Patent Publication Number: US-2023163577-A1

Title: Gas-insulated switchgear

Description:
TECHNICAL FIELD 
     The present disclosure relates to a gas-insulated switchgear. 
     BACKGROUND ART 
     A gas-insulated switchgear is switch equipment that includes device units such as a circuit breaker unit, a disconnector unit, and a ground switch unit and is configured such that main circuit parts subjected to high voltages are placed in a sealed container filled with an insulation gas such as sulfur hexafluoride (SF 6 ). Since the insulation gas is used in the sealed container, the main circuit parts of the device units can be arranged closely to each other, whereby size reduction can be achieved. 
     In such a gas-insulated switchgear, the circuit breaker unit, the disconnector unit, the ground switch unit, and the like are attached to a side surface of the sealed container via flange portions of the respective device units. 
     For simplifying the structure of the gas-insulated switchgear, in general, the side surface of the sealed container is formed to be flat and the device units are attached in a vertical line on a flat plane (see, for example, Patent Document 1). 
     CITATION LIST 
     Patent Document 
     Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-336658 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the gas-insulated switchgear, a plurality of device units such as the circuit breaker unit, the disconnector unit, and the ground switch unit are attached in a vertical line on the side surface of the sealed container via the flange portions. 
     At this time, the main circuit parts placed inside the sealed container and operation mechanisms of the device units placed outside the sealed container need to be arranged so as not to contact between the adjacent device units. 
     Regarding one device unit, it is assumed that the vertical-direction sizes of the operation mechanism placed outside the sealed container and the main circuit part placed inside the sealed container are different from each other, e.g., the operation mechanism is larger than the main circuit part. In this case, in order to prevent contact between the operation mechanisms of the adjacent device units, the device units need to be arranged with a widened interval therebetween in accordance with the sizes of the operation mechanisms. 
     Meanwhile, since the main circuit part and the operation mechanism form the same device unit, the main circuit parts smaller than the operation mechanisms are also arranged with the same interval therebetween. In other words, the main circuit parts are arranged with an interval larger than necessary, thus causing a problem of hampering size reduction of the gas-insulated switchgear. 
     The present disclosure has been made to solve the above problem, and an object of the present disclosure is to make it possible to reduce intervals between device units placed in a gas-insulated switchgear, thus achieving size reduction of the gas-insulated switchgear. 
     Solution to the Problems 
     A gas-insulated switchgear according to the present disclosure includes: a device housing having an operation door; a sealed container placed inside the device housing; and a circuit breaker unit and a ground switch unit attached to a side surface of the sealed container opposed to the operation door, via flange portions, wherein a distance from the operation door to the side surface of the sealed container opposed to the operation door is different between a part where the circuit breaker unit is attached and a part where the ground switch unit is attached. 
     Effect of the Invention 
     According to the present disclosure, it becomes possible to reduce intervals between the device units, thus achieving size reduction of the gas-insulated switchgear. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side sectional view of a gas-insulated switchgear in embodiment 1. 
         FIG.  2    is a side sectional view of a circuit breaker unit in embodiment 1. 
         FIG.  3    is a side sectional view of a ground switch unit in embodiment 1. 
         FIG.  4    is a side sectional view of a gas-insulated switchgear. 
         FIG.  5    is a side sectional view of a gas-insulated switchgear in embodiment 2. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the description of embodiments and the drawings, parts denoted by the same reference characters represent the same or corresponding parts. 
     Embodiment 1 
     Embodiment 1 will be described with reference to  FIG.  1    to  FIG.  4   .  FIG.  1    is a side sectional view of a gas-insulated switchgear according to embodiment 1, and  FIG.  2    and  FIG.  3    are side sectional views of a circuit breaker unit and a ground switch unit placed in the gas-insulated switchgear.  FIG.  4    is a side sectional view of a gas-insulated switchgear for comparison. 
