Switching device for medium voltage electrical units
By introducing an arc guide into the medium-voltage switchgear and using the grooves with separated ribs to control the arc path, the problem of contact heating caused by arcing is solved, and the reliability and durability of the device are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SCHNEIDER ELECTRIC IND SAS
- Filing Date
- 2025-11-27
- Publication Date
- 2026-05-29
AI Technical Summary
During the current establishment and interruption process, electric arcs can easily form between the contacts of medium-voltage switchgear, causing the contacts to heat up and be damaged, thus affecting the reliability of the device.
Design a switching device in which a moving contact and a fixed contact are connected by an arc guide. The arc guide is composed of grooves with ribs separating them, which controls the path of the arc and allows the arc to propagate in the arc guide to reduce heating of the contact.
By controlling the path of the electric arc, the risk of contact heating and damage is reduced, thereby improving the reliability and durability of the switching device.
Smart Images
Figure CN122117675A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of medium- or high-voltage electrical installations, i.e., voltage ranges from 1 kV to above 52 kV. These units can be housed within an insulating enclosure filled with pressurized gas to improve electrical insulation performance and prevent unwanted arcing within the enclosure. Background Technology
[0002] Some electrical units, such as circuit breakers, include switching devices for each phase of a power grid that alternately allow the establishment and interruption of current flow. These switching devices include moving contacts, such as rotating contacts, which can engage with stationary contacts to establish current. The moving contacts can also disengage from the stationary contacts to interrupt current flow.
[0003] During the current build-up and interruption phases, when the contacts are close to each other, an electric arc can form between the stationary and moving contacts. This arc causes intense heating of the contacts, especially if current is established in a short circuit. This heating can cause partial melting of the contacts and may damage them. Repeated contact damage during the current build-up phase can cause the switching device to fail.
[0004] This disclosure aims to provide a solution for improving the reliability of medium-voltage switchgear. Summary of the Invention
[0005] To this end, the present invention provides a switching device for a medium-voltage electrical unit, which has:
[0006] Including fixed contacts of electrical conductors,
[0007] A moving contact comprises two electrical conductors that extend parallel to each other and are spaced a certain distance apart.
[0008] The moving contact is configured to pivot relative to the pivot axis between a first position and a second position.
[0009] In the first position, the moving contact is separated from the stationary contact to prevent current flow between the contacts, and
[0010] In the second position, the moving contact is in contact with the stationary contact to allow current to flow between the contacts.
[0011] The fixed contact includes an arc guide extending from the electrical conductor of the fixed contact and pointing toward the moving contact. The arc guide is configured to generate an arc when a current is established between the fixed contacts.
[0012] The arc guide includes two grooves separated by ribs.
[0013] An electric arc generated by bringing two electrical contacts at different potentials close together passes through an arc guide. Therefore, the arc guide limits heating of both the stationary and moving contacts and reduces the risk of damage to them, thus improving the reliability of the switching device.
[0014] The features listed in the following paragraphs can be implemented independently of each other or in all technically possible combinations:
[0015] The movement of the moving contact from the first position (called the open position) to the second position (called the closed position) corresponds to the current-building phase in the switching device.
[0016] The movement of the moving contact from the second position (called the open position) to the second position (called the closed position) corresponds to the phase of current interruption in the switching device.
[0017] The arc guide is configured to provide a path for the arc.
[0018] In other words, the electric arc generated when the current is established passes through the arc guide.
[0019] The two electrical conductors of the moving contact are connected in a rotating manner about a common axis of rotation.
[0020] The two electrical conductors of the moving contact are made of copper.
[0021] The electrical conductor of the fixed contact is made of copper.
[0022] The arc conductor is made of ultra-hard steel, such as steel with a carbon content between 1% and 2%.
[0023] Alternatively, any other metal with good high-temperature resistance (significantly greater than that of copper) can be used.
[0024] According to one embodiment of the switching device, the grooves extend parallel to each other in a direction parallel to the pivot axis of the moving contact.
[0025] The depth of the groove can be greater than the width of the rib.
[0026] According to one embodiment, the bottom of the groove has a semi-circular profile.
[0027] According to one aspect of the switching device, the moving contact extends in a main direction perpendicular to the pivot axis.
[0028] According to one embodiment of the switching device, the moving contact includes a first reinforcing element.
[0029] The first reinforcing element includes a first portion supported on a first electrical conductor of the moving contact and a second portion extending perpendicularly to the first portion in the direction of a second electrical conductor of the moving contact.
[0030] The lateral edge of the second part of the first reinforcing element extends parallel to the rotation axis of the moving contact.
[0031] An electric arc generated by establishing current between the fixed and moving contacts is transmitted from the lateral edge of the first reinforcing element to the rib of the arc guide.
[0032] The lateral edge of the second part of the first reinforcing element is a certain distance away from the end of the electrical conductor opposite to the axis of rotation.
[0033] The first reinforcing element includes, for example, a plate.
[0034] The first reinforcing element is made of metal.
[0035] The first reinforcing plate is formed from folded metal strips.
[0036] The first reinforcing plate is, for example, made of steel.
[0037] The first reinforcing plate has a U-shaped profile.
[0038] According to one aspect of the switching device, when the moving contact moves from the first position to the second position, the lateral edge of the second part of the first reinforcing element is successively opposite to the first groove, the rib, and then the second groove.
[0039] The minimum distance between the rib and the lateral edge of the second part of the first reinforcing element is less than 3.0 mm.
[0040] This distance allows an electric arc to be ignited in a controlled manner between the moving contact and the arc guide, with at least a portion of the arc passing through the lateral edge of the second portion of the first reinforcing element.
[0041] According to one embodiment of the switching device, the moving contact includes a second reinforcing element.
