ELECTRIC PROTECTOR
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2020-09-30
- Publication Date
- 2026-04-08
AI Technical Summary
Existing electrical contactors experience separation of contact tips due to anti-parallel current flow, leading to undesired electrical arcs during high current conditions, which existing solutions fail to adequately address.
The electrical contactor system is designed with fixed and moving contacts shaped to generate an additional Lorentz force that counteracts separation forces by conducting current in parallel, using overlapping sections to attract the contact tips through symmetrical arrangements of fixed and moving bars.
This design effectively prevents contact tip separation by generating an attractive Lorentz force greater than the repulsive force, ensuring stable contact at high currents and reducing the risk of electrical arcs.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an electrical contactor system comprising at least one electrical contactor for high current applications.BACKGROUND
[0002] Contactors such as block contactors or bar contactors that comprise contact tips between two bars guide high current from and through the first bar over the flat surfaces of the contact tips to the second bar. The surfaces, however, cannot be produced perfectly flat, which has a negative effect on the robustness of the contactor. When two seemingly flat surfaces mate, the contact only takes place in a very small portion of the contact surface due to the roughness of the contact surface. In an electrical contact, the current flow is constricted to those few points. This leads to anti-parallel current flow in the contacting bodies. These anti-parallel currents create a Lorentz force that tries to separate these two bodies. This separation force increases quadratically with the amplitude of the current. It is common to use contact springs to ensure a certain contact force and a low-loss transmission of electrical current through the contact. At low currents, where the above-mentioned separation force is weaker than the contact spring force, the contact stays closed. However, at high currents (e.g. during a short circuit fault), the separation force can increase beyond the contact spring force. In such a case, the contact tips separate, and an undesired electrical arc takes place. US 4 467 301 A describes an electrical switch that has a fixed contact with two spaced apart L-shaped members. A contact bridge extends from a short leg of one L-shaped member to a corresponding short leg on the other L-shaped member. A conductor arm has a first section attached to the long legs of each of the L-shaped members and extends substantially coplanar with the contact bridge. The switch has a movable contact arm which in the closed switch state is parallel to the first section of the conductor arm.
[0003] US 2015 / 318134 A1 describes an electrical contactor with a first and a second moveable arm connected to a first terminal and a third and a fourth moveable arm connected to a second terminal, where the first and third arms and the second and fourth arms, respectively have contact sets and are overlapping each other. US 4 849 590 A describes a switch has contacts constructed so that an electrodynamic force is created by the current flowing through the switch which tends to maintain the switch in a closed state. US 20113 / 049905 A1 describes a power contact device comprising two stationary and movable contact elements, the two elements being in the form of two juxtaposed coiled turns arranged facing one another in the open position. WO 2006 / 035235 A1 describes an electrical contactor comprises a first electrically conductive cantilevered arm carrying a first contact adjacent its fixed end and a second contact adjacent its free end and a second electrically conductive cantilevered arm carrying a third contact adjacent its fixed end and a fourth contact adjacent its free end.SUMMARY
[0004] Therefore, an improved electrical contactor is desired.
[0005] The problem is solved by the subject-matter of the independent claim 1. Embodiments are provided by the dependent claims, the following description and the accompanying figures.
[0006] The invention is defined by the appended claims. Embodiments and examples not covered by the claims are presented to illustrate, and facilitate the understanding of, the claimed invention.
[0007] The described embodiments similarly pertain to the electrical contactor system. Synergetic effects may arise from different combinations of the embodiments although they might not be described in detail.
[0008] Technical terms are used by their common sense. If a specific meaning is conveyed to certain terms, definitions of terms will be given in the following in the context of which the terms are used.
[0009] According to the invention, an electrical contactor system comprising at least one electrical contactor for high current applications is provided.
