The present invention relates generally to connectors for high voltage and low-noise applications.
Partial discharge (e.g., electrical discharge) is of particular concern in applications where ultra-low electrical noise is sought or high reliability is required. In high-end equipment, very low amounts of partial discharge may result in erratic signals. That is, with highly sensitive equipment, even small discharges that occur within an interconnect system may be enough to interfere with the signal that is being transmitted.
This partial discharge may occur where there is a voltage gradient across entrapped air. Minimizing the partial discharge along boundaries between insulating materials is a challenge because a sealing region of traditional interconnects is prone to such conditions. Further, reducing partial discharge may also prolong longevity of systems, which is highly sought after in aerospace and deep space industries where the final product may not be easily serviced.
Various techniques are disclosed to provide low-noise connector solutions for high-end industrial, medical, military, and other high-reliability connector applications. For example, a low partial discharge high voltage connector reduces or removes partial discharge-causing elements for the connector design.
In one embodiment, a method includes mating a plug member with a receptacle member to provide a connector, wherein a seal member is disposed in a cavity provided by the plug member and/or the receptacle member; compressing, in response to the mating, the seal member at an initial contact region between an innermost layer and an outermost layer of the seal member; and, in response to the compressing, forcing air radially inward toward the innermost layer of the seal member and radially outward toward the outermost layer of the seal member away from the initial contact region to reduce partial discharge associated with the connector.
In another embodiment, a system includes a receptacle member; a plug member configured to mate with the receptacle member to provide a connector; and a seal member disposed in a cavity provided by the plug member and/or the receptacle member, wherein the seal member is configured to, in response to a mating of the plug member with the receptacle member, compress at an initial contact region between an innermost layer and an outermost layer of the seal member; and wherein the system is configured to, in response to a compressing of the seal member, force air radially inward toward the innermost layer of the seal member and radially outward toward the outermost layer of the seal member away from the initial contact region to reduce partial discharge associated with the connector.
The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.
Embodiments of the present invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.
The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced using one or more embodiments. In one or more instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. One or more embodiments of the subject disclosure are illustrated by and/or described in connection with one or more figures and are set forth in the claims.
In one or more embodiments, a low partial discharge high voltage connector (e.g., also referred to as a connector assembly) is provided that includes a hybrid electrical seal design configured to displace air from partial discharge sensitive regions of the connector to other regions of the connector where electrical flux is reduced (e.g., very low or at zero value). The seal and/or mating surface is convex shaped so that an initial contact of the seal and mating surfaces occurs at an initial contact region (e.g., an area of contact between the seal and mating surfaces) situated between the seal member's innermost layer and outermost layer. As compressible material of the seal member is compressed axially, the deformation of the compressible material progresses radially inward toward the innermost layer of the seal member and radially outward toward the outermost layer of the seal member away from the initial contact region. This geometry forces the inherent air to be pushed away from the central insulation region towards the innermost and outermost semi-conductive layers.
The pushed air collects in regions within or beyond the semi-conductive sections of the seal member where the gradient of the electrical field is reduced, preventing partial discharge from occurring in the sealed and connectorized sections. Since the sealing starts between the seal's innermost layer and outermost layer as opposed to the innermost layer or the outermost layer, each sealing distance is roughly half that of a traditional sealing mechanism. This reduction in sealing distance dramatically reduces the amount of mating force required to evacuate air from high stress regions.
That is, to prevent partial discharges from occurring in regions susceptible to localized dielectric breakdown, the connector must be mated with enough force to remove air from regions with high field gradient. General high-voltage connector designs in the current market that require low partial or micro discharges tend to require relatively large sealing diameters to compensate for the high electrical flux in a sealing region between a receptacle member and a plug member. Because the sealing region increases quadratically with the connector diameter, large connector designs face the challenging problem of maintaining reasonable sealing forces without sacrificing the ability to displace air from partial discharge sensitive regions of the connector.
