Breaking device

Abstract

To provide a breaking device for interrupting a current, which is more resilient to wear and has lower material losses.SOLUTION: A breaking device includes an electrically conducting outer member (50), an electrically conducting inner member (52) arranged radially inside the outer member (50) with respect to a breaking axis (48), and an electrically insulating or semiconducting breaking member (26) arranged radially between the outer member (50) and the inner member (52) with respect to the breaking axis (48), where the breaking member is arranged to move along the breaking axis (48) from a starting position to a protruding position in which the breaking member (26) protrudes from a space (59) within the outer member (50) for interrupting a current between the outer member (50) and the inner member (52), and the breaking member (26) includes an inner tubular element and an outer tubular element, where the outer tubular element is joined to an outer surface of the inner tubular element thereby defining a recess between the outer tubular element and the inner tubular element.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure generally relates to a cutoff device. In particular, a cutoff device for interrupting current is provided.

Background Art

[0002] In many fields such as power distribution systems, cutoff devices are important.

[0003] European Patent No. 3709325 discloses one type of cutoff device in the form of a tubular cutoff device, which includes a conductive inner member disposed radially inside a conductive outer member and an electrically insulating or semiconductive cutoff tube disposed radially between the outer member and the inner member. The cutoff tube separates the conductive members from each other and extends an arc generated by separating the conductive members from each other.

[0004] This cutoff device usually functions well. However, over time, due to material loss of the elements within the device, the arc extension effect is gradually reduced. This may lead to an increase in arc interruption time. Eventually, a cutoff failure may occur.

[0005] Therefore, an improved cutoff device is needed.

Summary of the Invention

[0006] One object of the present disclosure is to provide a cutoff device for interrupting current that is more resilient to wear and has less material loss.

[0007] A further object of the present disclosure is to provide a cutoff device for interrupting current that results in a high-speed interruption of current.

[0008] A further object of the present disclosure is to provide a cutoff device for interrupting current that results in a reliable interruption of current.

[0009] A further object of this disclosure is to provide a current interruption device that can be used multiple times to interrupt a current.

[0010] Another object of this disclosure is to provide a break-off device for interrupting current, which solves some or all of the aforementioned objectives in combination.

[0011] According to one embodiment, a breaker device for interrupting current, Conductive outer member, A conductive inner member is radially positioned inside the outer member with respect to the shielding shaft, It comprises an electrically insulating or semiconducting shielding member arranged radially between an outer member and an inner member with respect to the shielding shaft, The interrupting member is positioned to move along the interrupting axis from a starting position to a protruding position where the interrupting member protrudes from the space within the outer member in order to interrupt the current between the outer member and the inner member. A blocking device is provided, comprising an inner tubular element and an outer tubular element, wherein the blocking member is joined to the outer surface of the inner tubular element, thereby defining a recess between the outer tubular element and the inner tubular element.

[0012] More specifically, the recess can be defined between the inner surface of the outer tubular element and the outer surface of the inner tubular element.

[0013] The outer tubular element can be joined to the inner tubular element at a joining region on the outer surface of the inner tubular element. More specifically, the joining region can be formed as a cylindrical portion on the outer surface of the inner tubular element around the blocking axis.

[0014] The inner tubular element may additionally be provided with a first projection end, and the outer tubular element may be provided with a second projection end.

[0015] The first projection end may be positioned in a first plane perpendicular to the blocking axis, the second projection end may be positioned in a second plane perpendicular to the blocking axis, and the bottom of the recess may be located in a third plane, also perpendicular to the blocking axis.

[0016] The inner tubular element may have a first projection length, which may be the length between the first projection end and the region where the outer tubular element is joined to the inner tubular element. Similarly, the outer tubular element may have a second projection length, which may be the length between the second projection end and the region where the outer tubular element is joined to the inner tubular element. Thus, the first projection length of the inner tubular element may be the length of the inner tubular element along the barrier axis between the first plane and the third plane, and the second projection length of the outer tubular element may be the length of the outer tubular element along the barrier axis between the second plane and the third plane.

[0017] The second projection end can be positioned between the first projection end and the joining region in relation to the blocking axis.

[0018] In one variant, the second projection can be positioned substantially midway between the joining region and the first projection with respect to the blocking axis. The second projection can thereby be positioned substantially midway between the first projection and the region where the outer tubular element is joined to the inner tubular element. Thus, the second plane having the second projection can be positioned essentially midway between the first plane and the third plane. The distance between the second plane and the first plane may thereby be essentially the same as the distance between the first plane and the third plane.