[0042] The second reinforcing element includes a first portion supported on a second electrical conductor of the moving contact and a second portion extending perpendicularly to the first portion in the direction of the first electrical conductor of the moving contact.
[0043] The lateral edge of the second part of the second reinforcing element extends parallel to the rotation axis of the moving contact.
[0044] According to one embodiment, the lateral edges of the second portion of the first reinforcing element and the lateral edges of the second portion of the second reinforcing element extend aligned with each other.
[0045] The second reinforcing element includes, for example, a plate.
[0046] According to one aspect of the switching device, when the moving contact moves from the first position to the second position, the lateral edge of the second part of the second reinforcing element is successively opposite to the first groove, the rib, and then the second groove.
[0047] The minimum distance between the rib and the lateral edge of the second part of the second reinforcing element is less than 3.0 mm.
[0048] This distance allows for controlled arc initiation between the moving contact and the arc conductor.
[0049] The first and second reinforcing plates are mirror images of each other.
[0050] According to one aspect of the switching device, the electrical conductor of the fixed contact includes two contact portions that are in mechanical contact with the moving contact when the moving contact is in a second position known as the closed position, and the arc guide is a certain distance away from the two contact portions.
[0051] Therefore, the heating generated by the arc occurs in a portion of the stationary contact, which differs from the portion through which current flows in a steady state. This reduces damage to the stationary contact area involved in steady-state current conduction, thereby improving the reliability of the switching device.
[0052] According to one embodiment of the switching device, the rib extends laterally along the width, the groove extends laterally along the width, and the width of the rib is between 50% and 100% of the width of the groove.
[0053] According to one embodiment of the switching device, the arc guide includes a second rib located between a first lateral edge of the arc guide and a first groove.
[0054] According to one embodiment of the switching device, the arc guide includes a third rib located between a second lateral edge and a second groove of the arc guide.
[0055] This configuration allows the electric arc to pass through the first rib, then skip over the groove that separates the first rib from the second rib, and then jump again to the third rib, skipping the second groove.
[0056] At a given time, an electric arc forms between a given rib and the moving contact. The arc will not pass through two different ribs simultaneously. The alternation of ribs and grooves allows for better control of the arc's position. Therefore, the heat generated by the arc in the arc guide is more effectively controlled, thereby reducing damage to the arc guide.
[0057] According to an embodiment of the proposed switching device, one face of the first rib, one face of the second rib, and one face of the third rib extend in the same plane.
[0058] The common extension plane of the three ribs is parallel to the rotation axis of the moving contact and perpendicular to the main extension axis of the moving contact.
[0059] The three ribs can have the same width.
[0060] The width of a rib can vary from one rib to another.
[0061] According to one aspect of the switching device, the arc guide includes:
[0062] In the first connecting area between the rib and the first groove
[0063] In the second connecting area between the rib and the second groove
[0064] Furthermore, the minimum radius of curvature of the contour of the connecting region is less than 0.2 mm.
[0065] In other words, the connection area between the rib and the groove defining the rib is angular rather than circular. These connection areas form sharp edges. Therefore, the rib is clearly defined. Consequently, the electric arc is preferably directed toward the rib, rather than toward the groove that connects to the rib.
[0066] According to one aspect of the switching device, the arc guide includes:
[0067] The third connection area between the second rib and the first lateral edge of the arc guide.
[0068] Furthermore, the minimum radius of curvature of the contour of the third connecting region is greater than 0.5 mm.
[0069] According to one aspect of the switching device, the arc guide includes:
[0070] The fourth connection area between the third rib and the second lateral edge of the arc guide.
[0071] Furthermore, the minimum radius of curvature of the contour of the fourth connecting region is greater than 0.5 mm.
[0072] According to one embodiment of the switching device, the arc guide is fixed to the electrical conductor of the fixed contact by a screw passing through the arc guide.
[0073] The arc guide includes a channel opening for securing the screw.
[0074] The arc guide includes a channel groove for the anti-rotation pin.
[0075] According to one aspect of the switching device, the moving contact includes a guide rod configured to allow movement of the first conductor and the second conductor relative to each other.
[0076] Depending on the stage of operation, the movement can be the movement of the first conductor toward the second conductor, or the separation of the first conductor from the second conductor.
[0077] The moving contact includes an elastic element configured to apply a retracting force that tends to bring the first and second conductors closer together.
[0078] The moving contact includes a spacer configured to maintain a minimum distance between the first and second electrical conductors.
[0079] According to one embodiment of the switching device,
[0080] In this configuration, the electrical conductors of the moving contacts are arranged to move relative to each other in a direction parallel to the axis of rotation.
[0081] The switching device includes a mechanical guide rigidly connected to an electrical conductor of a fixed contact. The mechanical guide is configured to contact the two electrical conductors of the moving contact during a portion of the movement path of the moving contact from a first position to a second position. The mechanical guide includes a tapered profile whose width decreases as the distance from the electrical conductor of the fixed contact increases, so as to gradually separate the two electrical conductors of the moving contact from one position to the other as the moving contact moves from the first position to the second position.
[0082] The mechanical guide separates the two conductors of the moving contact before they reach the stationary contact, facilitating the insertion of the stationary contact between the conductors of the moving contact. This reduces the mechanical shock and friction associated with the insertion of the stationary contact, thus reducing mechanical wear on both the stationary and moving contacts. This improves the reliability and durability of the switching device.
[0083] In addition, the insulating properties of the mechanical guide are beneficial for positioning the electric arc on the ribs of the arc guide.
[0084] The mechanical guide includes a first support surface and a second support surface, the first support surface being configured to receive a first electrical conductor of a moving contact, and the second support surface being configured to receive a second electrical conductor of the moving contact.
