Current transformer for air circuit breaker

Abstract

A current transformer for an air circuit breaker is disclosed. The air circuit breaker according to one aspect of the present invention comprises: a housing which has an inner space and which is shaped as an enclosure that includes a terminal arrangement hole having a circular or rectangular terminal that passes therethrough and is arranged therein; and a signal CT unit using a Rogowski coil, which is arranged to wrap the circumference of the terminal arrangement hole in the inner space, thereby measuring a load state, wherein the Rogowski coil can include a Rogowski core which is made of an elastic material and which is arranged in the inner space while the diameter length in a first direction of the hole and the diameter length in a second direction of the hole are different from each other.

Description

Current transformer for air circuit breaker

[0001] The present invention relates to a current transformer for an air circuit breaker, and more specifically, to a current transformer for an air circuit breaker having improved assemblability by using a material having elasticity and hardness as a Rogowski core.

[0002] In general, an air circuit breaker (ACB) is a device that opens and closes a device that receives power from a power transmission system or line using air as an arcing medium, or cuts off the current in the event of a safety accident such as an overload or short circuit, and protects the power system and load equipment.

[0003] These air circuit breakers are located at the upper stage in the low-voltage distribution system to protect the circuit, and as can be seen in Korean Patent Publication No. 10-2021-0115587, their role is performed depending on whether the fixed contact (upper terminal) and the movable contact (lower terminal) are energized.

[0004] Meanwhile, for this purpose, the air circuit breaker measures the load status of the line internally, detects abnormalities in the load status or accidents, and includes a relay (OCR) to cut off the current when an abnormal current occurs.

[0005] In order for the relay of this air circuit breaker to operate normally, a current transformer (CT) that detects it must be installed, and current (power supply) and voltage (load current value) are supplied from the current transformer (CT).

[0006] For this purpose, current transformers typically utilize laminated core coils (magnetic cores). However, these laminated core coils are large and heavy, which poses the problem of poor linearity beyond a certain volume. To address this issue, current transformers are constructed using laminated core coils and Rogowski coils.

[0007] The part using this laminated core coil can be classified as a power CT, and the part using a Rogowski coil can be classified as a signal CT.

[0008] The applicant has presented an example of a power CT applicable to such a transformer, Korean Patent Publication No. 10-2020-0080007, “Transformer for an air circuit breaker.”

[0009] Meanwhile, unlike power CTs that use a magnetic core (laminated iron core coil) with a high permeability, which is a ferromagnetic material, to power the relay, signal CTs use a core made of general plastic rather than a ferromagnetic material to transmit the load current value, and wind coil wire around it to form a Rogowski coil.

[0010] In this way, the problem of not being able to produce linear output due to the saturation phenomenon of the ferromagnetic material when the load current increases is solved through the power CT and signal CT, and a constant value can be produced regardless of the size of the load current, providing stability in system protection.

[0011] Meanwhile, as described above, the air circuit breaker performs its function depending on whether its terminals are energized. These terminals, passing through the current transformer, serve as the main circuit.

[0012] As can be seen in Korean Patent Publication No. 10-2021-0115587, the existing shape of the lower terminal has a circular (cylindrical) shape.

[0013] Accordingly, the conventional transformer for an air circuit breaker has a circular terminal arrangement hole (through hole) formed in the same manner so that the lower terminal described above can be placed through it.

[0014] However, depending on the type of air circuit breaker and the user's request, air circuit breakers having a square (including rectangular) shape instead of a round terminal are being produced, and accordingly, the shape of the Rogowski core of the Rogowski coil constituting the signal CT inevitably needs to be modified, which is causing a problem.

[0015] In other words, in order to form a space within the limited transformer case (housing) through which a rectangular terminal can be placed, the shape of the Rogowski core needed to be an oval shape that could contain it.

[0016] Meanwhile, as is known, Rogowski coils can be manufactured by winding coil wire onto a Rogowski core in the shape of a circular ring using a winding machine to facilitate winding of the coil wire. For the normal operation of Rogowski coils, the number of turns of the coil wire wound in each section should not vary.

[0017] However, as described above, the shape of the terminal of the air circuit breaker inevitably changed from circular to rectangular, and accordingly, the shape of the Rogowski core also had an oval shape rather than a circular shape, which inevitably caused a problem in that the number of turns of the coil wire in each section had to differ.

