SE1400421A1 - Contact Elements for Medium to High Voltage Switches - Google Patents

Abstract

A medium or high voltage switch has a first set of contact elements (13a, 13b, 13c) and a second set of contact elements (14a, 14b, 14c). Each contact element consists of an insulating carrier (15) carrying conducting elements (16). In the closed state of the switch, the conducting elements (16) align to form one or more current paths between terminals (8, 9) of the switch along an axial direction (A) . For opening the switch, the contact elements are mutually displaced by means of two drives (18, 19) along a direction (D) perpendicular to the axial direction (A) with the conducting elements (16) mounted onto the contact elements by means of spring-loaded pins (161,162).(Fig. 3C)

Description

lO 15 20 25 30 35 2 CH-13154 liquid. The switch has a high voltage withstand capabil- ity and fast switching times. The conducting element pro- ject over the two opposite surfaces of the carrier that carries it and are slightly movable in axial direction in that slightly tiltable around a tilt axis, respect to the carrier carries it and/or it is wherein said tilt axis is perpendicular to the axial direction and to the direction of displacement. Each terminal forms a contact surface for contacting the conducting elements, wherein at least one of the terminals comprises a spring member that elastically urges the contact surface of the termi- nal against the conducting elements. This ensures a prop- er contacting force between the conducting elements them- selves and between the conducting elements and the con- tact surfaces and, with conducting elements being movable in axial direction the forces between all the conducting elements in a current path are substantially equal. lO 15 20 25 30 35 2 CH-13154 liquid. The switch has a high voltage withstand capabil- ity and fast switching times. The conducting element pro- ject over the two opposite surfaces of the carrier that carries it and are slightly movable in axial direction in that slightly tiltable around a tilt axis, respect to the carrier carries it and / or it is where said tilt axis is perpendicular to the axial direction and to the direction of displacement. Each terminal forms a contact surface for contacting the conducting elements, wherein at least one of the terminals comprises a spring member that elastically urges the contact surface of the terminal against the conducting elements. This ensures a prop- er contacting force between the conducting elements them- selves and between the conducting elements and the con- tact surfaces and, with conducting elements being movable in axial direction the forces between all the conducting elements in a current path are substantially equal .

While generally satisfactory it is seen as an object of the present invention to simplify the assembly of conducting elements onto their respective carriers and to improve the carrier itself.While generally satisfactory it is seen as an object of the present invention to simplify the assembly of conducting elements onto their respective carriers and to improve the carrier itself.

Summary of the Invention Hence, according to a first aspect of the in- vention, the switch has at least a first terminal and a second terminal for applying the current to be switched and at least a first set of contact elements and a second set of contact elements and a drive adapted to mutually displace the sets of contact elements relatively to each other along a displacement direction with. each contact element including an insulating carrier part that carries at least one conducting element with the positions of the conducting elements being such that in a first mutual po- sition of the contact elements the conducting elements form at least one conducting path between the first ter- minal and the second terminal, i.e. the switch is in the lO 15 20 25 30 35 3 CH-13154 closed, conducting position; and in a second mutual posi- tion of the contact elements the conducting elements are mutually displaced such that there is no conducting path formed by the conducting elements between the first ter- the switch is in its minal and the second terminal, i.e. opened, non-conducting position, with the conducting ele- ments mounted onto the carrier part are locked into their operating position by one or more spring-loaded pins.Summary of the Invention Hence, according to a first aspect of the in- vention, the switch has at least a first terminal and a second terminal for applying the current to be switched and at least a first set of contact elements and a second set of contact elements and a drive adapted to mutually displace the sets of contact elements relatively to each other along a displacement direction with. each contact element including an insulating carrier part that carries at least one conducting element with the positions of the conducting elements being such that in a first mutual po- sition of the contact elements the conducting elements form at least one conducting path between the first ter- minal and the second terminal, ie the switch is in the lO 15 20 25 30 35 3 CH-13154 closed, conducting position; and in a second mutual posi- tion of the contact elements the conducting elements are mutually displaced such that there is no conducting path formed by the conducting elements between the first ter- the switch is in its minal and the second terminal, i.e. opened, non-conducting position, with the conducting elements mounted onto the carrier part are locked into their operating position by one or more spring-loaded pins.

The pin or pins are best rounded to allow for a small limited rotation movement of a main body of the conducting element around the central axis of the pin.The pin or pins are best rounded to allow for a small limited rotation movement of a main body of the conducting element around the central axis of the pin.

Thus the main body of the conducting element is slightly tiltable around a tilting axis, wherein said tilt axis is perpendicular to the axial direction and to the direction of displacement. This allows the conducting element to axially position itself accurately when the switch is in its first, closed position, thereby improving current conduction.Thus the main body of the conducting element is slightly tiltable around a tilting axis, where said tilt axis is perpendicular to the axial direction and to the direction of displacement. This allows the conducting element to axially position itself accurately when the switch is in its first, closed position, thereby improving current conduction.

The invention allows for a connection between the carrier and the conducting elements which is essen- tially free of hetero-material, in. particular gluefree (free from glue).The invention allows for a connection between the carrier and the conducting elements which is essentially free of hetero-material, in. particular gluefree (free from glue).