[0019] In another variant, the second projection end can be positioned closer to the joining region than the first projection end with respect to the blocking axis. Thus, the second plane having the second projection end can be positioned closer to the third plane than the first plane. The distance between the second and third planes may consequently be smaller than the distance between the second and first planes.

[0020] In a further modified form, the second projection end can be located closer to the first projection end than the joining region with respect to the blocking axis. The second plane can thereby be located closer to the first plane having the first projection end than to the third plane having the bottom of the recess. This also means that the distance between the second plane and the first plane can be smaller than the distance between the second plane and the third plane.

[0021] The interruption device may further include an arc discharge chamber comprising an inner cavity for receiving an inner tubular element and an outer cavity for receiving an outer tubular element. More specifically, the inner cavity may be molded to receive a first projection length of the inner tubular element, and the outer cavity may be molded to receive a second projection length of the outer tubular element. The cavity may be formed of a body of an electrically insulating material, which may be a ceramic or polymer body, in which case the polymer may be a thermosetting or thermoplastic polymer, such as polyoxymethylene (POM), poly(methyl methacrylate) (PMMA), polyimide (PI), polyamide (PA), and / or polyolefin, such as polypropylene (PP) or polymethylpentene (PMP), or another such polymer.

[0022] The presence of inner and outer cavities also forms a wall between them, which faces a recess between the inner and outer tubular elements. More specifically, the end of the wall may be adapted to face the bottom of the recess.

[0023] Furthermore, at the projection position, the first projection end of the inner tubular element may be positioned to abut against the bottom of the inner cavity, the second projection end of the outer tubular element may be positioned to abut against the bottom of the outer cavity, and / or the bottom of the recess may be positioned to abut against the tip of the wall separating the inner cavity from the outer cavity.

[0024] The device can further comprise at least one ventilation opening for ventilating the arc discharge chamber when the blocking member moves from the starting position, in which case each ventilation opening leads to one of the cavities. In this case, it is possible for at least one first radial ventilation opening to lead to the inner cavity. Additionally, or alternatively, it is possible for at least one second radial ventilation opening to lead to the outer cavity. Each radial ventilation opening can additionally lead to the cavity via a ventilation channel.

[0025] The outer member, the inner member, the inner tubular element, and the outer tubular element may be substantially concentric with the blocking axis.

[0026] The blocking device can further comprise an actuator arranged to force the blocking member from the starting position to the protruding position.

[0027] The blocking device can additionally comprise a contact arrangement with a movable contact element, which contact arrangement is configured to selectively electrically disconnect the outer member and the inner member. More specifically, the contact arrangement can be configured to electrically disconnect the outer member and the inner member during the movement of the blocking member from the starting position to the protruding position.

[0028] The blocking member provides an electrical potential barrier between the outer member and the inner member. Due to the shape of the blocking member, the arc can be effectively trapped by moving the blocking member from the starting position to the protruding position.

[0029] As the blocking member moves from the starting position, the arc path between the inner member and the outer member becomes longer. More specifically, the blocking member extends the length of the arc by a distance at least corresponding to the sum of twice the first protruding length and twice the second protruding length. Thereby, the arc voltage can rise rapidly. The extended length of the arc path can ultimately cause the arc to disappear. Thereby, the circuit comprising the blocking device can be opened. The starting position and the protruding position of the blocking member can thus correspond to the closed position and the open position of the blocking device, respectively.

[0030] Since the interruption device comprises an interruption member having a tubular element, the interruption device constitutes a tubular circuit breaker. The interruption device can be used in AC and DC applications, for example, in low and medium voltage ranges. The interruption device may be active or passive (i.e., it does not require auxiliary power other than the circuit source to which it is applied). The interruption device according to this disclosure can be implemented, for example, as a switching device, a power supply device, a commutation switch, a disconnector, a passive DC circuit breaker, a passive AC circuit breaker, a load switch, or a current limiter.

[0031] The interrupting member may further be positioned to move backward along the interrupting axis from the projection position to the starting position. The interrupting device may be configured to interrupt the current multiple times.