[0010] The fixed and moving contacts of a contact system are shaped such that according to Ampère's law of force an additional Lorentz force is generated. The separation force primarily acts on the matching contact tips, e.g., the first contact tips, trying to separate the two tips from each other. By shaping the bars such that an additional Lorentz force is generated this separation force is counteracted. In particular, the additional Lorentz force is achieved by adjusting the fixed and moving contact bodies such that the electrical current is conducted in parallel in both bodies. A Lorentz force then acts on those paths and attracts them to each other. By proper shaping of the contacting bodies, i.e., adjusting the overlapping length of the parallel paths, the attraction force can be dimensioned to be larger than the separation force and contact separation can be avoided. The first contacts tips and, in the following, also the second and further contact tips, each address a pair of contact tips.
[0011] Throughout the disclosure, the expression "contact tips" may be used as a brief form of the expression "electrical contact tips".
[0012] The overlapping sections have a dimension such that a magnetic field caused by the current in the overlapping parts effects a Lorentz force attracting the first fixed bar and the moving bar, which is greater than the Lorentz force caused by current in the first electrical contact tips repelling the first fixed bar and the moving bar.
[0013] According to the invention, the electrical contactor comprises further a second fixed bar and second electrical contact tips. The second electrical contact tips are arranged between the second fixed bar and the moving bar electrically connecting the moving bar with the second electrical contact tips. The second fixed bar and the moving bar comprise overlapping sections arranged in parallel to each other, and the second fixed bar and the moving bar are configured to guide current in the same direction in the overlapping sections.
[0014] According to an embodiment, the first fixed bar, the first electrical contact tips and a first part of the moving bar form a first portion of the electrical contactor, and the second fixed bar, the second electrical contact tips and a second part of the moving bar form a second portion of the electrical contactor. The first and the second portions are built up essentially in the same way, and the first and the second portions are arranged rotation symmetrically around a center axis or are arranged mirror symmetrically with respect to a center plane, and are connected together by the moving bar.
[0015] According to an embodiment, the first fixed bar is configured to guide the current in a forward direction to the contact tips, and the moving bar comprises side paths that do not overlap the first fixed bar and are arranged such that they guide the current from the contact tips in a backward direction, and re-combine at a back end of the moving bar. The moving bar comprises a main path connecting with the side paths at the back end of the moving bar and overlapping a section of the first fixed bar. The moving bar is configured to guide the current from the back end of the moving bar in the forward direction to a front end of the moving bar.
[0016] According to an embodiment, the first fixed bar comprises a main path and side paths parallel to the main path, the side paths (320) diverging at a first fixed bar back end (324) from the main path (322) and re-combining at a fixed bar front-end. The first electrical contact tips are arranged at the first fixed bar front-end, wherein the first fixed bar is configured to guide the current in the main path in a backward direction to the first fixed bar back end and further in a forward direction to the first electrical contact tips. The moving bar comprises a main path and side paths each overlapping the fixed bar and is arranged such that it guides the current in the overlapping main path and side path in the same directions as in the corresponding main path and side path of the first fixed bar to a front end of the moving bar.
[0017] According to an embodiment, the fixed bar has a near overlapping section and a distant overlapping section with respect to the moving bar. The near overlapping section and the distant overlapping section are connected to each other at a front end and a back end of the first fixed bar, the first electrical contact tips are arranged at the back end of the first fixed bar, and the fixed bar is configured to guide the current such that it passes the first electrical contact tips in forward direction in the near overlapping section, flows in backward direction in the distant overlapping section to the first contact tips, and further in the moving bar in forward direction to a front end of the moving bar.
[0018] According to an embodiment, the overlapping sections of the first fixed bar and the moving bar have a rectangular spiral shape or round spiral shape, and the current is fed in into the overlapping section of the fixed bar from a section in a plane perpendicular to the plane of the overlapping section.
[0019] According to an embodiment, the electrical contactor further comprises a flexible conductor connecting the first fixed bar with the moving bar, and a second fixed bar, wherein the second fixed bar has a section overlapping with the moving bar and being in parallel to the moving bar. The first contactor connects the moving bar with the second fixed bar at a first end of the moving bar and the start of the overlapping section of the second fixed bar. The second electrical contact tips connect the moving bar with the second fixed bar at a second end of the moving bar and the end of the overlapping section of the second fixed bar.
[0020] According to an embodiment, the overlapping section has a meander shape.