[0018] Accordingly, there is an urgent need for the development of a technology that can stably manufacture Rogowski coils while improving assembly and assembling Rogowski coils in an oval shape within the limited space of a transformer.

[0019] The present invention is intended to solve the above-mentioned problems, and the purpose of the present invention is to provide a transformer for an air circuit breaker having improved assemblability by using a material having elasticity and hardness as a Rogowski core.

[0020] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0021] According to one aspect of the present invention, a current transformer for an air circuit breaker is provided.

[0022] A current transformer for an air circuit breaker comprises a housing having an internal space and a body shape including a terminal arrangement hole through which a round or square terminal is arranged; and a signal CT unit using a Rogowski coil that is arranged to surround the perimeter of the terminal arrangement hole in the internal space and measures a load state.

[0023] At this time, the Rogowski coil may include a Rogowski core made of an elastic material and arranged in such a way that the diameter length in the first direction and the diameter length in the second direction of the hole in the internal space are different from each other.

[0024] Meanwhile, the terminal arrangement hole may include a through hole in which a circular terminal can be arranged, and an expansion hole in which both sides of the through hole in the first or second direction are expanded to allow a square terminal to be arranged.

[0025] Meanwhile, the above-mentioned Rogowski core can be formed of a silicone material having a hardness of 75 Shore A to 90 Shore A through the test method of ASTM D2240 (Shore A).

[0026] Meanwhile, the housing may form at least one deformation prevention wall protruding in the third direction from the bottom surface adjacent to the Rogowski core in the internal space.

[0027] At this time, the Rogowski core may have a shape of a circular ring when not placed in the housing.

[0028] At this time, the Rogowski core may have a cross-section having an 'H' shape, including an outer first line wall and an inner second line wall that has a gap from the first line wall and forms a groove.

[0029] At this time, the Rogowski core may include at least one reinforcing wall that fills the gap between the first line wall and the second line wall.

[0030] Meanwhile, the housing may include a second cover equipped with the signal CT unit, and a first cover coupled to the second cover and equipped with a power CT unit that supplies power.

[0031] At this time, an insulating material separation plate may be further provided between the signal CT unit and the power CT unit.

[0032] At this time, as an example, the second cover may include a border wall that extends in a third direction along the border of the bottom surface to form an outer shape, a hollow wall that protrudes in a circular shape in the third direction from the bottom surface to form a through hole of the terminal arrangement hole, and an extension wall that extends while both sides of the hollow wall in the first direction or the second direction extend in the first direction or the second direction to form an extension hole of the terminal arrangement hole.

[0033] In addition, the second cover may further include at least one deformation-preventing wall that has a gap between the hollow wall and the hollow wall and forms a gently curved shape, and protrudes in a third direction from the bottom surface and has a length.

[0034] In addition, the second cover may further include at least one supporting protrusion that supports the power CT unit while being positioned so as to be positioned upward in the third direction of the signal CT unit on one side of the bottom surface.

[0035] Meanwhile, the power CT unit may include a rigid magnetic core having a hole through which the terminal passes; a secondary coil disposed adjacent to the magnetic core, inducing a secondary current through a current flowing in the terminal and supplying the secondary current; and a flux compensation member coupled to the magnetic core to compensate for the current induced in the secondary coil.

[0036] According to the above configuration, the transformer for an air circuit breaker according to the present invention can form a Rogowski coil of a stable shape by using a material having elasticity and hardness as a Rogowski core, and can be assembled in an oval shape in the housing space of the transformer, thereby improving the assembling efficiency.

[0037] In addition, by configuring a terminal arrangement hole including a circular through hole having a diameter of a setting and an expansion hole that is expanded on both sides in the first or second direction of the through hole, a circular or square terminal can be stably placed through it, thereby maximizing the stability and assemblability of the device.

[0038] In addition, since it has a terminal arrangement hole including a circular through hole having a diameter of a setting and an expansion hole that is expanded on both sides in the first or second direction of the through hole, it can be used for both circular terminals and square terminals as needed, thereby having the effect of maximizing versatility.

[0039] In addition, a deformation prevention wall is provided in the internal space of the housing where the Rogowski core is placed and is formed protruding adjacent to the Rogowski core, thereby having the effect of preventing the Rogowski core from being restored to its original circular shape by elastic force.