The main body is preferably an elongated rec- tangular cuboid with. two long flattened, contact faces oriented parallel to the plane of the contact element or its carrier part for contacting in operation the flat- tened contact face of a conducting element of an adjacent contact element. The cuboid main body has two further long faces and two small faces with such faces oriented in position perpendicular to the plane of the contact el- ement. The small faces can have blind holes to mount the pins. Preferably an elastic element such as a spring is mounted behind the pins in the blind hole to facilitate the assembly and offer a latching action to lock the con- ducting element in its place on the contact element or carrier part. In a preferred embodiment the conducting elements are mounted within openings of the carrier part 10 15 20 25 30 35 4 CH-13154 with the pin or pins having a forked tip to latch onto a side wall of the opening. The openings are made prefera- bly slightly wider than the distance between the second long faces or sides of the main body of the conducting elements, thus providing a small gap for a limited move- ment of the main body of the conducting elements within the opening of the carrier part in its mounted position.The main body is preferably an elongated rec- tangular cuboid with. two long flattened, contact faces oriented parallel to the plane of the contact element or its carrier part for contacting in operation the flat- tened contact face of a conducting element of an adjacent contact element. The cuboid main body has two further long faces and two small faces with such faces oriented in position perpendicular to the plane of the contact element. The small faces can have blind holes to mount the pins. Preferably an elastic element such as a spring is mounted behind the pins in the blind hole to facilitate the assembly and offer a latching action to lock the con- ducting element in its place on the contact element or carrier part. In a preferred embodiment the conducting elements are mounted within openings of the carrier part 10 15 20 25 30 35 4 CH-13154 with the pin or pins having a forked tip to latch onto a side wall of the opening. The openings are made prefera- bly slightly wider than the distance between the second long faces or sides of the main body of the conducting elements, thus providing a small gap for a limited move- ment of the main body of the conducting elements within the opening of the carrier part in its mounted position.

The pins are best made of a harder material than the main body, which in turn are typically manufac- tured using a nmterial of high electrical conductivity such as silver, copper or aluminium. The pins themselves can be made of steel, preferably hardened steel or plas- The is understood as a comparison of the hard- tic material with a comparable hardness to steel. term “harder' ness degree of different materials.The pins are best made of a harder material than the main body, which in turn are typically manufac- tured using a nmterial of high electrical conductivity such as silver, copper or aluminum. The pins themselves can be made of steel, preferably hardened steel or plas- The is understood as a comparison of the hard- tic material with a comparable hardness to steel. term “harder 'ness degree of different materials.

Further, the conducting element should advan- tageously project over the two opposite surfaces of the carrier that carries it. When a conducting element pro- jects above the surface of the surrounding carrier, it can be shown that the electrical field at the intersec- tion between the surface and the conducting element is smaller than for a device where the surface of the con- ducting element is substantially flush with the surface of the carrier.Further, the conducting element should advan- tageously project over the two opposite surfaces of the carrier that carries it. When a conducting element pro- jects above the surface of the surrounding carrier, it can be shown that the electric field at the intersection between the surface and the conducting element is smaller than for a device where the surface of the con- ducting element is substantially flush with the surface of the carrier.

While having a cuboid main body it is pre- ferred to have all contour lines or edges which are visi- ble after mounting in the carrier rounded, including the exposed contour lines of the pins.While having a cuboid main body it is pre- ferred to have all contour lines or edges which are visi- ble after mounting in the carrier rounded, including the exposed contour lines of the pins.

Another aspect of the invention relates to the material used to manufacture the carrier part and/or onto which It has been found that manufacturing the frame of the contact ele- a frame structure for the contact elements frame the conducting elements can be mounted. ments from an epoxy material reinforced by aramid fibers offers a superior performance in a DC switch as described above compared for example to the same structure manufac- tured from an epoxy material reinforced by glass fibers. 10 15 20 25 30 35 5 CH-13154 The switch is advantageously used in high voltage applications (i.e. for voltages above 72 kV), but it can also be used for medium voltage applications (be- tween some kV and 72 kV), particularly DC voltages.Another aspect of the invention relates to the material used to manufacture the carrier part and / or onto which It has been found that manufacturing the frame of the contact ele- a frame structure for the contact elements frame the conducting elements can be mounted. ments from an epoxy material reinforced by aramid fibers offers a superior performance in a DC switch as described above compared for example to the same structure manufac- tured from an epoxy material reinforced by glass fibers. 10 15 20 25 30 35 5 CH-13154 The switch is advantageously used in high voltage applications (ie for voltages above 72 kV), but it can also be used for medium voltage applications (be- tween some kV and 72 kV), particularly DC voltages.

Other advantageous embodiments are listed in the dependent claims as well as in the description below.Other advantageous embodiments are listed in the dependent claims as well as in the description below.

Brief Description of the Drawings The invention will be better understood and objects other than those set forth above will become ap- parent from the following detailed description thereof.Brief Description of the Drawings The invention will be better understood and objects other than those set forth above will become ap- parent from the following detailed description thereof.

