Patent Grant
10361040
The present invention relates to a switching device for an electrical circuit and to a method for controlling such switching device.
As known, switching devices are conceived for connecting/disconnecting parts of the electrical circuits into which they are installed.
To this aim, a switching device comprises at least one electrical phase, or pole, having a movable contact and a corresponding fixed contact. The movable contact can be actuated between a close position, in which it is coupled to the corresponding fixed contact in order to realize a conductive path for a current flowing through the phase, and an open position in which it is separated from the corresponding fixed contact in order to interrupt the conductive path.
The switching device comprises driving means and a kinematic chain for transmitting a force applied by the driving means to each one of its movable contacts. In particular, the driving means are adapted to drive the kinematic chain between a first operative position and a second operative position in order to actuate the movable contact relative to the corresponding fixed contact.
According to known solutions, the switching device further comprises control means for controlling the driving of the kinematic chain and, hence, the actuation of the movable contacts between the close and open positions. An example of a known switching device of this type is disclosed in the European patent application EP2523203.
The close position and the open position reached by the movable contacts must be kept until a further switching operation is required, even if one of these close and open positions is not energetically stable per se.
In other words, an undesired displacement of the movable contact from the close position to the open position or from the open position to the close position, such as displacements caused by disturbance forces applied to the kinematic chain, e.g. electromagnetic forces, vibrations and gravity, must be avoided.
If the control means and the driving means are properly supplied during the operation of the switching device, the control means control the driving means for adjusting undesired movements of the movable contact away from the reached close position or open position.
However, an undesired movement of the movable contact from the close position to the open position, or vice versa, must also be prevented in the case in that the control means and/or the driving means are not properly supplied. This critical condition can occur in the case of a fault power loss in a power supply associable to and suitable for operating the switching device.
For this reason, latching mechanisms are known in the art which are adapted to:
Such latching mechanisms are complex, expensive and bulky.
Hence, at the current state of the art, although known solutions perform in a rather satisfying way, there is still reason and desire for further improvements.
Such desire is fulfilled by a switching device for an electric circuit, the switching device comprising:
The kinematic chain is adapted to reach the second position from the first position before reaching a dead-point position, and the control means are adapted to:
Another aspect of the present disclosure is to provide an electrical installation comprising at least one switching device as the switching device defined by the annexed claims and disclosed in the following description.
Another aspect of the present disclosure is to provide a method for controlling a switching device for an electric circuit, the switching device comprising:
The kinematic chain is adapted to reach the second position from the first position before reaching a dead-point position, and the method comprises:
Another aspect of the present disclosure is to provide a computer readable medium comprising software instructions which, when executed by a computer, are adapted to carry out a method as the method defined by the annexed claims and disclosed in the following description.
Further characteristics and advantages will become more apparent from the description of one preferred but not exclusive embodiment of the switching device, electrical installation and control method according to the following disclosure, illustrated only by way of non-limiting examples with the aid of the accompanying drawings, wherein:
In particular, the one exemplary switching device disclosed and illustrated with the aid of the cited figures is a linear switching device, i.e. a device having its kinematic chain adapted to actuate the corresponding movable contact relative to the fixed contact along a linear axis.
This device is particularly adapted for medium voltage applications, i.e. applications having voltages in a range above 1 kV up to some tens of kV, and for connecting/disconnecting a power line of the electrical circuit to one or more associated loads, such as banks of capacitors.
However, it is to be set forth that a switching device according to the present disclosure:
It should be noted that in the detailed description that follows, identical or similar components, either from a structural and/or functional point of view, have the same reference numerals, regardless of whether they are shown in different embodiments of the present disclosure; it should also be noted that in order to clearly and concisely describe the present disclosure, the drawings may not necessarily be to scale and certain features of the disclosure may be shown in somewhat schematic form.
Further, when the term “suitable for”, or “adapted” or “arranged” or “configured” or “shaped” or “conceived”, is used herein while referring to any component as a whole, or to any part of a component, or to a whole combinations of components, or even to any part of a combination of components, it has to be understood that it means and encompasses correspondingly either the structure, and/or configuration and/or form and/or positioning of the related component or part thereof, or combinations of components or part thereof, such term refers to.
With reference to
With reference to
The switching device 1 according to the present disclosure comprises at least one phase 2 having a movable contact 3 which can be coupled to/separated from a corresponding fixed contact 4.
Hence, the movable contact 3 can be actuated between a close position, in which it is coupled to the corresponding fixed contact 4 in order to realize a conductive path for a current flowing through the phase 2, and an open position in which it is separated from the corresponding fixed contact 4 in order to interrupt such conductive path.
