between the coil 136 and the bulb 11.
The opening control-element is configured to simultaneously generate an opening current in the armatures 123 and 124 as well as an equivalent opening current in the armatures 223 and 224, so as to move the actuators 12 and 22 in opposite directions along the vertical orientation parallel to the A axis.
The coils 135 and 136 are connected to a capacitor or capacitive assembly (not shown) configured to generate an opening current in the coils 135 and 136. The opening-current peak thus flows through the coils 135 and 136, which then each generate an electromagnetic pulse.
The pulse generated in the coil 135 generates induced eddy currents in the armatures 124 and 223 whose electromagnetic field opposes that of the coil 135. Mechanical repulsive forces then occur between the energised coil 135 and the armatures 124 and 223, in orientations perpendicular to the surfaces 1242 and 2232 of the armatures 124 and 223 respectively.
The pulse generated in the coil 136 generates induced eddy currents in the armatures 123 and 224 whose electromagnetic field opposes that of the coil 136. Mechanical repulsive forces then occur between the energised coil 136 and the armatures 123 and 224, in orientations perpendicular to the surfaces 1232 and 2242 of the armatures 123 and 224 respectively.
These mechanical forces allow the actuators 12 and 22 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 12 and actuator 22 in that orientation, in opposite directions of opening of the switches 111 and 211.
According to an example of an embodiment of the invention, the coil 134 is connected to a capacitor or capacitive assembly (not shown) configured to generate a closing current in the coil 134. The closing-current peak thus flows through the coil 134 which then generates an electromagnetic pulse which generates induced eddy currents in the armature 123 and in the armature 223 whose electromagnetic field opposes that of the coil 134.
Magnetic repulsion forces then occur between the coil 134 and the armatures 123 and 223, in orientations perpendicular to the surfaces 1232 and 2232 of the armatures 123 and 223 respectively. These mechanical forces allow the actuators 12 and 22 to be accelerated sufficiently in the orientation parallel to the A axis to move the actuator 12 and actuator 22 in that orientation, in opposite directions of closing of the switches 111 and 211.
The vacuum bulb 31 has:
The line current is supplied and removed by electrical connections 3112 and 3114 connected to electrodes 3111 and 3113 respectively.
The contactor 3 comprises an actuator 32 integral with the mobile electrode 3113. The actuator 32 is used to operate the mobile electrode 3113 to open or close the switch 311 of the contactor 3. The actuator 32 is slidably mounted in the vertical orientation parallel to the A axis. The actuator 32 comprises an armature 322.
The contactor 3 also comprises:
The closing control-element is configured to simultaneously induce an opening current in the armature 322 and a current in the armature 422, so as to separate the electrodes 3111 and 3113 and so as to move the actuators 32 and 42 in opposite directions along the vertical orientation parallel to the A axis. To minimise the stresses on the frame created by the reaction forces, the two axes along which the movements of the actuators 32 and 42 take place are merged. The control-element thus makes it possible to close the circuit breaker 3 in a reduced time and to compensate for the reaction forces of the armature 322 on the coil 331 by the reaction forces of the armature 422 on the coil 331, as will be explained in detail below. Thus, compressive forces of the same magnitude are only applied to this coil 331, which reduces the size of its attachment to the frame 30. As a result of the compensation of these forces, the coil 331 undergoes less deformation and the air gap between the coil 331 and the armature 322 varies little over the life of the contactor 3. This ensures that the contactor 3 closes quickly, even after a large number of opening and closing operations. The vibrations generated when the contactor 3 is closed are also reduced.
Advantageously, the mobile mass integral with the actuator 42 is at least equal to half the mobile mass integral with the actuator 32, preferably equal to the mass of this actuator 32, in order to obtain optimal compensation of the reaction forces on the coil 331. The mobile mass attached to an actuator includes in particular the mass of the electrode in addition to that of the actuator itself.