[0040] In addition, the Rogowski core has the effect of increasing the ease of manufacturing and assembly and lowering the manufacturing cost by using a silicone material that has elasticity while having the hardness of the setting.

[0041] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0042] Figures 1 to 3 are drawings showing a state in which a transformer for an air circuit breaker according to one embodiment of the present invention is viewed from the outside.

[0043] Figure 4 is an exploded perspective view showing a transformer for an air circuit breaker according to one embodiment of the present invention.

[0044] Fig. 5 is a drawing showing a cross-section of Ⅰ-Ⅰ' for a current transformer for an air circuit breaker according to Fig. 1.

[0045] FIG. 6 is a drawing showing an example of a second cover of a housing applied to a transformer for an air circuit breaker according to one embodiment of the present invention.

[0046] FIG. 7 is a perspective view showing an example of a Rogowski core applied to a transformer for an air circuit breaker according to one embodiment of the present invention.

[0047] FIG. 8 is a drawing schematically showing the formation of a signal CT section by winding a coil wire around a Rogowski core applied to a transformer for an air circuit breaker according to one embodiment of the present invention to form a Rogowski coil and applying the Rogowski coil to the second cover of FIG. 6.

[0048] FIG. 9 is a drawing showing a state of use in which a Rogowski core is applied to a second cover in a transformer for an air circuit breaker according to one embodiment of the present invention.

[0049] FIG. 10 is a drawing showing a state in which a transformer for an air circuit breaker according to one embodiment of the present invention is mounted on an air circuit breaker and equipped with a terminal.

[0050] The present invention, in its best form, comprises a housing having an internal space in the shape of a body including a terminal arrangement hole through which a circular or square terminal is arranged; and a signal CT unit using a Rogowski coil arranged in the internal space while surrounding the perimeter of the terminal arrangement hole to measure a load state. At this time, the Rogowski coil is provided as a current transformer for an air circuit breaker, including a Rogowski core made of an elastic material and arranged in the internal space such that the diameter length in the first direction of the hole and the diameter length in the second direction are different from each other.

[0051] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. To clearly explain the present invention, parts irrelevant to the description are omitted in the drawings, and the same reference numerals designate identical or similar components throughout the specification.

[0052] The words and terms used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principles by which the inventor can define terms and concepts in order to best explain his or her invention.

[0053] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to a preferred embodiment of the present invention, and do not represent all of the technical ideas of the present invention, so there may be various equivalents and modified examples that can replace the configuration at the time of filing of the present invention.

[0054] In this specification, terms such as “include” or “have” are intended to describe the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0055] When a component is said to be "in front of," "behind," "above," or "below" another component, this includes not only being placed "in front of," "behind," "above," or "below" the other component in direct contact with it, but also if there is another component intervening therebetween. Furthermore, when a component is said to be "connected" to another component, this includes not only being directly connected to one another, but also being indirectly connected to one another, unless there are special circumstances.

[0056] In addition, the terms "X-axis", "Y-axis", and "Z-axis" used in the description will be understood with reference to the coordinate system illustrated in the drawing. In addition, although the X-axis direction is referred to as the first direction, the Y-axis direction as the second direction, and the Z-axis direction as the third direction in the description, this is only an example according to a relative viewpoint, and the first to third directions and the coordinate axes (X, Y, Z axes) are only introduced to explain the relative positions between components, and do not limit the absolute positions of each component.

[0057] In addition, in explaining the present invention, specific descriptions of related known functions or configurations will be omitted in order to avoid obscuring the gist of the present invention.

[0058]

[0059] Hereinafter, a current transformer for an air circuit breaker according to one embodiment of the present invention will be described with reference to the drawings.

[0060] As illustrated, a current transformer (100) for an air circuit breaker according to one embodiment of the present invention comprises a housing (110) having an internal space (S), a power CT unit (120) using a magnetic core laminated inside the housing (110), and a signal CT unit (130) using a Rogowski coil.

[0061] At this time, the housing (110) can have a body structure of a shape set through the combination of a first cover (110a) and a second cover (110b) that are combined as needed, and has a structure in which a power CT unit (120) can be mounted on the first cover (110a) and a signal CT unit (130) can be mounted on the second cover (110b).