[0032] The shielding member may be made of ceramic and / or polymer, in which case the polymer may be a thermosetting or thermoplastic polymer, such as POM, PMMA, PI, PA, PP and / or PMP, or another such polymer. Additionally, the inner tubular element may be formed of one insulating or semiconducting material and the outer tubular element may be formed of another insulating or semiconducting material. The shielding member may be electrically insulating or semiconducting, but not conductive.

[0033] The inner member may be connected to the inner electrical contacts of the electrical circuit, and the outer member may be connected to the outer electrical contacts of the electrical circuit. The outer and inner members may be of various shapes, for example, tubes, bars, or rods. The outer and inner members may be of the same type of shape or different types of shapes.

[0034] The outer and / or inner members may be conductive tubes.

[0035] The outer member, inner member, and blocking member may be substantially concentric with the blocking axis. In this case, a triaxial blocking device is formed.

[0036] The contact configuration may be configured to electrically disconnect the outer and inner members as the interrupting member moves from the starting position to the projection position. The interrupting member can push or otherwise actuate the movable contact elements of the contact configuration as it moves from the starting position to the projection position in order to electrically disconnect the outer and inner members.

[0037] Further details, advantages, and aspects of this disclosure will become apparent from the following embodiments, with the aid of the drawings. [Brief explanation of the drawing]

[0038] [Figure 1] A schematic perspective view of the blocking device. [Figure 2] A schematic side cross-sectional view of the blocking member of a blocking device. [Figure 3] A schematic side cross-sectional view of a portion of the first version of the blocking device, including the blocking member shown in Figure 2. [Figure 4] A schematic enlarged section of the mechanism used to interconnect the conductive inner and conductive outer members of a circuit breaker device. [Figure 5] A schematic diagram of the actuator used to activate the shutoff member. [Figure 6A] A schematic side cross-sectional view of a portion of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 6B] Another schematic side cross-sectional view of a part of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 6C] Another schematic side cross-sectional view of a part of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 6D] Another schematic side cross-sectional view of a part of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 6E] Another schematic side cross-sectional view of a part of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 6F]Another schematic side cross-sectional view of a part of the second version of a blocking device in which the blocking member moves from the starting position to the protruding position. [Figure 7] A schematic side cross-sectional view of part of the third version of the blocking device. [Modes for carrying out the invention]

[0039] The following describes interruption devices for interrupting electric current. The same reference numbers are used to indicate the same or similar structural features.

[0040] Figure 1 schematically shows a perspective view of a interruption device 10 configured to interrupt current. The interruption device 10 can be used in AC and DC applications, for example, in the low and medium voltage ranges.

[0041] The interruption device 10 in this example comprises an end section 12 and a wall 14, providing a volume in which an interruption member receiving structure is arranged. The interruption member receiving structure is provided for receiving an interruption member and is formed as a body of an electrically insulating material. Together the end section 12, the wall 14, and the interruption member receiving structure form an arc discharge chamber 16. The interruption device 10 further comprises an outer electrical contact 18 and an inner electrical contact 20. A plurality of axial ventilation openings 22 are formed in the end section 12, and a plurality of radial ventilation openings 24 are formed in the wall 14. At least the interruption member receiving structure may be made of an electrically insulating material, for example, ceramic, or a thermosetting or thermoplastic polymer, such as polyoxymethylene (POM), poly(methyl methacrylate) (PMMA), polyimide (PI), polyamide (PA), and / or polyolefin, such as polypropylene (PP) or polymethylpentene (PMP), or another such polymer. Additionally, the end section 12 and the wall 14 can be made from the same material.

[0042] Figure 2 shows a side cross-sectional view of an electrically insulating or semiconducting interrupting member 26 used in the interruption device 10. The interrupting member 26 comprises an inner tubular element 28 and an outer tubular element 36. Both elements are thus formed as tubes, with the inner tubular element 28 having an inner surface 32 and an outer surface 34, and the outer tubular element 36 having an inner surface 40 and an outer surface 42, in this case the inner surface is inside the tubular element and the outer surface is outside the tubular element. Both tubular elements are further positioned around an interruption axis 48. The intention is that the interrupting member 26, thereby the tubular elements 28 and 36, move along the interruption axis 48 when performing a current interruption operation.

[0043] The inner tubular element 28 is provided with a first projection end 30, which is positioned in a first plane perpendicular to the shut-off axis 48. The outer tubular element 36 is provided with a second projection end 38, which is positioned in a second plane perpendicular to the shut-off axis 48.

