Patent Grant
10622179
This application is the U.S. National Stage of PCT/FR2017/051168 filed May 15, 2017, which in turn claims priority to French Application No. 1654336, filed May 16, 2016. The contents of both applications are incorporated herein by reference in their entirety.
The invention relates to a breaker device for interrupting electric current flowing in an electrical circuit, and also to a secure electrical system including such a breaker device.
Electrical circuits may be protected at present by placing fuses in each of the phases. Such fuses serve to interrupt the electric current in the event of a high current appearing for a specific duration, and they are reliable in use in the case of faults with high fault currents. Nevertheless, for currents that are only a little greater than the nominal currents, such fuses may take a relatively long time to break and may possibly break incompletely. A break that is incomplete or that takes place too late can lead to unacceptable damage to the electrical system, and in particular to an electrical device powered by the electrical circuit. It is therefore desirable to improve the quality of the circuit breaking performed in the event of a malfunction occurring so as to improve the security and the lifetime of electrical systems.
There therefore exists a need to provide breaker devices that are relatively simple and that enable the quality of circuit breaking to be improved.
To this end, in a first aspect, the invention provides a breaker device for connecting in an electrical circuit, the device comprising at least one pyrotechnic initiator and a body having present therein:
the pyrotechnic initiator being configured to cause the breaker device to pass from a current-passing first configuration to a circuit-breaking second configuration, the movable breaker element being moved on passing from the first configuration to the second in order to disconnect said conductive portion.
On being actuated, the pyrotechnic initiator is configured to produce a pressurizing gas in order to pressurize the pressurizing chamber. The pressurizing gas exerts pressure on the movable breaker element so as to cause it to move. The movable breaker element moving in this way is configured to cause the device to pass into the second configuration in which the conductive portion is disconnected, i.e. a configuration in which the flow of electric current in the conductive portion is interrupted. Thus, when the device is in the second configuration, the electric current flowing in the electrical circuit is cut off.
The invention proposes a breaker device enabling circuit breaking to be performed quickly and reliably in a circuit in the event of excess electric current, thus making it possible to avoid damaging an electrical device powered by said circuit. More precisely, during normal operation of the system, the fusible element is conductive, and the voltage across the terminals of the fusible element is relatively low so that the current flowing through the igniter device of the pyrotechnic initiator is low enough to avoid initiating it. In contrast, when the current flowing through the fusible element exceeds the predetermined value, the fusible element trips, i.e. its resistance increases so as to initiate disconnection of the conductive portion. Thus, the voltage across the terminals of the fusible element increases when it trips, and as a result the current flowing through the igniter device increases, thereby serving to actuate the pyrotechnic initiator and cause the device to pass from the first configuration to the second so as to permanently interrupt the flow of current in the circuit. Another advantage of the invention is that a breaker solution is proposed that is compact and integrated insofar as the fusible element enabling the initiator to be triggered is present inside the breaker device and not outside it. The invention thus serves advantageously to simplify existing breaker systems by proposing an independent breaker device that directly integrates the element that will trigger circuit breaking, specifically the fusible element. This serves advantageously to avoid the need for an additional device to be present for sensing and/or analyzing voltage and/or current in order to enable the initiator to be triggered. Thus, combining breaking by means of the fusible element and breaking by moving the movable breaker element serves very significantly to improve the security of power supply systems in a manner that is relatively simple insofar as it makes it possible to ensure that complete breaking is performed independently and thereby to avoid situations in which the fusible element does not completely interrupt the current.
Advantageously, at least one resistor or diode may be connected in series in the line connecting the device for igniting the initiator to one of the terminals of the fusible element.
Such an embodiment serves advantageously to avoid any risk of the igniter device being degraded by the current flowing therethrough.
In an embodiment, the fusible element may be a separate component connected to the conductive portion. Under such circumstances, the fusible element constitutes an element that is distinct from the conductive portion and that is connected in series therewith, e.g. by soldering.
In a variant, the fusible element may be constituted by a narrow zone of the conductive portion. Under such circumstances, the conductive portion and the fusible element are constituted by the same material.
In an embodiment, the pressurizing chamber constitutes a first breaker device chamber, at least a fraction of the conductive portion being present in a second chamber that is present in the body, the movable breaker element separating the first chamber from the second chamber and presenting at least one projecting portion made of electrically insulating material, said at least one projecting portion facing the conductive portion, the movable breaker element being caused to move towards the conductive portion in order to break it by impact against the projecting portion on passing from the first configuration to the second.
Under such circumstances, the conductive portion is disconnected by being broken by impact against the projecting portion when the device passes from the first configuration to the second. Nevertheless, the present invention is not limited to such an embodiment in which the conductive portion is broken when the initiator is actuated.