[0062] Accordingly, the current transformer (100) for an air circuit breaker according to one embodiment of the present invention may have a structure in which a second cover (110b), a signal CT unit (130), a power CT unit (120), and a first cover (110a) are sequentially laminated and combined along the third direction (Z-axis direction), as confirmed in FIG. 4. At this time, a partition plate (140) may be further provided between the signal CT unit (130) and the power CT unit (120) for stable mounting and separation.

[0063] This separator (140) can serve to prevent short circuit by blocking contact between the signal CT unit (130) and the power CT unit (120) with an insulating material.

[0064] Meanwhile, the housing (110) applied to the transformer (100) for an air circuit breaker according to one embodiment of the present invention has a terminal arrangement hole (H) through which a round or square terminal is placed when mounted on an air circuit breaker (not shown).

[0065] Meanwhile, the terminal arrangement hole (H) may include a through hole (111) having a circular shape so that a circular terminal can be arranged, and an expansion hole (112) in which both sides of the through hole (111) in the first or second direction are expanded so that a square (or rectangular) terminal having a length exceeding the diameter (R) of the through hole (111) can be arranged.

[0066] Accordingly, the through hole (111) having a circular shape forms a first space (A1, Fig. 2) in which a circular terminal can be placed, and a part of the through hole (111) and an area of ​​the expansion hole (112) can form a second space (A2, Fig. 2) in which a square terminal (20, Fig. 10) can be placed.

[0067] Accordingly, the transformer (100) for an air circuit breaker according to one embodiment of the present invention can be applied to both circular and square terminals as needed.

[0068] The expansion hole (112) forming the second space (A2) in the city is provided on both sides of the second direction (Y-axis direction) of the through hole (111), and is illustrated as having an expansion length (a) in the first direction and an expansion width (b) in the second direction, but is not limited thereto, and of course, the expansion length and width can be formed narrower or wider depending on the size and shape of the square terminal (20, Fig. 10).

[0069] Also, referring to FIGS. 2 and 10, for example, the second space (A2) is illustrated as a space in which expansion holes (112) are formed on both sides in the second direction (Y-axis direction). However, depending on the terminal arrangement of the air circuit breaker, the second space (A2) may be a space in which expansion holes (112) are formed on both sides in the first direction (X-axis direction), or the second space (A2) may be a space in which expansion holes (112) are formed on both sides in the diagonal direction. In other words, the position of the expansion holes (112) forming the second space (A2) may be formed accordingly depending on the terminal arrangement of the air circuit breaker.

[0070] Meanwhile, the current transformer (100) for an air circuit breaker according to one embodiment of the present invention may further include a spacer portion (113, FIG. 3) to maintain a stable gap with the mounting portion and reduce vibration when mounted on an air circuit breaker (ACB). In the drawing, the spacer portion (113) is shown on one side of the second cover (110b), but it is of course possible to form it on one side of the first cover (110a) as needed.

[0071]

[0072] Referring again to FIGS. 4 and 5, a current transformer (100) for an air circuit breaker according to one embodiment of the present invention is provided with a power CT unit (120) mounted on a first cover (110a) constituting a housing (110).

[0073] This power CT unit (120) may have a structure that includes a rigid magnetic core (121) having a hole (121a) that corresponds to the terminal arrangement hole (H) of the housing (110) so that a terminal passes through it, a secondary coil (122) that is arranged adjacent to the magnetic core (121) so that a secondary current is induced through a current flowing in the terminal and supplies the secondary current, and a magnetic flux compensation member (123) that is coupled to the magnetic core (121) and compensates for the current induced in the secondary coil.

[0074] The magnetic core (121) may be a plate-shaped member having a predetermined thickness and made of a magnetic material, and the secondary coil (122) may be a coil wire wound around the core and may be formed to be long and coupled along the second direction of the length of the magnetic core (121), and the magnetic flux compensation member (123) may be a plate-shaped member having a predetermined thickness and may be formed to be laminated and coupled on both sides of the magnetic core (121).

[0075] The power CT unit (120) described above may be, for example, Republic of Korea Patent Publication No. 10-2020-0080007 disclosed by the applicant of the present invention, and a detailed description thereof will be omitted to avoid obscuring the gist of the present invention.

[0076] And, the transformer (100) for an air circuit breaker according to one embodiment of the present invention is provided with a signal CT unit (130) mounted on a second cover (110b) constituting a housing (110).