Such description makes reference to the annexed drawings, wherein: FIG. 1 known switch; shows a cross-sectional view of a FIG. 2 shows an enlarged cross-sectional view of the contact elements of FIG. 1; FIG. a contact element with carrier part and acceleration rod 3A shows a schematic perspective view of but without conducting elements; FIGs. 3A with a conducting element inserted into the car- 3B and 3C show an enlarged section of FIG. rier part; FIGs. 4A and 4B shows a schematic view of a main body of a conducting element at two different stages in accordance in the manufacturing process, respectively, with an example of the invention; and FIG. 4C shows a schematic view of a pin of a conducting element in accordance with an example of the invention. 10 15 20 25 30 35 6 CH-13154 Modes of Carrying Out the Invention An example of the present invention is now described in further detail using the switch design as described in the above cited applications US20l2/0256711, and US20l3/0098874. Accordingly, cludes a fluid-tight housing 1 enclosing a space 2 filled the switch of Fig. 1 in- with an insulating fluid, in particular SF6 or air at el- evated pressure or an oil.Such description makes reference to the annexed drawings, wherein: FIG. 1 known switch; shows a cross-sectional view of a FIG. 2 shows an enlarged cross-sectional view of the contact elements of FIG. 1; FIG. a contact element with carrier part and acceleration rod 3A shows a schematic perspective view of but without conducting elements; FIGs. 3A with a conducting element inserted into the car- 3B and 3C show an enlarged section of FIG. rier part; FIGs. 4A and 4B shows a schematic view of a main body of a conducting element at two different stages in accordance in the manufacturing process, respectively, with an example of the invention; and FIG. 4C shows a schematic view of a pin of a conducting element in accordance with an example of the invention. 10 15 20 25 30 35 6 CH-13154 Modes of Carrying Out the Invention An example of the present invention is now described in further detail using the switch design as described in the above cited applications US20l2 / 0256711, and US20l3 / 0098874. Accordingly, cludes a fluid-tight housing 1 enclosing a space 2 filled the switch of Fig. 1 in- with an insulating fluid, in particular SF6 or air at el- evated pressure or an oil.

Housing 1 forms a GIS-type metallic enclosure of manifold type and comprises two tube sections. A first and a which that tube section 3 extends along an axial direction A, second tube section 4 extends along a direction D, is called the displacement direction for reasons will become apparent below. Axial direction A is perpen- dicular or nearly perpendicular to displacement direction D. The tube sections are formed by a substantially cross- shaped housing section 5.Housing 1 forms a GIS-type metallic enclosure of manifold type and comprises two tube sections. A first and a which that tube section 3 extends along an axial direction A, second tube section 4 extends along a direction D, is called the displacement direction for reasons will become apparent below. Axial direction A is perpen- dicular or nearly perpendicular to displacement direction D. The tube sections are formed by a substantially cross-shaped housing section 5.

First tube section 3 ends in first and second support insulators 6 and 7, respectively. First support insulator 6 carries a first terminal 8 and second support insulator 7 carries a second terminal 9 of the switch.First tube section 3 ends in first and second support insulators 6 and 7, respectively. First support insulator 6 carries a first terminal 8 and second support insulator 7 carries a second terminal 9 of the switch.

The two terminals 8, 9 extending through the support in- sulators 6, 7 carry the current through the switch, sub- stantially along axial direction A.The two terminals 8, 9 extending through the support in- sulators 6, 7 carry the current through the switch, sub- stantially along axial direction A.

Second tube section 4 ends in a first and a second cap 10 and ll, respectively.Second tube section 4 ends in a first and a second cap 10 and ll, respectively.

First terminal 8 and second terminal 9 extend towards a center of space 2 and end at a distance from each other, with a switching arrangement 12 located be- 10 15 20 25 30 35 7 CH-13154 tween them, at the intersection region of first tube sec- tion 3 with second tube section 4.First terminal 8 and second terminal 9 extend towards a center of space 2 and end at a distance from each other, with a switching arrangement 12 located be- 10 15 20 25 30 35 7 CH-13154 tween them, at the intersection region of first tube section 3 with second tube section 4.

As can best be seen from Fig. 2, switching arrangement 12 comprises a first set of contact elements l3a, l3b, l4b, 14c. es three contact elements, l3c and a second set of contact elements l4a, In the embodiment shown here, each set compris- and, The first and second set may also have different numbers of contact el- e.g. the number is at least two contact elements per set. but that number may vary, for example, be two or more than three. ements, two and three, respectively. Advantageously, The contact elements of the two sets are stacked alternating- ly, i.e. each contact element of one set is adjacent to two contact elements of the other set unless it is locat- ed at the end of switching arrangement 12, in which case it is located between one contact element of the other set and one of the terminals 8, 9.As can best be seen from Fig. 2, switching arrangement 12 comprises a first set of contact elements l3a, l3b, l4b, 14c. es three contact elements, l3c and a second set of contact elements l4a, In the embodiment shown here, each set compris- and, The first and second set may also have different numbers of contact el- e.g. the number is at least two contact elements per set. but that number may vary, for example, be two or more than three. ements, two and three, respectively. Advantageously, The contact elements of the two sets are stacked alternating- ly, i.e. each contact element of one set is adjacent to two contact elements of the other set unless it is locat- ed at the end of switching arrangement 12, in which case it is located between one contact element of the other set and one of the terminals 8 , 9.

Each contact element comprises a plate-Shaped insulating carrier 15, one or more conducting elements 16 and an actuator rod 17. In the embodiment shown here, each carrier 15 carries two conducting elements 16. 1 and 2 show the switch in the closed 13b, 13c, l4a, l4b, where the conducting ele- Figs. state with the contact elements 13a, 14c in a first mutual position, ments 16 align to form two conducting paths 34 along axi- al direction A between the first and the second terminals 8, 9. the terminals 8, 9.Each contact element comprises a plate-Shaped insulating carrier 15, one or more conducting elements 16 and an actuator rod 17. In the embodiment shown here, each carrier 15 carries two conducting elements 16. 1 and 2 show the switch in the closed 13b, 13c, l4a, l4b, where the conducting ele- Figs. state with the contact elements 13a, 14c in a first mutual position, ments 16 align to form two conducting paths 34 along axi- al direction A between the first and the second terminals 8, 9. the terminals 8, 9.