The switching device 1 further comprises a kinematic chain 100 operatively associated to the movable contact 3, and driving means 200 adapted to move the kinematic chain 100 at least between a first position and a second position for actuating the movable contact 3 relative to the corresponding fixed contact 4. In other words, the kinematic chain 100 is adapted to transmit a mechanical force generated by the driving means 200 to the contact 3, for moving it between the close and open positions.
Preferably, the switching device 1 comprises a casing 5 housing the kinematic chain 100.
In the exemplary embodiment illustrated in
For example, the kinematic chain 100 illustrated in
The rotating means 101 are adapted to be driven by the driving means 200 so as rotate about the axis 102 at least between a first angular position, according to which the kinematic chain 100 is in the first position (illustrated in
For example, the driving means 200 for the kinematic chain 100 of each phase 2 comprise a rotating electrical motor 200.
The rotation of the means 101 from the first angular position to the second angular position and the rotation from the second angular position to the first angular position occur according to a first rotational direction and a second opposed rotational direction, respectively. For example, with reference to
The exemplary kinematic chain 100 illustrated in
The kinematic chain 100 of the switching device 1 according to the present disclosure is adapted to reach the second position from the first position before reaching a dead-point position, i.e. a position where the inertia of the kinematic chain 100 reaches a lower peak.
If the kinematic chain 100 is in a position between an initial position and the dead-point position, the kinematic chain 100 would tend to evolve towards the initial position when subjected to disturbance forces, e.g. forces other than the force generated by the driving means 200, such as vibrations, gravity or electromagnetic forces.
If instead the kinematic chain 100 is in a position between the dead-point position and an end position, the kinematic chain 100 would tend to evolve towards the end position when subjected to disturbance forces.
In particular, very small angular displacements of the rotating means 101 with respect to the dead-point angular position would not cause a linear displacement of the rod 105. In other words, the first derivative of the spatial position of the rod 105 with respect to the angular position of the rotating means 101 is substantially equal to zero at the dead-point angular position, and it has opposed signs before the reaching and after the crossing of the dead-point position.
The switching device 1 further comprises control means 300 adapted to control the driving means 200.
In particular, during normal operations of the switching device 1, the control means 300 are adapted to control the driving means 200 to move the kinematic chain 100 between its first and second operative positions, so as to actuate the movable contact 3 between the open and close positions.
This control can be implemented according to solutions which are available to the skilled in the art and, therefore, no further disclosed in details. For example, the control means 300 can be adapted to control the driving means 200 so as to synchronize the movement of the kinematic chain 100 between the first and second positions with an AC electrical waveform associated to the phase 2.
Since the kinematic chain 100 is adapted to reach its second position from the first position before reaching the dead-point position, the passage of the kinematic chain 100 through the dead-point position is avoided during the normal controlled switching operations of the device 1.
With reference to
In practice, the power supply 400 adequately supplies, while correctly working, the control means 300 and the associated driving means 200 for controlling and driving the movement of the kinematic chain 100. In particular, the control means 300 and the driving means 200 receive power enough to control and drive the movement of the kinematic chain 100 between the first and second positions, when an actuation of the movable contact 3 between the close and open positions is required.
The switching device 1 can be installed into the electrical installation 600 in such a way that at least the reached second position of the kinematic chain 100 is an instable mechanical position, i.e. a position where relevant disturbance forces can overcome the inertia and friction of the kinematic chain 100 and cause its movement towards the first position.
For example, the switching device 1 can be installed according to
However, the control means 300 are adapted to detect any undesired displacement of the movable contact 3 from the reached close position or open position, and consequently adjust the kinematic chain 100 through the driving means 200 in order to cause the return the movable contact 3 in the close position or open position.
In this way, under a correct working of the power supply 400, the control means 300 and driving means 200 are able to substantially hold the movable contact 3 in the reached open or close position, even if one of these positions is instable and until a further switching operation is required.
In the exemplary embodiment illustrated in the attached figures, the switching device 1 comprises at least one capacitor 401 associable to the power supply 400 for storing energy.
The capacitor 401 is operatively associated to the control means 300 and the driving means 200 for adequately supply them under normal operative conditions of the power supply 400, in such a way that:
Further, when the movable contact 3 has reached the close position, the control means 300 can control the driving means 200 to adjust the angular position of the rotating means 101 upon undesired displacements of the rod 105, so as to return the movable contact 3 in the close position. This task is particularly critical because the kinematic chain 100 as illustrated in
When the movable contact 3 has reached the open position, the control means 300 can also control the driving means 200 to adjust the angular position of the rotating means 101 upon undesired displacements of the rod 105 and return the movable contact 3 in the open position, even if such displacements are improbable since the kinematic chain 100 as illustrated in
Advantageously, the control means 300 of the switching device 1 according to the present disclosure are also adapted to:
The kinematic chain 100 in the reached third position and subjected to disturbance forces should not return towards the crossed dead-point position and, hence, from the dead point position to the second position, and from the second position to the first position. Instead, the kinematic chain 100 will tend to move from the third position further away from the crossed dead-point position, so as to operatively interact with the blocking means 50.