[0021] According to an embodiment, the electrical contactor further comprises a moving bar, and further contact tips, wherein the first fixed bar is in-between the moving bar and the further moving bar, and the further moving part comprises sections overlapping with the fixed bar.
[0022] According to an embodiment, the fixed bar has a circular shape forming a circle between 180° and 360° from a current input to an end point. The first electrical contact tips are arranged at the end point. The moving bar is forming a circle between 180° and 360° with same radius as the circle of the first fixed bar, running from the first electrical contact tips to an output, wherein the overlapping sections are between the input and the output.
[0023] According to an embodiment, the overlapping sections are arranged in a plurality of layers. That is, the arrangement may be three-dimensional with more than one layer or plane, respectively, of moving bars and / or fixed bars.
[0024] According to an embodiment, the electrical contactor is a single breaking contactor.
[0025] In case wherein the electrical contactor system comprises at least two electrical contactors as described above, the at least two electrical contactors are arranged in parallel forming parallel sections and are configured to conduct the current in parallel, wherein the parallel sections of the at least two electrical contactors are electrically connected to each other and / or wherein the parallel contactors are electrically connected to each other.
[0026] The parallel contactors being electrically connected to each other may be replaced by a single contactor, such that the moving bars are arranged in parallel, the fixed bars are arranged in parallel, and the arrangement of moving bars and fixed bars is connected together by, e.g., two single contactor, or two.
[0027] These and other features, aspects and advantages of the present invention will become better understood with reference to the accompanying figure and the following description.SHORT DESCRIPTION OF THE FIGURES
[0028] Figs. 1a and 1b show a schematic diagram of a double breaking electrical contactor 100 according to the state of the art, Fig. 1c and 1d show a schematic diagram of an electrical contactor realized as single breaking system according to the state of the art, Figs. 2a to 2c show in different views schematic diagrams of an arrangement of an electrical contactor according to an embodiment, Fig. 3a to 3d show schematic diagrams of an example of an arrangement of an electrical contactor according to an embodiment, Fig. 4a and Fig. 4b show schematic diagrams of a further example of an arrangement of an electrical contactor according to an embodiment, Fig. 5a and Fig. 5b show a schematic diagrams of a further example of an arrangement of an electrical contactor according to an embodiment, Fig. 6a and Fig. 6b show a schematic diagram of another example similar to the arrangement in Fig. 5a and Fig. 5b according to an embodiment, Fig. 7 shows a schematic diagram of a more complex example of an arrangement of an electrical contactor according to an embodiment, Fig. 8 shows a schematic diagram of a further example of an arrangement of an electrical contactor according to an embodiment, Fig. 9 shows a schematic diagram of an electrical contactor that is obtained by mirroring the arrangement of Fig. 8 according to an embodiment, Figs. 10a to 10d show schematic diagrams of an example that is similar to the one of Fig. 9, with the difference that the paths are rectangular instead of circular according to an embodiment, Fig. 11 shows a schematic diagram of an electrical contactor according to a further embodiment, Fig. 12 shows a schematic diagram of a system comprising several instances of electrical contactors as shown in Fig. 11 according to an embodiment, Fig. 13 shows a schematic diagram of a variation of the system 1200 as depicted in Fig. 12 according to an embodiment. DETAILED DESCRIPTION OF EMBODIMENTS
[0029] Figs. 1a and 1b show a schematic diagram of an electrical contactor 100 according to the state of the art. The electrical contactor 100 forms a contact system that comprises a first fixed bar 102, a second fixed bar 104, and a moving bar 106. The fixed bars 102, 104 are connected to the moving bar with contact tips 110, 112. Fig. 1a shows the contacts in an open state and Fig. 1b in a closed state. The arrangement allows a current to flow as indicated by the arrows from the first fixed bar 102 via the contact tips 110 to the moving bar 106, and from there over the contact tips 112 to the fixed bar. The surfaces between the contact tips are only seemingly flat, but actual electrical contact takes place only on a very small fraction of this seemingly flat surface due to the microstructure of the mating surfaces of the contact tips 110 and 112. As a consequence, currents may flow in an anti-parallel way so that Lorentz forces may arise that effect a separation of contact tips 110 and contact tips 112, respectively.