The conducting paths 34 carry the current between Their number can be greater than one in order to increase continuous current carrying capabil- ity.The conducting paths 34 carry the current between Their number can be greater than one in order to increase continuous current carrying capabil- ity.

For example an arrangement with three con- ducting elements 16 in each insulating carrier 15 leads to three conducting paths 34 when the switch is closed. A non-inline arrangement with four contact elements 16 in each 15 results insulating carrier in four conducting paths 34 when the switch is closed and so forth. 10 15 20 25 30 35 8 CH-13154 The contact elements 13a, 13b, 13c, 14a, l4b, 14c are moved in operation along the displacement direc- tion D into a second position, where the conducting ele- ments 16 are staggered in respect to each other and do not form a conducting path. In Fig. 2, the position of the conducting elements in this second position is shown in dotted lines under reference number 16'. As can be seen, the conducting elements 16' are now separated from each other along direction D, thereby creating several contact gaps, thereby quickly providing a high dielectric withstand level.For example an arrangement with three con- ducting elements 16 in each insulating carrier 15 leads to three conducting paths 34 when the switch is closed. A non-inline arrangement with four contact elements 16 in each 15 results insulating carrier in four conducting paths 34 when the switch is closed and so forth. 10 15 20 25 30 35 8 CH-13154 The contact elements 13a, 13b, 13c, 14a, l4b, 14c are moved in operation along the displacement direc- tion D into a second position, where the conducting elements 16 are staggered in respect to each other and do not form a conducting path. In Fig. 2, the position of the conducting elements in this second position is shown in dotted lines under reference number 16 '. As can be seen, the conducting elements 16 'are now separated from each other along direction D, thereby creating several contact gaps, thereby quickly providing a high dielectric withstand level.

To achieve such a displacement, and as best the actuator rods 17 are connected A first drive 18 the actuator rods 17 of the first set of contact elements can be seen in Fig. 1, to two drives 18, 19. is connected to l3a, 13b, 13c, and a second drive 19 is connected to the actuator rods 17 of the second set of contact elements l4a, 14b, l4c.To achieve such a displacement, and as best the actuator rods 17 are connected A first drive 18 the actuator rods 17 of the first set of contact elements can be seen in Fig. 1, to two drives 18, 19. is connected to l3a, 13b, 13c, and a second drive 19 is connected to the actuator rods 17 of the second set of contact elements l4a, 14b, l4c.

In the embodiment shown in Figs. 1 and 2, the switch is opened by pulling the actuator rods 17 away from the center of the switch, thereby bringing the con- ducting elements into their second, staggered position.In the embodiment shown in Figs. 1 and 2, the switch is opened by pulling the actuator rods 17 away from the center of the switch, thereby bringing the con- ducting elements into their second, staggered position.

Alternatively, the rods 17 can be pushed towards the cen- ter of the switch, ducting elements into a staggered position.Alternatively, the rods 17 can be pushed towards the center of the switch, ducting elements into a staggered position.

The drives 18, which also allows to bring the con- 19 can e.g. operate on the re- pulsive Lorentz-force principle and be of the type dis- closed in US 7 235 751, scribed in detail herein. and they are therefore not de- Each drive is able to displace one set of contact elements along the displacement direc- tion D. They are adapted and controlled to move the first and second sets in opposite directions at the same time in order to increase the travelling length as well as ac- celeration and speed of displacement.The drives 18, which also allows to bring the con- 19 can e.g. operate on the re- pulsive Lorentz-force principle and be of the type dis- closed in US 7 235 751, scribed in detail herein. and they are therefore not de- Each drive is able to displace one set of contact elements along the displacement direc- tion D. They are adapted and controlled to move the first and second sets in opposite directions at the same time in order to increase the traveling length as well as acceleration and speed of displacement.

The drives 18, 19 are arranged in opposite end regions of second tube section 4. 10 15 20 25 30 35 9 CH-13154 It should be noted that the full stroke (e.g. 20 mm per drive) of the drives may not be necessary to travel in order for the contact system to provide the di- electric strength required, but a distance much shorter (e.g. shorter time, 10 mm per drive), which can be reached in an even suffices. This also provides certain safety in case of backtravel upon reaching the end-of-stroke po- sition and damping phase of the actuators. A sufficient separation of the conducting elements 16 can be reached within 1 or 2 ms (milliseconds).The drives 18, 19 are arranged in opposite end regions of second tube section 4. 10 15 20 25 30 35 9 CH-13154 It should be noted that the full stroke (eg 20 mm per drive) of the drives may not be necessary to travel in order for the contact system to provide the di- electric strength required, but a distance much shorter (eg shorter time, 10 mm per drive), which can be reached in an even suffices. This also provides certain safety in case of backtravel upon reaching the end-of-stroke position and damping phase of the actuators. A sufficient separation of the conducting elements 16 can be reached within 1 or 2 ms (milliseconds).