     First, with reference to  FIG.  1    to  FIG.  3   , the structure of a gas-insulated switchgear  100  according to embodiment 1 will be described. 
       FIG.  1    is a side sectional view of the gas-insulated switchgear  100  according to embodiment 1. As shown in  FIG.  1   , the gas-insulated switchgear  100  is configured such that device units are placed in the device housing  1 , and an operation door  4  is provided at a left side surface of the device housing  1  while a back door  5  is provided at a right side surface. 
     The gas-insulated switchgear  100  has, inside thereof, sealed containers  2 ,  3  filled with an insulation gas such as sulfur hexafluoride (SF 6 ). Here, an example in which two sealed containers  2 ,  3  are provided at upper and lower stages will be described. 
     A ground switch unit  6  switchable to a disconnector is provided at a side surface of the upper sealed container  2  opposed to the operation door  4 , via a flange portion protruding at a center part. Similarly, a back-side ground switch unit  7  switchable to a disconnector is provided at a side surface of the sealed container  2  opposed to the back door  5 , via a flange portion. 
     The upper sealed container  2  and device units placed in the upper sealed container  2  of the gas-insulated switchgear  100  in embodiment 1 shown in  FIG.  1    are configured in the same manner as in a gas-insulated switchgear  120  shown in  FIG.  4    described later for comparison with the gas-insulated switchgear  100  of embodiment 1, and do not represent any characteristics of the present disclosure. Therefore, description about the upper sealed container  2  is omitted below. 
     Of the side surfaces of the lower sealed container  3 , at a side surface opposed to the operation door  4 , a circuit breaker unit  10  and a ground switch unit  20  are attached so as to be arranged at upper and lower positions, via flange portions protruding from center parts, respectively. 
     The configurations, operations, and the like of the circuit breaker unit  10  and the ground switch unit  20  which are placed in the sealed container  3  and used in embodiment 1 will be described with reference to  FIG.  2    and  FIG.  3   . 
       FIG.  2    is a side sectional view of the circuit breaker unit  10 . As shown in  FIG.  2   , a protruding plate-shaped flange portion  13  is formed at a center part of the circuit breaker unit  10 . The flange portion  13  is attached to a side surface of the sealed container  3  and the circuit breaker unit  10  is placed at the sealed container  3 . 
     An operation mechanism  14  is provided at the left of the flange portion  13  on the drawing sheet of  FIG.  2    and is placed outside the sealed container  3 . On the other hand, a part enclosed by an elliptic broken line at the right of the flange portion  13  on the drawing sheet is the main circuit part  12  and is placed inside the sealed container  3 . A vacuum interrupter  16  is provided in the main circuit part  12 . 
     The operation mechanism  14  stores an operation device and the like for operating the main circuit part  12 . The operation mechanism  14  stores a spring operation mechanism including a large-sized energized spring for operating the vacuum interrupter  16  at high speed, and has a protrusion  15  protruding downward of the operation mechanism  14  as shown in a round dotted-dashed line. 
       FIG.  3    is a side sectional view of a ground switch unit  20 . As shown in rectangular broken lines in  FIG.  3   , the ground switch unit  20  includes two ground switch units  21 ,  31  having at least ground switch functions and arranged as a pair at upper and lower positions, such that the first ground switch unit  21  is switchable to a disconnector and the second ground switch unit  31  is not switchable to a disconnector. These units are joined by a shared flange portion  23  at their respective center parts. 
     The switchable first ground switch unit  21  and the non-switchable second ground switch unit  31  have operation mechanisms  24 ,  34  at the left of the flange portion  23  on the drawing sheet. The operation mechanisms  24 ,  34  are placed outside the sealed container  3 . 
     Parts enclosed in round broken lines at the right of the flange portion  23  on the drawing sheet are main circuit parts  22 ,  32 . The main circuit parts  22 ,  32  are placed inside the sealed container  3 . 
