Transition Resistor Assembly for Installing On-Load Tap Changer of Transformer

Abstract

The present invention relates to a transition resistor assembly for installing a load tap changer of a transformer, which improves heat dissipation to reduce failures caused by coil disconnection, allows for easy replacement of the faulty element in the event of a failure, and facilitates structural modification according to resistance capacity. To solve the above problem, the transition resistor assembly for installing a load tap changer of a transformer according to the present invention comprises: a rectangular plate-shaped base plate having first and second slit holes formed in pairs at a predetermined distance apart to penetrate the upper and lower surfaces at both ends, and a plurality of through holes formed at the corners that penetrate the upper and lower surfaces; a first terminal of a predetermined size, in which both ends are respectively inserted through the pair of first slit holes, and then the protruding ends are bent and fixed to the base plate; and a second terminal of a predetermined size, in which both ends are respectively inserted through the pair of second slit holes, and then the protruding ends are bent and fixed to the base plate. The invention is characterized by comprising: a resistance coil of a predetermined length, one end of which is connected to the first terminal and the other end of which is wound multiple times on the base plate and then connected to the second terminal; a first connecting cable of a predetermined length, one end of which is grounded to the first terminal; a second connecting cable of a predetermined length, one end of which is grounded to the second terminal; and a plurality of spacers installed to be positioned on one side of the base plate through a fixing screw penetrating the through hole, thereby separating the base plate from an adjacent structure at a predetermined distance.

Description

Technology Field

[0001] The present invention relates to a transition resistor assembly for installing a load tap changer of a transformer, and more specifically, to a transition resistor assembly for installing a load tap changer of a transformer that is installed inside an on-load tap changer (OLTC) installed in a transformer, which disperses (limits) the arc energy generated when the contacts are opened and closed while the transformer voltage is operating (load), thereby reducing the potential difference between the contacts, and consequently reduces the arc energy and shortens the duration of the arc energy. Background Technology

[0002] Generally, a transition resistor is installed in the load tap changer of a transformer to temporarily insert into the circuit during the load tap switching process. This limits the current, thereby reducing the potential difference between contacts and mitigating the arc energy generated during tap switching.

[0003] As a prior art for a transition resistor as described above, a load selector with a switching resistor attached, disclosed in Korean Patent Publication No. 1995-0034335 (hereinafter referred to as the 'Patent Document'), is disclosed.

[0004] The above patent document describes a load selector with a switching resistor attached, comprising a switch shaft having a connection system consisting of a cylindrical oil container arranged to have a fixed tab connected inside, a switch connection arranged inside and rotated by a driving means and directly connected to a load branch line, and two auxiliary switch connections each connected to a load branch line by a switching resistor. In this load selector, the electrically conductive clamping ring, consisting of two parts, is provided with a ring in the connection system and electrically connected in series to form a switching resistor, and a connection flange having at least one resistor bundle connected is arranged on the switch shaft, and the resistor bundle is composed of a small frame of resistors connected vertically to each other and electrically connected together.

[0005] However, the conventional switching resistors for installing load tap changers (hereinafter collectively referred to as "transition resistors") described above are formed by electrically connecting multiple transition resistors in series or by a structure in which a coil (resistance wire) is wound on an insulating bobbin having a predetermined diameter and length. Since these conventional transition resistors consist of a resistor with a fixed shape, it is difficult to change the resistance capacity, and consequently, there is the difficulty of having to change the entire shape and arrangement to change the resistance capacity.

[0006] In addition, in the case of transition resistors with coins wound on a bobbin, poor heat dissipation leads to the accumulation of fatigue in the coil, and there is a problem where failures frequently occur, such as the coil breaking due to insulation degradation and fluctuations in resistance values.