[0077] This signal CT section (130) is composed of a Rogowski coil in which a coil wire (11, Fig. 8) is wound around a Rogowski core (200).

[0078] In the city, only the Rogowski core (200) constituting the Rogowski coil is shown, but it is self-evident that it should be understood that the coil wire (11, Fig. 10) is wound around the outer surface of the Rogowski core (200) is omitted.

[0079] In this way, the relay (OCR) of the air circuit breaker to which the current transformer (100) for the air circuit breaker of the present invention having a power CT section (120) and a signal CT section (130) is applied is operated by the current supplied through the power CT section (120) and controls the air circuit breaker according to the signal size of the current input through the signal CT section (130).

[0080]

[0081] Meanwhile, as described above, the transformer (100) for an air circuit breaker according to one embodiment of the present invention has a terminal arrangement hole (H) in the housing (110) so that it can be applied to a square terminal as well.

[0082] Accordingly, the signal CT unit (130) is arranged to surround the terminal arrangement hole (H) on the internal space (S) of the housing (110), so that the load state can be measured using a Rogowski coil.

[0083] At this time, the Rogowski core (200, Fig. 4) of the Rogowski coil is made of a material that has elasticity and a set hardness.

[0084] Accordingly, in the internal space (S) of the housing (110), the Rogowski core (200) can be arranged with different diameter lengths (r-α) in the first direction and (r+β) in the second direction according to the square terminal (20, Fig. 10).

[0085] In other words, assuming that the Rogowski core (200) before being mounted on the second cover (110b) of the housing (110) has a circular ring shape with a diameter (r, FIG. 9), when such a Rogowski core (200) is mounted on the second cover (110b), it has an elliptical ring shape that is compressed in the first direction and stretched in the second direction according to the shape of the terminal (20, FIG. 10). Accordingly, the Rogowski core (200) when mounted on the housing cannot help but have a state in which the diameter length (r-α) in the first direction and the diameter length (r+β) in the second direction are different from each other, as shown in the drawing (see FIGS. 9 and 10).

[0086] The shape deformation of the Rogowski core (200) depending on the state when it is not mounted on the housing (110) and the state when it is mounted on the housing (110) may be because the Rogowski core (200) is a material that has elasticity while having the set hardness.

[0087] For this purpose, preferably, the Rogowski core (200) is made of a silicone material having a hardness of 75 Shore A to 90 Shore A as determined by the test method of ASTM D2240 (Shore A).

[0088] Referring again to FIG. 8, the Rogowski coil is formed by winding a coil wire (11) onto a Rogowski core (200) in the shape of a circular ring having a diameter (r) using a winding machine (10).

[0089] At this time, when winding the coil wire (11) onto the Rogowski core (200) using a winding machine (10), the shape of the circular ring of the Rogowski core (200) must not be deformed.

[0090] This is because if the shape of the Rogowski core (200) is deformed while the coil wire (11) is being wound, the number of times the coil wire (11) is wound may vary depending on the part, or a problem may arise where some parts are wound densely and other parts are wound roughly.

[0091] In order to solve such a problem, it is preferable that the Rogowski core (200) applied to the current transformer (100) for the air circuit breaker of the present invention uses silicone having a hardness of 75 Shore A to 90 Shore A as tested by the ASTM D2240 (Shore A) test method as described above.

[0092] ASTM D2240 is a standard test method of the American Society for Testing and Materials (ASTM) that defines a "hardness test method" and is widely known as a standard for Shore A hardness measurement methods, so a detailed description thereof will be omitted to avoid obscuring the gist of the present invention.

[0093] Meanwhile, if the hardness of the silicon forming the Rogowski core (200) is less than 75 Shore A, the Rogowski core (200) may be too soft for winding the coil wire, and a problem may arise in which the shape of the Rogowski core (200) is deformed during the winding operation of the coil wire (11).

[0094] In addition, when the hardness of the silicon exceeds 90 Shore A, the shape of the Rogowski core (200) may not be deformed during the operation of winding the coil wire (11) in a state where the Rogowski core (200) is too hard, but when the elasticity is too small or absent, a problem may occur where it is difficult to mount the Rogowski core (200) in a state where the length in the first direction and the length in the second direction are different from each other, as shown in (c) of FIG. 8 or FIG. 9, when mounting it in the housing (110) of the current transformer (100) for an air circuit breaker.

