Earthing Switchgear

Abstract

The present invention relates to an earthing switchgear that has an arc induction section provided inside a fixed section, and that can prevent damage to the fixed contact by guiding the arc that occurs at the movable contact when the movable contact and the fixed contact approach or move away from each other toward the arc induction section.

Description

[Technical Field]

[0001] The present invention relates to an earthing switchgear, and more particularly to an earthing switchgear that has an arc induction section provided inside a fixed section, and that can prevent damage to the fixed contacts by guiding an arc generated at the movable contacts toward the arc induction section when the movable contacts and the fixed contacts approach or move away from each other. [Background technology]

[0002] Generally, Gas Insulated Switchgear (GIS) is installed on electric lines for indoor and outdoor power plants and substations, and is configured to be able to manually switch load current under normal operating conditions. It is also a switchgear for extra-high voltage power systems that safely cuts off abnormal current when an accident or short circuit occurs, protecting the power system and power equipment.

[0003] The gas-insulated switchgear consists of switching equipment such as circuit breakers (CB), disconnecting switches (DS), current transformers (CT), earthing switches (ES), and busbars, all housed in a sealed metal tank filled with inert gas.

[0004] Earthing switches are divided into two types: one is an equipment earthing switch, which is installed between a circuit breaker and a disconnecting switch and on a busbar, and which performs a grounding function for the circuit during maintenance of the circuit breaker, disconnecting switch, or busbar, ensuring the safety of workers, and the other is a line earthing switch, which is installed on the line side of an extra-high voltage transmission line, and which performs a fault current input function in addition to the grounding function of an equipment earthing switch.

[0005] The earthing switch is installed inside the gas insulated switchgear and serves to prevent safety accidents by earthing the main circuit for safety in the event of abnormal voltage occurrence, accidents or other maintenance and inspection.

[0006] The earthing switch is configured to include a movable element that reciprocates according to the operation of an operating device, a movable contact that contacts the movable element in an open state, a fixed contact that contacts and disengages according to the reciprocating movement of the movable element, and a connecting bar that energizes the earth side in a closed state.

[0007] When the earthing switch is in an open state and an operating device is operated in response to a closing signal, a movable element connected to the operating device slides and closes the fixed contact.

[0008] The current flows through the fixed contact, the movable element, the movable contact, and the connecting bar in this order to the ground side.

[0009] Conversely, in the breaking operation, when the operating device operates in response to an open signal in the closed state, the moving element slides in the opposite direction and is separated from the fixed contact, thereby breaking the flow of current.

[0010] When the movable contact and the fixed contact of the earthing switch move closer to each other or move away from each other, an arc may occur.

[0011] In other words, at the beginning of arc generation, the arc is generated mainly between the moving contact of the mover and the fixed contact of the stator, but if the arc generation time continues, the arc heat is conducted to the contact parts (moving contact and fixed contact) that carry the current of the main circuit, causing the contact parts to melt.

[0012] To solve this problem, a grounding switch having an arc inducing portion (pre-arc contact) inside the stator is disclosed in Korean Utility Model Publication No. 20-0411499.

[0013] In a conventional earthing switch, a pre-arcing contact corresponding to the movable contact of the movable part is formed vertically at the center of a finger forming a fixed part, and a coupling groove is formed at a certain depth below the movable contact into which the pre-arcing contact is inserted and coupled, and an incision groove is formed above the pre-arcing contact, so that it can be inserted flexibly into the coupling groove.

[0014] However, in the case of a conventional earthing switch including a pre-arcing contact, since the pre-arcing contact is arranged on the same line as the fixed contact, there is a problem in that irregularly occurring pre-arcing may occur not only in the pre-arcing contact but also in the fixed contact, which may damage the fixed contact.

[0015] Furthermore, the conventional earthing switchgear has a structure in which the pre-arcing contact is inserted into the communicating hole of the moving element, which limits the degree of freedom in designing the pre-arcing contact.