[0085] Furthermore, the distance between the two supporting surfaces gradually decreases as the distance to the electrical conductor of the fixed contact increases.
[0086] The mechanical guide is made of electrically insulating material.
[0087] The mechanical guide is made of a material with a low coefficient of friction.
[0088] The support surface of the mechanical guide has a recess.
[0089] According to one embodiment of the switching device, the mechanical guide includes a housing for receiving a portion of the arc guide.
[0090] Mechanical guides can be molded onto arc guides.
[0091] The housing for receiving mechanical guides includes a base defined by three sides.
[0092] The housing for receiving the mechanical guide can have a shape that is complementary to a portion of the arc guide.
[0093] The arc guide is positioned between the mechanical guide and the electrical conductor of the fixed contact.
[0094] The mechanical guide includes a channel opening for securing the screw.
[0095] The mechanical guide has a support surface on which the head of the fixing screw rests.
[0096] The supporting surface of the mechanical guide and the receiving housing extend in a parallel plane.
[0097] The support surface is set backward from the edge of the mechanical guide.
[0098] The recess is larger than the thickness of the screw head. Therefore, the screw head itself is positioned rearward from the edge of the mechanical guide. In other words, the screw head is opposite the insulating material in all directions perpendicular to the screw's axis. This construction prevents the formation of an electric arc between the moving contact and the screw head.
[0099] According to one embodiment of the switching device, the electrical conductor of the fixed contact includes a U-shaped bend.
[0100] Furthermore, the arc guide is fixed to the U-shaped bend.
[0101] The electrical conductor of the fixed contact comprises two parallel portions interconnected by a link.
[0102] The link section has a semi-circular shape.
[0103] The fixing screw and anti-rotation pin extend in a direction parallel to the two parallel portions of the electrical conductor of the fixing contact.
[0104] The present invention also relates to a medium-voltage electrical unit configured to allow current to flow in a medium-voltage power grid comprising three phases.
[0105] The electrical unit includes the switching devices described above, which are respectively installed on each phase. Attached Figure Description
[0106] Further features, details, and advantages will become clear by reading the following detailed description and analyzing the accompanying drawings, in which:
[0107] Figure 1This is a schematic diagram of the electrical unit according to the present invention;
[0108] Figure 2 This is an overall perspective view of an electrical unit including a switching device according to the invention, the switching device being in the open position.
[0109] Figure 3 yes Figure 2 The diagram shows the overall perspective view of the electrical unit, with the switch in the closed position.
[0110] Figure 4 These are detailed perspective views of an embodiment of the proposed switching device.
[0111] Figure 5 yes Figure 4 Another detailed perspective view of the switching device shown.
[0112] Figure 6A and Figure 6B It shows Figure 4 and Figure 5 A detailed view of the fixed contacts of the switching device shown.
[0113] Figure 7A and Figure 7B It shows Figure 4 and Figure 5 A further detailed perspective view of the components of the switching device shown.
[0114] Figure 8 yes Figure 4 and Figure 5 Another detailed perspective view of the components of the switching device shown.
[0115] Figure 9 yes Figure 4 and Figure 5 A detailed side view of the components of the switching device shown.
[0116] Figure 10 yes Figure 4 and Figure 5 A detailed front view of the switching device shown. Detailed Implementation
[0117] To make the accompanying drawings easier to read, various elements are not necessarily depicted to scale. In these drawings, the same elements have the same reference numerals. Some elements or parameters may be indexed, that is, designated, for example, as first element or second element, or actually designated as first element and second element, etc. The purpose of this indexing is to distinguish similar but not identical elements or parameters. This indexing does not imply a priority of one element or parameter relative to another, and the names are interchangeable. When a given element is included in a designated device, this does not preclude the presence of other elements in that device.
[0118] Figure 1 The medium-voltage electrical unit 100 is shown schematically.
[0119] The medium-voltage electrical unit 100 is configured to allow current to flow in a medium-voltage power grid including three phases Ph1, Ph2, and Ph3.
[0120] The electrical unit 100 includes switching devices 30, 30', 30 according to the invention, respectively arranged on each phase Ph1, Ph2, Ph3.
[0121] Each switching device 30, 30', 30" includes fixed contacts 1, 1', 1" and moving contacts 2, 2', 2".
[0122] The three switching devices 30, 30', and 30" are integrated with the common actuator 50, thereby enabling simultaneous control of the three switching devices 30, 30', and 30".
[0123] The switching devices 30, 30', and 30" of the electrical unit 100 can be the same.
[0124] The proposed switching device 30 is a switching device for the medium voltage electrical unit 100, and will be described in detail below.
[0125] The proposed switching device 30 includes:
[0126] Including the fixed contact 1 of the electrical conductor 3,
[0127] The moving contact 2 includes two electrical conductors 4A and 4B that extend parallel to each other and are spaced a certain distance apart.
[0128] The moving contact 2 is configured to pivot relative to the pivot axis R2 between a first position P1 and a second position P2, in which the moving contact 2 is separated from the fixed contact 1 to prevent current from flowing between contacts 1 and 2, and in the second position P2, the moving contact 2 is in contact with the fixed contact 1 to allow current to flow between contacts 1 and 2.
[0129] The fixed contact 1 includes an arc guide 5 extending from the electrical conductor 3 of the fixed contact 1 and pointing toward the moving contact 2. The arc guide 5 is configured to cause an arc generated when a current is established between the fixed contact 1 and the moving contact 2 to follow the arc guide 5, and the arc guide 5 includes two grooves 6 separated by ribs 7.
[0130] An electric arc is generated by bringing two electrical contacts 1 and 2, which are at different potentials, close together. The generated arc passes through the arc guide 5, rather than directly from one contact to the other. Therefore, the arc guide 5 limits the heating of the stationary contact 1 and the moving contact 2, and reduces the risk of damage to these contacts. The reliability of the switching device 30 is improved.
