Patent Publication Number: US-2022238255-A1

Title: Spiral wound conductor for high current applications

Description:
PRIORITY 
     This patent application claims the benefit under 35 U.S.C. § 119(e) of U.S. Patent Application No. 63/142,312, entitled “Spiral Wound Conductor for High Current Applications,” filed on Jan. 27, 2021, the contents of which are incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to a cable, and more particularly, to a spiral wound conductor for high current applications. 
     BACKGROUND 
     The advancement of electric vehicles has created an increased need for charging equipment that delivers electric power. Some applications (e.g., certain fast-charging vehicle chargers) are designed to work with continuous currents of  100  Amps or more. Generally, the higher the current flow in a certain conductor the more heat is generated. Conductors between the charging equipment and the vehicle have traditionally been sized larger to match the higher current draws. By increasing the cross section area of the conductor, however, a weight and volume of the charging cable may become too cumbersome or heavy to handle or manipulate. 
     SUMMARY 
     The disclosed embodiments provide for a cable configured for high current applications. The cable includes a conducting member having a conductor surrounded by an insulating layer, and a cooling conduit having a tubular portion and a coolant. The coolant is configured to flow within the tubular portion to cool the conductor. The conducting member is spiral wound around the cooling conduit along a length of the cooling conduit to increase a contact area between the conducting member and the cooling conduit to thereby improve a transfer of heat from the conducting member to the cooling conduit. 
     In some embodiments, a method for manufacturing a cable configured for high current applications is disclosed. The method includes winding a conducting member around a length of a cooling conduit in a spiral arrangement; and configuring the conducting member to increase a contact area between the conducting member and the cooling conduit to thereby improve a transfer of heat from the conducting member to the cooling conduit. The conducting member includes a conductor surrounded by an insulating layer and the cooling conduit includes a tubular portion and a coolant, the coolant configured to flow within the tubular portion to cool the conductor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments herein may be better understood by referring to the following description in conjunction with the accompanying drawings in which like reference numerals indicate identical or functionally similar elements. Understanding that these drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1A  illustrates a cross section of prior art cables. 
         FIG. 1B  illustrates a cross section of a prior art cable with cooling conduit. 
         FIG. 2  illustrates a perspective view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 3  illustrates a side cross-section view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 4  illustrates a top cross-section view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 5  illustrates a cutaway section view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 6  illustrates a cutaway section and detail view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 7  illustrates a perspective cross-section view of a cable configured for high current applications, in accordance with various aspects of the subject technology; 
         FIG. 8  illustrates a perspective cross-section view of a cable configured for high current applications, in accordance with various aspects of the subject technology; and 
         FIG. 9  illustrates an example method for manufacturing a cable configured for high current applications, in accordance with various aspects of the subject technology. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. 
     Certain applications, such as those involving electric vehicles, require high current. Generally, the higher the current flow in a certain conductor the more heat is generated as a consequence of resistance. Conventional conductors have a circular perimeter, as shown in  FIG. 1A . Such conventional conductors  104  are typically individually surrounded by an insulator  102 . Because each prior art cable  101 A-C includes an insulator  102  surrounding a conductor  104 , in areas  105  where the cables  101 A-C are adjacent to one another, the insulators  102  of the cables increase a dimension of the cables  101 A-C thereby adding to their physical size and weight, potentially rendering them difficult to handle. To reduce the resistance of a conductor, a cross section of the conductor  104  may be increased. Increasing the size of the conductor, however, also increases the weight and volume of the conductor, making the conductor too cumbersome or heavy to handle or manipulate. Alternatively, heat generated as a result of the high current may be transferred from the conductor to a cooling conduit disposed proximate to the conductor. As shown in  FIG. 1B , prior art systems may utilize a cooling conduit  111  that includes a tube  112  and coolant  114  that flows within the tube  112 . A contact area  120  between the conducting member  101  and the cooling conduit  111  consists of a single point of contact, as viewed in the cross section shown in  FIG. 1B , thereby rendering any heat transfer via conduction inefficient due to the minimal contact area between the conducting member  101  and the cooling conduit  111 . Accordingly, there is a need for certain embodiments of a cable for high current applications that effectively and efficiently transfers heat generated by high current flow within the conductor. 