To significantly reduce the force required to completely displace air in the sealing region, a convex geometry is utilized. This convex geometry is applicable to connectors regardless of the seal member's material or its manufacturing method. While not exclusive to the following manufacturing methods, the seal member may be integrated as part of the connector body with an overmold design or as a standalone component to be captured mechanically and/or bonded either to become a receptacle or plug end of a connector. The annular ring where the seal member and the mating surface initially make contact is between or in the middle of the seal member's innermost layer and outermost layer. As the plug and receptacle of the connector assembly begins to engage, the seal compresses starting between the seal member's innermost layer and outermost layer, progressing radially inward toward the innermost layer of the seal member and radially outward toward the outermost layer of the seal member away from the initial contact region. This middle-out sealing design reduces the longitudinal distance required to fully mate the sealing region by a significant margin when compared to that of conical seals on similar high voltage, low discharge connector designs without sacrificing the effectiveness of the air removal mechanism. This, in turn, dramatically reduces the force required to get an equivalent compression along the sealing surface. Consequently, the effort to remove air from the sealed regions and the effectiveness of the seal's ability to squeeze air away from high electrical field sections are optimized.
While the aforementioned middle-out sealing design is independently applicable to all high voltage connector designs, its effectiveness is amplified when used in conjunction with a hybrid semi-conductor seal member. The hybrid seal design is a multi-part seal comprising of alternating semi-conductive and insulative layers. While the insulative region acts as the portion to prevent electrical breakdown, the semi-conductive layers act as a protective barrier that prevents partial discharges that occur from gaseous pockets, cracks, voids, or inclusions by removing any and all electrical flux as in accordance with Gauss's flux theorem—charge is reduced in the void that is surrounded by conductor. Furthermore, the elimination of plasma formation or ionized air reduces the seeding of the avalanching behavior of dielectric breakdown, especially when seeding location occurs at a triple junction.
The electrical circuit between the receptacle member and the plug member of the low partial discharge high voltage connector is completed by compressing the semi-conductive layer of the seal member to the mating surfaces of the plug member and the receptacle member. Once the air is displaced from the seal member's insulated surfaces and within or behind the semi-conductive layer and electrically conductive shell of the plug member and the receptacle member, the cavity provided by the plug member and/or the receptacle member, in which the seal member is disposed, will no longer produce partial discharge.
Turning now to the drawings,
Innermost layer 108 is constructed of a semi-conductive material. In some embodiments, innermost layer 108 is overmolded by middle layer 110 constructed of an insulative material and middle layer 110 is then overmolded by outermost layer 112 constructed of a semi-conductive material, all in concentric annular rings. In some embodiments, innermost layer 108, middle layer 110, and outermost layer 112 are coextruded simultaneously. Innermost layer 108, constructed of a semi-conductive material, acts as the first shielding layer to attenuate an electrical field on displaced air pockets that may be discharging had the material been made of non-conductive properties that do not maintain the same electrical potential as a conductive member of receptacle member 102 and a conductive member of plug member 104. Middle layer 110, constructed of an insulative material, prevents breakdown between innermost layer 108 and outermost layer 112. Outermost layer 112, constructed of a semi-conductive material, functions similarly to innermost layer 108 except that outmost layer maintains an electrical potential of an exterior conductive shell of receptacle member 102 and an exterior conductive shell of plug member 104. Therefore, the hybrid construction of semi-conductive (innermost layer 108), insulative (middle layer 110), semi-conductive (outermost layer 112) layers collectively provide a pliant interface to facilitate air being pushed middle-out. This configuration allows for a uniform radial e-field distribution along the entire length of low partial discharge high voltage connector assembly 100 unlike that of traditional connector designs using a fully insulative seal. By having innermost layer 108 and outermost layer 112 constructed of semi-conductive materials, overvoltages and ionization of surrounding gases may no longer occur due to Gauss's flux theorem.