[0044] The outer tubular element 36 is joined to the inner tubular element 28 at a joining region 44 on the outer surface 34 of the inner tubular element 28, in which case the joining region 44 may be formed as a cylindrical portion of the outer surface around the blocking axis 48. As a result, a circular recess 46 is defined between the inner tubular element 28 and the outer tubular element 36. More specifically, the recess 46 is defined between the inner surface 40 of the outer tubular element 36 and the outer surface 34 of the inner tubular element 28.

[0045] The second projection end 38 is located between the first projection end 30 and the joining region 44 in relation to the blocking axis 48. The second plane having the second projection end 38 is thereby positioned along the blocking axis 48 between the first plane having the first projection end 30 and the third plane where the bottom of the recess 46 between the inner tubular element 28 and the outer tubular element 36 is located. In this example, the second projection end 38 is positioned substantially midway between the first projection end 30 and the region where the outer tubular element 36 is joined to the inner tubular element 28, i.e., the second plane having the second projection end is positioned midway between the first plane and the third plane. The distance between the second plane and the first plane is therefore essentially the same as the distance between the second plane and the third plane.

[0046] The inner tubular element 28 also has a first projection length which is the length between the first projection end 30 and the joining region 44 to which the outer tubular element 36 is joined to the inner tubular element 28, and the outer tubular element 36 has a second projection length which is the length between the second projection end 38 and the joining region 44 to which the outer tubular element 36 is joined to the inner tubular element 28. In other words, the first projection length of the inner tubular element 28 is the length along the blocking axis 48 between the first plane having the first projection end 30 and the third plane having the bottom of the recess 46, and the second projection length of the outer tubular element 36 is the length along the blocking axis 48 between the second plane having the second projection end 38 and the third plane having the bottom of the recess 46.

[0047] The shielding member 26 may be made of an insulating material, which may be a ceramic or a thermosetting or thermoplastic polymer, such as POM, PMMA, PI, PA, PP, and / or PMP or another such polymer. Alternatively, the shielding member may be made of a semiconducting material. It is also possible that the inner tubular element is made of one insulating or semiconducting material and the outer tubular element is made of another insulating or semiconducting material. The inner tubular element 28 and the outer tubular element 36 of the shielding member 26 may also each have a circular cross-section. As can be seen in Figure 2, the shielding member 26 is concentric with the shielding axis 48.

[0048] Figure 3 shows a partial side cross-sectional view of a shut-off device comprising an arc discharge chamber 16 and a shut-off member 26, in which case the shut-off member is becoming a protruding position. The arc discharge chamber 16 may be filled with air, gas, or other fluid.

[0049] The interruption member receiving structure within the arc discharge chamber 16 comprises an inner cavity 54 for receiving the inner tubular element 28 of the interruption member 26 and an outer cavity 56 for receiving the outer tubular element of the interruption member 26. The cavities 54 and 56 may therefore be formed within a body of an electrically insulating material, which may be ceramic, or a thermosetting or thermoplastic polymer, such as POM, PMMA, PI, PA, PP, and / or PMP, as mentioned above. Both cavities may be ring-shaped with a depth corresponding to the projection length of the corresponding tubular element of the interruption member 26. More specifically, the inner cavity 54 may be molded to receive a first projection length of the inner tubular element 28. The inner cavity 54 may thereby have a depth in the direction along the interruption axis 48, corresponding to the first projection length of the inner tubular element 28. The bottom of the inner cavity 54 may also be formed in this case by an end section 12. The outer cavity 56 can similarly be shaped to accommodate the second projection length of the outer tubular element 36. The outer cavity 56 can thereby have a depth in the direction along the blocking axis 48 that corresponds to the second projection length of the outer tubular element of the blocking member 26. By providing the inner cavity 54 and the outer cavity 56, a wall is also formed between them, which faces the recess 46 between the inner tubular element 28 and the outer tubular element 36.

[0050] Within the arc discharge chamber 16, there are further at least one ventilation opening 22, 24A for ventilating the arc discharge chamber 16 when an arc interruption occurs, in which case each ventilation opening leads to a corresponding cavity. As can be seen in the example in Figure 3, the axial ventilation openings 22 of the first group lead to the bottom of the inner cavity 54. It can also be seen that the radial ventilation openings 24A of the first group also lead to the inner cavity 54 via the corresponding ventilation channel 58A. Each radial ventilation opening can thereby lead to the cavity via the ventilation channel. At least one first ventilation opening within the radial ventilation openings of the first group leads to the inner cavity 54.