As shown in Fig. 2, each terminal 8, 9 car- ries a contact plate 32 forming a contact surface 33 con- tacting the conducting elements 16 when the switch is in its first position. The contact plates 32 are mounted to the terminals 8, 9 in axially displaceable manner, with springs 20 elastically urging the contact surface 33 against the conducting elements, thereby compressing the conducting elements 16 in their aligned state for better conduction. In the embodiment of Fig. 2, helical compres- sion springs 20 are used for this purpose, but other types of spring members can be used as well. Also, even though it is advantageous, if there is at least one spring' member 20 in each terminal 8, 9, a compression force for the aligned conducting elements 16 can also be generated by means of a spring member(s) in only one of the terminals 8, 9 to reduce the contact resistance be- tween the elements 16 in the closed position of the switch.As shown in Fig. 2, each terminal 8, 9 car- ries a contact plate 32 forming a contact surface 33 con- tacting the conducting elements 16 when the switch is in its first position. The contact plates 32 are mounted to the terminals 8, 9 in axially displaceable manner, with springs 20 elastically urging the contact surface 33 against the conducting elements, thereby compressing the conducting elements 16 in their aligned state for better conduction. In the embodiment of Fig. 2, helical compression springs 20 are used for this purpose, but other types of spring members can be used as well. Also, even though it is advantageous, if there is at least one spring 'member 20 in each terminal 8, 9, a compression force for the aligned conducting elements 16 can also be generated by means of a spring member (s) in only one of the terminals 8, 9 to reduce the contact resistance be- tween the elements 16 in the closed position of the switch.

A perspective schematic view of a single con- tact element 13a prior to its full assembly is shown in FIG. 3A. and the actuator rod 17.A perspective schematic view of a single contact element 13a prior to its full assembly is shown in FIG. 3A. and the actuator rod 17.

The contact element includes a carrier part 15 In the example shown both parts are made together as a single part from the same materi- al. The carrier part 15 has a frame structure with cut- 152 to mount further conduct- out sections or holes 151, ing elements 16 and/or other elements. The carrier part l5has a central opening 153 and further cut-out sections 10 15 20 25 30 35 10 CH-13154 at one end to reduce the mass which has to be accelerated at each operation of the switch without reducing the me- chanical stability unduly.The contact element includes a carrier part 15 In the example shown both parts are made together as a single part from the same materi- al. The carrier part 15 has a frame structure with cut- 152 to mount further conduct- out sections or holes 151, ing elements 16 and / or other elements. The carrier part l5has a central opening 153 and further cut-out sections 10 15 20 25 30 35 10 CH-13154 at one end to reduce the mass which has to be accelerated at each operation of the switch without reducing the me- chanical stability unduly .

The material used to make the frame structure of the contact element 13a of FIG. reinforced with aramid fibers. 3A is an epoxy resin fiber epoxy materials have been found to be prone to electri- Glass reinforced cally induced erosion processes and to lower insulation breakdown strength, which can be avoided with the epoxy resin reinforced with aramid fibers. The later material is still capable of withstanding the high. acceleration forces during switching.The material used to make the frame structure of the contact element 13a of FIG. reinforced with aramid fibers. 3A is an epoxy resin fiber epoxy materials have been found to be prone to electri- Glass reinforced cally induced erosion processes and to lower insulation breakdown strength, which can be avoided with the epoxy resin reinforced with aramid fibers. The later material is still capable of withstanding the high. acceleration forces during switching.

An enlarged section of the carrier part 15 is referred to below in figures 3B and 3C. This section in- cludes a hole or opening 151 for the insertion of a con- ducting element 16 as described in the following.An enlarged section of the carrier part 15 is referred to below in figures 3B and 3C. This section in- cludes a hole or opening 151 for the insertion of a con- ducting element 16 as described in the following.

FIG. for use to manufacture a conducting element 16 for inser- 4A is a cross-section of a main body 160 tion into the carrier part 15 of a contact element such 3A above. The main body 160 of conducting element 16 has essentially a rectangular cu- as the frame shown in FIG. boid shape with an aspect ratio of approximately 5:1. It Both ends or small faces of the main body 160 are machined in- All edges of the main body 160 is made of aluminium coated with a silver layer. to semi-spherical shape. are rounded.FIG. for use to manufacture a conducting element 16 for inser- 4A is a cross-section of a main body 160 tion into the carrier part 15 of a contact element such 3A above. The main body 160 of conducting element 16 has essentially a rectangular cu- as the frame shown in FIG. boid shape with an aspect ratio of approximately 5: 1. It Both ends or small faces of the main body 160 are machined in- All edges of the main body 160 are made of aluminum coated with a silver layer. to semi-spherical shape. are rounded.

The shape of the main body 160 is chosen such that the width in direction of the displacement is small to ensure that conducting elements 16 can be separated with a correspondingly small displacement of the contact -14c. the direction of displacement and the axial elements 13a lar to both, direction of the switch, The length in a direction perpendicu- i.e. in direction of the tilting axis as defined above, however is chosen to ensure a large contact area between two neighbouring conducting elements (16) in the closed state. 10 15 20 25 30 35 ll CH-13154 In Fig. 4B a cross-section of the main body 160 of a conducting element 16 is shown with a blind bore or hole 163 drilled into each of the rounded ends or small faces. The bore 163is used to accommodate a spring 161 and a pin 162.The shape of the main body 160 is chosen such that the width in direction of the displacement is small to ensure that conducting elements 16 can be separated with a correspondingly small displacement of the contact -14c. the direction of displacement and the axial elements 13a lar to both, direction of the switch, The length in a direction perpendicu- i.e. in direction of the tilting axis as defined above, however is chosen to ensure a large contact area between two neighboring conducting elements (16) in the closed state. 10 15 20 25 30 35 ll CH-13154 In Fig. 4B a cross-section of the main body 160 of a conducting element 16 is shown with a blind bore or hole 163 drilled into each of the rounded ends or small faces. The bore 163is used to accommodate a spring 161 and a pin 162.