[0131] The movement of the moving contact 2 from the first position P1 (referred to as the open position) to the second position P2 (referred to as the closed position) corresponds to the current establishment phase in the switching device 30.
[0132] Conversely, the movement of the moving contact 2 from the second position P2 (referred to as the closed position) to the first position P1 (referred to as the open position) corresponds to the current switching phase in the switching device 30.
[0133] Figure 3 The switch device 30 is shown in the second position P2 (referred to as the closed position). Figure 2 , Figure 4 and Figure 5 as well as Figure 10 A switching device 30 is shown in an intermediate position Pi between the open position P1 and the second position P2. Figure 2 In this context, the movement from the first position P1, known as the open position, to the second position P2, known as the closed position, corresponds to the rotation of the moving contact 2 relative to the pivot axis R2 in a clockwise direction.
[0134] The two electrical conductors 4A and 4B of the moving contact 2 are connected by rotation around a common axis of rotation R2.
[0135] The two electrical conductors 4A and 4B of the moving contact 2 are made of copper.
[0136] The two electrical conductors 4A and 4B of the moving contact 2 are commonly referred to as "conductor knives".
[0137] Each conductor 4A, 4B of the moving contact 2 has an overall shape of a straight rod. The straight rod has a flat shape.
[0138] Each electrical conductor 4A, 4B extends in the longitudinal direction, which is called the main extension direction and corresponds to the length of the electrical conductor.
[0139] Each conductor 4A, 4B extends in a transverse direction perpendicular to the longitudinal direction, corresponding to the width of the conductor.
[0140] exist Figures 2 to 4 In the middle, direction L2 is parallel to the longitudinal direction of conductors 4A and 4B, and direction T2 is parallel to the transverse direction of conductors 4A and 4B.
[0141] The direction E2, which is perpendicular to both the longitudinal direction L2 and the transverse direction T2, corresponds to the thickness of electrical conductors 4A and 4B.
[0142] The thickness of each conductor is less than 30% of its width. The width of each conductor 4A, 4B is less than 30% of its length.
[0143] Each electrical conductor 4A, 4B includes two parallel planes. These two planes are parallel to the plane formed by the longitudinal direction L2 and the transverse direction T2. Therefore, the two planes are perpendicular to the pivot axis R2.
[0144] Each conductor 4A, 4B includes a first face 4A-i, 4B-i (referred to as the inner face) facing the other conductor 4B, 4A. In other words, the inner face of one conductor 4A, 4B faces the inner face of the other conductor 4B, 4A.
[0145] Each electrical conductor 4A and 4B includes a second surface 4A-e and 4B-e (referred to as the outer surface), which are surfaces opposite to the inner surface.
[0146] When the current is established, corresponding to the movement from the first position P1 to the second position P2, the conductor 3 of the fixed contact 1 is inserted between the two conductors 4A and 4B of the moving contact 2.
[0147] When electrical contact is established, the electrical conductor 3 of the fixed contact 1 makes mechanical contact with the electrical conductor 4A and the electrical conductor 4B of the moving contact 2.
[0148] The electrical conductor 3 of the fixed contact 1 is made of copper.
[0149] The fixed contact 1 includes a heat sink 29 fixed to the electrical conductor 3. The heat sink 29, which is made of copper itself, increases the thermal inertia of the fixed contact 1, thus reducing its heating.
[0150] The arc guide 5 is configured to guide the electric arc.
[0151] In other words, the electric arc generated when the current is established passes through the arc guide 5. Similarly, the electric arc generated when the current is switched passes through the arc guide 5.
[0152] Figure 3 The passage of the electric arc is illustrated schematically. Each arrow indicated by the symbol A represents a portion of the arc.
[0153] The arc conductor 5 is made of ultra-hard steel, such as steel with a carbon content between 1% and 2%, which is a mass content.
[0154] Alternatively, any other metal with good high-temperature resistance (significantly greater than that of copper) can be used.
[0155] Based on the example shown, especially Figure 4 In the middle, the grooves 6 extend parallel to each other in a direction parallel to the pivot axis R2 of the moving contact 2.
[0156] Each groove 6 forms a non-open recess. Two consecutive grooves 6 are separated by a portion of the material forming the rib 7.
[0157] The moving contact 2 extends in the main direction L2, which is perpendicular to the pivot axis R2.
[0158] Figure 9 The arc guide 5, taken separately, is shown in detail in a contour diagram.
[0159] The depth p6 of the groove 6 can be greater than the width l7 of the rib 7.
[0160] The depth p6 of the groove can vary from one groove to another.
[0161] According to the example shown, the base of groove 6 has a semi-circular profile.
[0162] The groove 6 is obtained, for example, by machining. Then, the shape of the base of the groove is complementary to the shape of the milling cutter used to form the groove.
[0163] Alternatively, the groove 6 can be obtained by molding. In this case, the shape of the groove 6 corresponds to a shape complementary to the shape of the counterpart formed in the mold.
[0164] Based on the example shown, and as Figure 4 , Figure 5 and Figure 10 As shown, the moving contact 2 includes a first reinforcing element 9A.
[0165] The first reinforcing element 9A includes a first portion 11A supported on a first electrical conductor 4A of the moving contact 2 and a second portion 12A extending perpendicularly to the first portion 11A along the direction of a second electrical conductor 4B of the moving contact 2.
[0166] The lateral edge 13A of the second part 12A of the first reinforcing element 9A extends parallel to the rotation axis R2 of the moving contact 2.
[0167] like Figure 4 As schematically shown, the electric arc generated by establishing a current between the fixed contact 1 and the moving contact 2 is transmitted from the lateral edge 13A of the first reinforcing element 9A to the rib of the arc guide 5.
