Abstract:
The present invention relates to a structure of a switchgear with an arc protection system including an arc optical sensor to detect an arc, a relay to determine an occurrence or non-occurrence of a fault current by receiving an arc signal detected by the arc optical sensor, and an arc eliminator to earth an arc-generated side bus bar in response to an operating signal with respect to the determined fault current, wherein the arc eliminator has a test position or a service position within the switchgear.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Pursuant to 35 U.S.C. §119(a), this application claims the benefit of an earlier filing date of and the right of priority to Korean Application No. 10-2015-0100626, filed on Jul. 15, 2015, the contents of which are all incorporated by reference herein in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This specification relates to a structure of a switchgear, and more particularly, a structure of a switchgear with an arc eliminator, capable of repairing and maintaining the arc eliminator even in an active state of an upper circuit breaker without breaking it, by mounting the arc eliminator in the switchgear in a pushing and pulling manner. 
         [0004]    2. Background of the Invention 
         [0005]    In general, when an arc fault (arc flash) is generated in a switchgear, a person located outside may be put in danger. Most of arc energy which is very great damages the switchgear and the damaged switchgear cannot be reused. This may bring about a user&#39;s great loss from the economic perspective. 
         [0006]    An arc eliminator is a high-speed earthing switch with closing capability. Once an arc flash is generated in a switchgear, an optical sensor installed near the switchgear immediately detects the generated arc fault. Accordingly, an exclusive relay sends an operating signal to an arc eliminator such that the arc eliminator can perform an earthing operation. 
         [0007]    The fault current is discharged through the earthing operation and thus the arc is automatically eliminated at the fault-generated point. 
         [0008]    Therefore, the arc eliminator should be connected to a bus bar in order to eliminate the fault current. Although not illustrated, the arc eliminator and the bus are connected by the following three methods. 
         [0009]    For an installation at an upper portion as a first connecting method, the arc eliminator is installed at an upper portion of a bus bar compartment of a circuit breaker panel and connected directly to a bus bar. 
         [0010]    For an installation at a lateral surface as a second connecting method, the arc eliminator is installed at a side of a bus bar compartment of a switchgear and connected directly to a bus bar. 
         [0011]    For an installation of an arc eliminator-exclusive panel as a third connecting method, one arc eliminator panel is installed at a side of a circuit breaker panel, and the arc eliminator is installed at the arc eliminator panel. In this instance, a bus bar compartment of the exclusive panel is connected to a bus bar compartment of another circuit breaker panel. 
         [0012]    As such, since the arc eliminator is connected directly to the bus bar in the related art, the maintenance of the arc eliminator is allowed only after opening an upstream circuit breaker, other load sides are powered off as well. 
         [0013]    For the installation of the arc eliminator at the upper portion of the bus bar compartment, the arc eliminator is located higher than a reference switchgear and an arc discharge device installed in the bus bar compartment should be re-located at another position. 
         [0014]    In addition, for the lateral installation of the arc eliminator, it is difficult to further ensure an installation space of the switchgear. 
       SUMMARY OF THE INVENTION 
       [0015]    Therefore, an aspect of the detailed description is to provide a structure of a switchgear with an arc eliminator, capable of minimizing a loss caused due to an arc fault by preventing the arc fault, and repairing and maintaining the switchgear with an arc eliminator mounted therein in a pushing and pulling manner. 
         [0016]    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 structure of a switchgear with an arc eliminator, in a structure of a switchgear comprising an arc optical sensor to detect an arc, a relay to determine an occurrence or non-occurrence of a fault current by receiving an arc signal detected by the arc optical sensor, and an arc eliminator to earth an arc-generated side bus bar in response to an operating signal with respect to the determined fault current, wherein the arc eliminator is coupled to a cradle conveyer to be horizontally movable back and forth within the switchgear so as to be located at a test position or a service position. 
         [0017]    The structure of the switchgear may be provided on the same panel together with the arc eliminator according to one of an upstream bus bar structure, a downstream bus bar structure, a riser panel structure, a tie panel structure and a cable insert structure. 