A cross-section of such a pin 162 is shown in FIG. 4C. It has an essentially cylindrical shape with one rounded end. A central cut 164 is machined into the rounded end rendering this end of the pin into a two fork. each prong are again all rounded. pronged The in radial direction outer corners of A fully mounted conducting element 16 within the frame structure of a contact element l3a (as shown in FIG. 3A) with FIG. 3B showing a perspective view on an enlarged section of FIG. pre-cut hole 151 of the carrier 15 of the contact element 13a. all external thus providing a better protection against discharges and/or is illustrated in figures 3B and 3C, 3A with a conducting element 16 inserted into the Due the manufacturing steps as described above, exposed edges and corners are rounded, arc-forming in a medium and high voltage environment.A cross-section of such a pin 162 is shown in FIG. 4C. It has an essentially cylindrical shape with one rounded end. A central cut 164 is machined into the rounded end rendering this end of the pin into a two fork. each prong are again all rounded. pronged The in radial direction outer corners of A fully mounted conducting element 16 within the frame structure of a contact element l3a (as shown in FIG. 3A) with FIG. 3B showing a perspective view on an enlarged section of FIG. pre-cut hole 151 of the carrier 15 of the contact element 13a. all external thus providing a better protection against discharges and / or is illustrated in figures 3B and 3C, 3A with a conducting element 16 inserted into the Due the manufacturing steps as described above, exposed edges and corners are rounded, arc-forming in a medium and high voltage environment.

The cross-section along the dash-dotted line X-X in FIG. 3B and perpendicular to the plane of the opening 151 within the frame structure of the contact el- (as shown in FIG. 3A) element 16 inserted is shown in FIG. 3C. ement 13a and with an conducting The conducting element 16 is shown in its as- sembled and mounted state. The conducting element 16 in- cludes the main body 160 and two pins each inserted into one of the blind holes 163 at either end of the main body. Also located within the blind hole 163 is a springy In the absence of forces the forked part of the pin 162 in direction out of its blind hole. or an elastic element 161. springy element 161 pushes the upper, A conducting element 16 as described can be mounted into an opening 151 and thus onto the carrier 15 of a contact element by exerting a force on the pin or 10 15 20 25 30 35 12 CH-13154 pins 162 and by releasing this force, after the conduct- ing element is in its desired position. After the release of the force, the pins loch against the walls of the The width of the cut 164 matched by the thickness of carrier wall at this loca- opening 151. in each pin is tion. Thus a secure fastening is achieved without any At the each contact element can be easily assembled further fastening means such as screws or glues. same time, and conducting elements can be easily mounted or re- placed.The cross-section along the dash-dotted line X-X in FIG. 3B and perpendicular to the plane of the opening 151 within the frame structure of the contact el- (as shown in FIG. 3A) element 16 inserted is shown in FIG. 3C. ement 13a and with an conducting The conducting element 16 is shown in its as- sembled and mounted state. The conducting element 16 in- cludes the main body 160 and two pins each inserted into one of the blind holes 163 at either end of the main body. Also located within the blind hole 163 is a springy In the absence of forces the forked part of the pin 162 in direction out of its blind hole. or an elastic element 161. springy element 161 pushes the upper, A conducting element 16 as described can be mounted into an opening 151 and thus onto the carrier 15 of a contact element by exerting a force on the pin or 10 15 20 25 30 35 12 CH-13154 pins 162 and by releasing this force, after the conducting element is in its desired position. After the release of the force, the pins loch against the walls of the The width of the cut 164 matched by the thickness of carrier wall at this loca- opening 151. in each pin is tion. Thus a secure fastening is achieved without any At the each contact element can be easily assembled further fastening means such as screws or glues. same time, and conducting elements can be easily mounted or re-placed.

Instead of or in addition to the two-pronged fork, the pin can be designed, for example with a smaller to be inserted into holes within the side 151. considered inferior to the example presented above as it pin at the top, wall of the openings However this alternative is further weakens the structural integrity of the carrier part 15 or requires at least a local increase in its thickness.Instead of or in addition to the two-pronged fork, the pin can be designed, for example with a smaller to be inserted into holes within the side 151. considered inferior to the example presented above as it pin at the top, wall of the openings However this alternative is further weakens the structural integrity of the carrier part 15 or requires at least a local increase in its thickness.

It is also possible, for example with a fur- ther cut perpendicular to the first cut 164 to structure the tip of the pin as four-pronged fork with each prong at the corner of a rectangular. Again, this alternative is considered inferior as it weakens the prongs and gen- erates more edges and small features on the surfaces of the carrier. The latter can again be the location of dis- charges and/or arc-forming in a medium and high voltage environment.It is also possible, for example with a fur- ther cut perpendicular to the first cut 164 to structure the tip of the pin as a four-pronged fork with each prong at the corner of a rectangular. Again, this alternative is considered inferior as it weakens the prongs and generates more edges and small features on the surfaces of the carrier. The latter can again be the location of dis- charges and / or arc-forming in a medium and high voltage environment.

