Patent Publication Number: US-9431194-B2

Title: Supporting structure of closing resistor for high voltage circuit breaker

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2014-0144385, filed on Oct. 23, 2014, the contents of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     This specification relates to a supporting structure of a closing resistor for a high voltage circuit breaker, and more particularly, a supporting structure of a closing resistor for a high voltage circuit breaker, capable of stably supporting the closing resistor of the high voltage circuit breaker such that the closing resistor cannot be twisted even by an impact applied upon a closing operation. 
     2. Background of the Disclosure 
     In general, a high voltage circuit breaker (for example, a gas-insulated switchgear) is an electric device which is installed on a circuit between a power source side and a load side of an electric power system to forcibly open and close the circuit in a normal current-flowing state or safely breaking a current upon an occurrence of a fault current, such as ground fault or short-circuit, on the circuit. The high voltage circuit breaker is generally used for high voltage equipment. 
     The high voltage circuit breaker is provided with various additional components. For example, a capacitor or a closing resistor is installed to reduce steep-increasing of voltage which is generated upon a closing operation. 
       FIGS. 1 and 2  illustrate the invention disclosed in Korean Registration Patent No. 10-0606423 titled “Contacting structure of closing resistor contacts for gas-insulated switchgear.”  FIG. 1  illustrates a configuration of a circuit breaker of the related art gas-insulated switchgear, and  FIG. 2  is an enlarged view of part ‘A’ of  FIG. 1 , which illustrates an open state of the closing resistor. 
     As illustrated in  FIGS. 1 and 2 , a circuit breaker A of high voltage equipment is divided into a moving part  1  and a fixed part  2 , each of which is separately assembled and fixed in an enclosure (tank)  5 . A closing resistor  4  is provided at one side of the fixed part  2 , and a closing resistor moving unit  3  is provided at one side of the moving part  1 . 
     In the circuit breaker A, it is important that the centers of the moving part  1  and the fixed part  2  are located on the same straight line so as to be brought into contact with or separated from each other. However, various additional components attached make it difficult to maintain such linear motion when a rated voltage increases more. 
     Also, when the rate voltage increases more, driving force of a driving unit for breaking the circuit becomes stronger, which may cause more impacts to be applied to the fixed part  2  upon closing the circuit breaker. Furthermore, the closing resistor  4  and the closing resistor moving unit  3  directly collide with each other without sliding, which causes great impact resistance. Accordingly, the moving part  1  may be twisted due to its rotation or a coupling force of the fixed part  2  may be lowered. 
     SUMMARY OF THE DISCLOSURE 
     Therefore, to obviate the related art problems, an aspect of the detailed description is to provide a supporting structure of a closing resistor for a high voltage circuit breaker, capable of providing resistance to a torsional moment upon a closing operation by increasing supporting force between a closing resistor and a fixed part of the circuit breaker, and of preventing a coupled state between the closing resistor and the fixed part from being weakened. 
     To achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a supporting structure of a closing resistor for a high voltage circuit breaker, the structure including a fixed part main circuit conductor, a supporting conductor installed on an upper surface of the fixed part main circuit conductor, a connecting conductor connected to one end of the supporting conductor, a closing resistor unit coupled to one side of the fixed part main circuit conductor with being spaced apart therefrom, and a coupling conductor provided to couple the supporting conductor and the closing resistor unit to each other, wherein the supporting conductor and the connecting conductor are provided with a coupling rib and a coupling groove, respectively, to be coupled to each other in an inserting manner. 
     Here, the closing resistor unit may be coupled to the fixed part main circuit conductor by a vertical insulating support plate. 
     The supporting structure may further include a horizontal insulating support plate installed with being spaced apart from the vertical insulating support plate and configured to connect the fixed part main circuit conductor and the closing resistor unit to each other. 
     The vertical insulating support plate may be provided in plurality. 
     A circumferential coupling portion may protrude from an outer circumferential surface of the fixed part main circuit conductor, and the vertical insulating support plate may be coupled to the circumferential coupling portion. 
     The coupling rib may be formed long in a vertical direction of the supporting conductor and the coupling groove may be formed in a form of a slot in a vertical direction of the connecting conductor, so as to be resistant to twisted moment generated centering on the connecting conductor as a shaft. 
     The coupling conductor may be coupled to the supporting conductor and the closing resistor unit by screws. 
     An annular insulating support plate may be inserted to a part of the closing resistor unit, wherein one side of the coupling conductor is coupled to a mounting portion of the supporting conductor, and the other side of the coupling conductor is coupled to the annular insulating support plate. 
     A supporting structure of a closing resistor for a high voltage circuit breaker may be implemented as a multi-point supporting structure including both a support by a vertical insulating support plate, an annular insulating support plate, a horizontal insulating support plate and a coupling conductor, and a support by a coupling rib and a coupling groove between a supporting conductor and the connecting conductor. This may result in generating stable resistance to twisted moment. 