         [0018]    The structure of the switchgear may include, in addition to the arc eliminator disposed therein, a plurality of tulip contacts provided on a front surface, a shutter-driving device provided on a side surface, a cradle conveyer provided at a lower surface, and bushings contactable with the tulip contacts. 
         [0019]    The arc eliminator may be placed at the service position in a manner that the arc eliminator moves along rails, the shutter-driving device opens a shutter plate obscuring the bushings, and the tulip contacts are inserted into the bushings to be brought into contact with internal conductors. 
         [0020]    The riser panel structure may be a structure in which the arc eliminator is connected between an upstream bus bar and a downstream bus bar. 
         [0021]    The tie panel structure may be configured such that the arc eliminator is connected between an upstream bus bar and a downstream bus bar, and a tie panel circuit breaker is connected between one of the upstream bus bar and the downstream bus bar and the arc eliminator. 
         [0022]    The cable insert structure may be configured such that the arc eliminator is connected to a downstream bus bar, and a main circuit breaker is provided between the arc eliminator and the cable insert structure. 
         [0023]    A structure of a switchgear with an arc eliminator according to the present invention can minimize a loss caused due to an arc fault by preventing the arc fault, and allow maintenance of the switchgear with the arc eliminator which is provided therein in a pushing and pulling manner. 
         [0024]    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 invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The accompanying drawings, which are included to provide a further understanding of the invention 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 invention. 
           [0026]    In the drawings: 
           [0027]      FIG. 1  is a configuration view schematically illustrating an arc protection system (APS) in accordance with the present invention; 
           [0028]      FIG. 2  is a perspective view schematically illustrating a structure of a switchgear with an arc eliminator in accordance with the present invention; 
           [0029]      FIG. 3  is a schematic view illustrating a configuration of the arc eliminator in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0030]      FIG. 4  is a lateral view of the structure of the switchgear with the arc eliminator in accordance with the present invention, which schematically illustrates a state that the arc eliminator is separated from a bushing; 
           [0031]      FIG. 5  is a lateral view of the structure of the switchgear with the arc eliminator in accordance with the present invention, which schematically illustrates a state that the arc eliminator is coupled to the bushing; 
           [0032]      FIG. 6  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to an upstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0033]      FIG. 7  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to an upstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0034]      FIG. 8  is a configuration view illustrating the structure of the switchgear with the arc eliminator which is applied to a downstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0035]      FIG. 9  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to a downstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0036]      FIG. 10  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to a riser panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0037]      FIG. 11  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the riser panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0038]      FIG. 12  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to a tie panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0039]      FIG. 13  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the tie panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; 
           [0040]      FIG. 14  is schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to a cable insert structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention; and 
           [0041]      FIG. 15  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the cable insert structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    Description will now be given in detail of a structure of a switchgear with an arc eliminator according to the present invention, with reference to the accompanying drawings. 
         [0043]      FIG. 1  is a configuration view schematically illustrating an arc protection system (APS) in accordance with the present invention. 
         [0044]    As illustrated in  FIG. 1 , the arc protection system according to the present invention may include a relay  110 , an arc eliminator control device  120  connected to the relay  110 , an arc eliminator  130  connected to the arc eliminator control device  120  and receiving an operating current applied from the arc eliminator control device  120 , an arc optical sensor  150  detecting an arc fault (or arc flash)  190 , a slave  140  sending the detected arc fault signal to the relay  110 , a current transformer  160  connected to the relay  110 , a transformer  162  and an upstream circuit breaker (CB)  170  both connected to one side of the current transformer  160 , and a main circuit breaker  180  connected to another side of the current transformer  160 . 
         [0045]    Here, the current transformer  160  connected to the relay  110  may measure a level of a secondary current of the transformer  162 . When a secondary overcurrent or a fault current of the transformer  162  flows, the current transformer  160  transmits a signal to the relay  110  and operates the main circuit breaker  180 . 
         [0046]    The transformer  162  is a device which transforms a high voltage into a low voltage, and may refer to a distribution type transformer. 
         [0047]    The upstream circuit breaker  170  is a primary protection device of the transformer  162 , and the main circuit breaker  180  is a secondary protection device of the transformer  162 . 