[0030] The electrical contactor 100 may also be realized in a single breaking fashion as shown in Figures 1c and 1d. In this arrangement, the total contact resistance is halved since there is only one contact interface in the current path rather than two. However, the additional resistance of the flexible conductor is now added to the circuit. Again, a separation force applies to the contact tips due to current constriction.
[0031] Fig. 2 to Fig. 13 show examples of arrangements that counteract the separation of the one or more contact tip pairs. As a general solution, the presented examples show electrical contactor arrangements with a first fixed bar 202, a moving bar 206, and a first electrical contact tips 210 arranged between the first fixed bar 202 and the moving bar 206 electrically connecting the first fixed bar 202 with the moving bar 206. E.g., the first fixed bar 202 and the moving bar 204 comprise overlapping sections arranged in parallel to each other, and the first fixed bar 202 and the moving bar 206 are configured to guide current in the same direction in the overlapping sections. The overlapping sections have a dimension such that a magnetic field caused by the current in the overlapping parts effects a Lorentz force attracting the first fixed bar and the moving bar, which is greater than the Lorentz force caused by current in the first contact tips repelling the first fixed bar 202 and the moving bar 206.
[0032] Some arrangements in the shown examples are essentially rotation symmetrical around a center axis 290 or show a mirror symmetry with respect to a center plane.
[0033] The input side of the current is called the first portion 240 in this disclosure and the current output side is called the second portion 242, where the structure of the first and the second portions 240, 242 is essentially identical, and arranged such that the first portion 240 theoretically turned around the center axis of the arrangement maps to the second portion 242. The two portions 240, 242 are connected by the moving bar, where e.g., a main path or side paths form a bridge, which connects the two portions. A side path is usually formed when the main path is split, wherein the man path conducts the total current and the side paths conduct parts of the total current, depending on the geometry. The flow of the current results from the geometry of the structure and is only explained for one of the two portions. The focus of the current flow is on sections where the fixed bars and the moving bar overlap, and wherein in the overlapping sections the current flows in the same direction, thereby producing Lorentz forces that attract the moving bar to the fixed bar.
[0034] The same reference signs are used for the electrical contactor 200 throughout Fig. 2 to Fig. 13, although the realization differs. The same applies to the first 202 and second 204 fixed bars and the moving bars 206, the first 210 and the second 212 contact tips, the first and the second portion 240, 204 and some other parts. In some embodiments, portions of the arrangement are duplicated or mirrored, respectively. In such cases, also parts such as contacts, contact tips, and the moving bar are duplicated. These duplicated parts are denominated with the same reference signs as their original, since no differentiation is necessary.
[0035] Fig. 2a, 2b and 2c show in different views an arrangement of an electrical contactor 200 with a first portion 240 and a second portion 242. Fig. 2a is a three-dimensional diagram with a top view on the moving bar 206. In the example of Fig. 2a-2c, the first fixed bar 202 is configured to guide the current in a forward direction to the contact tips 210 in the first portion 240. The flow of the current is indicated by bold arrows. The moving bar 206 comprises side paths 220 in the first portion 240 that do not overlap the fixed bar 202 and that are arranged such that they guide the current from the contact tips 210 in a backward direction to the back end 224 of the moving bar 206 where the side paths re-combine and proceed further in the main path 222. The main path 222 overlaps in a section 230 with the fixed bar 202. The moving bar 206 is thus configured to guide the current from the back end 224 of the moving bar 206 in the forward direction to a front end 234 of the moving bar 206 in parallel to the current in the first fixed bar 202.
[0036] The front end 234 of the moving bar 206 is part of a second portion 242 of the arrangement in the example of Fig. 2a-2c. The second portion 242 is symmetrical to the first portion 240. The main path 230 splits into two side paths 226 at the front-end 234 of the moving bar 206 and allows the current to flow in a backward direction to the contact tips 212, where the side paths 226 are re-combined. The contact tips 212 connects the moving bar 206 with the second fixed bar 204 and allows the current to flow in a forward direction in parallel to the current in overlapping section 232 of the main path 228 of moving bar 206.