     Therefore, it may be possible to prevent the twisted moment which may be generated due to an eccentric center of gravity, which is caused by a closing resistor unit installed at one side of a fixed part main circuit conductor in the spaced manner. 
     Also, a loose screw between the supporting conductor and the connecting conductor, which may be caused due to an impact applied by repetitive opening and closing operations, can be prevented. 
     Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the disclosure. 
       In the drawings: 
         FIG. 1  is a lateral view illustrating a configuration of a circuit breaker of a gas-insulated switchgear according to the related art; 
         FIG. 2  is an enlarged view of part ‘A’ of  FIG. 1 , which illustrates an open state of a closing resistor; 
         FIG. 3  is a perspective view of a supporting structure of a closing resistor for a high voltage circuit breaker in accordance with one exemplary embodiment of the present invention; 
         FIG. 4  is a rear view of the supporting structure of the closing resistor for the high voltage circuit breaker in accordance with the one exemplary embodiment of the present invention; 
         FIG. 5  is an exploded perspective view of a supporting conductor and a connecting conductor illustrated in  FIG. 3 ; and 
         FIG. 6  is a planar view illustrating an operating state of the supporting structure of the closing resistor for the high voltage circuit breaker in accordance with the one exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Description will now be given of preferred configurations of the present invention, with reference to the accompanying drawings. However, those preferred embodiments of the present invention are merely illustrative to help those skilled in the art easily practice the invention, but should not be construed to limit the technical scope of the present invention. 
       FIG. 3  is a perspective view of a supporting structure of a closing resistor for a high voltage circuit breaker in accordance with one exemplary embodiment of the present invention, and  FIG. 4  is a rear view of the supporting structure of the closing resistor for the high voltage circuit breaker in accordance with the one exemplary embodiment of the present invention.  FIG. 5  is an exploded perspective view of a supporting conductor and a connecting conductor illustrated in  FIG. 3 . Hereinafter, description will be given in detail of a supporting structure of a closing resistor for a high voltage circuit breaker in accordance with each embodiment of the present invention, with reference to the accompanying drawings. 
     A supporting structure of a closing resistor for a high voltage circuit breaker may include a fixed part main circuit conductor  10 , a supporting conductor  20  provided on an upper surface of the fixed part main circuit conductor  10 , a connecting conductor  30  connected to one end of the supporting conductor  20 , a closing resistor unit  40  coupled to one side of the fixed part main circuit conductor  10  with being spaced apart therefrom, and a coupling conductor  60  to couple the supporting conductor  20  and the closing resistor unit  40  to each other. The supporting conductor  20  and the connecting conductor  30  are provided with a coupling rib  27  and a coupling groove  32 , respectively, so as to be coupled to each other in an inserting manner. 
     The fixed part main circuit conductor  10  defines a body of the fixed part of the circuit breaker. 
     A fixed arc contactor  11  is provided on a front surface of the fixed part main circuit conductor  10  to generate arc when coming in contact with a moving part (not illustrated). 
     The supporting conductor  20  is coupled to an upper surface of the fixed part main circuit conductor  10 . A supporting base  12  is provided on the upper surface of the fixed part main circuit conductor  10 , and a lower coupling portion  22  which is coupled to the supporting base  12  is provided on one side of the supporting conductor  20 . The supporting base  12  and the lower coupling portion  22  may protrude from the upper surface of the fixed part main circuit conductor  10  and a lower surface of the supporting conductor  10 , respectively. Surfaces of the supporting base  12  and the lower coupling portion  22  which are coupled to each other may be planar. 
     The supporting conductor  20  may be coupled to the fixed part main circuit conductor  10  by screws. To this end, a plurality of screw holes  23  may be formed at the lower coupling portion  22 , and operation grooves  24  for insertion of screws may be formed on the lower coupling portion  22 . 
     A mounting portion  25  to which the coupling conductor  60  is mounted is formed at a central portion of the supporting conductor  20 . The mounting portion  25  may be formed in a shape of a recess crossing the central portion of the supporting conductor  20 . 
     A side coupling portion  26  is disposed on the other side of the supporting conductor  20 . The side coupling portion  26  is brought into contact with a coupling portion  31  of the connecting conductor  30 . The coupling rib  27  is provided on the side coupling portion  26 . The coupling rib  27  may be formed long along a vertical direction of the side coupling portion  26 . A plurality of screw holes  28  may be formed near the coupling rib  27 . 
     The connecting conductor  30  is coupled to the other side of the supporting conductor  20 . The coupling portion  31  is located on a lower portion of the connecting conductor  30 . The coupling groove  32  in which the coupling rib  27  of the supporting conductor  20  is insertable is formed on the coupling portion  31 . The coupling groove  32  may be formed in a shape of a slot along a vertical direction of the coupling portion  31 . As the coupling rib  27  and the coupling groove  32  are formed long, when the supporting conductor  20  and the connecting conductor  30  are coupled to each other, a yaw effect is not generated in the supporting member  20  and the connecting conductor  30 . That is, the supporting conductor  20  may have increased resistance with respect to torsional moment which is generated centering on the connecting conductor  30  as a shaft. Therefore, the supporting conductor  20  can be prevented from being twisted. 