     The operation mechanisms  24 ,  34  have circuit boards  25 ,  35  for controlling the operation mechanisms  24 ,  34 . In many cases, the circuit boards  25 ,  35  are placed at the upper parts of the operation mechanisms  24 ,  34 . 
     The main circuit part  22  of the switchable first ground switch unit  21  includes a disconnector terminal  26 , a ground terminal  28 , and a movable conductor  27 . The movable conductor  27  performs switching of a conduction state between the disconnector terminal  26  and the ground terminal  28 . Thus, the first ground switch unit  21  has both functions as a disconnector and a ground switch through switching of the movable conductor  27 . 
     In the non-switchable second ground switch unit  31 , the main circuit part  32  includes only a ground terminal  38  and a movable conductor  37  and thus does not include a disconnector terminal unlike the first ground switch unit  21 . Therefore, the second ground switch unit  31  has only a ground switch function without having a disconnector function. 
     In the above description of embodiment 1, it is described that the ground switch unit  20  includes the first ground switch unit  21  and the second ground switch unit  31 . However, without limitation thereto, a configuration having only one of the first ground switch unit  21  and the second ground switch unit  31  may be employed, and also in this case, the same effects can be provided. 
     The circuit breaker unit  10  and the ground switch unit  20  are placed at the side surface of the sealed container  3  opposed to the operation door  4 , via their respective flange portions  13 ,  23 . 
     In the gas-insulated switchgear  100  of embodiment 1 shown in  FIG.  1   , a step is formed on the side surface opposed to the operation door  4 , of the side surfaces of the sealed container  3 . As seen from the operation door  4  side, on the same side surface of the sealed container  3 , the part where the flange portion  23  of the ground switch unit  20  is attached is located on the back side relative to the part where the flange portion  13  of the circuit breaker unit  10  is attached. 
     Here, the shapes of the circuit breaker unit  10  and the ground switch unit  20  placed at the above stepped side surface of the sealed container  3  will be discussed. 
     In the ground switch unit  20  of embodiment 1, as shown in  FIG.  1    and  FIG.  3   , the height-direction sizes of the two operation mechanisms  24 ,  34  located outside the sealed container  3  and the height-direction sizes of the two main circuit parts  22 ,  32  located inside the sealed container  3  are considered to be almost equal when compared to each other. 
     On the other hand, in the circuit breaker unit  10  shown in  FIG.  1    and  FIG.  2   , when the height-direction sizes of the operation mechanism  14  and the main circuit part  12  are compared to each other, the operation mechanism  14  has the protrusion  15  storing the spring operation mechanism and the height-direction size of the operation mechanism  14  is larger than that of the main circuit part  12 . 
     Therefore, as in the gas-insulated switchgear  100  of embodiment 1 shown in  FIG.  1   , on the side surface of the sealed container  3 , the part where the flange portion  23  of the ground switch unit  20  is attached is located on the back side relative to the part where the circuit breaker unit  10  is attached as seen from the operation door  4  side, so that the protrusion  15  of the circuit breaker unit  10  and the operation mechanism  24  of the first ground switch unit  21  do not contact with each other and thus interference therebetween can be avoided. 
     As a result, as shown in  FIG.  1   , the circuit breaker unit  10  and the ground switch unit  20  can be arranged with a narrowed interval therebetween at a part shown by an arrow  43 . 
     In embodiment 1, it has been described that the operation mechanism  14  of the circuit breaker unit  10  has the protrusion  15  and the height-direction size of the operation mechanism  14  of the circuit breaker unit  10  is larger than that of the main circuit part  12  as shown in  FIG.  1    and  FIG.  2   . Conversely, also in a case where the height-direction size of the main circuit part  12  is larger than that of the operation mechanism  14  of the circuit breaker unit  10 , by using the same method, the main circuit parts  12 ,  22  of the circuit breaker unit  10  and the ground switch unit  20  do not contact with each other and thus interference therebetween can be avoided. 