[0037] The moving bar 206 is arranged in three dimensions, such that a bridge 226 is formed in the main path 222, 228 to connect the first portion 240 with the second portion 242. The arrangement is rotation symmetrical around axis 290.
[0038] Figures 3a to 3d show a further example of an arrangement of an electrical contactor 200. The flow of the current is indicated by bold arrows. Fig. 3a shows mainly the first and second fixed bars 202, 204 in a three-dimensional bottom view. Fig. 3b shows mainly the moving bar 206 in a three-dimensional top view. Fig. 3c shows a top view of the arrangement, where the moving bar 206 is on the top side, and Fig. 3d shows a side view with the moving bar 206 on top of the first 202 and second 204 fixed bars, which are connected each to the moving bar by contact tips 210, 212. The left side in Fig. 3d forms the first portion 240 and the right side the second portion 242 of the electrical contactor 200. As shown in Fig. 3a, the first fixed bar 202 comprises a main path 322 and side paths 320 parallel and next to the main path 322. The side paths 320 diverge at a fixed bar back end 324 from the main path 322 and re-combine at a fixed bar front-end 334, where the contact tips 210 are arranged. The fixed bar 202 is configured to guide the current in the main path 322 in a backward direction to the fixed bar back end 324 and further in a forward direction to the contact tips 210, which leads the current to the moving bar 206. As depicted in Fig. 3b, the moving bar 206 comprises a main path 352 and side paths 350, each overlapping essentially the first fixed bar 202. The moving bar 206 is arranged such that it guides the current in the overlapping sections in the same directions as the fixed bar 202 to a front end 354 of the moving bar 206. The overlapping sections are, for example, main paths 322 of the first fixed bar 202 and main path 352 of the moving bar 206, or side paths 320 that overlap side paths 350 at least in parts. Portions 240 and 242 are rotation symmetrical around an axis 290.
[0039] Compared to the arrangement shown in Figures 2a to 2c, the Lorentz force in the separation direction of the contact tips caused by each side path conducting half of the current in the direction opposite to the fixed bar is avoided and the attraction improved. This means that in the arrangement of Figures 3a to 3d, a Lorentz force acts on the side paths, increasing the effect of the attraction force acting on the middle section of the moving bar 206.
[0040] Fig. 4a and Fig. 4b show a further example of an arrangement of an electrical contactor 200 comprising a first fixed bar 202 in a first portion 240, a second fixed bar 204 in a second portion 242, and a simple moving bar 206 connected to the fixed bars 202, 204 by contact tips 210, 212. The fixed bar 202 has a near overlapping section 402 and a distant overlapping section 404 with respect to the moving bar 206, wherein the near overlapping section 402 and the distant overlapping section 404 are connected to each other at a front end 424 and a back end 426 of the fixed bar 202. The contact tips 210 is arranged at the back end 426 of the fixed bar 202 and the fixed bar 202 is configured to guide the current such that it passes the contact tips 210 in forward direction in the near overlapping section 402, flows in backward direction in the distant overlapping section 202 to the contact tips 210, and further in the moving bar 206 in forward direction to a back end 434 of the moving bar 206. At the back end 434, the current flows through the contactor 212 into the fixed bar 204 of the second portion 242. From the contactor 212 the current flows first to and through the distant overlapping section 454 of the second fixed bar 204, and further to and through the near overlapping section 452 to an output 450. The arrangement is rotation symmetric with respect to axis 290 and lies in a plane defined by axes 290, 291.
[0041] Fig. 5a and Fig. 5b show a further example of an arrangement of an electrical contactor 200 comprising a first fixed bar 202 in a first portion 240, a second fixed bar 204 in a second portion 242, and a moving bar 206 connected to the fixed bars 202, 204 by contact tips 210, 212. The overlapping sections 502 of the first fixed bar 202 and the moving bar 206 have a rectangular spiral shape. The current is fed in into the overlapping section 502 of the fixed bar 202 from a section 504 in a plane 290', 291 perpendicular to the plane 291, 292 of the overlapping section 502. The arrangement is symmetrical with respect to the plane formed by axes 290 and 291. The input 510 and the output 512 are thus below the plane 291, 292 formed by the rectangular spiral such that an input 510 or output 512 section is parallel to the plane 291, 292 and connected to the rectangular spiral 502 by a section 504 that is perpendicular to the section 504. Also in this arrangement, the direction of the current is identical in overlapping sections 502 of the moving bar 206, and the first 202 and second 204 fixed bar. The two portions 240, 242 are mirrored with respect to plane defined by axes 290, 291.