Receptacle member 102, which is also illustrated separately in the cross-sectional view of
Plug member 104, which is illustrated separately in the cross-sectional view of
Plug member 104 further comprises a cable assembly 138 comprising conductor 140, inner semi-conductive layer 142, insulative layer 144, outer semi-conductive layer 146, and braided mesh shield 148. Cable assembly 138 extending to the right in the drawing may be coupled to a piece of electronic equipment. Conductor 140 is coupled to the other end of conductive socket pin 134 in a permanent manner, such as through crimping, soldering, or the like, thereby maintaining a continuous electrical field. Inner semi-conductive layer 142 is molded around conductor 140 and attenuates the electrical field of conductor 140. Insulative layer 144 is molded around inner semi-conductive layer 142 and prevents breakdown between inner semi-conductive layer 142 and outer semi-conductive layer 146. Outer semi-conductive layer 146 is molded around insulative layer 144 and maintains an electrical potential of cable assembly 138. The transitional gap between cable assembly 138 and the outer portion of plug member 104 is comprised of a voidless insulation material 150 with braided mesh shield 148 embedded in voidless insulation material 150. That is, gaps in braided mesh shield 148 allow the voidless insulation material 150 to embed within the gaps thereby bonding the braided mesh shield 148 and voidless insulation material 150. Braided mesh shield 148 further bonded to exterior conductive shell 128 to increase the outer diameter of exterior conductive shell 128 thereby maximizing a creep distance from conductor 140 prior to losing the shielding benefits of outer semi-conductive layer 146.
When receptacle member 102 and plug member 104 are mated, seal member 106 is inserted into receptacle member 102 and coupling nut 152 rotates around the threads 154 of exterior conductive shell 114 of receptacle member 102 so as to fully mate receptacle member 102 to plug member 104 Coupling nut 152 rotates on threads 154 to be fully mated up when a catch 156 of coupling nut 152 meets stop 158 of plug member 104. In accordance with the illustrative embodiments, the middle-out sealing design may be accomplished in different ways.
In a first embodiment, the faces of middle layer 110 of seal member 106, which mate with mating face 122 of insulative layer 116 of receptacle member 102 and mating face 136 of insulative layer 130 of plug member 104, have a convex shape.
In either embodiment, when the mating faces of seal member 106 initially mate with mating face 122 of insulative layer 116 of receptacle member 102 and mating face 136 of insulative layer 130 of plug member 104, middle layer 110 compresses radially inward toward the innermost layer 108 of the seal member 106 and radially outward toward the outermost layer 112 of the seal member 106 away from the initial contact region. This middle-out sealing design reduces the longitudinal distance required to fully mate seal member 106 by a significant margin when compared to that of conical seals on similar high voltage, low discharge connector designs without sacrificing the effectiveness of the air removal mechanism. This, in turn, dramatically reduces the force required to get an equivalent compression along the sealing surface. Consequently, the effort to remove air from the sealed regions and the effectiveness of the seal's ability to squeeze air away from high electrical field sections are optimized.
Where applicable, various embodiments provided by the present disclosure can be implemented using hardware, software, or combinations of hardware and software. Also, where applicable, the various hardware components and/or software components set forth herein can be combined into composite components comprising software, hardware, and/or both without departing from the spirit of the present disclosure. Where applicable, the various hardware components and/or software components set forth herein can be separated into sub-components comprising software, hardware, or both without departing from the spirit of the present disclosure. In addition, where applicable, it is contemplated that software components can be implemented as hardware components, and vice-versa.
Software in accordance with the present disclosure, such as program code and/or data, can be stored on one or more computer readable mediums. It is also contemplated that software identified herein can be implemented using one or more general purpose or specific purpose computers and/or computer systems, networked and/or otherwise. Where applicable, the ordering of various steps described herein can be changed, combined into composite steps, and/or separated into sub-steps to provide features described herein. For example, in some embodiments, software controlled machines (e.g., 3D printers) may be used to manufacture seal member 106 and/or other components described herein.
Embodiments described above illustrate but do not limit the invention. It should also be understood that numerous modifications and variations are possible in accordance with the principles of the present invention. Accordingly, the scope of the invention is defined only by the following claims.
Number | Name | Date | Kind |
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3323097 | Tordoff | May 1967 | A |
Number | Date | Country |
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H 1-140572 | Feb 1999 | JP |
2001-503564 | Mar 2001 | JP |
2015-076163 | Apr 2015 | JP |
2017-103854 | Jun 2017 | JP |
Number | Date | Country | |
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20230108394 A1 | Apr 2023 | US |