[0168] The lateral edge 13A of the second part 12A of the first reinforcing element 9A is a certain distance away from the end of the electrical conductor 4A opposite to the axis of rotation R2.
[0169] The lateral edge 13A of the second part 12A of the first reinforcing element 9A is disposed rearward from the end of the moving contact 2 opposite to the axis of rotation R2, so as to allow the moving contact 2 to pass through without contacting the arc guide 5 during rotation of the moving contact 2.
[0170] The first reinforcing element 9A includes, for example, a plate.
[0171] The first reinforcing element 9A is made of metal.
[0172] The first reinforcing plate 9A is formed by folded metal strips.
[0173] The first reinforcing plate 9A is, for example, made of steel.
[0174] The first reinforcing plate 9A has a U-shaped profile. The first portion 11A of the first reinforcing element 9A forms the base of the U-shaped profile.
[0175] The base of the U-shaped profile is supported on the outer side surface 4A-e of the first electrical conductor 4A of the contact moving device 2.
[0176] The second part 12A forms the first wing of the U-shaped profile. The third part 12A' forms the second wing of the U-shaped profile. The second part 12A and the third part 12A' extend in a parallel plane.
[0177] As the moving contact 2 moves from the first position P1 to the second position P2, the lateral edge 13A of the second portion 12A of the first reinforcing element 9A is successively opposite the first groove 6, the rib 7, and then the second groove 6. During this rotational movement from the first position P1 to the second position P2, each point of the lateral edge 13A of the second portion 12A of the first reinforcing element 9A traces an arc-shaped trajectory, the center of which is located on the pivot axis R2.
[0178] The minimum distance between rib 7 and the lateral edge 13A of the second part 12A of the first reinforcing element 9A is less than 3.0 mm.
[0179] This minimum distance is obtained for a given angular position of the moving contact 2. This minimum distance enables an arc to be induced in a controlled manner between the moving contact 2 and the arc guide 5. At least a portion of the arc passes through the lateral edge 13A of the second portion 12A of the first reinforcing element 9A.
[0180] Similarly, the moving contact 2 includes a second reinforcing element 9B. The second reinforcing element 9B includes a first portion 11B supported on the second electrical conductor 4B of the moving contact 2 and a second portion 12B extending perpendicularly to the first portion 11B along the direction of the first electrical conductor 4A of the moving contact 2. The lateral edge 13B of the second portion 12B of the second reinforcing element 9B extends parallel to the rotation axis R2 of the moving contact 2.
[0181] Based on the example shown, especially Figure 4 In the middle, the lateral edge 13A of the second portion 12A of the first reinforcing element 9A and the lateral edge 13B of the second portion 12B of the second reinforcing element 9B extend aligned with each other.
[0182] The second reinforcing element 9B includes, for example, a plate.
[0183] The first reinforcing plate 9A and the second reinforcing plate 9B are symmetrical about each other with respect to a plane perpendicular to the pivot axis R2. The first reinforcing plate 9A and the second reinforcing plate 9B are mirror images of each other.
[0184] Therefore, the second reinforcing plate 9B has a U-shaped profile. The base of the U-shape is supported on the outer lateral surface 4B-e of the second electrical conductor 4B of the moving contact 2.
[0185] The second part 12B forms the first wing of the U-shaped profile, and the third part 12A' forms the second wing of the U-shaped profile.
[0186] When the moving contact 2 moves from the first position P1 to the second position P2, the lateral edge 13B of the second part 12B of the second reinforcing element 9B is in sequence opposite to the first groove 6, the rib 7, and then the second groove 6.
[0187] The minimum distance between rib 7 and the lateral edge 13B of the second portion 12B of the second reinforcing element 9B is less than 3.0 mm. Similar to the first reinforcing element 9A, this minimum distance allows for controlled arcing between the moving contact 2 and the arc guide 5. At least a portion of the arc passes through the lateral edge 13B of the second portion 12B of the second reinforcing element 9B.
[0188] The conductor 3 of the fixed contact 1 includes two contact portions 8A and 8B. When the moving contact 2 is in the second position P2, which is called the closed position, the two contact portions 8A and 8B are in mechanical contact with the moving contact 2, and the arc guide 5 is a certain distance away from the two contact portions 8A and 8B.
[0189] In other words, when the moving contact 2 is in the second position P2, the two contact portions 8A and 8B that are in mechanical contact with the moving contact 2 are separated from the arc guide 5. These two contact portions 8A and 8B are the parts through which current flows, where the current flows in a steady state.
[0190] Therefore, the heating generated by the passing of the electric arc occurs in a portion of the fixed contact 1, which is different from the portions 8A and 8B through which the current passes in a steady state. This reduces damage to the regions 8A and 8B of the fixed contact 1 that participate in current conduction in a steady state, thereby improving the reliability of the switching device 30.
[0191] exist Figure 2 The two contact portions 8A and 8B of the conductor 3 can be seen, with the moving contact 2 in a position different from the closed position P2. The two contact portions 8A and 8B are... Figure 3 They are not visible because they are obscured by the moving contact 2.
[0192] According to one embodiment of the switching device 30, the rib 7 extends laterally along the width l7, the groove 6 extends laterally along the width l6, and the width l7 of the rib 7 is between 50% and 100% of the width l6 of the groove 6.
[0193] The lateral extension direction of rib 7 and groove 6 is perpendicular to the pivot axis R2 and the main extension direction L2 of the moving contact 2. The longitudinal extension direction of rib 7 and groove 6 is parallel to the pivot axis R2.
[0194] Based on the example shown, and as Figure 9 As shown, the arc guide 5 includes a second rib (represented as 7-2) located between the first lateral edge 10-1 of the arc guide 5 and the first groove (represented as 6-1).