In practice, the reached third position is a safety position avoiding the return of the kinematic chain 100 towards the first position.
In this way, considering an installation of the switching device 1 in which the second position of the kinematic chain 100 is mechanically instable, the kinematic chain 100 is brought from the instable second position to the third safety position by the control means 300 and the driving means 200, before the switching device 1 cannot be further operated by means of the power supply 400 under loss condition.
Preferably, according to the exemplary embodiment illustrated in
Preferably, the control means 300 are adapted to control the driving means 200 for moving the kinematic chain 100 away from the second position, when the loss condition is detected, in such a way that the kinematic chain 100 in the reached third position is spaced away from the blocking means 50. In this case, the kinematic chain 100 is adapted to move away from the third position in so as to contact the blocking means 50.
In other words, the reached third position is mechanically instable and the kinematic chain 100, when subjected to relevant disturbance forces overcoming its inertia and friction, can move from the third position further away from the crossed dead-point position, towards the corresponding blocking means 50 which block this movement.
In this way, the kinematic chain 100 can reach a locked position which is mechanically stable because the kinematic chain 100 subjected to disturbance forces will not move to return towards the dead-point position, neither it will further move in another direction because it is blocked by the means 50.
Alternatively, the control means 300 are adapted to control the driving means 200 for moving the kinematic chain 100 away from the second position, when the loss condition is detected, in such a way that the kinematic chain 100 in the third position is in contact with the blocking means 50. In this case, the reached third position is directly a locked position which is mechanical stable, because the kinematic chain 100 subjected to disturbance forces will not move to return towards the dead-point position, neither it will further move in another direction because it is blocked by the means 50.
With reference to the exemplary embodiment illustrated in
In particular, the rotating means 101 under this controlled motion pass through the angular dead-point position (according to which the kinematic chain 100 is in the dead-point position as illustrated in
In the exemplary embodiment illustrated in
With reference to
In practice, the third reached position (
Preferably, the kinematic chain 100 is also configured in such a way that the movable contact 3 remains in contact with respect to the corresponding fixed contact 4 during the rotation of the means 101 from the third angular position to the final angular position.
In the exemplary embodiment illustrated in
Alternatively, the controlled rotation of the means 101 from the second angular position to the third angular position is such that at least one element of the kinematic chain 100, e.g. the linkage element 104 or the rotating means 101 themselves, is in contact with the wall 50 when the rotating means 101 are in the third angular position. In this case, the third position reached by the kinematic chain 100 is directly a mechanically stable locked position.
With reference to
Preferably, the predetermined threshold is set so as in the at least one capacitor 401 remains energy enough for driving the movement of the kinematic chain 100 from the second position to the third position. In this way, the third safety position can be reached before that the energy stored in the at least one capacitor 401 falls below a critical amount necessary for supplying the control means 300 and the driving means 200.
Preferably, the control means 300 of the switching device 1 according to the present disclosure are adapted to:
For example, the control means 300 of the exemplary switching device 1 illustrated in
In this way, the initial condition before the detection of the loss condition is advantageously automatically restored, as soon as the power supply 400 can adequately supply the switching device 1 to operate.
With reference to cited
Advantageously, the method 500 comprises:
Preferably, the controlling of the driving means 200 according to the method step 502 is such that the kinematic chain 100 in the third position is spaced away from the blocking means 50.
Alternatively, the controlling of the driving means 200 according to the method step 502 is such that the kinematic chain 100 in the third position is in contact with the blocking means 50.
Preferably, the controlling of the driving means 200 according to the method step 502 is designed to occur according to the fact that the blocking means 50 comprise a wall 50 of the casing 5 housing the kinematic chain 100.
For example, when the method 500 is applied to control the exemplary switching device 1 above disclosed and illustrated in
Preferably, as illustrated in
In this way, when the kinematic chain 100 is subjected to relevant disturbance forces, the rotating means 101 can rotate further clockwise from the third angular position, until the linkage element 104 comes in contact to the wall 50 (kinematic chain 100 in the mechanically stable locked position illustrated in
Alternatively, the controlled rotation is such in that in the reached third angular position the linkage element 104 or the rotating means 100 are in contact with the wall 50. In this case, the third position reached by the kinematic chain 100 is directly a mechanically stable locked position.
With reference to
In this case, the method 500 preferably also comprises:
In this way, the third safety position can be reached before that the energy stored in the at least one capacitor 401 falls below a critical amount necessary for supplying the control means 300 and the driving means 200.
Preferably, the method 500 further comprises:
In this way, the initial condition before the execution of method step 501 is advantageously automatically restored, as soon as the power supply 400 can adequately supply the switching device 1 to operate. Hence, the method 500 can be repeated again as soon as another loss condition of the power supply 400 is detected.