It should be noted that the springy element 161 together with the cylindrical shape of each pin 162 enable small tilting movements of the main body 161 out of the plane of the carrier part 15. This aspect becomes important when the conducting elements 16 of two adjacent contact elements, e.g.It should be noted that the springy element 161 together with the cylindrical shape of each pin 162 enable small tilting movements of the main body 161 out of the plane of the carrier part 15. This aspect becomes important when the conducting elements 16 of two adjacent contact elements, eg

FIG. 1 come into contact during the closing or opening of the switch. position the flattened long sides of the main body 160 contact element 13a and. 14a of The tilting ensures that in the final closed are fully in contact with each other and thus reduce the lO 15 20 25 13 CH-13154 contact resistance and limit the heat generated at the interface (16). between the neighbouring conducting elements A switch with spacer elements as described above has applications for example in a high voltage cir- cuit breaker as illustrated in the FIG. 5 and described in the accompanying text of US 2013/0098874. rangement the switch is connected in series with solid In such ar- state breakers and in parallel with a second set of solid state breakers.FIG. 1 come into contact during the closing or opening of the switch. position the flattened long sides of the main body 160 contact element 13a and. 14a of The tilting ensures that in the final closed are fully in contact with each other and thus reduce the lO 15 20 25 13 CH-13154 contact resistance and limit the heat generated at the interface (16). between the neighboring conducting elements A switch with spacer elements as described above has applications for example in a high voltage cir- cuit breaker as illustrated in the FIG. 5 and described in the accompanying text of US 2013/0098874. rangement the switch is connected in series with solid In such ar- state breakers and in parallel with a second set of solid state breakers.

While in the present description preferred it should be noted that the invention is not limited to those and can embodiments of the invention are described, be implemented in other ways within the scope of the fol- lowing claims. 10 15 20 25 30 14 CH-13154 Reference numerals : housing : space , 4: tube sections , 7: support insulators 9: 1 2 3 5: housing section 6 8, terminals 10, 11: caps 12: switching arrangement 13a, l3b, 13c: 14a, 14b, 14c: 15: insulating carrier part 151,152,153: first set of contact elements second set of contact elements recesses, openings of the carrier 16, 16': conducting elements 160: main body of conducting element 161: springy element 162: pin 163: blind hole 164: cut through pin 17: actuator rods 18: drive 19: drive 20: springs 32: contact plate 33: contact surface 34: conducting pathWhile in the present description preferred it should be noted that the invention is not limited to those and can embodiments of the invention are described, be implemented in other ways within the scope of the fol- lowing claims. 10 15 20 25 30 14 CH-13154 Reference numerals: housing: space, 4: tube sections, 7: support insulators 9: 1 2 3 5: housing section 6 8, terminals 10, 11: caps 12: switching arrangement 13a, l3b , 13c: 14a, 14b, 14c: 15: insulating carrier part 151,152,153: first set of contact elements second set of contact elements recesses, openings of the carrier 16, 16 ': conducting elements 160: main body of conducting element 161: springy element 162: pin 163: blind hole 164: cut through pin 17: actuator rods 18: drive 19: drive 20: springs 32: contact plate 33: contact surface 34: conducting path

Claims (12)