[0195] The arc guide 5 also includes a third rib (represented as 7-3) between the second lateral edge 10-2 and the second groove (represented as 6-2) of the arc guide 5.
[0196] This configuration allows the arc to pass through the second rib 7-2 during the movement that allows the current to be established, then jump over the groove 6-1 that separates the second rib 7-2 from the first rib 7, and then jump again to the third rib 7-3 by jumping over the second groove 6-2.
[0197] At a given time, an electric arc forms between a given rib and the moving contact 2. The arc will not pass through two different ribs simultaneously. The alternation of ribs and slots allows for better control of the arc's position. Therefore, the dissipation of heat generated by the arc in the arc guide 5 is better controlled, thereby reducing damage to the arc guide 5.
[0198] Based on the example shown, and as Figure 8 As shown, the face 14-1 of the first rib, the face 14-2 of the second rib, and the face 14-3 of the third rib extend in the same plane P7.
[0199] The common extension plane P7 of the three ribs is parallel to the rotation axis R2 of the moving contact 2 and perpendicular to the main extension axis L2 of the moving contact 2.
[0200] The three ribs 7 can have the same width l7.
[0201] The width l7 of a rib can vary from one rib to another.
[0202] Arc guide 5 includes:
[0203] In the first connecting region 21-1 between rib 7 and first groove 6,
[0204] In the second connecting region 21-2 between rib 7 and the second groove 6
[0205] Furthermore, the minimum radius of curvature of the contours connecting regions 21-1 and 21-2 is less than 0.2 mm.
[0206] In other words, the connecting regions 21-1 and 21-2 between the rib 7 and the groove 6 defining the rib 7 are angular and not circular. These connecting regions 21-1 and 21-2 form sharp edges. Therefore, the rib 7 is clearly defined. Consequently, the electric arc is preferably guided toward the rib 7, rather than toward the groove 6 that borders the rib 7. This allows for better control over the position of the electric arc.
[0207] Arc guide 5 includes:
[0208] The third connecting region 21-3 between the second rib 7 and the first lateral edge 10-1 of the arc guide 5
[0209] Furthermore, the minimum radius of curvature of the contour of the third connecting region 21-3 is greater than 0.5 mm.
[0210] Similarly, the arc guide 5 includes:
[0211] The fourth connecting region 21-4 between the third rib 7 and the second lateral edge 10-2 of the arc guide 5
[0212] Furthermore, the minimum radius of curvature of the profile of the fourth connecting region 21-4 is greater than 0.5 mm.
[0213] Therefore, the area defining the outer edge of the arc guide 5 is rounded to avoid any risk of injury when the arc guide is installed on the electrical conductor 3 of the fixed contact 1.
[0214] In the example shown, the conductor 3 of the fixed contact 1 includes a U-shaped portion 3-2, and the arc guide 5 is fixed to the U-shaped portion 3-2.
[0215] The electrical conductor 3 of the fixed contact 1 includes two parallel portions 3-1 and 3-3 interconnected by a connecting portion 3-2. The connecting portion 3-2 has a semi-circular shape.
[0216] The arc guide 5 is secured to the electrical conductor 3 of the fixed contact 1 by a screw 22 passing through the arc guide 5. The arc guide 5 includes a channel opening 23 for securing the screw 22.
[0217] According to the illustrated embodiment, the arc guide 5 includes a groove 25 for the passage of the anti-rotation pin 24. Figure 6A and Figure 6B More specifically, the fixing screw 22 and the anti-rotation pin 24 extend parallel to each other.
[0218] One end of the anti-rotation pin 24 is disposed in a complementary-shaped opening in the conductor 3 of the fixed contact 1. The opposite end of the anti-rotation pin 24 protrudes from the conductor 3.
[0219] The fixing screw 22 and the anti-rotation pin 24 extend in a direction parallel to the two parallel portions 3-1 and 3-3 of the electrical conductor 3 of the fixing contact 1.
[0220] Especially Figure 4 , Figure 5 and Figure 10 As shown, the moving contact 2 includes a guide rod 18, which is configured to allow the first conductor 4A and the second conductor 4B to move relative to each other.
[0221] Depending on the stage of operation, the movement can bring the first conductor 4A and the second conductor 4B closer together, or it can separate the first conductor 4A and the second conductor 4B from each other.
[0222] The moving contact 2 includes an elastic element 19 configured to apply a retracting force that tends to bring the first conductor 4A and the second conductor 4B closer together.
[0223] The elastic element 19 here is a helical spring.
[0224] The first end of the spring 19 is supported on the washer 31 fixed to the guide rod 18. The second end of the spring 19 is supported on the first portion 11A of the first reinforcing element 9A.
[0225] The shoulder of the guide rod 18 is supported on the first part 11B of the second reinforcing element 9B.
[0226] The moving contact 2 includes a spacer 20 configured to maintain a minimum distance between the first electrical conductor 4A and the second electrical conductor 4B.
[0227] The spacer 20 is disposed between the first conductor 4A and the second conductor 4B.
[0228] The spacer is coaxial with guide rod 18.
[0229] The spacer 20 is in the form of a tube, and the guide rods 18 pass through the middle of the tube respectively.
[0230] The axial surfaces of the spacer 20 form adjacent surfaces. When the fixed contact 1 and the moving contact 2 are separated, the electrical conductors 4A and 4B of the moving contact 2 are supported on the adjacent surfaces.
[0231] When the fixed contact 1 is not in contact with the conductors 4A and 4B, the spring 19 presses the conductor 4A against the first axial surface of the spacer 20 and presses the conductor 4B against the second axial surface of the spacer 20.
[0232] In addition to the arc guide 5, the switching device 30 may also include a mechanical guide 15, which facilitates the movement of the conductor blades 4A and 4B relative to each other during the current establishment phase.
