Busbar connection device

Abstract

The busbar connecting device (100, 110) disclosed herein connects a solid insulated busbar (3) composed of a busbar conductor (3a) and an insulating protective cover (3b) covering the busbar conductor (3a), and comprises: a busbar insulating adapter (1) having through holes (18) and busbar mounting holes (15) intersecting each other, wherein the through holes are in a vertical direction and the busbar mounting holes are for the solid insulated busbar (3) to be inserted in a horizontal direction; and stud bolts (5) installed on the busbar insulating adapter (1). On one side of the through hole (18), the solid insulated busbar (3) is fixed by a fixing conductor member (6); the bushing (2) is composed of a current-carrying conductor (2a) connected to a stud bolt (5) and a bushing molded part (2b) covering the current-carrying conductor (2a); an electric field relief shield (9) is provided in the busbar insulating adapter (1); the electric field relief shield is configured to cover the periphery of the inserted solid insulated busbar (3), and an annular recess (10) is provided on the outer surface.

Description

Technical Field

[0001] The present disclosure relates to a busbar connection device. Background Art

[0002] Since devices used in gas-insulated switchgears operate at high voltages, if a shape such as a needle that increases the electric field is formed in a voltage application portion, this portion may become a starting point and cause flashover.

[0003] For example, Patent Document 1 describes that when current is switched on and off at the contacts of a vacuum valve installed in an insulating switchgear to interrupt an accident current, the contacts melt, and the opening and closing may cause a protrusion to form on the contacts. To address this issue, a method is known in which one contact is convex and the other concave, creating a protrusion inside the concave shape, thereby improving withstand voltage performance.

[0004] Furthermore, gas-insulated switchgear utilizes the excellent insulating properties of sulfur hexafluoride (SF6) gas to achieve compact equipment, thereby contributing to space reduction in electrical rooms. By housing the high-voltage main circuit within a sealed container and sealing the aforementioned SF6 gas with excellent insulating properties, gas-insulated switchgear enables a more compact layout of the main circuit equipment. Furthermore, in recent years, environmentally friendly gases such as dry air have also been used as alternatives to SF6 gas.

[0005] Regarding the busbar portion of such a gas-insulated switchgear, as a general gas busbar method, a busbar box is connected when the gas-insulated switchgear is installed, and the busbar conductors inside the busbar box are connected. However, in recent years, as described in non-patent document 1, there are also cases where on-site gas processing operations are no longer required when installing the gas-insulated switchgear by using solid insulated busbars.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 10-233145.

[0009] Non-patent literature

[0010] Non-patent document 1: NKT company product catalog 26 589 12. Summary of the Invention

[0011] Technical problem to be solved by the invention

[0012] The insulating adapter used for the aforementioned solid-insulated busbar is equipped with an electric field mitigation shield made of conductive resin to mitigate the electric field. The shield is manufactured using a mold, but the mold must be removed after fabrication, making it difficult to manufacture using a single mold. Multiple molds are typically combined for fabrication. Consequently, burrs may form at the parting line between the molds. If burrs form in areas with high electric fields, the electric field at the tip of the burr increases during high-voltage voltage application tests, potentially causing discharge and potentially flashover.

[0013] The present disclosure is made to solve the above-mentioned problems, and its purpose is to obtain a busbar connection device that can prevent local flashover starting from the burrs even when burrs remain on the outer surface of the electric field relaxation protective cover, and can maintain high voltage resistance.

[0014] Technical solutions used to solve technical problems

[0015] The busbar connection device disclosed herein is a busbar connection device for connecting a solid insulated busbar composed of a busbar conductor and an insulating protective cover covering the busbar conductor. The busbar connection device includes: a busbar insulating adapter, the busbar insulating adapter having a through hole and a busbar mounting hole that intersect each other, the through hole being in a vertical direction, and the busbar mounting hole being for inserting the solid insulated busbar from a horizontal direction; a stud bolt, the stud bolt being mounted on one side of the through hole of the busbar insulating adapter and fixing the solid insulated busbar via a fixing conductor member; and a bushing, the bushing consisting of a current-carrying conductor and a bushing molded part, the current-carrying conductor being connected to the stud bolt, the bushing molded part covering the current-carrying conductor, the busbar insulating adapter having an electric field relaxation protective cover, the electric field relaxation protective cover being configured to cover the circumference of the inserted solid insulated busbar, and having an annular recess provided on its outer surface, with a protrusion at least partially at the bottom of the recess.

[0016] Effects of the Invention

[0017] According to the busbar connection device disclosed herein, since an annular recess for accommodating protrusions such as burrs is provided on the outer surface of the electric field relaxation shield made of conductive resin, which constitutes a part of the busbar connection device, local flashover originating from the burrs can be prevented. This has the effect of improving the insulation resistance of the busbar insulating adapter and maintaining the high voltage resistance of the busbar connection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing a busbar connecting device according to the first embodiment.

[0019] Figure 2It is a cross-sectional view of a mold for molding an electric field relaxation protective cover made of a conductive resin in a comparative example.

[0020] Figure 3 This is a cross-sectional view of a mold for molding the electric field relaxation cover of the busbar connection device according to the first embodiment.

[0021] Figure 4 This is a schematic diagram of an electric field relaxation cover made of conductive resin provided in the busbar insulation adapter of the busbar connection device according to the first embodiment.