[0051] Each of the axial ventilation openings 22 and radial ventilation openings 24A is constructed by a through-hole. The axial ventilation opening 22 extends from inside the arc discharge chamber 16 through the end section 12. The radial ventilation opening 24A extends from inside the arc discharge chamber 16 through the wall 14 via the ventilation channel 58A. The ventilation openings 22 and 24A are configured to ventilate the volume within the arc discharge chamber 16 when the shut-off member 26 begins to move from its starting position.

[0052] As can also be seen in Figure 3, the interruption device 10 includes, in addition to the interruption member 26, a conductive outer member 50 and a conductive inner member 52, all of which may be formed as tubes or have tubular elements. Therefore, the interruption device 10 may be called a tubular circuit breaker.

[0053] The inner member 52 is positioned radially inside the outer member 50 with respect to the blocking shaft 48. The blocking member 26 is positioned radially between the outer member 50 and the inner member 52 with respect to the blocking shaft 48.

[0054] In this example, the outer member 50 and the inner member 52 are each conductive tubes concentric with the interruption shaft 48. Each of the outer member 50 and the inner member 52 has a circular cross-section. Since the elements of the arc interruption member are also tubular, the interruption device 10 is therefore a triaxial interruption device. However, one or both of the outer member 50 and the inner member 52 can have a shape other than a tube. The outer member 50 is connected to an outer electrical contact 18, and the inner member 52 is connected to an inner electrical contact 20 (not shown).

[0055] As shown in Figure 3, a space 59 is defined between the outer member 50 and the inner member 52. The space 59 is for the initial or starting position of the interrupting member 26, which rests in this space when the circuit breaker is closed by the electrical contact between the outer member 50 and the inner member 52. The interrupting member 26 is then moved out of this space 59 into the arc discharge chamber 16 as it moves from the starting position to the protruding position in order to interrupt the arc.

[0056] As can be seen in Figure 4, the interruption device 10 further comprises a contact arrangement. The contact arrangement is configured to selectively electrically disconnect the outer member 50 and the inner member 52. For this purpose, the outer member 50 has an outer member tip equipped with a tap point 66, and the inner member 52 has an inner member tip equipped with a first contact pad 64. A movable contact element 60 is also joined to the outer member 50 at the tap point 66 and is pivotable around the tap point 66. The movable contact element 60 comprises a second contact pad 62, and when the interruption member is in the starting position, the movable contact element 60 covers the space 59 and the second contact pad 62 is in contact with the first contact pad 64. When the interruption member is moved to the protruding position, the interruption member pushes the movable contact element 60 upward, causing the contact element 60 to pivot in a first direction around the tap point 66. This further separates the contact pads 62 and 64 from each other. Furthermore, the closing element 69 is connected to a movable contact element 60, which can be actuated to pivot the contact element 60 in a second opposite direction around the tap point 66 in order to connect the contact pads 62 and 64 to each other.

[0057] The tip of the outer member and the tip of the inner member are positioned adjacent to the arc discharge chamber 16.

[0058] The interruption device 10 further comprises an actuator. The actuator may be of various types for forcing the interruption member 26 away from its starting position. One example of an actuator is schematically shown in Figure 5, where the actuator 70 is exemplified as a ballistic actuator in the form of a Thomson drive. The actuator 70 comprises a Thomson coil 72, an armature 74, an armature relaxation cushion 76, and an actuator 78 bonded to the interruption member (not shown). The Thomson coil 72 and the armature 74 are arranged to provide energy for the ballistic movement of the interruption member 26.

[0059] Next, the operation of the interrupting device will be explained with reference to Figures 6A to 6F, which show the movement of the interrupting member 26 within a portion of the interrupting device when interrupting an arc.

[0060] In these figures, a slightly modified shutoff device is used. It can be seen that the outer tubular element 36 of the shutoff member is shorter than in the first example shown in Figures 2 and 3. In this example, the second projection end is located closer to the region where the outer tubular element 36 is joined to the inner tubular element 28 than the first projection end 30, i.e., the second plane having the second projection end is located closer to the third plane having the bottom of the recess than the first plane having the first projection end 30. The distance between the second plane and the third plane is therefore smaller than the distance between the second plane and the first plane. Furthermore, in addition to the radial ventilation opening 24A having the first group of axial ventilation openings 22 and the first group of ventilation channels 58A, there is also a second group of radial ventilation openings 24B in the wall of the device, which has at least one second radial ventilation opening within the wall, and this ventilation opening leads to the outer cavity 56 via the ventilation channel 58B. The connection between the conductive outer member 50 and the outer electrical contact 18 is also shown.