[0233] Therefore, according to the example shown, where the conductors 4A and 4B of the moving contact 2 are configured to move relative to each other in a direction parallel to the rotation axis R2, the switching device 30 includes a mechanical guide 15 rigidly connected to the conductor 3 of the fixed contact 1. The mechanical guide 15 is configured to contact the two conductors 4A and 4B of the moving contact 2 during a portion of the movement of the moving contact 2L from a first position P1 to a second position P2. The mechanical guide 15 has a tapered profile, the width of which decreases as the distance from the conductor 3 of the fixed contact 1 increases, such that as the moving contact 2 moves from the first position P1 to the second position P2, the two conductors 4A and 4B of the moving contact 2 gradually separate from each other.
[0234] Mechanical guide 15 separates the two conductors 4A and 4B of the moving contact 2 before they reach the fixed contact 1. Therefore, the distance separating the two conductors 4A and 4B gradually increases before and during the stage of establishing mechanical contact between the conductors 4A and 4B of the moving contact 2 and the conductor 3 of the fixed contact 1. This facilitates the insertion of the fixed contact 1 between the conductors 4A and 4B of the moving contact 2. Consequently, mechanical shock and friction associated with the insertion of the fixed contact 1 are reduced. This reduces mechanical wear on both the fixed contact 1 and the moving contact 2, improving the reliability and lifespan of the switching device 30.
[0235] In addition, the insulating properties of the mechanical guide 15 are beneficial for positioning the electric arc on the rib 6 of the arc guide 5.
[0236] The mechanical guide 15 has a tapered profile, the thickest part of which is located on one side of the electrical conductor 3 of the fixed contact 1, and the thinnest part is located on the opposite side, that is, the side closest to the moving contact 2 when the moving contact 2 is in the open position P1.
[0237] The mechanical guide 15 includes a first support surface 16A configured to receive a first electrical conductor 4A of the moving contact 2 and a second support surface 16B configured to receive a second electrical conductor 4B of the moving contact 2. The distance d between the two support surfaces 16A and 16B gradually decreases as the distance D from the electrical conductor 3 of the fixed contact 1 increases.
[0238] The mechanical guide 15 has an overall shape of a parallelepiped, with its two opposing faces 16A and 16B being non-parallel. The mechanical guide 15 is located between the electrical conductor 3 of the fixed contact 1 and the virtual intersection line between the first support surface 16A and the second support surface 16B.
[0239] The mechanical guide 15 is made of electrically insulating material.
[0240] The mechanical guide 15 is formed of a material with a low coefficient of friction.
[0241] The support surfaces 16A and 16B of the mechanical guide 15 include a recess 26, more specifically in Figure 7A and Figure 7B As can be seen in the text.
[0242] According to the example shown, the mechanical guide 15 includes a housing 17 for receiving a portion of the arc guide 5. The housing 17 for receiving the mechanical guide 15 includes a base defined by three sides.
[0243] Figure 7A Mechanical guide 15 is shown, and Figure 7B The arc guide 5 is shown; the two components are separate.
[0244] Here, the housing 17 for receiving the mechanical guide 15 has a shape that is complementary to a portion of the arc guide 5.
[0245] According to one embodiment (not shown), the mechanical guide 15 can be molded onto the arc guide 5.
[0246] In this configuration, the mechanical guide 15 and the arc guide 5 form a non-removable sub-assembly.
[0247] Part B shows an exploded view of the main components of the fixed contact 1. Part B also shows a cross-sectional view of the same assembled components.
[0248] The arc guide 5 is disposed between the mechanical guide 15 and the electrical conductor 3 of the fixed contact 1.
[0249] The fixing screw 22 passes through the mechanical guide 15 and the arc guide 5 in sequence.
[0250] The mechanical guide 15 includes a channel opening 27 for securing the screw 22.
[0251] The mechanical guide 15 includes a support surface 28 on which the head of the fixing screw 22 rests.
[0252] The channel opening 27 formed in the mechanical guide 15 is aligned with the channel opening 23 formed in the arc guide 5.
[0253] The supporting surface 28 of the mechanical guide 15 and the receiving housing 17 extend in a parallel plane.
[0254] The support surface 28 is positioned rearward from the edge of the mechanical guide 15.
[0255] The recess is greater than the thickness of the head of screw 22. Therefore, the head of screw 22 itself is positioned rearward from the edge of the mechanical guide 15. In other words, the head of screw 22 is opposite to the electrically insulating material in all directions perpendicular to the axis of screw 22. This configuration prevents the formation of an electric arc between the moving contact 2 and the head of screw 22.
[0256] The presence of the mechanical guide 15 on the switching device 30 is optional. According to the example shown here, the switching device 30 includes an arc guide 5 and a mechanical guide 15.
[0257] According to one embodiment (not shown), the switching device 30 includes a mechanical guide 15 but is not equipped with an arc guide.
[0258] In this context, a switching device 30 for a medium-voltage electrical unit 100 is proposed, the switching device 30 having:
[0259] Including the fixed contact 1 of the electrical conductor 3,
[0260] The moving contact 2 includes two electrical conductors 4A and 4B that extend parallel to each other and are spaced a certain distance apart.
[0261] The moving contact 2 is configured to pivot about the pivot axis R2 between a first position P1 and a second position P2:
[0262] In the first position P1, the moving contact 2 is separated from the fixed contact 1 to prevent current flow between contacts 1 and 2.
[0263] In the second position P2, the moving contact 2 is in contact with the fixed contact 1 to allow current to flow between contacts 1 and 2.
[0264] In this configuration, the electrical conductors 4A and 4B of the moving contact 2 are arranged to move relative to each other in a direction parallel to the rotation axis R2.