         [0048]    In the arc protection system having such configuration according to the present invention, when the arc fault  190  is generated on a bus bar of the switchgear, the arc optical sensor  150  which is installed at a corresponding panel detects the arc fault  190 , and transmits a signal to the relay  110  through the slave  140 . 
         [0049]    Simultaneously, the relay  110  recognizes the fault current through the current transformer  160  and transmits an operating signal to the arc eliminator control device  120 . The arc eliminator control device  120  then fast transmits an operating signal to the arc eliminator  130 . 
         [0050]    In this instance, the arc eliminator  130  operates to earth the bus bar. And, the fault current which causes the arc then flows on the ground through an earthing circuit. The arc is thus automatically eliminated at a portion where the arc is generated. 
         [0051]      FIG. 2  is a perspective view schematically illustrating a structure of a switchgear  100  with an arc eliminator in accordance with the present invention. 
         [0052]    As illustrated in  FIG. 2 , the arc eliminator  130  is disposed within the switchgear  100  according to the present invention. 
         [0053]      FIG. 3  is a schematic view illustrating a configuration of the arc eliminator in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0054]    As illustrated in  FIG. 3 , the arc eliminator  130  disposed within the switchgear  100  according to the present invention may include a plurality of tulip contacts  132  provided on a front surface thereof, a shutter-driving device  134  provided on a side surface, and a cradle conveyer  136  provided on a lower surface thereof. 
         [0055]      FIG. 4  is a lateral view of the structure of the switchgear with the arc eliminator in accordance with the present invention, which schematically illustrates a state that the arc eliminator is separated from bushings. 
         [0056]    As illustrated in  FIG. 4 , when the arc eliminator  130  is mounted within the switchgear  100 , the arc eliminator  130  is located at a test position where the arc eliminator  130  is not connected to rear bushings  210 . 
         [0057]      FIG. 5  is a lateral view of the structure of the switchgear with the arc eliminator in accordance with the present invention, which schematically illustrates a state that the arc eliminator is coupled to the bushings. 
         [0058]    As illustrated in  FIG. 5 , in a state that a front door is closed and a manual operating handle (not illustrated) is inserted through an operation hole (not illustrated), when the manual operating handle is rotated, the arc eliminator  130  is moved forward along rails (not illustrated), which are disposed within a panel, along with the lower cradle conveyer  136 . 
         [0059]    In response to the arc eliminator  130  moved forward along the rails, the shutter-driving device (see  134  of  FIG. 3 ) opens a shutter plate (not illustrated), which obscures the bushings  210 , and accordingly the tulip contacts  132  are inserted into the bushings  210  so as to be brought into contact with internal conductors. 
         [0060]    When the tulip contacts  132  are completely brought into contact with the conductors, as illustrated in  FIG. 5 , the arc eliminator  130  may be located at a service position and the cradle conveyer  136  (see  FIG. 3 ) is not moved any more. 
         [0061]    On the other hand, when the manual operation handle is rotated in an opposite direction to switch the arc eliminator  130  from a service position into a test position, the cradle conveyer  136  is moved outward. 
         [0062]    In response, the tulip contacts  132  are completely separated from the conductors located within the bushings  210  and moved away from the bushings  210 . Accordingly, the shutter-driving device  134  is released and the shutter plate is restored to its original position to obscure the bushings  210 . 
         [0063]    When the arc eliminator  130  is located at the test position, the cradle conveyer  136  may not be moved outward any more. 
         [0064]    Hereinafter, various embodiments of the structure of the switchgear with the arc eliminator according to the present invention will be described with reference to  FIGS. 6 to 15 . 
         [0065]    Examples of the structure of the switchgear with the arc eliminator may include an upstream bus bar structure, a downstream bus bar structure, a riser panel (PNL) structure, a tie PNL structure, and a cable insert structure. 
         [0066]      FIG. 6  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to an upstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0067]      FIG. 7  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to an upstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0068]      FIGS. 6 and 7  illustrate a first switchgear  100   a  which is a first embodiment of the switchgear with the arc eliminator according to the present invention. The structure of the first switchgear  100   a  is a structure in which the arc eliminator  130  is connected to an upstream bus bar  101 . In this instance, the arc eliminator  130  which is connected to the upstream bus bar  101  within the first switchgear  100   a  may serve to earth the bus bar upon an occurrence of a fault on the bus bar. 