Specifically, in another embodiment, the conductive portion presents a first electrically conductive element and a second electrically conductive element, and the movable breaker element presents a third electrically conductive element, the third electrically conductive element establishing electrical connection between the first and second conductive elements when the breaker device is in the first configuration, and the third conductive element being disengaged from at least one of the first and second conductive elements so as to prevent electric current flowing between them when the device is in the second configuration.
Under such circumstances, electric current can flow between the first conductor and the second conductor via the third conductor when the device is in the first configuration. In contrast, when the device is in the second configuration, the first and second conductors are no longer electrically connected, but without the conductive portion being broken. This electrical disconnection is the result of a conductive element of the movable breaker element moving when the device passes from the first configuration to the second configuration. Thus, under such circumstances, the conductive portion is disconnected by eliminating the electrical connection between at least two of its conductive elements, but without said conductive portion being broken as a result of the movable breaker element moving when the device passes from the first configuration to the second. As described in greater detail below, in this embodiment, the movable breaker element may be made entirely out of electrically conductive material, or it may include a third electrically conductive element together with an electrically insulating portion.
In an embodiment, the device may have a single conductive portion. Under such circumstances, the breaker device may be for connection a single-phase power supply circuit.
In a variant, the device may include a plurality of conductive portions, a respective fusible element being connected in series with each of the conductive portions, the initiator possibly being connected to the terminals of each fusible element and each fusible element possibly being configured to trip when the current passing through it exceeds the predetermined value so as to actuate the initiator. Under such circumstances, the breaker device may be for connection to a polyphase power supply circuit. By way of example, the polyphase power supply circuit may be a three-phase circuit, or in a variant it may have two phases or at least four phases. Unless specified to the contrary, the term “phase of the circuit” should be understood as the electrical conductor corresponding to said phase of the electrical circuit.
With a plurality of conductive portions, all of the conductive portions are electrically disconnected simultaneously when the device passes from the first configuration to the second configuration. This serves advantageously to perform a complete and simultaneous interruption of the current flowing in the circuit.
The invention also provides a secure electrical system comprising at least:
In an embodiment, the electrical system may also comprise a monitor element for monitoring the electrical device and configured to actuate the initiator when the value of an operating parameter of the electrical device reaches a predetermined value.
This embodiment is advantageous for achieving a complete break of the circuit in the event of a malfunction occurring in the electrical device that is to be powered but without necessarily involving excess current in the power supply circuit.
The operating parameter may be pressure or temperature. Thus, the monitor element of the electrical device may be configured to actuate the pyrotechnic initiator when the temperature of the electrical device or the pressure of at least a portion of the electrical device exceeds a predetermined value.
The present invention also provides a vehicle including at least one secure electrical system as described above. By way of example, the vehicle may be an aircraft, a train, or a car.
The present invention also provides an installation including at least one secure electrical system as described above.
By way of example, the electrical device may be a train motor. In a variant, the electrical device may be a heat pump or a power installation.
Other characteristics and advantages of the invention appear from the following description of particular embodiments of the invention, given as non-limiting examples, and with reference to the accompanying drawings, in which:
In
The breaker device 1 comprises a pyrotechnic initiator 3 having an igniter device 9 with two electrical conductors 5 (only one of the conductors being shown in
The device 1 comprises a body 11 in which first and second chambers 7 and 12 are present. By way of example, the body 11 may be made of a thermoplastic or thermosetting material. The pyrotechnic initiator 3 has a sealing gasket 6 made of elastically deformable material pressing against an inside wall 14 of the body 11. In the example shown, the igniter device 9 is housed in the body 11. The body 11 also presents two through channels 11a, with each of the conductors 5 extending in a respective one of the channels 11a. The first chamber 7 constitutes a pressurizing chamber and it is in communication with an outlet S of the pyrotechnic initiator 3. On being actuated, the pyrotechnic initiator 3 is configured to pressurize the first chamber 7. In the example shown, the pyrotechnic charge 4 is present in the first chamber 7. Nevertheless, it would not go beyond the ambit of the invention for the charge to be present outside the first chamber so long as the chamber remains in communication with an outlet from the pyrotechnic initiator.
An electrically conductive portion 8 is present in the second chamber 12 (see
The conductive portion 8 is provided with a fuse 40 that is connected in series therewith. In this example, the fusible element 40 constitutes an element that is distinct from the conductive portion 8 and that has been fitted thereto. By way of example, the fuse 40 could be soldered or clipped to the conductive portion 8, In the example shown, the fuse 40 together with its insulating shell 41 has been soldered to the conductive portion 8. In this example, the fuse 40 comprises a fusible core present inside an electrically insulating shell 41, The insulating shell 41 may contain a powder of electrically insulating material, such as silica, with the fusible core present therein. Using a fusible core in association with its insulating shell serves advantageously to improve the lifetime of the fusible core, thereby further improving the reliability of the breaker device. In a variant, it would be possible for the conductive portion to incorporate only the fusible element of a commercial fuse (without its insulating shell 41), In addition, in this example, the fuse 40 is present in the second chamber 12, which is present inside the body 11.
