This invention relates to electrical devices, and more specifically to movable contact assemblies that are used in high-voltage switches.
High-voltage switches are essential devices in an electrical power grid, and are designed to isolate different sections of the electrical grid. In order to create a physical separation between two poles, the switches perform various movements.
For high-voltage switches, the movement takes place by means of the rotation of a pole isolator. Various devices for performing this movement are currently available on the market. However, they pose problems of wear and poor conductivity. The present invention seeks to solve the technical problems of wear and poor conductivity, as well as other problems that are present.
The presence of movement in a switch requires the use of movable electrical contacts in the construction of the devices. The movement of the electrical contacts in the switches takes the form of rotation or displacement. The electrical contacts can operate with or without the interruption of the physical link.
A high-voltage switch is constructed with rounded tubular conductors in order to reduce overheating and energy loss, and in order to provide a switch with light construction or low weight. The individual resistances of some of the components used in switch construction, and the resistance of the contact interfaces, play a crucial role in the normal operation of the equipment.
Ideal movable electrical contact systems must have a minimum number of contact interfaces; low transition resistance; low pressure force; no contact wear; a high current rating and short-circuit capacity; corrosion-resistant construction; the ability to withstand thermal cycling; the ability to accommodate misalignments; low weight; and the ability to be easily inspected and replaced.
The first goal of the invention is to provide a high-voltage disconnect switch with a rotary contact assembly and with a minimal number of contact interfaces.
The use of contacts with a reduced aluminum section that are installed perpendicularly directly into the primary conductor allows the construction of a rotary assembly through the use of only four conductive elements.
Electrical contacts with spring bushings that have a reduced aluminum section will have a safe material section and the contact pressure necessary for the transfer of the rated electrical current. they will allow the electrical equipment to withstand higher short-circuit ranges while maintaining contact pressure afterward.
Another goal of the invention is to provide electrical switching devices with electrical contacts that include spring bushings with a reduced aluminum section, with a pre-installation feature that uses grooved contact surfaces and avoids multiple bolted assemblies, in order to achieve low interface resistance.
Another goal of the invention is to provide electrical contacts that include spring bushings with a reduced aluminum section that can be installed directly on tubular conductors with no additional electrical or mechanical parts, while reducing the number of electrical interfaces in the electrical switching device.
Another goal of the invention is to provide electrical contacts with a low operating force.
Another goal of the invention is to provide an electrical contact assembly with a fixed contact-interface area or zone.
Another goal of the invention is to provide an electrical contact assembly with two contact parts that can easily be disassembled.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to achieve all of the necessary contact pressure solely from the plastic deformation of the aluminum, and without depending on the partial pressure of the elastic deformation of the copper extensions or fingers.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section that uses the mechanical properties of the aluminum as an element to transfer the pressure to the contact assembly.
Another goal of the invention is to provide electrical contacts with a spring bushing (3) with a reduced aluminum section, with a compact design and a reduced space requirement, for incorporation into electrical switching devices.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with simple construction consisting of three components (i.e., a male cylindrical conductor, a spring bushing with a reduced aluminum section, and a female cylindrical conductor).
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, and with stable contact pressure and the ability to adapt to the mechanical wear of the contacts.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with a clearly defined contact zone or area.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to withstand high rated-current density in the electrical contact portion.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, which contacts are able to maintain low contact resistance for prolonged periods of time during stationary operation in the closed position.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, in order to have sufficient flexibility resulting from the reduction of the cross-section of the aluminum of the contacts.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to withstand thermal shocks and electrodynamic forces during their exposure to short-circuit currents.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to prevent any risk of creating a meltdown between the contact and the facing part of the contact when the contact is subjected to a short circuit.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with equal contact force in the contact assembly for each contact element and/or extension.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to eliminate any movement of the contact (i.e., contact vibration) and any degradation of the contact caused by micro-arcing erosion.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section in order to distribute the force of the mechanical deformation of the aluminum through the reduced section, including spherical reductions, multiple spherical reductions, multiple angular reductions, and angular reductions.
Another goal of the invention is to provide electrical contacts with a spring bushing with a reduced aluminum section, with the ability to adapt to misalignment, thanks to the flexibility of the contacts provided in the reduced aluminum section.
These goals are achieved by providing a high-voltage switch with a perpendicular tubular installation of electrical contacts with a reduced aluminum section of the present invention, with useful contact pressure that can be calculated accurately, the area of physical interaction between the male cylindrical conductor and the tubular conductor, the contact area, and the form of the contact surface, which are all highly adaptable for misaligned assemblies; conservation of precise contact pressure, limited contact movement, high conductivity of the component materials, high efficiency in the elimination of oxides during the sliding movement, independent contact extensions, and the use of floating pressure distribution.
Brief Description of the figures
This invention relates to rotary contacts and to their incorporation into tubular conductors for use in movable switching assemblies. The movable contact systems according to this invention are designed to provide switching with a low number of interface contacts, low resistance, and low operating force. All of the elements of the contact assembly are designed to be produced by machining, extrusion, or stamping, and to provide an assembly with solder-free construction.