[0007] Therefore, there is a need to develop a transition resistor assembly with an improved structure that enhances heat dissipation to reduce failures caused by coil disconnection, allows for easy replacement of the faulty component in the event of a failure, and facilitates structural modifications based on resistance capacity. Prior art literature

[0008] KR 10-1995-0034335 A (1995. 12. 28.)KR 10-2023129 B1 (2019. 09. 11.)KR 10-2219309 B1 (2021. 02. 17.)KR 10-2389344 B1 (2022. 04.) 18.) The problem to be solved

[0009] The present invention was devised to solve the problems associated with the conventional transition resistor for a load tap changer as described above. The objective of the present invention is to provide a transition resistor assembly for a transformer load tap changer that improves heat dissipation to reduce failures caused by coil disconnection, allows for easy replacement of the faulty component in the event of a failure, and facilitates structural modification according to resistance capacity. means of solving the problem

[0010] A transition resistance assembly for installing a load tap changer of a transformer according to the present invention for solving the above problem comprises: a rectangular plate-shaped base plate having first and second slit holes formed in pairs at a predetermined distance apart to penetrate the upper and lower surfaces at both ends, and a plurality of through holes formed at the corners that penetrate the upper and lower surfaces; a first terminal of a predetermined size, having both ends inserted through the pair of first slit holes, and then having the protruding ends bent and fixed to the base plate; a second terminal of a predetermined size, having both ends inserted through the pair of second slit holes, and then having the protruding ends bent and fixed to the base plate; a resistance coil of a predetermined length, having one end connected to the first terminal and the other end wound multiple times on the base plate and then connected to the second terminal; a first connecting cable of a predetermined length, having one end grounded to the first terminal; and a second connecting cable of a predetermined length, having one end grounded to the second terminal. It is characterized by including a plurality of spacers installed to be positioned on one side of the base plate through a fixing screw penetrating the through hole, thereby separating the base plate from an adjacent structure at a predetermined distance.

[0011] Furthermore, another feature of the present invention is that the transition resistance assembly is configured such that a plurality of base plates are stacked and installed at a predetermined interval vertically by the length of the spacer according to the capacity of the arc energy, the free end of the first connecting cable is connected to the first terminal of another base plate stacked relatively higher, and the free end of the second connecting cable is connected to the second terminal of another base plate stacked relatively lower, so that a plurality of resistance coils wound on each of the vertically stacked plurality of base plates are electrically connected in a line.

[0012] In addition, another feature of the present invention is that the base plate is made of mica having a predetermined thickness, the first and second terminals are made of silver-plated copper terminals, and the first and second connecting cables are covered with silicone material.

[0013] In addition, another feature of the present invention is that the first and second connecting cables are fixed to the first and second terminals through soldering. Effects of the invention

[0014] According to the present invention, since the transition resistance assembly is installed in a stacked manner such that the gap between base plates is vertically spaced by the length of the spacer, there is an advantage in that the number can be easily increased or decreased to match the required resistance capacity.

[0015] In addition, due to the spaced-apart space between the base plates, the heat generated in the resistance coil is transferred through the base plates and quickly dissipated, so there is an advantage of reducing failures caused by the resistance coil being disconnected due to overheating. Brief explanation of the drawing

[0016] FIG. 1 is a schematic diagram showing an example of a transition resistance assembly for installing a load tap changer of a transformer according to the present invention. FIG. 2 is a side view showing an example of a transition resistance assembly for installing a load tap changer of a transformer according to the present invention. FIG. 3 is a drawing showing an example of a base plate according to the present invention. FIG. 4(a) is a drawing showing an example of the first and second terminals according to the present invention. FIG. 4(b) is a cross-sectional view showing an example in which the first and second terminals according to the present invention are installed on a base plate. FIG. 5 is a drawing showing an example in which a resistance coil and first and second connecting cables according to the present invention are connected to first and second terminals. FIG. 6 is a drawing showing an example in which a plurality of transition resistance assemblies according to the present invention are stacked and installed. Specific details for implementing the invention

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0018] The present invention aims to provide a transition resistor assembly for installing a transformer load tap changer, which improves heat dissipation to reduce failures caused by coil disconnection, allows for easy replacement of the fault element in the event of a failure, and facilitates structural changes according to resistance capacity. For this purpose, the transition resistor assembly (1) of the present invention includes a base plate (10), first and second terminals (20A, 20B), a resistance coil (30), first and second connecting cables (40A, 40B), and a spacer (50), as shown in FIGS. 1 and 2.