     The disclosed technology addresses the foregoing limitations of conventional conducting members with cooling conduits by utilizing a conductor that is spiral wound around a cooling conduit along a length of the cooling conduit to increase a contact area between the conductor and the cooling conduit, thereby improving a transfer of heat from the conductor to the cooling conduit. 
       FIG. 2  illustrates a perspective view of a cable  200  configured for high current applications, in accordance with various aspects of the subject technology. The cable  200  comprises a conducting member  201  comprising a conductor  204  surrounded by an insulating layer  202 . The conductor  204  is composed of a material having low electrical resistance and may be formed of a solid conducting material or stranded conducting material. In one aspect, the conductor  204  has a profile or cross-section that includes a flat or planar portion, such as a square, rectangle, or other shape having a flat or planar portion. The insulating layer  202  is formed of a non-conductive material such as rubber, polymer, or other materials exhibiting electrical insulating properties. 
     The cable  200  also includes a cooling conduit  211  comprising a tubular portion  212  and a coolant  214 . In one aspect, the tubular portion  212  may be hollow to allow the coolant  214  to flow therein. In this example, the coolant  214  is configured to flow within the tubular portion  212  to cool the conductor  204  by drawing heat away from the conductor  204  via conduction. As the coolant  214  flows within the tubular portion  212 , heat is transferred from the conductor  204  to the tubular portion  212  due to a temperature difference between the conductor  204  and the coolant  214 . As the coolant  214  flows through the tubular portion  212 , heat is dissipated away from the conductor  204  by the flowing coolant  214 . The coolant  214  may be air, a liquid, such as a solvent, water, ethylene glycol mixture, or any other liquid or mixture as would be known by a person of ordinary skill to absorb heat. 
     A first heat sink  230 A may be disposed at a first end of the cooling conduit  211  to draw heat generated by the conductor  204  toward the toward the first end. In addition, a second heat sink  230 B may be disposed at a second end of the cooling conduit  211  to draw heat generated by the conductor  204  toward the toward the second end. 
       FIG. 3  illustrates a side cross-section view of the cable  200  configured for high current applications, in accordance with various aspects of the subject technology. The conducting member  201  is spiral wound around the cooling conduit  211  along a length of the cooling conduit  211  to increase a contact area  220  between the conducting member  201  and the cooling conduit  211  to thereby improve a transfer of heat from the conducting member  201  to the cooling conduit  211 . Specifically, because the conductor  204  of the conducting member  201  has a planar surface  206  that is in contact with the tubular portion  212  of the cooling conduit  211 , an area  220  in contact with the cooling conduit  211  is greater when compared to the contact area  120  provided by prior art cables (as shown in  FIG. 1B ). The greater the contact area, the better the efficiency of heat transfer from the conductor  204  to the coolant  214 . In addition, winding the conductor  204  around the tubular portion  212  of the cooling conduit  211 , along a length of the cooling conduit  211 , further increases the contact area  220  between the conducting member  201  and the cooling conduit  211 . As shown in  FIG. 3 , the contact area  220  is the area between the conducting member  201  and the cooling conduit  211  that includes the planar surface  206  of the conducting member  201  in contact with the cooling conduit  211  as the conducting member  201  is wound along the length of the cooling conduit  211 . 
       FIG. 4  illustrates a top cross-section view of the cable  200  configured for high current applications, in accordance with various aspects of the subject technology. As compared to the single point of contact area  120  of prior art cables, as shown in  FIG. 1B , the contact area  220  of the conducting member  201  is significantly larger thereby enabling more efficient transfer of heat from the conductor  204  to the coolant  214 . 
       FIG. 5  illustrates a cutaway section view of the cable  200  configured for high current applications, in accordance with various aspects of the subject technology. In one aspect, the cable  200  may include an outer cover  221  surrounding an outer periphery of the conducting member  201 . As shown, the conducting member  201  may include an uninsulated conductor  204 . In this example, the outer cover  221  may be formed of an insulating material and the cooling conduit  211  may also be formed of an insulating material. 