[0042] Fig. 6a and Fig. 6b show a similar arrangement as Fig. 5a and Fig. 5b, however, the two portions 240, 242 are rotation symmetrical with respect to axis 290. The arrows in Fig. 6a show the flow of the current in the moving bar 206, and the arrows in Fig. 6b show the flow of the current in the fixed bars 202, 204. Comparing the arrows in Fig. 6a and 6b, it can be seen that the direction of the current is identical in the overlapping sections, so that the effect of attraction due to Lorentz forces can be achieved in the overlapping sections. This arrangement allows for using the same geometry for the two fixed bars 202, 204, thereby reducing the manufacturing effort.
[0043] Fig. 7 shows a more complex example of an arrangement of an electrical contactor 200, which is formed by two arrangements as shown in Fig. 6 that are mirrored at the plane defined by axes 291, 292. It is noted that also the contact tips 210, 212 are duplicated in this arrangement. Now the two instances of the moving bar 206 need to be moved in opposing directions along the axis 290 to make and break the circuit. The total current carrying capacity is increased by increasing the total conductor cross sectional area.
[0044] Fig. 8 shows a further example of an arrangement of an electrical contactor 200 comprising a first fixed bar 202 in a first portion 240, a second fixed bar 204 in a second portion 242, and a moving bar 206 connected to the fixed bars by contact tips 210, 212. The fixed bars 202, 204 have a circular shape forming a circle between 180° and 360° from a current input 802 to an end point 810. The first contact tips 210 are arranged at the end point 810. The moving bar 204 is forming a circle between 180° and 360° with same radius as the circle of the first fixed bar 202, running from the contact tips 210 to an output 820, wherein the overlapping sections are between the input 802 and the output 820.
[0045] Thus, the fixed bars 202, 204 and the moving bar 206 each have circular sections of, e.g., 270°, that are connected on one end such that the current flows along a way of 1.5 circles, of which a half circle of the fixed bar 202, 204 and of the moving bar 204 of the corresponding portion 240, 242 are overlapping. In this way, the current flows in the overlapping sections in the same direction. Similar geometries may be possible. For example, the size of the circular sections may be varied.
[0046] The electrical contactor 200 shown in Fig. 9 is obtained by mirroring the arrangement of Fig. 8 at the plane defined by the axes 291 and 292.
[0047] Figures 10a to 10d show an example that is similar to the one of Fig. 9, with the difference that the paths are rectangular instead of circular. Fig. 10a indicates nearly the complete flow of the current by the arrows. The flow starts at the input 1060 of the first fixed bar 202 and ends at the output 1062 of the second fixed bar 204. The flow circulates rectangular through the first fixed bar 202, through the contact tips 210 upwards and downwards to the first and second moving bars 206 with sections overlapping the first fixed bar 202, further to bridges 1064 and 1066, and in an inverse way over the contact tips 212 to the second fixed bar 204 to the output 1062. Fig. 10c shows the arrangement without the top moving bar. Attention may be paid to the parallel flows indicated in Figures 10a and 10b, effecting the attracting Lorentz forces. Fig. 10b shows a top view and Fig. 10d a side view of the arrangement.
[0048] Fig. 11 shows an electrical contactor 200 with a first fixed bar, a flexible conductor 1150, a moving bar 206, contact tips 210, 211 and a second fixed bar 204. The second fixed bar 204 has a section overlapping and being in parallel with the moving bar 206.