[0019] The base plate (10) is configured to allow the first and second terminals (20A, 20B), the resistance coil (30), and the spacer (50), which will be described later, to be fixedly installed.

[0020] As shown in FIG. 3, this base plate (10) is formed in the shape of a rectangular plate having a predetermined size and thickness, and the base plate (10) can be formed to have a length (L) of 75 to 85 mm, a width (W) of 35 to 45 mm, and a thickness of 3 to 5 mm. This allows it to be easily installed within the limited space of a load tap switch (not shown), and at the same time, a sufficient area is secured for winding the resistance coil (30) described later, thereby allowing the required resistance value to be easily obtained.

[0021] In addition, the base plate (10) can be configured to be made of metal materials such as iron, copper, and aluminum to ensure heat absorption and release performance, and more preferably, it can be made of mica which has excellent heat resistance and high dielectric breakdown strength, while maintaining a structurally stable state even at high temperatures.

[0022] And as shown in FIG. 3, the base plate (10) has first and second slit holes (11, 12) formed at both ends for installing first and second terminals (20A, 20B), which will be described later, respectively.

[0023] At this time, the first slit hole (11) and the second slit hole (12) are composed of a pair of elongated holes (11A, 12A, 11B, 12B) spaced apart from each other by a predetermined distance, and both ends of the first terminal (20A) are inserted through and fixed into the elongated holes (11A, 11B) of the first slit hole (11), and both ends of the second terminal (20B) are inserted through and fixed into the elongated holes (12A, 12B) of the second slit hole (12).

[0024] In addition, a through hole (13) having a predetermined diameter is formed at the corner portion of the base plate (10) so as to be spaced apart from the first and second slit holes (11, 12), and a spacer (50) described later is installed and fixed to one side of the base plate (10) through the through hole (13) using a fixing screw (51).

[0025] The first and second terminals (20A, 20B) are each mounted in the first and second slit holes (11, 12) of the base plate (10) and are configured to be silver-plated copper plates to electrically connect the resistance coil (30) described later in series.

[0026] These first and second terminals (20A, 20B) include an upper grounding portion (21) having a predetermined length in the horizontal direction in accordance with the spacing of the elongated holes (11A, 12A, 11B, 12B) as shown in FIG. 4(a), and lower grounding portions (22, 23) formed such that one end is connected to each end of the upper grounding portion (21) and the other end has a predetermined length in the vertical direction.

[0027] At this time, the lower grounding portion (22, 23) is inserted through the elongated holes (11A, 12A, 11B, 12B) of the base plate (10) as shown in FIG. 4(b), and then the downwardly protruding ends are bent so that they face each other, and subsequently the two ends facing each other are firmly fixed through soldering, thereby forming electrically conductive terminals on the upper and lower surfaces of the base plate (10).

[0028] The resistance coil (30) is configured to have a predetermined resistance when current flows while electrically connecting the first and second terminals (20A, 20B).

[0029] As shown in FIGS. 1 and 5, one end of the resistance coil (30) is fixed to the first terminal (20A) by soldering, and the other end is wound multiple times to wrap around the outer surface of the base plate (10), and then fixed to the second terminal (20B) by soldering.

[0030] At this time, the resistance coil (30) is made of a metal material having a diameter of 0.6 to 1 mm, and the resistance coil (30) is wound 20 to 25 times on a base plate (10) having a set width (W), length (L), and thickness (T), so that the resistance value naturally becomes 4.5 to 5.5 Ω.

[0031] One end of the first connecting cable (40A) is grounded to the first terminal (20A) through soldering, and one end of the second connecting cable (40B) is grounded to the second terminal (20B) through soldering, and the first and second connecting cables (40A, 40B) are entirely covered with silicone material, and an O-type or Y-type terminal (not shown in the drawing) is fixed to the free end.