       FIG. 6  illustrates a cutaway section and detail view of the cable  200  configured for high current applications, in accordance with various aspects of the subject technology. In other aspects, the conducting member  204  may include a plurality of conductors  204 A-C. For example, the conducting member  204  may include a first conductor  204 A, a second conductor  204 B, and a third conductor  204 C. The conductors  204 A-C may be insulated by the insulating layer  202 . As compared to the prior art cables shown in  FIG. 1A  where cables are individually insulated resulting in area  105  occupied by insulating material, the insulating layer  202  insulates each of the conductors  204 A-C, thereby resulting in a reduced area  205  occupied by insulating material. 
       FIG. 7  illustrates a perspective cross-section view of a cable  300  configured for high current applications, in accordance with various aspects of the subject technology. The cable  300  includes a conductor  304  surrounded on an outer surface by an insulating layer  302 . In one aspect, the conductor  304  may be hollow to allow a coolant  314  to directly flow through the conductor  304 . In this example, the conductor  304  may comprise a conductive sleeve, pipe, tube or other structure having an enclosed interior area that allows a coolant  314  to flow therein. Optionally, the cable  300  may also include a tubular portion  312  disposed within the hollow area of the conductor  304 . In this embodiment, the coolant  314  is configured to flow through the tubular portion  312 . As discussed above, the coolant  314  may comprise a fluid such as a liquid, mixture, or air. Alternatively, the coolant  314  may comprise a solid material with high thermal conductivity (e.g., diamond, silver, copper, gold, aluminum nitride, silicon carbide, aluminum, tungsten, graphite, graphene, etc.) to conduct the heat away from the conductor  304 . In this example, the heat sinks  230 A, B, as shown in  FIG. 2 , may be disposed at one or more ends of the coolant  314  to draw heat toward the heat sinks  230 A, B, and away from the conductor  304 . 
       FIG. 8  illustrates a perspective cross-section view of a cable  400  configured for high current applications, in accordance with various aspects of the subject technology. In some aspects, the cooling conduit may be disposed outside of a conductor and may completely surround the conductor. For example, cable  400  includes a tubular portion  412  disposed on an outermost periphery of the cable  400 . Disposed within the tubular portion  412  is a coolant  414  for conducting heat away from the conductor  404 . The conductor  404  is disposed within and is completely surrounded by the coolant  414 . The conductor  404  may also be surrounded by an insulating layer  402 . In one aspect, to maintain a position of the conductor  404  within the coolant  414 , the tubular portion  412  may include two or more extenders  416  that are configured to engage an outer surface of the insulating layer  402  to maintain the conductor  404  in positon. 
       FIG. 9  illustrates an example method  500  for manufacturing a cable configured for high current applications, in accordance with various aspects of the subject technology. It should be understood that, for any process discussed herein, there can be additional, fewer, or alternative steps performed in similar or alternative orders, or in parallel, within the scope of the various embodiments unless otherwise stated. 
     At operation  510 , a conducting member is wound around a length of a cooling conduit in a spiral arrangement. The conducting member includes a conductor surrounded by an insulating layer. The cooling conduit comprises a tubular portion and a coolant. The coolant is configured to flow within the tubular portion to cool the conductor. The coolant may be air, liquid, or a mixture. Exemplary liquids may include water, a solvent, or an ethylene glycol mixture. 
     At operation  520 , the conducting member is configured to increase a contact area between the conducting member and the cooling conduit to thereby improve a transfer of heat from the conducting member to the cooling conduit. The conducting member may have a square or a rectangular cross section, or a shape having a planar surface that allows contact with the cooling conduit. The contact area between the conducting member and the cooling conduit comprises the planar surface of the conducting member. Because the conducting member utilizes a planar surface along its length and is wound so that the planar surface is in contact with the cooling conduit, a contact area between the conducting member and the cooling conduit is significantly increased when compared to prior art cables (as shown in  FIG. 1B ). The increased contact area enables more efficient transfer of heat from the conducting member to the cooling conduit via conduction. 
     At operation  530 , an outer cover is disposed over an outer periphery of the conducting member. At operation  540 , a first heat sink may be disposed at a first end of the cooling conduit to draw heat toward the first end. At operation  550 , a second heat sink may be disposed at a second end of the cooling conduit to draw heat toward the second end. 
     In some aspects, the conducting member may include more than one conductor. For example, the conducting member may utilize a first and second conductor separated and surrounded by the insulating layer. In another example, the conducting member may utilize a first, second, and third conductor separated and surrounded by the insulating layer. Additional conductors are contemplated and within the scope of the disclosure. 
     Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.