[0016] Furthermore, since the pre-arcing contact is smaller than the movable contact, there is a problem in that the performance of inducing the pre-arcing is inferior. Summary of the Invention [Problem to be solved by the invention]

[0017] Therefore, in order to solve the problems of the prior art described above, an object of the present invention is to provide an earthing switchgear in which an arc inducing section is provided inside a fixed section, and an arc generated at the movable contact when the movable contact and the fixed contact move toward or away from each other is guided toward the arc inducing section, thereby preventing damage to the fixed contact. [Means for solving the problem]

[0018] According to a feature of the present invention for achieving the above object, the earthing switchgear of the present invention includes a housing, a movable part provided inside the housing, installed so as to be capable of reciprocating motion by an operator, and equipped with a movable contact at an end thereof, a fixed part arranged at a predetermined distance from the movable part, and equipped with a fixed contact that is selectively grounded or short-circuited with the movable contact in accordance with the reciprocating motion of the movable part, and an arc induction part provided inside the fixed contact, installed so as to be able to rise and fall inside the fixed contact, and that induces an arc generated at the movable contact when the movable contact approaches or moves away from the fixed contact.

[0019] The arc inducing unit includes an arc inducing body provided inside the fixed part and having an elastic member mounting groove formed on an upper surface and a lifting bar guide groove formed on a lower surface; a bar-shaped lifting bar provided inside the arc inducing body and movable up and down along the lifting guide groove; an arc inducing head fixed to an end of the lifting bar and made of a conductive material, for inducing an arc when the movable contacts are adjacent to each other; and an elastic member made of an elastic body and provided inside the elastic member mounting groove, one end of which is in close contact with one side of the arc inducing head and elastically supports the arc inducing head.

[0020] The arc inducing head is disposed so as to protrude further upward than the fixed contact.

[0021] The movable part further includes a fluid containing part formed of an empty space and filled with a fluid.

[0022] A fluid injection hole is further provided at one side of the fluid receiving portion, the fluid injection hole extending vertically through the interior of the movable portion, one end of the fluid injection hole communicating with the fluid receiving portion and the other end of the fluid injection hole communicating with the outside, for injecting fluid onto the arc guiding portion.

[0023] The fluid filled in the fluid container is sprayed onto the arc guiding portion when the fixed contact and the movable contact are separated.

[0024] The fluid is made of insulating gas and is sprayed onto the lower part of the movable contact to suppress the generation of an arc. [Effects of the Invention]

[0025] The earthing switchgear according to the present invention has the following effects.

[0026] The earthing switchgear according to the present invention has an arc induction section provided inside the fixed section, and when the movable contact moves towards or away from the fixed contact, the arc generated at the movable contact is induced towards the arc induction section, thereby having the advantage of preventing damage and breakage of the fixed contact due to arc generation.

[0027] In addition, the arc inducing head of the arc inducing unit is installed inside the fixed unit so as to be vertically movable, so that even after the movable contact is short-circuited with the fixed contact, the movable contact and the arc inducing head are maintained in a grounded state, thereby minimizing the arc generated on the fixed contact side.

[0028] In addition, after the movable contact and the arc inducing section are short-circuited, a fluid consisting of insulating gas is injected toward the arc inducing section to suppress the generation of an arc, thereby preventing damage and breakage of the movable contact due to the generation of an arc. [Brief explanation of the drawings]

[0029] [Figure 1] 1A and 1B are a front view and a cross-sectional view showing the configuration of a preferred embodiment of a grounding switchgear according to the present invention. [Figure 2] 1 is a cross-sectional view showing the configuration of a movable part and a fixed part constituting an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view showing a state in which a movable contact and a fixed contact constituting an embodiment of the present invention are grounded. [Figure 4] 1 is a cross-sectional view showing a state in which a movable contact and a fixed contact constituting an embodiment of the present invention are short-circuited; [Figure 5] 1 is a cross-sectional view showing a state in which a movable contact constituting an embodiment of the present invention is short-circuited by a fixed contact and is retained; DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, several embodiments of the present invention will be described in detail with reference to the drawings. When assigning reference numerals to components in each drawing, it should be noted that the same components are assigned the same numerals as much as possible, even if they are displayed in different drawings. Furthermore, when describing the embodiments of the present invention, if it is determined that a detailed description of related known structures or functions would hinder understanding of the embodiments of the present invention, such detailed description will be omitted.

[0031] Furthermore, when describing components of an embodiment of the present invention, terms such as "first," "second," "A," "B," "(a)," and "(b)" may be used. These terms are used to distinguish a component from other components, and do not limit the nature, order, or sequence of the components. When a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the component may be directly coupled or connected to the other component, or that another component may be "coupled," "coupled," or "connected" between the components.