[0061] However, for the purpose of this overview, the contact arrangement, including actuators and movable contact elements, has been omitted.

[0062] The blocking member 26 is configured to move upward along the blocking axis 48 from its starting position in Figures 6A to F in order to reach the protruding position.

[0063] The interrupting member 26 is then moved by the actuator 70 from the starting position along the interrupting axis 48 to the protruding position, where the interrupting member 26 protrudes into the arc discharge chamber 16.

[0064] Initially, the interrupting member 26 is in a starting position, where it is contained within the space 59 between the conductive outer member 50 and the conductive inner member 52. Then, when current interruption is desired, the interrupting member 26 is moved by an actuator from the starting position along the interruption axis 48. At some point, the inner tubular element 28 moves the contact element of the contact arrangement so that it is separated from the conductive inner member 52, thereby creating an arc A between the conductive outer member 50 and the conductive inner member 52. See Figure 6A.

[0065] The arc generates overpressure within the arc discharge chamber 16. This overpressure is released through the ventilation openings 22, 24A, and 24B. Furthermore, ventilation of the arc discharge chamber 16 through the ventilation openings 22, 24A, and 24B occurs as soon as the shut-off member 26 begins to move.

[0066] As the shut-off member 26 moves from the starting position to the projection position, the shut-off member 26 thus pushes the movable contact element 60 of the contact arrangement from an electrically connected state to an electrically disconnected state. The outer member 50 is thereby electrically disconnected from the inner member 52, and the arc A is ignited between the outer member 50 and the inner member 52. However, it should be recognized here that the use of the shut-off member 26 as an “extruder” is only one of several ways in which the contact arrangement electrically disconnects the outer member 50 and the inner member 52.

[0067] The inner tubular element 28 of the blocking member 26 then begins to enter the arc discharge chamber 16, and more specifically, the inner cavity 54 of the arc discharge chamber 16. This causes the arc A between the inner member 52 and the outer member 50 to extend around the first projection end 30. See Figure 6B.

[0068] As the interrupting member 26 continues to move along the interrupting axis, the inner tubular element 28 moves further into the inner cavity 54. As a result, the arc proceeds from the tip of the inner member 52, along the inner surface 32 of the inner tubular element 28, around the first projection end 30, and then back along the outer surface 34 of the inner tubular element 28. If the outer tubular element 36 has not yet entered the arc discharge chamber, the arc then continues to the tip of the outer member 50. See Figure 6C. This movement, therefore, further extends or stretches the arc A.

[0069] As movement along the blocking axis continues, the outer tubular element 36 then begins to enter the outer cavity 56, thereby advancing the arc A from the tip of the inner member 52, passing through the inner surface 32 of the inner tubular element 28, turning the first projection end 30, returning along the outer surface 34 of the inner tubular element 28, entering the recess 46 between the inner tubular element 28 and the outer tubular element 36, turning the tip of the wall separating the inner cavity 54 and the outer cavity 56, continuing along the inner surface 40 of the outer tubular element 36, changing direction at the second projection end 38, then continuing along the outer surface 42 of the outer tubular element 36, and contacting the tip of the outer member 50. See Figure 6D.

[0070] Figure 6E shows the same path of arc A as the blocking member is approaching the projection position, that is, as the first projection end 30 of the inner tubular element 28 approaches the bottom of the inner cavity 54 and the second projection end 38 of the outer tubular element 36 approaches the bottom of the outer cavity 56.

[0071] Ultimately, the interrupting member 26 reaches the protruding position shown in Figure 6F. In this case, the first protruding end 30 reaches and abuts the bottom of the inner cavity 54, the second protruding end 38 reaches and abuts the bottom of the outer cavity 56, and the bottom of the recess 46 between the inner tubular element 28 and the outer tubular element 36 receives and abuts the tip of the wall between the inner cavity 54 and the outer cavity 56, thereby interrupting the arc. The first protruding end 30 of the inner tubular element 28 thus abuts the bottom of the inner cavity 54, the second protruding end 38 of the outer tubular element 36 abuts the bottom of the outer cavity, and the bottom of the recess 46 abuts the tip of the wall separating the cavities 54 and 56. Thus, the arc is cut and the current can be stopped. As an alternative, it is possible for only one or two portions of the blocking member at the first projection end, the second projection end, and the bottom of the recess to actually contact the corresponding portion of the arc discharge chamber at the projection position.