As shown in
As shown in
The female cylindrical conductor (7) and the secondary conductor (6) are fixed in relation to each other, and are movable in relation to the main tubular conductor (10). The expected path of the electrical current runs from the primary tubular conductor (10) to the male cylindrical conductor (2) and to the female cylindrical conductor (7).
As shown more clearly in
As shown in
The function of the upper coupling edge (2b) is to receive the female cylindrical conductor (7), which is made from a copper extrusion and which has an upper surface (7a) consisting of a wall having a given thickness, with a central upper opening (7b) and a hollow internal space (7c) that provides a free space whose function is to receive the male cylindrical conductor (2), because its diameter (A) is smaller than the diameter (B) of the upper coupling edge (2b) of the male cylindrical conductor (2). The female cylindrical conductor (7) also includes a keyway (c7) consisting of a hole that passes through the entire thickness of the upper surface (7a) of the said female cylindrical conductor (7).
As mentioned earlier, the diameter (B) of the male cylindrical conductor (2) is larger than the diameter (A) of the female cylindrical conductor (7). After the insertion of the male cylindrical conductor (2) into the female cylindrical conductor (7), pressure is applied by means of the elastic deformation of the spring bushing (3) with a reduced aluminum section.
As shown in
The electrical contact between the primary tubular conductor (10) and the male cylindrical conductor (2) may also be made by means of a threaded surface.
The secondary conductor (6) of the second assembly is a contact plate having a given thickness. It includes a lower cylindrical free space and a central opening whose diameter is smaller than the diameter of the central opening, and also includes a keyway (c6) consisting of a hole that passes through the entire thickness of the secondary conductor (6). The function of the lower cylindrical free space of the said secondary conductor (6) is to receive the female cylindrical conductor (7).
As shown in
The diameter of the free space in the secondary conductor (6) is smaller than the outside diameter of the female cylindrical conductor (7). The electrical contact between the secondary conductor (6) and the female cylindrical conductor (7) may also be made by means of the compression of the grooved surface of the female cylindrical conductor (7) inside it. The openings in the primary conductor (10), in the secondary conductor (6), in the male cylindrical conductor (2), in the spring bushing (3) with a reduced aluminum section, in the female cylindrical conductor (7), and in the main pin (1) are all coaxial. This arrangement makes it possible to limit the path of the electrical current to the four constituent parts of the rotary assembly.
As shown in
The male cylindrical contact (2) and the primary tubular conductor (10) are held together by the main pin (1), which passes through the reduced aluminum section of the spring bushing (3) and the primary fitting (4). The female cylindrical conductor (7) is held in place by the secondary fitting (5), whose function is to serve as a rotation guide for the system, and which passes through the secondary conductor (6) and the female cylindrical conductor (7). The primary and secondary conductors are held in place by means of the main pin (1).
As shown in
Before being installed on the isolator (20), the primary tubular conductor (10) is held in place, by means of a compressed grooved contact interface (10b′), between the male cylindrical conductor (2) and the free space of the lower cylindrical opening (10b) in the primary tubular conductor (10). The contact assembly is installed on the isolator (20) by means of two mounting screws (30) that pass through the upper assembly holes (10c) of the main tubular conductor (10) and the lower assembly holes (10d).
In order for the outside diameter of the male cylindrical conductor (2) to match the inside diameter of the free space of the lower cylindrical opening (10b) in the primary tubular conductor (10), the rotary contacts may be installed directly in the primary tubular conductor (10), with the use of the groove as the interface of the main conductor for the transfer of the current.
The perpendicular installation of a tubular object inside another object that has a relatively similar diameter produces a broad surface for interaction between them, and provides a rotary assembly with a sufficient surface area for the transfer of the electric current.
The technical advantages of the present invention are that it:
1. Allows the adjustment of the entire contact area between the male cylindrical conductor (2) and the tubular conductor (10), through the selection of similar dimensions for the conductors.
2. Allows the use of unsoldered thin-walled tubular conductors.
3. Resolves an issue relating to the provision of pressure for rotating electrical contacts with extremely small dimensions.
4. Allows the adjustment of the entire operational force, through the accurate selection of the number of contact extensions and of the pressure value of each contact extension.
5. Allows the construction of rotary contact assemblies without the use of complex systems for the provision of additional pressure.
6. Allows the construction of a contact assembly through the use of materials with low relative magnetic permeability.
7. Provides a contact assembly with an electrically isolated pressure supply system. (The anodized aluminum creates a layer of aluminum oxide that possesses significant dielectric properties.)
8. The anodized aluminum surface makes it possible to provide an electrical contact assembly that has a high degree of resistance to salt air and resistance to the galvanic corrosion of the materials.
9. The construction of tubular extrusions makes it possible to produce electrical contact assemblies with minimal losses of material due to machining.
Number | Date | Country | Kind |
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MX/A/2014/004937 | Apr 2014 | MX | national |
This application is the National Stage entry in the United States of International Application No. PCT/CA2015/050338 filed Apr. 22, 2015, which claims the priority and benefit of Mexican Patent Application No. MX/a/2014/004937 filed Apr. 24, 2014, the entireties of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2015/050338 | 4/22/2015 | WO | 00 |