     The coupling portion  31  is provided with a plurality of screw holes  32  which communicate with the screw holes  28  of the side coupling portion  26  of the supporting conductor  20 . Operation grooves  34  for insertion of screws are formed on a rear side of the coupling portion  31 . 
     The supporting conductor  20  and the connecting conductor  30  are supported by high supporting force resulting from the screw coupling and rib coupling, 
     The closing resistor unit  40  is installed at a side surface of the fixed part main circuit conductor  10  with being spaced apart therefrom. A vertical insulating support plate  45  is disposed to couple the closing resistor unit  40  to the fixed part main circuit conductor  10 . The vertical insulating support plate  45  is formed in a shape of a plate vertical to an axial direction of the fixed part main circuit conductor  10 . The vertical insulating support plate  45  may be provided in plurality for stable support of the closing resistor unit  40 . 
     A circumferential coupling portion  15  to which the vertical insulating support plate  45  can be coupled may protrude from an outer circumferential surface of the fixed part main circuit conductor  10 . The vertical insulating support plate  45  may be coupled to the circumferential coupling portion  15  by screws. 
     To fixedly support the fixed part main circuit conductor  10  and the closing resistor unit  40 , a horizontal insulating support plate  50  may be installed with being spaced apart from the vertical insulating support plate  45 . The horizontal insulating support plate  45  may be located at one side of the supporting conductor  20  on the fixed part main circuit conductor  10 . Referring to  FIG. 3 , the horizontal insulating support plate  50  is installed with being spaced from the vertical insulating support plate  45  in x, y and z-axial directions. Accordingly, the closing resistor unit  40  is stably supported on the fixed part main circuit conductor  10 , so as to have resistance to forces in the x, y and z-axial directions and the torsional moment centering on the x, y and z-axial directions. 
     An annular insulating support plate  46  may be provided on a part of the closing resistor unit  40 . The annular insulating support plate  46  may be coupled in a manner of being inserted to the part of the closing resistor unit  40 . A vertical plate  47  may protrude from a part of the annular insulating support plate  46  toward the fixed part main circuit conductor  10  so as to be coupled to the fixed part main circuit conductor  10 . The annular insulating support plate  46  supports the coupling conductor  60 . 
     The coupling conductor  60  is provided to couple the supporting conductor  20  and the closing resistor unit  40  to each other. One side of the coupling conductor  60  is coupled to the mounting portion  35  of the supporting conductor  20 , and the other side of the coupling conductor  60  is coupled to the annular insulating support plate  46 . Operation grooves  61  are provided on the coupling conductor  60  to couple the coupling conductor  60  to the supporting conductor  20  and the annular insulating support plate  46 . The coupling conductor  60  also serves to apply supporting force between the supporting conductor  20  and the closing resistor unit  40 . 
     The closing resistor unit  40  is coupled to the fixed part main circuit conductor  10  in the spaced manner while being stably supported by the vertical insulating support plate  45 , the horizontal insulating support plate  50 , the coupling conductor  60  and the annular insulating support plate  46 . 
     In detail, the vertical insulating support plate  45  and the horizontal insulating support plate  50  are installed at positions spaced apart from each other along a lengthwise direction of the fixed part main circuit conductor  10 , thereby having resistance to torsional moment centering on the y and x-axial directions. 
     Also, the coupling conductor  60  and the vertical insulating support plate  45  are installed at positions spaced apart from each other along a horizontal direction of the fixed part main circuit conductor  10 , thereby having resistance to torsional moment centering on the y and z-axial directions. 
     Consequently, by a triangular supporting structure of the vertical insulating support plate  45 , the horizontal insulating support plate  50  and the coupling conductor  60 , the closing resistor unit  40  can remain stable without being twisted from the fixed part main circuit conductor  10  upon an impact applied during a closing operation. 
     In addition, the connecting conductor  30  and the supporting conductor  20  coupled to each other can stably be supported without being twisted as the coupling rib  27  is inserted into the coupling groove  32 . Referring to  FIG. 6 , a moment of rotating (twisting) in a counterclockwise direction centering on the connecting conductor  30  is generated due to an impact which is applied when closing the moving part. The supporting structure according to the one embodiment of the present invention is implemented as a multi-point supporting structure including both the support by the vertical insulating support plate  45 , the annular insulating support plate  46 , the horizontal insulating support plate  50  and the coupling conductor  60 , and the support by the coupling rib  27  and the coupling groove  32  between the supporting conductor  20  and the connecting conductor  30 . This may result in generating stable resistance to such twisted moment. 
     Therefore, it may be possible to prevent the twisted moment which is likely to be generated due to an eccentric center of gravity, which is caused by the closing resistor unit  40  installed at one side of the fixed part main circuit conductor  10  in the spaced manner. 
     Also, a loose screw between the supporting conductor  20  and the connecting conductor  30 , which may be caused due to an impact applied by repetitive opening and closing operations, can be prevented. 
     As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.