[0072] The shut-off member 26 can then be returned from the protruding position to the starting position for reuse of the shut-off device 10. The return movement can be performed, for example, manually or by the actuator 70 or the closing element 69 of the contact arrangement.

[0073] As explained above and as can be seen in Figures 6A-F, arc A is moved from the inner member 52 over the first and second projection ends of the blocking member 26 and returned to the outer member 50. The blocking member 26 thereby lengthens the arc path between the outer member 50 and the inner member 52, allowing the arc to pass over this extended length.

[0074] In other words, the interrupting member 26 extends the arc over a considerable distance, which corresponds to the sum of twice the length of the first projection and twice the length of the second projection. In some implementations, this stress on the arc at the projection location causes the arc to extinguish. The projection location thereby constitutes one position on the interrupting member 26 for interrupting the current between the outer member 50 and the inner member 52.

[0075] The radial ventilation openings 24 allow gas to flow out of both cavities 54 and 56, and out of the arc discharge chamber 16. The radial ventilation openings 24A and 24B, as well as the axial ventilation opening 22, thus allow the arc to move and avoid excessive pressure inside the arc discharge chamber 16.

[0076] It is thus seen that a blocking member, comprising an inner tubular element and an outer tubular element, is inserted between two coaxially arranged conductive members. This tube enters the arc discharge chamber, where the arc is stretched, extended between the cavity walls of the arc discharge chamber, and finally interrupted.

[0077] By implementing the interruption member as an inner and outer second tubular element, the electrical lifetime of the interruption device is improved compared to when only one tubular element is used.

[0078] The interruption device 10 was prototyped and proven to successfully interrupt DC currents in the range of 100V to 10kV at currents of 5A to 6kA. This prototype also demonstrated that the interruption device 10 can interrupt the current multiple times at voltages up to 2kV. Furthermore, this prototype demonstrated that the arc discharge chamber 16 can be reduced in both length and diameter without significantly altering its performance.

[0079] During the interruption of the nominal current, the inner tubular element first enters the arc discharge chamber, and the arc voltage can rise to approximately 1.2kV, for example, while the nominal current can drop to at least 400A to 500A, for example. Next, the outer tubular element begins to enter the arc discharge chamber, and in this example, the arc voltage rises to over 2kV together with the inner tubular element. At the moment the outer tubular element enters the arc discharge chamber, the current drops significantly below the nominal current (1kA), so arc erosion, i.e., material loss, on the inner tubular element is not severe. Moreover, since the overall arc discharge time is shorter compared to when only one tubular element is used, arc erosion on the outer tubular element is also not as severe. Therefore, the electrical life is extended.

[0080] Furthermore, by using a breaker member in conjunction with the inner and outer tubular elements, it may be possible to increase the arc voltage in the arc discharge chamber to a higher level than when using only one tubular element. This can be, for example, 1.2 to 2.0 times higher depending on the length of the outer tubular element. Alternatively, the melting of the tubular elements can be reduced. This can also be achieved by a minimal increase in the size of the breaker device.

[0081] The use of an interrupting member having an inner tubular element and an outer tubular element therefore allows for faster interruption of DC current, provides additional arc length to improve withstand voltage at nominal current, and enables a rise in higher arc voltage.

[0082] The withstand voltage capability of the interruption device 10 is mainly determined by the stroke length of the interruption member 26. The current interruption capability is mainly determined by the strength of the interruption member 26 in withstanding arc pressure. The stroke length, the speed of the interruption member 26, the thickness and length of the interruption member 26, etc., may be changed depending on the mounting configuration.

[0083] As can be seen above, the projection length of the outer tubular element can be varied. The projection length of the outer tubular element of the blocking member can be extended, for example, compared to the previously given example. As can be seen in the example of Figure 7, the second projection end can be located closer to the first projection end than to the joining region with respect to the blocking axis, that is, the second plane having the second projection end can be located closer to the first plane having the first projection end than to the third plane having the bottom of the recess. As a result, the distance between the second plane and the first plane can be smaller than the distance between the second plane and the third plane.