[0032] Figure 1 shows a front view and a cross-sectional view showing the configuration of a preferred embodiment of a grounding switchgear according to the present invention, Figure 2 shows a cross-sectional view showing the configuration of the movable and fixed parts that constitute an embodiment of the present invention, Figure 3 shows a cross-sectional view showing the state in which the movable side contact and the fixed side contact that constitute an embodiment of the present invention are grounded, Figure 4 shows a cross-sectional view showing the state in which the movable side contact and the fixed side contact that constitute an embodiment of the present invention are short-circuited, and Figure 5 shows a cross-sectional view showing the state in which the movable side contact that constitutes an embodiment of the present invention is short-circuited with the fixed side contact and is retained.

[0033] As shown in these figures, the earthing switchgear according to the present invention is disclosed as comprising a housing 10, a movable part 20 provided inside the housing 10 and installed so as to be capable of reciprocating motion by an operating device, and having a movable contact 30 formed at its end, a fixed part 40 arranged at a predetermined distance from the movable part 20 and having a fixed contact 44 formed therein that is selectively grounded or short-circuited with the movable contact 30 in accordance with the reciprocating motion of the movable part 20, and an arc induction part 50 provided inside the fixed contact 44 and installed so as to be able to rise and fall inside the fixed contact 44, and that induces an arc generated at the movable contact 30 when the movable contact 30 approaches or moves away from the fixed contact.

[0034] The housing 10 has a chamber-shaped exterior and defines an internal space 12. An operator 14 and a movable part 20 are installed in the internal space 12. The operator 14 is a typical operator for a grounding switchgear, and a detailed description thereof will be omitted. The operator 14 is fixed to one side of the movable part 20 and serves to operate the movable part 20 by reciprocating it up and down.

[0035] As shown in FIG. 2, the movable portion 20 is largely composed of a movable body portion 22, a fluid containing portion 24, a movable contact point 30, and the like.

[0036] The movable body 22 is cylindrical and elongated in the vertical direction. The movable body 22 is disposed inside the housing 10 and moves up and down in response to the operation of the operating device 14.

[0037] In addition, according to the vertical movement of the movable body part 22, a movable contact 30 and a fixed contact 44, which will be described later, can be grounded or short-circuited.

[0038] A fluid containing portion 24 is formed inside the movable body portion 22. The fluid containing portion 24 is formed as a cylindrical empty space inside the movable body portion 22. The inside of the fluid containing portion 24 is a portion to be filled with a fluid 26, which will be described later.

[0039] The fluid 26 is a general insulating gas, and a detailed description thereof will be omitted. The fluid 26 is filled inside the fluid container 24 and is injected toward the bottom of the moving part 20 using a piston injection method. The fluid 26 is an insulating gas, and is injected toward the bottom of the moving part 20 to suppress the generation of an arc.

[0040] A fluid injection hole 28 is formed at the bottom of the fluid receiving part 24. The fluid injection hole 28 is vertically formed through the center of the movable body part 22. One end of the fluid injection hole 28 is connected to the fluid receiving part 24, and the other end is connected to the outside of the movable part 20.

[0041] The fluid injection hole 28 communicates with the fluid receiving part 24 and serves as a passage for guiding the fluid 26 to be injected toward the lower part of the movable part 20 when the fluid 26 is injected.

[0042] A movable contact 30 is provided on the lower surface of the movable body 22. The movable contact 30 has a cylindrical shape and is fixedly provided on the lower surface of the movable body 22. The movable contact 30 is a general movable contact, and a detailed description thereof will be omitted. The movable contact 30 selectively comes into contact with a fixed contact 44 (described below) in response to the vertical movement of the movable body 22, thereby passing current during a grounding operation.

[0043] A fixed part 40 is provided below the movable part 20. As shown in Fig. 3, the fixed part 40 is mainly composed of a fixed shield part 42, a fixed contact 44, an arc guide part 50, and the like.

[0044] The fixed shield part 42 has a generally hollow cylindrical shape, and a number of components are installed inside the fixed shield part 42. The interior of the fixed shield part 42 is a portion where a number of components are installed and protected.