[0049] The first contact tips 210 connects the moving bar 206 with the second fixed bar 204 at a first end 1110 of the moving bar 206 and at the start 1130 of the overlapping section of the second fixed bar 204. The electrical contactor 200 further comprises a second contact tips 211. The second contact tips 211 connects the moving bar 206 with the second fixed bar 204 at a second end 1120 of the moving bar 206 and at the end 1140 of the overlapping section of the second fixed bar 204.
[0050] The moving bar or contact, respectively, now comprises two contact tips, however this would still be a single breaking system since the two contact tips 210, 211 are not connected in series. Instead, they are connected in parallel. The parallel flow of the current in the moving and fixed bars lead to an attraction force that drags the two bars 204, 206 in opposing directions along the axis 209.
[0051] Several instances of electrical contactors 200 as shown in Fig. 11 can be used in parallel to form a system 1200 that increases the current carrying capacity, as depicted in Fig. 12. The instances of the first fixed bar 202 in Fig. 12 could also be combined in a single block to simplify the construction.
[0052] Fig. 13 shows a variation of the system 1200 depicted in Fig. 12. The attraction force can be increased by increasing the length of the overlapping sections of the fixed and moving bars. For applications where space is limited, a meander or snake-like shape as shown in Fig. 13 can be adopted for increasing the effective overlap length. Instead of curves, the meander shape may be rectangular or have another geometrical shape.
[0053] In the claims the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the claims.
Claims
1. Electrical contactor system comprising at least one electrical contactor for high current applications, wherein each of the at least one electrical contactors comprises a first fixed bar (202); a second fixed bar (204); a moving bar (206); first electrical contact tips (210) arranged between the first fixed bar (202) and the moving bar (206) and separably electrically connecting the first fixed bar (202) with the moving bar (206); second electrical contact tips (211, 212) arranged between the moving bar (202) and the second fixed bar (204); wherein the moving bar (206), the first fixed bar (202) and the second fixed bar are electrical conductors configured to conduct high current through the contactor from the first fixed bar (202) over the first electrical contact tips (210) and the moving bar (206) to the second electrical contact tips (211, 212); wherein the first fixed bar (202) and the moving bar (206) comprise overlapping sections (230) that are arranged in parallel to each other; characterized in that the moving bar (206) has a geometrical structure providing a forward and backward direction or a curved direction of the current; wherein the first fixed bar (202) and the moving bar (206) are configured to guide current in the same direction in the overlapping sections (230); and wherein the overlapping sections (230) have a dimension such that a magnetic field caused by the current in the overlapping parts (230) effects a Lorentz force attracting the first fixed bar (202) and the moving bar (206), which is greater than the Lorentz force caused by current in the first electrical contact tips (210) repelling the first fixed bar (202) and the moving bar.
2. Electrical contactor system according to claim 1, wherein the second fixed bar (204) and the moving bar (206) comprise overlapping sections (230) arranged in parallel to each other; and wherein the second fixed bar (204) and the moving bar (206) are configured to guide current in the same direction in the overlapping sections (230).
3. Electrical contactor system according to any of the previous claims, wherein the first fixed bar (202), the first electrical contact tips (210) and a first part of the moving bar (206) form a first portion (240) of the electrical contactor (200), and the second fixed bar (204), the second electrical contact tips (212) and a second part of the moving bar (206) form a second portion (242) of the electrical contactor (200); wherein the first (240) and the second (242) portions are built up essentially in the same way; and wherein the first (240) and the second (242) portions are arranged rotation symmetrically around a center axis (290), or are arranged mirror symmetrically with respect to a center plane (290, 291), and are connected together by the moving bar (206).
4. Electrical contactor system according to any of the previous claims, wherein the first fixed bar (202) is configured to guide the current in a forward direction to the first electrical contact tips (210); wherein the moving bar (206) comprises side paths (220) that do not overlap the first fixed bar (202) and that are arranged such that they guide the current from the first electrical contact tips (210) in a backward direction, and which re-combine at a back end (224) of the moving bar (206); wherein the moving bar (206) comprises a main path (226) connecting with the side paths (220) at the back end (224) of the moving bar (206) and overlapping a section of the first fixed bar (202); and wherein the moving bar (206) is configured to guide the current from the back end (224) of the moving bar (206) in the forward direction to a front end (234) of the moving bar (206).