The actuator 32 here comprises a rod 321. The rod 321 may have a dielectric material element 3210 to eliminate any risk of arcing between a control zone of the circuit breaker 3 and the mobile electrode 3113. The rod 321 also has one or more extensions 320, advantageously made of conductive material. The extension 320 here extends beyond the armature 322. The armature 322 is integral with the rod 3210. The dielectric element 3210 of the rod 321 is advantageously tubular in shape.
The armature 322 advantageously takes the form of a plate located between a planar coil 333 and the (here also planar) coil 331. The planar coil 333 belongs to an opening control-element of the contactor 3. The planar coil 333 is the opening coil. The coil 333 is therefore positioned opposite the armature 322 of the actuator 32, on the opposite side to the coil 331.
The armature 322 here has a lower conductive surface 3221 facing the coil 331 and an upper conductive surface 3222 facing the coil 333. The surfaces 3221 and 3222 may be formed in one piece in a solid plate or may be mounted on a plate-like support of a different material. The surfaces 3221 and 3222 are perpendicular to the A axis. Advantageously, the surfaces 3221 and 3222 are metallic. The material of the armature 322 may be selected for its high conductivity to density ratio; the armature material 322 may thus advantageously be aluminium. Advantageously, the armature surfaces 3221 and 3222 (as well as the coil 331) are axisymmetrical with respect to the A axis, so that force torques are compensated on the different elements of the armature 322.
A planar coil 332 is placed opposite the coil 333 symmetrically with respect to the coil 331. The coils 331, 332 and 333 are attached to the frame 30.
The actuator 42 also has a rod 421, advantageously tubular in shape, identical in shape to the rod 321.
The armature 422 here has an upper conducting surface 4221 facing the coil 331 and a lower conducting surface 4222 facing the coil 131. The surfaces 4221 and 4222 may be formed in one piece in a solid plate or may be mounted on a support. The surfaces 4221 and 4222 are perpendicular to the A axis. The surfaces 4221 and 4222 are metallic. The material of the armature 422 may be selected for its high conductivity to density ratio; the armature material 422 may thus advantageously be aluminium. The armature 422 is integral with the rod 4210.
The extension 320 of the actuator 32 passes through the armature 422 and the coil 331. The extension 420 of the actuator 42 passes through the armature 322 and the coil 331. This configuration allows the actuators 32 and 42 to guide each other in sliding in the orientation parallel to the A axis perpendicular to the surfaces 3221, 3222, 4221 and 4222.
The armature 322 is advantageously disc-shaped. The rod 321 may have a plurality of extensions 320 extending in the orientation parallel to the A axis perpendicular to the surface 3222 and to the surface 3221 around the A axis of the armature 322.
The armature 322 is pierced with orifices in which the extensions 420 of the rod 421 of the actuator 42 slide. There are advantageously as many orifices as there are extensions 420 of the rod 421 and the former are symmetrically distributed around the A axis.
According to an example of an embodiment of the invention, the coil 331 is connected to a capacitor or capacitive assembly (not shown) configured to generate a closing current in the coil 331. The opening-current peak thus flows through the coil 331 which then generates an electromagnetic pulse which generates induced eddy currents in the armature 322 and in the armature 422 whose electromagnetic field opposes that of the coil 331. Mechanical repulsive forces then occur between the energised coil 331 and the armatures 322 and 422.
Forces occur in orientations perpendicular to the surfaces 3221 and 3222 respectively. These forces allow the actuator 32 to be accelerated sufficiently in the orientation parallel to the A axis to move it in that orientation, in a closing direction. In a similar fashion, the actuator 42 is simultaneously moved in an opposite direction to the actuator 32.
When the extensions 320 and 420 are made of conductive material, a force appears in an orientation perpendicular to the A axis. This force is used to generate a magnetic centering of the actuator 32 and the actuator 42 with respect to the A axis.
When the switch 311 of the contactor 3 is in the closed state (the configuration shown in
Variations of the contactor 3 similar to those presented for the circuit breakers 1 can be envisaged: another switch operated by the actuator 42.
Number | Date | Country | Kind |
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2005552 | May 2020 | FR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/063925 | 5/25/2021 | WO |