[0045] A fixed contact 44 is provided inside the fixed shield part 42. The fixed contact 44 is a general fixed contact, and a detailed description thereof will be omitted. The fixed contact 44 is made of a conductive material and has a circular ring shape. The fixed contact is disposed at the upper end of the inside of the fixed shield part 42, and is a part in which the movable contact 30 is housed and grounded and electrically connected.

[0046] An arc inducing unit 50 is provided inside the fixed contact 44. The arc inducing unit 50 includes an arc inducing body 52, a lifting bar 58, an arc inducing head 62, an elastic member 64, and the like.

[0047] The arc induction body 52 has a cylindrical shape and is installed inside the fixed shield part 42. The arc induction body 52 is installed inside the fixed shield part 42 and serves to guide the vertical movement of a lifting bar 58 (described later) and to support an elastic member 64 (described later).

[0048] An elastic member mounting groove 54 is formed on the upper surface of the arc induction body 52. ​​The elastic member mounting groove 54 is recessed to a predetermined depth and is a portion in which a part of an elastic member 64, which will be described later, is accommodated.

[0049] A lifting bar guide groove 56 is formed on the bottom surface of the arc induction body 52. ​​The lifting bar guide groove 56 is cylindrically recessed to a predetermined depth in the center of the bottom surface of the arc induction body 52. ​​A portion of a lifting bar 58 (described later) is installed inside the lifting bar guide groove 56, and the vertical movement of the lifting bar 58 is guided.

[0050] A lifting bar 58 is installed inside the lifting bar guide groove 56. The lifting bar 58 has a bar shape and is elongated in the vertical direction. A portion of the lifting bar 58 is installed in the lifting bar guide groove 56. The remaining portion of the lifting bar 58 protrudes above the arc induction body 52 through a lifting hole 60 that penetrates vertically through the center of the top surface of the arc induction body 52.

[0051] The lifting bar 58 is provided on the arc induction body 52 so as to be movable up and down, and serves to move an arc induction head 62 (described later) up and down.

[0052] An arc induction head 62 is fixed to the upper end of the lifting bar 58. The arc induction head 62 is cylindrical and made of a conductive material. The arc induction head 62 is fixed to the upper end of the lifting bar 58. The arc induction head 62 is provided so as to be able to move up and down within the fixed contact 44 in accordance with the up and down movement of the lifting bar 58. The arc induction head 62 is disposed higher than the fixed contact 44. When the movable contact 30 moves to the fixed contact 44 for a grounding operation, the arc induction head 62 is disposed so as to move adjacent to the movable contact 30 before the fixed contact 44. Therefore, the arc induction head 62 serves to induce an arc that may occur at the movable contact 30 (see FIG. 4).

[0053] An elastic member 64 is installed inside the elastic member mounting groove 54. The elastic member 64 is a general spring, and a detailed description thereof will be omitted. One end of the elastic member 64 is in close contact with the bottom surface of the elastic member mounting groove 54, and the other end is in close contact with the lower surface of the arc inducing head 62. The elastic member 64 is installed below the arc inducing head 62 and serves to elastically support the arc inducing head 62 in an upward direction.

[0054] That is, since the arc inducing head 62 is elastically supported by the elastic member 64, the movable contact 30 and the arc inducing head 62 are maintained in close contact with each other during the grounding operation, and the arc inducing head 62 can move downward. As a result, the fixed contact 44, which is located further below the arc inducing head 62, and the movable contact 30 can be grounded.

[0055] The operation of the earthing switchgear of the present invention having the above-described configuration will be described below with reference to FIGS.

[0056] First, the earthing switchgear operates in a grounded state and a short-circuited state. When the earthing switchgear is in the grounded state, the operating device 14 operates in response to a ground signal. Then, in response to the operation of the operating device 14, the movable part 20, which is provided on the operating device 14 so as to be capable of vertical reciprocating motion, moves linearly downward.

[0057] 4, the movable part 20 gradually moves downward and first comes adjacent to the arc inducing head 62 before being grounded to the fixed contact 44. As a result, the arc (ARC) generated at the movable contact 30 is induced to the arc inducing head 62.

[0058] The movable contact 30 and the arc inducing head 62 are kept in close contact with each other, and the movable contact 30 continues to move downward until it is finally grounded to the fixed contact 44, as shown in FIG. 3, thereby completing the grounding operation.