5. Electrical contactor system according to any of claims 1 to 3, wherein the first fixed bar (202) comprises a main path (322) and side paths (320) parallel to the main path (322), the side paths (320) diverging at a first fixed bar back end (324) from the main path (322) and re-combining at a fixed bar front-end (334); wherein the first electrical contact tips (210) are arranged at the fixed bar front-end (334); wherein the fixed bar is configured to guide the current in the main path (322) in a backward direction to the first fixed bar back end (324) and further in a forward direction to the first electrical contact tips (210); and wherein the moving bar (206) comprises a main path (352) and side paths (350) each overlapping the first fixed bar (202) and is arranged such that it guides the current in the overlapping main path (352) and side path (350) in the same directions as in the corresponding main path (322) and side path (320) of the first fixed bar (202) to a front end (354) of the moving bar (206).
6. Electrical contactor system according to any of claims 1 to 3, wherein the first fixed bar (202) has a near overlapping section (402) and a distant overlapping section (404) with respect to the moving bar (206); wherein the near overlapping section (402) and the distant overlapping section (404) are connected to each other at a front end (424) and a back end (426) of the first fixed bar; wherein the first electrical contact tips (210) are arranged at the back end (426) of the fixed bar; and wherein the first fixed bar (202) is configured to guide the current such that it passes the first electrical contact tips (210) in forward direction in the near overlapping section (402), flows in backward direction in the distant overlapping section (404) to the first electrical contact tips (210), and further in the moving bar (206) in forward direction to a front end (434) of the moving bar (206).
7. Electrical contactor system according to any of claims 1 to 3, wherein the overlapping sections (502) of the first fixed bar (202) and the moving bar (206) have a rectangular spiral shape or round spiral shape; and wherein the current is fed in into the overlapping section (502) of the first fixed bar (202) from a section in a plane (290', 291) perpendicular to the plane (291, 292) of the overlapping section (502).
8. Electrical contactor system according to any of claims 1 to 3, wherein the electrical contactor (200) further comprises a flexible conductor (1150) connecting the first fixed bar (202) with the moving bar (206), and a second fixed bar (204); wherein the second fixed bar (204) has a section overlapping with the moving bar (206) and being in parallel to the moving bar (206); wherein the first electrical contact tips (210) connect the moving bar (206) with the second fixed bar (204) at a first end (1110) of the moving bar (206) and at the start (1130) of the overlapping section of the second fixed bar (204); and wherein the second electrical contact tips (211) connect the moving bar (206) with the second fixed bar (204) at a second end (1120) of the moving bar (206) and at the end (1140) of the overlapping section of the second fixed bar (204).
9. Electrical contactor system according to claim 8, wherein the overlapping section has a meander shape.
10. Electrical contactor system according to any of the previous claims, wherein the electrical contactor (200) comprises a further moving bar (206), and further electrical contact tips, wherein the first fixed bar (202) is in-between the moving bar (206) and the further moving bar (206), and the further moving bar comprises sections overlapping with the first fixed bar (202).
11. Electrical contactor system according to any of claims 1 to 3, wherein the first fixed bar (202) has a circular shape forming a circle between 180° and 360° from a current input (802) to an end point (810); wherein the first electrical contact tips (210) are arranged at the end point (810), and the moving bar (206) is forming a circle between 180° and 360° with same radius as the circle of the first fixed bar (202), running from the first electrical contact tips (210) to an output (820); and wherein the overlapping sections are between the input (802) and the output (820).
12. Electrical contactor system according to any of the previous claims, wherein the overlapping sections are arranged in a plurality of layers.
13. Electrical contactor system according to any of the previous claims, wherein the electrical contactor (200) is a single breaking contactor (200).
14. Electrical contactor system according to any of the previous claims, wherein, in case of at least two electrical contactors, the at least two electrical contactors (200) are arranged in parallel forming parallel sections and are configured to conduct the current in parallel, wherein the parallel sections of the at least two electrical contactors (200) are electrically connected to each other and / or wherein the parallel contactors (200) are electrically connected to each other.