[0084] Another difference that can be observed in Figure 7 is the absence of a first group of radial ventilation openings leading to the inner cavity 54, and the presence of only a second group of radial ventilation openings 24B and axial ventilation openings 22 leading to the outer cavity 56.

[0085] While this disclosure has been described with reference to exemplary embodiments, it will be understood that the present invention is not limited to those described above. For example, it will be understood that the dimensions of parts may be changed as needed.

Claims

1. A disconnecting device (10) for interrupting an electric current, comprising: A conductive outer member (50); an electrically conductive inner member (52) disposed radially inward of the electrically conductive outer member (50) relative to a blocking axis (48); an electrically insulating or semi-conductive interrupting member (26) disposed radially between the conductive outer member (50) and the conductive inner member (52) relative to the interrupting axis (48), the interrupting member (26) being disposed to move along the interrupting axis (48) from a starting position to a protruding position at which the interrupting member (26) protrudes from a space (59) within the conductive outer member (50) to interrupt a current between the conductive outer member (50) and the conductive inner member (52) by the interrupting member (26); The blocking device (10), wherein the blocking member (26) comprises an inner tubular element (28) and an outer tubular element (36), the outer tubular element (36) being joined to an outer surface (34) of the inner tubular element (28) thereby defining a recess (46) between the outer tubular element (36) and the inner tubular element (28).

2. 2. The shutoff device (10) of claim 1, wherein the outer tubular element (36) is joined to the inner tubular element (28) at a joining region (44) of the outer surface (34) of the inner tubular element (28), the inner tubular element (28) having a first protruding end (30) and the outer tubular element (36) having a second protruding end (38), the second protruding end (38) being located between the first protruding end (30) and the joining region (44) in relation to the shutoff axis (48).

3. 3. The shutoff device (10) of claim 2, wherein the second prong end (38) is located substantially midway between the interface area (44) and the first prong end (30) relative to the shutoff axis.

4. The shutoff device (10) of claim 2, wherein the second prong end (38) is located closer to the joining area (44) relative to the shutoff axis (48) than the first prong end (30).

5. The shutoff device (10) of claim 2, wherein the second lug end (38) is located closer to the first lug end (30) relative to the shutoff axis (48) than the joining area (44).

6. 6. The interruption device (10) of claim 1, further comprising an arc discharge chamber (16) having an inner cavity (54) for receiving the inner tubular element (28) and an outer cavity (56) for receiving the outer tubular element (36).

7. 7. The interruption device (10) of claim 6 dependent on claim 2, wherein, in the protruding position, the first protruding end (30) of the inner tubular element (28) is arranged to abut a bottom of the inner cavity (54), the second protruding end (38) of the outer tubular element (36) is arranged to abut a bottom of the outer cavity (56), and / or the bottom of the recess (46) is arranged to abut an edge of a wall of the arc discharge chamber (16) separating the inner cavity (54) from the outer cavity (56).

8. 7. The interrupting device (10) of claim 6, wherein the interrupting member (26) further comprises at least one vent opening (22, 24; 24A, 24B) for venting the arc discharge chamber (16) when the interrupting member (26) is moved from the starting position, each vent opening leading to one of the cavities (54, 56).

9. The isolation device (10) of claim 8, wherein at least one first radial vent opening (24A) leads into said inner cavity (54).

10. The isolation device (10) of claim 8, wherein at least one second radial vent opening (24B) leads into said outer cavity (56).

11. 10. The isolation device (10) of claim 9, wherein each radial ventilation opening communicates with a cavity (54, 56) via a ventilation channel (58A, 58B).

12. The shutoff device (10) of any one of claims 1 to 5, wherein the conductive outer member (50) and / or the conductive inner member (52) are conductive tubes.

13. 12. The shutoff device (10) of claim 11, wherein the conductive outer member (50), the conductive inner member (52), the inner tubular element (28), and the outer tubular element (36) are substantially concentric with the shutoff axis (48).

14. The shutoff device (10) of any one of claims 1 to 5, further comprising an actuator (70) arranged to urge the shutoff member (26) from the start position to the protruding position.

15. 6. The interruption device (10) of claim 1, further comprising a contact arrangement comprising a movable contact element (60) configured to selectively electrically disconnect the conductive outer member (50) and the conductive inner member (52).

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