[0032] Additionally, considering that a plurality of transition resistance assemblies (1) are stacked, one end of the first connecting cable (40A) may be fixed to the upper ground portion (21) of the first terminal (20A) located on the upper surface of the base plate (10), and one end of the second connecting cable (40B) may be fixed to the lower ground portion (22) of the second terminal (20B) located on the lower surface of the base plate (10).

[0033] Additionally, although the first and second connecting cables (40A, 40B) are shown and described above only as being fixed to the first and second terminals (20A, 20B) through soldering, alternatively, a bolt of a predetermined size may be installed to penetrate the first and second terminals (20A, 20B), and a nut may be assembled to the tip of such a bolt so that the first and second connecting cables (40A, 40B) can be fixed or separated from the first and second terminals (20A, 20B) by the assembly of the bolt and nut as needed.

[0034] The spacer (50) is installed to be positioned on one side of the base plate (10) through a fixing screw (51) that passes through a through hole (13) formed in the base plate (10), thereby maintaining the spaced-out state of the base plate (10) with a predetermined distance from an adjacent structure.

[0035] These spacers (50) may be composed of cylindrical tubes of a predetermined length having a predetermined diameter as shown in FIG. 1.

[0036] Alternatively, it may be composed of a column of a predetermined length with a polygonal cross-sectional shape, such as a square prism or a hexagonal prism.

[0037] These spacers (50) may be made of the same mica material as the base plate (10), or alternatively, may be made of any one of the known insulating materials with excellent heat resistance and insulation performance, such as ceramic.

[0038] Additionally, a hole of a predetermined diameter (not shown in the drawing) is formed in the spacer (50) so that both ends are connected and penetrates the interior, and a fixing screw (51) of a predetermined length is installed through the through hole (13) of the base plate (10) through this hole, and then the tip of the fixing screw (51) protruding through the spacer (50) is fixed to the frame (not shown) of the load tap changer so that the spacer (50) is fixed so that it is not separated from the base plate (10).

[0039] The transition resistance assembly (1) according to the present invention, configured as described above, is formed by stacking a plurality of them vertically to match the required resistance value. For example, as shown in FIG. 6, three transition resistance assemblies (1) are stacked vertically and can be installed to sequentially penetrate the through hole (13) of the stacked base plate (10) and the spacer (50) through a fixing screw (51) having a predetermined length.

[0040] In this case, the second terminal (20B) of the base plate (10) located in the middle and the second terminal (20B) of the base plate (10) located above are connected to each other through the second connecting cable (40B), and the first terminal (20A) of the base plate (10) located in the middle and the first terminal (20A) of the base plate (10) located below are connected to each other through the first connecting cable (40A).

[0041] Due to this connection structure, the resistance coils (30) wound on the three base plates (10) are electrically connected in a line, thereby forming a transition resistor with a resistance value of 13.5 to 16.5 Ω.

[0042] That is, when two transition resistor assemblies (1) are stacked and operated, a transition resistor with a resistance value of 9 to 11 Ω is formed, and when four transition resistor assemblies (1) are stacked and operated, a transition resistor with a resistance value of 18 to 22 Ω is easily formed.

[0043] Meanwhile, although the base plate (10) is shown and described above as being formed in the shape of a rectangular plate with a predetermined width and length and a predetermined thickness, it can be modified so that the thickness of the middle part is formed relatively thicker than the thickness of both ends in the width direction, thereby ensuring that when a plurality of transition resistance assemblies (1) are stacked, the space between both ends in the width direction is further secured. As a result, the heat generated from the resistance coil (30) can be easily and quickly dissipated toward the ends where the space between them is wider.

[0044] As explained above, in the present invention, the transition resistance assembly is installed in a stacked manner such that the gap between base plates is vertically spaced by the length of the spacer, thereby allowing the number to be easily increased or decreased to match the required resistance capacity.

[0045] In addition, due to the spaced-apart space between the base plates, the heat generated in the resistance coil is transferred through the base plates and quickly dissipated, so failures caused by the resistance coil being disconnected due to overheating are reduced.