         [0069]    In this manner, when an arc fault occurs on the upstream bus bar  101  of the first switchgear  100   a,  the arc optical sensor  150  (see  FIG. 1 ) which is installed on the corresponding panel detects the arc, and sends a signal to the relay  110  (see  FIG. 1 ) through the slave  140  (see  FIG. 1 ). 
         [0070]    Afterwards, the relay  110  recognizes a fault current and sends an operating signal to the arc eliminator control device  120  (see  FIG. 1 ). The arc eliminator control device  120  then fast sends an operating signal to the arc eliminator  130 . 
         [0071]    Accordingly, when the arc eliminator  130  earths the upstream bus bar  101 , the fault current causing the arc flows to the ground through an earthing circuit. This may result in automatically eliminating the arc at the arc-generated portion. 
         [0072]    Meanwhile,  FIG. 8  is a configuration view illustrating the structure of the switchgear with the arc eliminator which is applied to a downstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0073]      FIG. 9  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to a downstream bus bar structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0074]      FIGS. 8 and 9  illustrate a second switchgear  100   b  which is a second embodiment of the switchgear with the arc eliminator according to the present invention. The structure of the second switchgear  100   b  is a structure in which the arc eliminator  130  is connected to a downstream bus bar  103 . In this instance, the arc eliminator  130  which is connected to the downstream bus bar  103  within the second switchgear  100   b  may serve to earth the bus bar upon an occurrence of a fault on the bus bar. 
         [0075]    In this manner, when an arc fault occurs on the downstream bus bar  103  of the second switchgear  100   b,  the arc optical sensor  150  (see  FIG. 1 ) which is installed on the corresponding panel detects the arc, and sends a signal to the relay  110  (see  FIG. 1 ) through the slave  140  (see  FIG. 1 ). 
         [0076]    Afterwards, the relay  110  recognizes a fault current and sends an operating signal to the arc eliminator control device  120  (see  FIG. 1 ). The arc eliminator control device  120  then fast sends an operating signal to the arc eliminator  130 . 
         [0077]    Accordingly, when the arc eliminator  130  earths the downstream bus bar  103 , the fault current causing the arc flows to the ground through an earthing circuit. This may result in automatically eliminating the arc at the arc-generated portion. 
         [0078]    Meanwhile,  FIG. 10  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to a riser panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0079]      FIG. 11  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the riser panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0080]      FIGS. 10 and 11  illustrate a third switchgear  100   c  which is a third embodiment of the switchgear with the arc eliminator according to the present invention. The structure of the third switchgear  100   c  is a structure in which the arc eliminator  130  is connected between the upstream bus bar  101  and the downstream bus bar  103 . In this instance, the arc eliminator  130  which is connected to the upstream bus bar  101  and the downstream bus bar  103  within third the switchgear  100   c  may serve to earth the bus bar upon an occurrence of a fault on the bus bar. 
         [0081]    In this manner, when an arc fault occurs on the upstream bus bar  101  or the downstream bus bar  103  of the third switchgear  100   c,  the arc optical sensor  150  (see  FIG. 1 ) which is installed on the corresponding panel detects the arc, and sends a signal to the relay  110  (see  FIG. 1 ) through the slave  140  (see  FIG. 1 ). 
         [0082]    Afterwards, the relay  110  recognizes a fault current and sends an operating signal to the arc eliminator control device  120  (see  FIG. 1 ). The arc eliminator control device  120  then fast sends an operating signal to the arc eliminator  130 . 
         [0083]    Accordingly, when the arc eliminator  130  earths the upstream bus bar or the downstream bus bar  103 , the fault current causing the arc flows to the ground through an earthing circuit. This may result in automatically eliminating the arc at the arc-generated portion. 