[0265] Furthermore, the switching device 30 includes a mechanical guide 15 rigidly connected to the electrical conductor 3 of the fixed contact 1. The mechanical guide 15 is configured to contact the two electrical conductors 4A and 4B of the moving contact 2 during a portion of the movement of the moving contact 2 from the first position P1 to the second position P2. The mechanical guide 15 includes a tapered profile whose width decreases as the distance from the electrical conductor 3 of the fixed contact 1 increases, so as to gradually separate the two electrical conductors 4A and 4B of the moving contact 2 from the first position P1 to the second position P2.
Claims
1. A switching device (30) for a medium-voltage electrical unit (100), the switching device (30) comprising: Fixed contact (1), the fixed contact includes an electrical conductor (3); The moving contact (2) includes two electrical conductors (4A, 4B) that extend parallel to each other and are spaced a certain distance apart. The moving contact (2) is configured to pivot about a pivot axis (R2) between a first position (P1) and a second position (P2). In the first position, the moving contact (2) is separated from the fixed contact (1) to prevent current flow between the contacts (1, 2), and In the second position, the moving contact (2) is in contact with the fixed contact (1) to allow current to flow between the contacts (1, 2). in, The fixed contact (1) includes an arc guide (5) extending from an electrical conductor (3) of the fixed contact (1) and pointing toward the moving contact (2), the arc guide (5) being configured such that an arc generated when a current is established between the fixed contact (1) and the moving contact (2) follows the arc guide. The arc guide (5) includes two grooves (6) separated by ribs (7).
2. The switching device (30) according to claim 1, wherein, The grooves (6) extend parallel to each other in a direction parallel to the pivot axis (R2) of the moving contact (2). Furthermore, the moving contact (2) extends in the main direction (L2) perpendicular to the pivot axis (R2).
3. The switching device (30) according to claim 1 or 2, wherein, The moving contact (2) includes a first reinforcing element (9A). The first reinforcing element (9A) includes a first portion (11A) supported on a first electrical conductor (4A) of the moving contact (2) and a second portion (12A) extending perpendicularly to the first portion (11A) in the direction of a second electrical conductor (4B) of the moving contact (2). The lateral edge (13A) of the second portion (12A) of the first reinforcing element (9A) extends parallel to the rotation axis (R2) of the moving contact (2).
4. The switching device (30) according to the preceding claim, wherein, The moving contact (2) includes a second reinforcing element (9B). The second reinforcing element (9B) includes a first portion (11B) supported on a second electrical conductor (4B) of the moving contact (2) and a second portion (12B) extending perpendicularly to the first portion (11B) in the direction of the first electrical conductor (4A) of the moving contact (2). The lateral edge (13B) of the second portion (12B) of the second reinforcing element (9B) extends parallel to the rotation axis (R2) of the moving contact (2).
5. The switching device (30) according to any one of the preceding claims, wherein, The electrical conductor (3) of the fixed contact (1) includes two contact portions (8A, 8B), which are in mechanical contact with the moving contact (2) when the moving contact (2) is in the second position (P2) which is called the closed position, and wherein the arc guide (5) is a certain distance away from the two contact portions (8A, 8B).
6. The switching device (30) according to any one of the preceding claims, wherein, The rib (7) extends laterally according to the width (l7), wherein the groove (6) extends laterally through the width (l6), and wherein the width (l) of the rib (7) is between 50% and 100% of the width (l6) of the groove (6).
7. The switching device (30) according to any one of the preceding claims, wherein, The arc guide (5) includes: The second rib (7) between the first lateral edge (10-1) and the first groove (6) of the arc guide (5), and The third rib (7) is located between the second lateral edge (10-2) and the second groove (6) of the arc guide (5).
8. The switching device (30) according to any one of the preceding claims. in, The electrical conductors (4A, 4B) of the moving contact (2) are configured to move relative to each other in a direction parallel to the axis of rotation (R2). Furthermore, the switching device (30) includes a mechanical guide (15) rigidly connected to the electrical conductor (3) of the fixed contact (1), the mechanical guide (15) being configured to contact the two electrical conductors (4A, 4B) of the moving contact (2) during a portion of the movement of the moving contact (2) from the first position (P1) to the second position (P2), the mechanical guide (15) including a tapered profile whose width decreases as the distance from the electrical conductor (3) of the fixed contact (1) increases, so that the two electrical conductors (4A, 4B) of the moving contact (2) gradually separate from each other as the moving contact (2) moves from the first position (P1) to the second position (P2).
9. The switching device (30) according to the preceding claim, wherein, The mechanical guide (15) has a first support surface (16A) and a second support surface (6B), the first support surface being configured to receive a first electrical conductor (4A) of the moving contact (2), and the second support surface being configured to receive a second electrical conductor (4B) of the moving contact (2). Furthermore, the distance between the two support surfaces (16A, 16B) gradually decreases as the distance from the electrical conductor (3) of the fixed contact (1) increases.
10. The switching device (30) according to claim 8 or 9, wherein, The mechanical guide (15) includes a housing (17) for receiving a portion of the arc guide (5). Furthermore, the arc guide (5) is arranged between the mechanical guide (15) and the electrical conductor (3) of the fixed contact (1).
11. The switching device (30) according to any one of the preceding claims, wherein, The electrical conductor (3) of the fixed contact (1) includes a U-shaped bend (3-2). Furthermore, the arc guide (5) is attached to the U-shaped bend (3-2).
12. A medium-voltage electrical unit (100) configured to allow current to flow in a medium-voltage power grid comprising three phases (Ph1, Ph2, Ph3), The electrical unit (100) includes switching devices (30, 30', 30”) arranged on each phase (Ph1, Ph2, Ph3) according to any one of the preceding claims.