[0046] For the convenience of explanation, drawings illustrating preferred embodiments and configurations shown in the drawings have been described above using reference numerals and names; however, as this is merely one embodiment according to the present invention, the scope of the rights should not be interpreted as being limited to the shapes shown in the drawings and the names assigned thereto. It is considered entirely obvious that modifications to various shapes predictable from the description of the invention and simple substitutions with configurations having the same function fall within the scope of modifications that a person skilled in the art can easily implement. Explanation of the symbols

[0047] 1: Transition resistor assembly 10: Base plate 11: 1st slit hole 11A, 11B: Elongated hole 12: Second slit hole 12A, 12B: Long hole 13: Through hole 20A: First terminal 20B: Second terminal 21: Upper grounding part 22: Lower grounding section 30: Resistance coil 40A: 1st connecting cable 40B: 2nd connecting cable 50: Spacer 51: Fixing screw L: Length of base plate T: Thickness of base plate W: Width of the base plate

Claims

Claim 1 In a transition resistor assembly (1) installed in a load tap changer of a transformer, the transition resistor assembly (1) comprises: a rectangular plate-shaped base plate (10) having first and second slit holes (11, 12) formed in pairs at a predetermined distance apart to penetrate the upper and lower surfaces at both ends, and a plurality of through holes (13) located at the corners that penetrate the upper and lower surfaces; a first terminal (20A) of a predetermined size, with both ends inserted through the pair of first slit holes (11) respectively, and then the protruding ends are bent and fixed to the base plate (10); a second terminal (20B) of a predetermined size, with both ends inserted through the pair of second slit holes (12) respectively, and then the protruding ends are bent and fixed to the base plate (10); and one end connected to the first terminal (20A) and the other end wound multiple times on the base plate (10), and then the second A resistance coil (30) of a predetermined length connected to a terminal (20B); a first connecting cable (40A) of a predetermined length, one end of which is grounded to the first terminal (20A); and a second connecting cable (40B) of a predetermined length, one end of which is grounded to the second terminal (20B). and a plurality of spacers (50) installed to be positioned on one side of the base plate (10) through a fixing screw (51) penetrating the through hole (13) to separate the base plate (10) from an adjacent structure at a predetermined distance; wherein the base plate (10) is made of mica having a predetermined thickness, the first and second terminals (20A, 20B) are made of silver-plated copper terminals, the first and second connecting cables (40A, 40B) are covered with silicone material, the first and second slit holes (11, 12) are composed of a pair of elongated holes (11A, 12A, 11B, 12B) spaced apart from each other at a predetermined distance, and the first and second terminals (20A, 20B) are in a horizontal direction in accordance with the spacing of the elongated holes (11A, 12A, 11B, 12B). Upper grounding portion (21) having a predetermined length;A transition resistor assembly for installing a load tap changer of a transformer, comprising: a lower grounding part (22, 23) having one end connected to each end of the upper grounding part (21) and the other end formed to have a predetermined length in the vertical direction; wherein the lower grounding part (22, 23) is inserted through the elongated hole (11A, 12A, 11B, 12B), then bent so that the downwardly protruding ends face each other, and subsequently the ends facing each other are fixed through soldering so that electrically conductive terminals are formed on the upper surface and the lower surface of the base plate (10), respectively. Claim 2 A transition resistance assembly for installing a load tap changer of a transformer according to claim 1, wherein the transition resistance assembly (1) is configured such that a plurality of base plates (10) are stacked and installed with a predetermined spacing between them vertically according to the arc energy capacity, the free end of the first connecting cable (40A) is connected to the first terminal (20A) of another base plate (10) stacked relatively higher, and the free end of the second connecting cable (40B) is connected to the second terminal (20B) of another base plate (10) stacked relatively lower, so that a plurality of resistance coils (30) wound on each of the vertically stacked base plates (10) are electrically connected in a line. Claim 3 delete Claim 4 A transition resistor assembly for installing a load tap changer of a transformer, wherein, in claim 1, the first and second connecting cables (40A, 40B) are fixed to the first and second terminals (20A, 20B) through soldering.

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