         [0084]    Meanwhile,  FIG. 12  is a schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to a tie panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0085]      FIG. 13  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the tie panel structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0086]      FIGS. 12 and 13  illustrate a fourth switchgear  100   d  which is a fourth embodiment of the switchgear with the arc eliminator according to the present invention. The structure of the fourth switchgear  100   d  is a structure in which the arc eliminator  130  is connected between the upstream bus bar  101  and the downstream bus bar  103  and a tie panel circuit breaker  230  is connected between one of the upstream bus bar  101  and the downstream bus bar  103  and the arc eliminator  130 . In this instance, the arc eliminator  130  which is connected to the upstream bus bar  101  and the downstream bus bar  103  within the fourth switchgear  100   c  may serve to earth the bus bar upon an occurrence of a fault on the bus bar. 
         [0087]    In this manner, when an arc fault occurs on one of the upstream bus bar  101  and the downstream bus bar  103  of the fourth switchgear  100   d,  the arc optical sensor  150  (see  FIG. 1 ) which is installed on the corresponding panel detects the arc, and sends a signal to the relay  110  (see  FIG. 1 ) through the slave  140  (see 
         [0088]      FIG. 1 ). 
         [0089]    Afterwards, the relay  110  recognizes a fault current and sends an operating signal to the arc eliminator control device  120  (see  FIG. 1 ). The arc eliminator control device  120  then fast sends an operating signal to the arc eliminator  130 . 
         [0090]    Accordingly, when the arc eliminator  130  breaks one of the upstream bus bar  101  and the downstream bus bar  103  using the tie panel circuit breaker  230  and earths another bus bar, the fault current causing the arc flows to the ground through an earthing circuit. This may result in automatically eliminating the arc at the arc-generated portion. In this instance, the tie panel circuit breaker  230  may serve to connect and protect the bus bars. 
         [0091]    Meanwhile,  FIG. 14  is schematic view illustrating the structure of the switchgear with the arc eliminator which is applied to cable insert structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0092]      FIG. 15  is a configuration view illustrating an internal circuit of the structure of the switchgear with the arc eliminator which is applied to the cable insert structure, in the structure of the switchgear with the arc eliminator in accordance with the present invention. 
         [0093]      FIGS. 14 and 15  illustrate a fifth switchgear  100   e  of the cable insert structure which is a fifth embodiment of the switchgear with the arc eliminator according to the present invention. The structure of the fifth switchgear  100   e  is a structure in which the arc eliminator  130  is connected to the downstream bus bar  103  and a main circuit breaker  180  is connected between the arc eliminator  130  and the cable insert structure. In this instance, the arc eliminator  130  which is connected to the downstream bus bar  103  within the fifth switchgear  100   e  may serve to earth the bus bar upon an occurrence of a fault on the bus bar. 
         [0094]    In this manner, when an arc fault occurs on the downstream bus bar  103  of the fifth switchgear  100   e,  the arc optical sensor  150  (see  FIG. 1 ) which is installed on the corresponding panel detects the arc, and sends a signal to the relay  110  (see  FIG. 1 ) through the slave  140  (see  FIG. 1 ). 
         [0095]    Afterwards, the relay  110  recognizes a fault current and sends an operating signal to the arc eliminator control device  120  (see  FIG. 1 ). The arc eliminator control device  120  then fast sends an operating signal to the arc eliminator  130 . 
         [0096]    Accordingly, when the arc eliminator  130  earths the downstream bus bar  103 , the fault current causing the arc flows to the ground through an earthing circuit. This may result in automatically eliminating the arc at the arc-generated portion. In this instance, the main circuit breaker  180  may serve to protect an inlet port or an outlet port of the cable. 
         [0097]    As described above, a structure of a switchgear with an arc eliminator according to the present invention can minimize a loss due to an arc fault by preventing the arc fault, and allow maintenance of the switchgear in which the arc eliminator is mounted in a pushing and pulling manner. 
         [0098]    Specifically, the present invention can be configured such that a relay sends an operating signal upon an occurrence of an arc fault and the arc eliminator fast operates to eliminate the arc. At ordinary times, the arc eliminator is always open and thus current may not flow. 
         [0099]    Also, the arc eliminator can be drawn out using a cradle when the arc eliminator is required to be repaired and maintained, which may allow the switchgear to operate in a normal state without being powered off. 
         [0100]    Those embodiments have been described with reference to the drawings but the present invention may not be limited to those. 
         [0101]    The present invention has been explained with reference to the embodiments which are merely exemplary. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.