     In embodiment 1, it has been described that the operation mechanism  14  of the circuit breaker unit  10  has the protrusion  15  toward the ground switch unit  20  as shown in  FIG.  1   . Conversely, also in a case where the operation mechanism  24  of the ground switch unit  20  has a protrusion toward the circuit breaker unit  10 , by using the same method, they can be prevented from contacting with each other and thus interference therebetween can be avoided. In addition, also in a case where a protrusion is formed on the main circuit part of the circuit breaker unit  10  or the ground switch unit  20 , by using the same method, they can be prevented from contacting with each other and thus interference therebetween can be avoided. 
     The gas-insulated switchgear  120  shown in  FIG.  4    is for comparison with the gas-insulated switchgear  100  shown in  FIG.  1   , and the flange portions  13 ,  23  of the circuit breaker unit  10  and the ground switch unit  20  are attached to a flat side surface of the sealed container  3  for simplifying the structure. 
     In other words, the circuit breaker unit  10  and the ground switch unit  20  are placed so as to be aligned with each other backward as seen from the operation door  4  side. 
     As described above, in the ground switch unit  20 , the height-direction sizes of the operation mechanisms  24 ,  34  placed outside the sealed container  3  and the main circuit parts  22 ,  32  placed inside the sealed container  3  are almost equal to each other, whereas in the circuit breaker unit  10 , since the operation mechanism  14  has the protrusion  15 , the height-direction size of the operation mechanism  14  placed outside the sealed container  3  is larger than that of the main circuit part  12  placed inside the sealed container  3 . 
     Therefore, as in the gas-insulated switchgear  120  shown in  FIG.  4   , when the circuit breaker unit  10  and the ground switch unit  20  are placed at the same distance as seen from the operation door  4  side, they need to be arranged with a widened interval therebetween at a part shown by an arrow  42  in  FIG.  4    so as to prevent contact and interference between the protrusion  15  of the circuit breaker unit  10  and the operation mechanism  24  of the first ground switch unit  21  of the ground switch unit  20  or between the protrusion  15  and the circuit board  25  on the operation mechanism  24 . 
     On the other hand, the main circuit parts  12 ,  22 ,  32  of the circuit breaker unit  10  and the ground switch unit  20 , which are placed inside the sealed container  3 , do not have such protrusions  15 , and therefore need not be arranged with a widened interval. Nevertheless, as described above, since the operation mechanisms  14 ,  24 ,  34  placed outside the sealed container  3  need to be arranged with a widened interval, the main circuit parts  12 ,  22 ,  32  arranged with the same interval as the operation mechanisms  14 ,  24 ,  34  end up having an interval widened more than necessary. 
     As described above, in the gas-insulated switchgear  100  shown in embodiment 1, since the interval between the circuit breaker unit  10  and the ground switch unit  20  can be narrowed, the sealed container  3  can be made small, whereby the gas-insulated switchgear  100  can be downsized. At the same time, conductors connecting from a power cable  41  to the main circuit parts  22 ,  32  of the ground switch unit  20  and the like can be shortened, whereby power loss is reduced and heat generation in the gas-insulated switchgear  100  can be suppressed. 
     Embodiment 2 
       FIG.  5    is a side sectional view of a gas-insulated switchgear  110  according to embodiment 2 of the present disclosure. 
     In the gas-insulated switchgear  120  shown in  FIG.  4   , on the side surface of the lower sealed container  3 , the circuit breaker unit  10  and the ground switch unit  20  are arranged in line on the same plane as seen from the operation door  4  side, via the respective flange portions  13 ,  23 . 
     In such arrangement of the device units in the gas-insulated switchgear  120 , the protrusion  15  formed on the operation mechanism  14  of the circuit breaker unit  10  and storing the spring operation mechanism, and the circuit board  25  on the operation mechanism  24  of the first ground switch unit  21 , contact and interfere with each other, and therefore it is necessary to arrange the circuit breaker unit  10  and the ground switch unit  20  with a widened interval therebetween. 