[0095] As a specific example, such a logoski core (200) may have a shape of a circular ring when not mounted to the housing (110) (Fig. 8 (a)).

[0096] Meanwhile, as another embodiment, the Rogowski core (200) may have a shape for easy winding of the coil wire (11) and cost reduction.

[0097] Referring to FIG. 7, as an example, the Rogowski core (200) may have a shape of a circular ring having a hole (201), and may include an outer first line wall (210) and an inner second line wall (230) that forms a groove (220) while having a gap from the first line wall (210), so that the cross-section when cut may have an 'H' shape.

[0098] As such, since the Rogowski core (200) has an 'H' shape in its cross section including the first line wall (210) and the second line wall (230), even if the Rogowski core (200) is placed in the housing (110) and has an oval shape, the coil wire (11) that is wound can be maintained in its correct position without being pushed. In other words, the coil wire (11) that is wound can be maintained in its correct position even when an external force is applied for mounting, as it has a structure that wraps around the thin first line wall (210) and the second line wall (230).

[0099] Meanwhile, the Rogowski core (200) may include at least one reinforcing wall (240) that fills the gap between the first line wall (210) and the second line wall (230). This will help prevent deformation of the Rogowski core (200) when winding the coil wire (11, Fig. 8).

[0100]

[0101] Meanwhile, referring again to FIGS. 4, 6 and 9, a current transformer (100) for an air circuit breaker according to one embodiment of the present invention forms a housing (110) including a second cover (110b) in which a signal CT unit (130) is mounted and protected, and a first cover (110a) in which a power CT unit (120) for supplying power is mounted and protected, and which is coupled to the second cover (110b).

[0102] The connection between the first cover (110a) and the second cover (110b) can be achieved by using various connection methods (bolts, nuts, etc.), and a hook connection method for detachment can be used. The connection structure between the first cover (110a) and the second cover (110b) can be applied with various known structures and functions, and thus a detailed description thereof will be omitted in order to avoid obscuring the gist of the present invention.

[0103] Meanwhile, the above-described Rogowski core (200) is mounted on the second cover (110b) constituting the housing (110) and constitutes the signal CT section (130).

[0104] For this purpose, referring to Fig. 6, the second cover (110b) has a border wall (110b-1) that extends upward in the third direction along the border of the bottom surface (110b-4) to form an outer shape for stable mounting of the Rogowski core (200), and has an inner space (S) therein.

[0105] And, the second cover (110b) has a hollow wall (110b-2) that forms a circle upward in the third direction (Z-axis direction) from the bottom surface (110b-4) so ​​that a circular through hole (111) is formed for forming a terminal arrangement hole (H).

[0106] In addition, the second cover (110b) has an extended expansion wall (110b-3) in which both sides of the hollow wall (110b-2) in the first direction or the second direction are extended in the first direction or the second direction so that an expansion hole (112) is formed for forming a terminal arrangement hole (H).

[0107] Meanwhile, the second cover (110b) has a gap (d1) between the hollow wall (110b-2) and forms a gentle curve, and may further include at least one deformation prevention wall (116) protruding upward in the third direction from the bottom surface (110b-4) and having a length.

[0108] In addition, the second cover (110b) may further include at least one supporting protrusion (115) that supports the power CT unit (120, FIG. 4) that is positioned while being secured to the upper portion of the third direction of the signal CT unit (130, FIG. 4) on one side of the bottom surface (110b-4).

[0109] It goes without saying that the size, position and shape of the hollow wall (110b-2), expansion wall (110b-3), deformation prevention wall (116) and support protrusion (115) of the second cover (110b) can be changed according to the size of the transformer (100) for the air circuit breaker and the size of the Rogowski core (200).

[0110]

[0111] As described above, the transformer (100) for an air circuit breaker according to one embodiment of the present invention can form a Rogowski coil of a stable shape by using a material having a set hardness and elasticity as a Rogowski core (200), and can be assembled in an oval shape on the inner space (S) of the housing (110) of the transformer (100), thereby improving the assembling ability.

[0112] In addition, by configuring a terminal arrangement hole (H) including a circular through hole (111) having a diameter (R) of a setting and an expansion hole (112) that is expanded on both sides in the first or second direction of the through hole (111), a circular or square terminal can be stably placed through it, thereby maximizing the stability and assemblability of the device.