The operation of the exemplary switching device 1 illustrated in
Such switching device 1 is considered installed in the corresponding electrical installation 600 so as to be positioned as illustrated in the
It is further considered a starting condition as illustrated in
With reference also to
When a loss condition of the power supply 400 occurs, the control means 300 detect it (method step 501). For example, the control means 300 detect when the energy stored into the least one capacitor 401 falls below a predetermined threshold due to the loss condition of the power supply 400.
When the loss condition is detected, the control means 300 control the driving means 200 to rotate clockwise the means 101 about the axis 102, from the second angular position to the third angular position (according to which the kinematic chain 100 is the third position illustrated in
In order to operate the movement of the kinematic chain 100 from the second position to the third position, the predetermined threshold for detecting the loss condition is preferably set so as in the at least one capacitor 401 remains energy enough for rotating the means 101 from the second angular position to the third angular position (method step 503). In this way, when in the at least one capacitor 401 there is no more energy for operating the switching device 1, the kinematic chain 100 has already reached the third position.
This third position is a safety position which avoids an undesired return of the kinematic chain 100 to the second position, and from the second position to the first position.
Indeed, if the kinematic chain 100 is subjected to relevant disturbance forces, the rotating means 101 would further rotate clockwise, because they have already crossed the angular dead-point position.
However, this further clockwise rotation is stopped at the final angular position by the wall 50 of the casing 5, in such a way that the kinematic chain 100 reaches the stable locked position illustrated in
In this locked position, even if the control means 300 and/or driving means 200 do not receive power enough to operate, the rod 105 will not be subjected to undesired displacements by disturbance forces.
When the loss condition of the power supply 400 ceases, the control means 300 detect it (method step 504) and control the driving means 200 to rotate the means 101 counterclockwise to return in the second angular position according to which the kinematic chain is in the second position illustrated in
In this way, as soon as enough power is still available for the switching device 1, the starting condition before the power loss is automatically restored.
In practice, it has been seen how the switching device 1 and related control method 500 allow achieving the intended object offering some improvements over known solutions.
In particular, the controlled reaching of the safety third position by the kinematic chain 100, when a loss condition of the power supply 400 is detected, allows to use very simple blocking means 50 in order to reach a stable locked position.
Indeed, the kinematic chain 100 in the reached third position and subjected to relevant disturbance forces should not return towards the crossed dead-point position, but it will tend to move from the third position further away from the dead-point position.
Hence, the blocking means 50 need only to provide an element, or surface, on which the kinematic chain 100 abuts during its movement away from the third position, so as to block such movement and reach a mechanically stable locked position.
Alternatively, the blocking means 50 need only to provide an element, or surface, of contact for at least one element of the kinematic chain 100 in the third position, so as to prevent a further movement away from such third position.
For example, in the embodiment illustrated in
The fact that the blocking means 50 can be realized so as to occupy a small volume, or through elements already conceived for the switching device 1, such as the wall 50, is particularly advantageous in view of their housing in small volumes, such as the internal volume of the casing 5 of each phase 2.
The switching device 1 and related electrical installation 600 and control method 500 thus conceived are also susceptible of modifications and variations, all of which are within the scope of the inventive concept as defined in particular by the appended claims.
For example, even if the exemplary embodiment illustrated in
Even if in the exemplary embodiment illustrated in
Even if in the exemplary embodiment illustrated in
Even if in the exemplary embodiment illustrated in
The control means 300 according to the above disclosure can be for example any suitable electronic device or combination of electronic devices adapted to:
Without limiting purposes, the control means 300 can comprise for example: microcontrollers, microcomputers, minicomputers, a digital signal processors (DSPs), optical computers, complex instruction set computers, application specific integrated circuits, a reduced instruction set computers, analog computers, digital computers, solid-state computers, single-board computers, or a combination of any of these.
In practice, all parts/components can be replaced with other technically equivalent elements; in practice, the type of materials, and the dimensions, can be any according to needs and to the state of the art.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/060371 | 5/20/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/176754 | 11/26/2015 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5744923 | Strauss et al. | Apr 1998 | A |
| 20030137373 | Grumel | Jul 2003 | A1 |
| 20040099639 | Valdermarsson | May 2004 | A1 |
| 20120325628 | Besana | Dec 2012 | A1 |
| 20130153377 | Reuber | Jun 2013 | A1 |
| 20130248338 | Belloni et al. | Sep 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 2421017 | Feb 2012 | EP |
| 2722862 | Apr 2014 | EP |
| 9424521 | Oct 1994 | WO |
| Entry |
|---|
| International Search Report and Written Opinion, PCT/EP2014/060371, ABB Technology AG, dated Jan. 27, 2015, 9 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20170256369 A1 | Sep 2017 | US |