     On the other hand, in the gas-insulated switchgear  110  of embodiment 2, as shown in the side sectional view of the gas-insulated switchgear  110  in  FIG.  5   , the circuit breaker unit  10  and the ground switch unit  20  are attached to the side surface of the lower sealed container  3 , and this is the same as in the gas-insulated switchgear  120  shown in  FIG.  4   . 
     However, in embodiment 2, the flange portion  13  of the circuit breaker unit  10  is located on the back side relative to the flange portion  23  of the ground switch unit  20  as seen from the operation door  4  side, and thus the circuit breaker unit  10  is placed at a position shifted backward. 
     Of the ground switch unit  20 , in general, the circuit board  25  placed on the operation mechanism  24  of the first ground switch unit  21  can be transferred to a desired position on the operation mechanism  24 . 
     Therefore, the circuit breaker unit  10  is placed backward as seen from the operation door  4  side and the circuit board  25  on the operation mechanism  24  is placed on a side close to the operation door  4 , whereby the protrusion  15  of the circuit breaker unit  10  and the circuit board  25  of the first ground switch unit  21  can be prevented from contacting with each other and thus interference therebetween can be avoided. As a result, the circuit breaker unit  10  and the ground switch unit  20  can be arranged with a narrowed interval therebetween. 
     Since the interval between the circuit breaker unit  10  and the ground switch unit  20  is narrowed, the gas-insulated switchgear  120  can be downsized, and at the same time, conductors connecting from the power cable  41  to the ground switch unit  20  and the like can be shortened, whereby power loss is reduced and heat generation in the gas-insulated switchgear  120  can be suppressed. 
     In the gas-insulated switchgears  100 ,  110  shown in  FIG.  1    and  FIG.  5   , arrangement of the circuit breaker unit  10  and the ground switch unit  20  for performing switching of the main circuit or the like has been described as an example. 
     At the side surface of the sealed container  3  in the gas-insulated switchgear  100 ,  110 , device units such as an instrument transformer unit and an arrester unit may be placed, and the circuit breaker unit including the operation mechanism  14  having the protrusion  15  may be used for the instrument transformer unit, the arrester unit, and the like. Also in this case, by forming a step on the side surface of the sealed container  3 , the interval between the circuit breaker unit and other device units can be narrowed, whereby the gas-insulated switchgear  100 ,  110  can be downsized and heat generation in the gas-insulated switchgear  100 ,  110  can be suppressed by reduction of power loss and the like. 
     Although the disclosure is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects, and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations to one or more of the embodiments of the disclosure. 
     It is therefore understood that numerous modifications which have not been exemplified can be devised without departing from the scope of the present disclosure. For example, at least one of the constituent components may be modified, added, or eliminated. At least one of the constituent components mentioned in at least one of the preferred embodiments may be selected and combined with the constituent components mentioned in another preferred embodiment. 
     DESCRIPTION OF THE REFERENCE CHARACTERS 
       1  device housing 
       2  sealed container 
       3  sealed container 
       4  operation door 
       5  back door 
       6  ground switch unit 
       7  back-side ground switch unit 
       10  circuit breaker unit 
       12  main circuit part 
       13  flange portion 
       14  operation mechanism 
       15  protrusion 
       16  vacuum interrupter 
       20  ground switch unit 
       21  ground switch unit 
       22  main circuit part 
       23  flange portion 
       24  operation mechanism 
       25  circuit board 
       26  disconnector terminal 
       27  movable conductor 
       28  ground terminal 
       31  ground switch unit 
       32  main circuit part 
       34  operation mechanism 
       35  circuit board 
       37  movable conductor 
       38  ground terminal 
       41  power cable 
       42  arrow 
       43  arrow 
       100  gas-insulated switchgear 
       110  gas-insulated switchgear 
       120  gas-insulated switchgear