[0059] Conversely, when the earthing switchgear is short-circuited, the operating device 14 operates in response to a short-circuit signal. As the operating device 14 operates, a movable part 20 provided on the operating device 14 so as to be capable of vertical reciprocating motion moves linearly upward.

[0060] 5, the movable part 20 gradually moves upward and is short-circuited with the fixed contact 44. At this time, even if the movable contact 30 and the fixed contact 44 are short-circuited, the movable contact 30 and the arc inducing head 62 maintain a state of close contact.

[0061] In other words, by positioning the arc inducing head 62 further above the fixed side contact 44, the arc inducing head 62 can be maintained in close contact with the movable side contact 30 even after the fixed side contact 44 and the movable side contact 30 are short-circuited.

[0062] When the movable contact 30 moves upward by a certain distance or more, a short circuit occurs between the movable contact 30 and the arc inducing head 62. At the same time, the fluid 26 filled in the fluid container 24 is sprayed downward, thereby suppressing the arc that occurs during the short circuit.

[0063] Therefore, in the earthing switchgear according to the present invention, an arc inducing section 50 is provided inside the fixed section 40, and when the movable contact 30 approaches or moves away from the fixed contact 44, an arc generated at the movable contact is induced toward the arc inducing section 50, thereby preventing damage and breakage of the fixed contact 44 due to the generation of an arc.

[0064] Furthermore, since the arc inducing head 62 of the arc inducing unit 50 is provided inside the fixed unit 40 so as to be movable up and down, the movable contact 30 and the arc inducing head 62 are kept grounded even after the movable contact is short-circuited with the fixed contact, thereby minimizing the arc generated on the fixed contact 44 side.

[0065] In addition, after the movable contact 30 and the arc inducing section 50 are short-circuited, a fluid 26 made of insulating gas is injected toward the arc inducing section 50 to suppress the generation of an arc, thereby minimizing damage and breakage of the movable contact 30 due to the generation of an arc.

[0066] The scope of the present invention is not limited to the above-described exemplary embodiments, and many other variations based on the present invention will be possible within the above technical scope by a person of ordinary skill in the art.

Claims

1. Housing and a movable part provided inside the housing, reciprocally movable by an operating device, and having a movable contact at one end; a fixed part provided with a fixed-side contact that is disposed at a predetermined distance from the movable part and selectively grounds or shorts the movable-side contact in response to the reciprocating motion of the movable part; an arc induction unit that is provided inside the fixed side contact, that is installed so as to be able to rise and fall inside the fixed side contact, and that induces an arc that occurs at the movable side contact when the movable side contact approaches or moves away from the fixed side contact.

2. 2. The earthing switchgear according to claim 1, wherein the arc inducing portion is disposed so as to protrude further upward than the fixed contact.

3. The earthing switchgear according to claim 1, wherein the arc guide portion is arranged so as to be elastically supported in the direction of the movable contact.

4. The arc induction unit is an arc induction body installed inside the fixing part, the arc induction body having an elastic member mounting groove formed on an upper surface thereof and a lifting bar guide groove formed on a lower surface thereof; a bar-shaped lifting bar provided inside the arc induction body and movable up and down along the lifting guide groove; an arc induction head fixed to an end of the lifting bar, made of a conductive material, for inducing an arc when the movable contact is adjacent to the arc induction head; 2. The earthing switchgear according to claim 1, further comprising: an elastic member made of an elastic body, disposed inside the elastic member mounting groove, one end of which is in close contact with one side of the arc inducing head to elastically support the arc inducing head.

5. The earthing switchgear according to claim 1, further comprising a fluid containing section formed of an empty space and filled with a fluid inside the movable section.

6. On one side of the fluid containing portion, 6. The earthing switchgear according to claim 5, further comprising a fluid injection hole that penetrates the movable part vertically, one end of which communicates with the fluid containing part and the other end of which communicates with the outside, for injecting fluid onto the arc guiding part.

7. The fluid filled inside the fluid storage portion is The earthing switchgear according to claim 5, wherein when the fixed contact and the movable contact are separated, the gas is jetted onto the arc inducing portion.

8. 8. The earthing switchgear according to claim 7, wherein the fluid is made of insulating gas and is sprayed onto the lower part of the movable contact to suppress the generation of an arc.

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