[0113] In addition, since it has a terminal arrangement hole (H) including a circular through hole (111) having a diameter (R) of a setting and an expansion hole (112) that is expanded on both sides in the first or second direction of the through hole (111), it can be used for both circular terminals and square terminals as needed, thereby maximizing the versatility of the transformer for an air circuit breaker.

[0114] In addition, a deformation prevention wall (116) protruding and formed adjacent to the Rogowski core (200) in the housing (110, i.e., the internal space (S) of the second cover (110b) in which the Rogowski core (200) is placed can be provided, thereby preventing the Rogowski core (200) from being restored to its original circular shape by elastic force, thereby increasing stability.

[0115] Meanwhile, the Rogowski core (200) can be made of a silicone material that has elasticity while maintaining the hardness of the setting, thereby increasing the ease of manufacturing and assembly and lowering the manufacturing cost.

[0116] Although the embodiments of the present invention have been described, the spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

Claims

1. A housing having an internal space and a body shape including a terminal arrangement hole through which a round or square terminal is arranged; and, A signal CT unit using a Rogowski coil that is arranged to surround the perimeter of the terminal arrangement hole in the above internal space and measures the load state is included. The above Rogowski coil is, A current transformer for an air circuit breaker, comprising a Rogowski core made of an elastic material and arranged so that the diameter length in the first direction and the diameter length in the second direction of the hole in the internal space are different from each other.

2. In paragraph 1, The above terminal arrangement hole is, A through hole where a circular terminal can be placed, A current transformer for an air circuit breaker, which includes an expansion hole in which a square terminal can be placed by expanding both sides of the first or second direction of the above-mentioned through hole.

3. In paragraph 1, The above Rogowski core is, A current transformer for an air circuit breaker, formed of a silicone material having a hardness of 75 Shore A to 90 Shore A according to the test method of ASTM D2240 (Shore A).

4. In paragraph 1, The above housing, A transformer for an air circuit breaker, wherein at least one deformation prevention wall is formed in the internal space adjacent to the Rogowski core and protrudes in a third direction from the bottom surface.

5. In paragraph 1, The above Rogowski core is, A current transformer for an air circuit breaker having a circular ring shape when not placed in the above housing.

6. In paragraph 1, The above Rogowski core is, A transformer for an air circuit breaker, comprising an outer first line wall and an inner second line wall having a gap from the first line wall and forming a groove, the cross-section of which has an 'H' shape.

7. In paragraph 6, The above Rogowski core is, A transformer for an air circuit breaker, comprising at least one reinforcing wall that fills the gap between the first line wall and the second line wall.

8. In paragraph 1, The above housing, A second cover equipped with the above signal CT unit, A current transformer for an air circuit breaker, comprising a first cover coupled to the second cover and having a power CT unit for supplying power.

9. In paragraph 8, A current transformer for an air circuit breaker, wherein an insulating material separation plate is further provided between the signal CT section and the power CT section.

10. In paragraph 8, The above second cover, A border wall extending in a third direction along the border of the floor surface to form an outer shape, A hollow wall protruding in a circular shape in the third direction from the bottom surface to form a through hole of the terminal arrangement hole, A transformer for an air circuit breaker, comprising an extended expansion wall in which both sides of the hollow wall in the first direction or the second direction are extended in the first direction or the second direction to form an expansion hole of the terminal arrangement hole.

11. In paragraph 10, The above second cover, A transformer for an air circuit breaker, further comprising at least one deformation prevention wall having a gap between the hollow wall and the hollow wall and forming a shape of a gentle curve, and protruding in a third direction from the bottom surface.

12. In paragraph 10, The above second cover, A transformer for an air circuit breaker, further comprising at least one supporting projection for supporting the power CT unit, which is arranged to be positioned upward in the third direction of the signal CT unit on one side of the floor surface.

13. In paragraph 8, The above power CT unit, A rigid magnetic core having a hole through which the terminal passes, A secondary coil arranged adjacent to the magnetic core, inducing a secondary current through the current flowing in the terminal, and supplying the secondary current, and A current transformer for an air circuit breaker, comprising a flux compensation member coupled to the magnetic core to compensate for the current induced in the secondary coil.

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