Each electrical conductor 5 is connected to a distinct terminal of the fuse 40. More precisely, the side wall 22 of the body 11 has channels 23a and 23b through which the electrical conductors 24a and 24b extend. The first electrical conductor 24a connects a first terminal of the fuse 40 to a first conductor 5 of the igniter device 9. The second electrical conductor 24b connects a second terminal of the fuse 40, different from the first terminal, to a second conductor 5 of the igniter device 9, different from the first conductor. Thus, when an electric current greater than a predetermined value is conveyed by the phase 10 and the conductive portion 8, the fuse 40 trips. As a result, the resistance across the terminals of the fuse 40 increases, thereby giving rise to a potential difference that is sufficient to actuate the igniter device 9 and thus to break the electric current. Selecting the fuse characteristics that should be used in order to obtain circuit breaking at the desired current level comes within the general knowledge of the person skilled in the art. In particular, it may be observed that the fuse does not need to withstand a high voltage, which means that it is possible to use fuses having a relatively low breakdown voltage. The breaker device may be used in a system that involves a voltage of less than 100 volts (V), for example.
At least one resistor or diode (not shown) may advantageously be connected in series in the line connecting the fuse 40 to the igniter device 9 in order to reduce the current flowing through the igniter device 9 and thus avoid any degradation of the igniter device in the presence of the nominal current.
The conductive portion 8 is present on a support 18. In the example shown, the support 18 has the structure of a slide for engaging in an opening 22a in the side wall 22 of the body 11. The support 18 defines a recessed portion 20 situated under the conductive portion 8 when the device 1 is in the first configuration. The support 18 presents a groove 19 in which the conductive portion 8 is received. The conductive portion 8 is for connecting in a phase 10 of the power supply circuit. By way of example, this connection may be performed by soldering. The ends of the conductive portion 8 are connected in a phase 10 of the power supply circuit.
The example device 1 of
There follows a description of assembling the various elements of the breaker device 1 shown in
Initially, the body 11 is overmolded onto the pyrotechnic initiator 3. The breaker element 15 is then inserted by force through the bottom 25. As shown in
With reference to
The device 1 is initially in the first configuration in which an electric current (arrow I) can flow in the phase 10 and in the conductive portion 8 (the fuse 40 is conductive). While the device 1 is in the first configuration, the breaker element 15 is in a first position, referred to as a “high” position. When the current flowing in the conductive portion 8 exceeds a predetermined value, the fuse 40 trips. Thus, the resistance across the terminals of the fuse increases, thereby enabling the pyrotechnic initiator to be actuated. Actuating the pyrotechnic initiator 3 serves to cause the breaker device to go from the first configuration to a second configuration in which the flow of electric current in the conductive portion 8 is interrupted (conductive portion disconnected). More precisely, actuating the pyrotechnic initiator serves to initiate combustion of one or more pyrotechnic charges 4 so as to generate combustion gas (arrows F) that pressurizes the first chamber 7 (see
A maintenance operation can be performed after the power supply circuit has been broken in order to remove the breaker device in the second configuration and replace it with a breaker device in the first configuration. The supply of power to the electrical device by means of the power supply circuit can then be restarted.
The example breaker device 1 described above with reference to
The first chamber 7 constitutes a pressurizing chamber and it is in communication with an outlet S of the pyrotechnic initiator 3. In the example of
Furthermore, each electrical conductor 5 is connected to a distinct terminal of the fusible element 130. As in the example of
In the example of
Actuating the initiator causes the movable breaker element 15 to move towards the conductive portion 180 so as to break it, in a manner analogous to that described with reference to
The above-described examples disconnect the conductive portion by breaking it by means of the movable breaker element. With reference to
The breaker device 211 has a hollow body 216 made of electrically insulating material defining a cavity 219, a pyrotechnic initiator 223, and a conductive portion having two primary electrically conductive tabs 213 and 214 that lead into the cavity 219. In this example, the conductive portion thus has a first electrically conductive element (conductive tab 213) and a second electrically conductive element (conductive tab 214). The first and second electrically conductive elements 213 and 214 are offset along the longitudinal axis Y of the cavity 219 in the example shown.