10 15 20 25 30 35 15 CH-13154 Claims10 15 20 25 30 35 15 CH-13154 Claims 1. A high or medium voltage switch comprising a first and a second terminal (8, 9), a first and a second set of contact elements (l3a, l3b, l3c; l4a, l4b, l4c) and the second terminal (8, 9), arranged between the first at least a first drive (18) for mutually dis- (l3a, l3b, l3c; l4a, (D), (l3a, l3b, comprises an insulating carrier part (16), wherein in a first mutual position of (l3a, 13b, l3c; l4a, l4b, l4c) the ducting elements (16) of said contact elements (l3a, l3c; l4a, l4b, l4c) fornl at least one conducting (34) in an axial direction (A) said second terminals (8, 9) placing the sets of contact elements l4b, l4c) along a displacement direction l3c; (15) wherein each contact element l4a, l4b, l4c) carrying at least one conducting element and said contact elements con- l3b, path between said first and in a direction transversally (D), and wherein in a sec- ond mutual position of said contact elements (l3a, l3b, l3c; l4a, l4b, l4c) (16) are mu- tually displaced and do not form said conducting path, to said displacement direction the conducting elements characterized in that the conducting elements (l3a, l3b, l3c; spring-loaded pin (16) are fastened to the contact elements l4a, l4b, l4c) with at (l6l,l62) allowing for a limited amount of rotation or tilting of each conducting element (16) (161,162). least one around its re- spective at least one pinA high or medium voltage switch comprising a first and a second terminal (8, 9), a first and a second set of contact elements (l3a, l3b, l3c; l4a, l4b, l4c) and the second terminal (8, 9), arranged between the first at least a first drive (18) for mutually dis- (l3a, l3b, l3c; l4a, (D), (l3a, l3b, comprises an insulating carrier part (16), wherein in a first mutual position of (l3a, 13b, l3c; l4a, l4b, l4c) the ducting elements (16) of said contact elements (l3a, l3c; l4a, l4b, l4c) fornl at least one conducting (34) in an axial direction ( A) said second terminals (8, 9) placing the sets of contact elements l4b, l4c) along a displacement direction l3c; (15) wherein each contact element l4a, l4b, l4c) carrying at least one conducting element and said contact elements con - l3b, path between said first and in a direction transversally (D), and wherein in a sec- ond mutual position of said contact elements (l3a, l3b, l3c; l4a, l4b, l4c) (16) are mu- tually displaced and do not form said conducting path, to said displacement direction the conducting elements characterized in that the conducting elements (l3a, l3b, l3c; spring-loaded pin (16) are fastened to the contact elements l4a, l4b, l4c) with at (l6l, l62) allowing for a limited amount of rotation or tilting of each conducting element (16) (161,162). at least one around its re- spective at least one pin 2. The switch of claim l, (16) cuboid as main body wherein the con- ducting element comprises an elongated rectangular (160) contacting in operation the flattened contact side of the conducting element (16) of an adjacent con- (13a, 13b, l3c; l4a, l4b, l4c) comprises at least one spring-loaded pin with two flattened long contact faces for tact element and further (l61,l62) par- 10 15 20 25 30 35 16 CH-13154 tially inserted into a blind hole (163) of the small faces of the main body (160). at at least one2. The switch of claim l, (16) cuboid as main body wherein the con- ducting element comprises an elongated rectangular (160) contacting in operation the flattened contact side of the conducting element (16) of an adjacent con- (13a, 13b, l3c; l4a, l4b, l4c) comprises at least one spring-loaded pin with two flattened long contact faces for tact element and further (l61, l62) par- 10 15 20 25 30 35 16 CH-13154 tially inserted into a blind hole (163) of the small faces of the main body (160). at least one 3. The switch of claim 2 with the conducting (161,162) at both small faces of (16) ly inserted into blind holes (160). element having spring-loaded pins (163) partial- the main body3. The switch of claim 2 with the conducting (161,162) at both small faces of (16) ly inserted into blind holes (160). element having spring-loaded pins (163) partial- the main body 4. The switch of claim 2 or 3, wherein the (160) of the conducting element (16) is located within a hole (151) (15) such that the flattened contact faces of the main body are parallel main body in the carrier part to the plane of the carrier and the one or more pins (l6l,162) lock with the side walls of the hole (151).4. The switch of claim 2 or 3, wherein the (160) of the conducting element (16) is located within a hole (151) (15) such that the flattened contact faces of the main body are parallel main body in the carrier part to the plane of the carrier and the one or more pins (l6l, 162) lock with the side walls of the hole (151). 5. The switch of claim 4, wherein the tip of (16l,162) (164) with a width matching the thickness of the carrier part (15) (15). the one or more pins includes a recess such that the pin can latch onto the carrier5. The switch of claim 4, wherein the tip of (16l, 162) (164) with a width matching the thickness of the carrier part (15) (15). the one or more pins includes a recess such that the pin can latch onto the carrier 6. The switch of claim 4 or 5, wherein the width of the hole (151) is slightly larger than the width of the main body (160) (16) such that a rotational movement around the at least one (161,l62) tional direction about a tilt axis defined. by the at (161,162). of the contacting element pin is limited to less than 5° in each rota~ least one pin6. The switch of claim 4 or 5, wherein the width of the hole (151) is slightly larger than the width of the main body (160) (16) such that a rotational movement around the at least one (161, l62) tional direction about a tilt axis defined. by the at (161,162). of the contacting element pin is limited to less than 5 ° in each rota ~ at least one pin 7. The switch of any of the preceding claims, (161,162) er material than the main body (160). wherein the at least one pin is made of a hard-7. The switch of any of the preceding claims, (161,162) er material than the main body (160). where the at least one pin is made of a hard- 8. The switch of any of the preceding claims, wherein all exposed contours of the conducting element (16) pin including all exposed contours of the at least one (161,162) are rounded. 10 15 20 25 30 35 17 CH-131548. The switch of any of the preceding claims, wherein all exposed contours of the conducting element (16) pin including all exposed contours of the at least one (161,162) are rounded. 10 15 20 25 30 35 17 CH-13154 9. The switch of any of the preceding claims, (15) the mounted on it is free of hetero- wherein the connection between the carrier and (16) in particular gluefree. conducting element material,9. The switch of any of the preceding claims, (15) the mounted on it is free of hetero- wherein the connection between the carrier and (16) in particular gluefree. conducting element material, 10. A DC switch, particularly in accordance with any of the preceding claims, wherein at least a car- (15) (16) is made of a material comprising a composite of epoxy resin rier part for mounting conducting elements reinforced with aramid fibers.10. A DC switch, particularly in accordance with any of the preceding claims, wherein at least a car- (15) (16) is made of a material comprising a composite of epoxy resin rier part for mounting conducting elements reinforced with aramid fibers. 11. The switch of claim 10, (15) (17) (15) (18,18) and closing the switch are essentially wherein at least the carrier part and an actuator rod connecting the carrier part with za drive for opening made of a single sheet of material comprising a composite of epoxy resin reinforced with aramid fibers providing a frame with re- and/or holes (151) (16). cesses for mounting conducting ele- ments11. The switch of claim 10, (15) (17) (15) (18,18) and closing the switch are essentially wherein at least the carrier part and an actuator rod connecting the carrier part with za drive for opening made of a single sheet of material comprising a composite of epoxy resin reinforced with aramid fibers providing a frame with re- and / or holes (151) (16). cesses for mounting conducting elements 12. A current breaker comprising the switch of any of the preceding claims, said current breaker fur- ther comprising a primary branch and a secondary branch in parallel, at least one solid state breaker arranged in the primary branch, a plurality of solid state breakers (arranged in series in the secondary branch, wherein a number of solid state breakers in the secondary' branch is larger than. a number of solid state breakers in the primary branch, and wherein said switch is arranged in said primary branch in series to said solid state breaker of said primary branch.12. A current breaker comprising the switch of any of the preceding claims, said current breaker fur- ther comprising a primary branch and a secondary branch in parallel, at least one solid state breaker arranged in the primary branch, a plurality of solid state breakers (arranged in series in the secondary branch, where a number of solid state breakers in the secondary 'branch is larger than. a number of solid state breakers in the primary branch, and where said switch is arranged in said primary branch in series to said solid state breaker of said primary branch.