The breaker device 211 also has a movable breaker element 220 configured to move in the cavity 219. In this example, the cavity 219 is cylindrical and the movable breaker element 220 is itself essentially cylindrical. In the example shown, the movable breaker element 220 comprises a first portion made of an electrically insulating material and a second portion made of an electrically conductive material. The movable breaker element 220 comprises a split tube 221 including at least one electrically conductive element. In the example shown in
When the device 211 is in the first configuration as shown in
In this example, the pyrotechnic initiator 223 comprises a conventional pyrotechnic gas generator installed in the hollow body so as to communicate with the cavity 219. A pressurized chamber 225 is defined between the pyrotechnic initiator 223 and one of the axial end faces of the piston 222. More particularly, in this example, the piston 222 has a cavity 226 in its upstream face facing towards the pyrotechnic initiator 223, and this cavity 226 constitutes a portion of the pressurizing chamber 225. In the initial position in which the slide 222 is practically in contact with the initiator 223, i.e. with the pressurizing chamber 225 reduces to its minimum volume, both electrically conductive tabs 213 and 214 are electrically connected together via the split tube 221 in a first position referred to as an “initial” position. Electrical contact takes place via the third conductive element (specifically the split tube 221), as mentioned above.
The two conductive tabs have two respective rings 213a and 214a about the axis Y that are offset axially along that axis (which axis corresponds to the travel direction of the movable breaker element 220) and these rings 213a and 214a are in tight contact with the conductive portion of the movable breaker element (specifically the split tube 221) while it is in said first position. In this example, the inside faces of the rings 213a and 214a are flush with the wall of the cavity 219. Advantageously, in said first position, the split tube 221 is engaged as a force fit between the rings 213a and 214a of said primary conductive tabs 213 and 214, thereby guaranteeing an excellent electrical connection between said primary conductive tabs throughout the period preceding actuation of the breaker device 211.
In
On actuation of the pyrotechnic initiator 223, the movable breaker element 220, and consequently the split tube 221, moves towards a second position in the cavity (
In this manner, in said initial, first position, the two rings 213a and 214a on a common axis along which they are axially offset are connected together electrically via the split metal tube 221. In the example shown, the insulating slide 222 is inserted inside the slidable split tube 221. An upstream or first portion 241 of cylindrical shape and of diameter substantially equal to the diameter of the cavity 219 slides along the inside faces of said cavity. In its upstream face that faces upwards in
A slot is advantageously formed in at least one of said grooves and is configured to form a calibrated passage for discharging air from the pressurizing chamber while assembling the piston 222 in the support 212 of the pyrotechnic initiator 223. The piston 222 situated at least in part upstream from the split tube, serves to transmit to said tube 221 the pressure force generated by the gas in the pressurizing chamber 225 so as to enable the circuit to be broken by moving said tube 221. The first portion 241 is extended by a downstream, second portion 242 of slightly smaller diameter that is selected to enable it to be inserted, possibly by force, into the inside of the split tube once it has been inserted between the rings 213a and 214a. This second portion may serve as a guide element for the split tube as it moves inside the cavity 219. In an advantageous embodiment, it may also form a clamping element additional to the split tube against the rings 213a and 214a.
As can be seen in the drawings, the cavity 219 is extended downstream by a guide portion 245 that serves to guide the split tube 221 when it passes from the first position to the second so as to ensure that it follows a rectilinear path. A damping pad 29 is inserted in the bottom of the cavity 219. Where necessary, the damping pad 29 serves to reduce the energy of the impact of the conductive split tube 221 and the insulating piston 222 when these two parts come into contact with the bottom of the body 216.
The above-described secure electrical systems 30 and 300 may be mounted in a vehicle such as an aircraft or a train or they may be present in an industrial installation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16 54336 | May 2016 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2017/051168 | 5/15/2017 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/198937 | 11/23/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5990572 | Yasukuni | Nov 1999 | A |
| 20050034595 | Kordel | Feb 2005 | A1 |
| 20050083164 | Caruso | Apr 2005 | A1 |
| 20080137253 | George | Jun 2008 | A1 |
| 20130056344 | Borg | Mar 2013 | A1 |
| 20140061011 | Nakamura | Mar 2014 | A1 |
| 20150206681 | Marlin | Jul 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 101295610 | Oct 2008 | CN |
| 101809703 | Aug 2010 | CN |
| 197 12 387 | Oct 1997 | DE |
| 20 2015 106793 | Jan 2016 | DE |
| 2 775 539 | Sep 1999 | FR |
| 2 797 990 | Mar 2001 | FR |
| 2 489 101 | Sep 2012 | GB |
| 2014-049272 | Mar 2014 | JP |
| Entry |
|---|
| International Preliminary Report on Patentability and the Written Opinion of the International Searching Authority as issued in International Patent Application No. PCT/FR2017/051168, dated Nov. 20, 2018. |
| International Search Report as issued in International Patent Application No. PCT/FR2017/051168, dated Jul. 25, 2017. |
| Number | Date | Country | |
|---|---|---|---|
| 20190287751 A1 | Sep 2019 | US |