[0022] Figure 5 It is a cross-sectional view of a recessed portion of an electric field relaxation cover made of a conductive resin provided in the busbar insulation adapter of the busbar connection device according to the first embodiment.

[0023] Figure 6 It is a cross-sectional view of a recessed portion of an electric field relaxation cover made of a conductive resin provided in an insulating adapter for a busbar in a busbar connection device according to a second embodiment.

[0024] Figure 7 It is a cross-sectional view of a recessed portion of an electric field relaxation cover made of a conductive resin provided in an insulating adapter for a busbar in a busbar connection device according to a third embodiment. DETAILED DESCRIPTION

[0025] Implementation Method 1

[0026] Figure 1 1 shows busbar connection devices 100 and 110 according to the first embodiment. The busbar connection device 100 constitutes a part of a gas-insulated switchgear (not shown).

[0027] Figure 1 1 and 2 show busbar connection devices 100 connected to the ends of solid insulated busbars 3 and busbar connection devices 110 connected continuously to solid insulated busbars 3. The following description will focus on the structure of busbar connection devices 100 connected to the ends of solid insulated busbars 3 unless otherwise specified.

[0028] The busbar connection devices 100 and 110 are mainly composed of an insulating adapter 1 for a busbar and a bushing 2, wherein the insulating adapter 1 for a busbar has a busbar mounting hole 15 and a through hole 18. The busbar mounting hole 15 is for connecting a solid insulated busbar 3, and the through hole 18 is for installing the bushing 2 and inserting the stud bolt 5 for fixing the solid insulated busbar 3. The bushing 2 is installed in the bushing mounting hole 2c.

[0029] The solid insulated busbar 3 consists of a busbar conductor 3a and an insulating shield 3b covering the busbar conductor 3a. The insulating shield 3b is made of an insulating resin such as silicone rubber or epoxy resin. At the ends of the solid insulated busbar 3, the busbar conductor 3a is exposed from the insulating shield 3b.

[0030] The busbar insulation adapter 1 will be described in more detail.

[0031] The busbar insulation adapter 1 is made of a relatively soft insulating material such as silicone resin or ethylene propylene resin. It has a vertical through-hole 18 and a busbar mounting hole 15 formed horizontally, intersecting the through-hole 18. The T-shaped busbar insulation adapter 1 is used to connect a solid insulated busbar 3 to a terminal busbar connection device 100, while the cross-shaped busbar insulation adapter 1 is used to connect a busbar connection device 110 continuously to the solid insulated busbar 3.

[0032] Two arc-shaped fixing conductor members 6 made of a metal with good electrical conductivity such as copper or aluminum are provided in the space where the vertical through-hole 18 provided in the busbar insulating adapter 1 intersects with the horizontal busbar mounting hole 15. A substantially cylindrical anti-tilt conductor member 8 is also incorporated therein, sandwiched between the two arc-shaped fixing conductor members 6.

[0033] The fixing conductor member 6 and the tilt prevention conductor member 8 form a cylindrical space in the horizontal direction, perpendicular to the axial direction of the current-carrying conductor 2a of the bushing 2, which will be described later. The portion of the end of the solid insulated busbar 3 where the busbar conductor 3a is exposed is inserted into this cylindrical space.

[0034] The busbar insulation adapter 1 is fixed to a bushing 2 that is mounted in a gas-insulated switchgear (not shown) through a bushing mounting hole 2c.

[0035] Next, the bushing 2 will be described.

[0036] The bushing 2 includes a current-carrying conductor 2 a , and the periphery of the current-carrying conductor 2 a is covered with a bushing mold 2 b made of an insulating material such as epoxy resin.

[0037] The fixing conductor member 6 is provided with an opening for passing the stud bolt 5 in the axial direction of the current-carrying conductor 2a of the bushing 2. The portion of the busbar conductor 3a of the solid insulated busbar 3 exposed from the insulation molding 3b is inserted into a cylindrical hole formed by inserting the solid insulated busbar 3 into the horizontal busbar mounting hole 15 provided in the busbar insulation adapter 1 and combining the solid conductor member 6 with the anti-tilt conductor member 8.

[0038] After the fixed insulated busbar 3 is inserted into the busbar mounting hole 15 , the stud bolts 5 are tightened with nuts 7 , and the fixed insulated busbar 3 is pressed into the fixing conductor member 6 , thereby fixing the solid insulated busbar 3 to the busbar insulating adapter 1 .

[0039] An insulating plug 4 made of an insulating material such as epoxy resin is inserted into a portion of the busbar insulating adapter 1 that opens upward in the axial direction of the bushing 2 while expanding the diameter of the busbar insulating adapter 1 .

[0040] During operation of a gas-insulated switchgear (not shown), a high voltage is applied to the anti-tilt conductor member 8 and the busbar conductor 3a of the solid-insulated busbar 3. While it is desirable to minimize the electric field, this is structurally difficult. Therefore, within the busbar insulating adapter 1, an electric field mitigation shield 9 made of a conductive resin is provided at locations where the electric field is high in the anti-tilt conductor member 8 and the busbar conductor 3a. This shields the high-electric-field portions of the anti-tilt conductor member 8 and the busbar conductor 3a, thereby improving voltage resistance.

[0041] Furthermore, an electric field relaxation cover 11 made of a conductive resin and having the same structure as that of the electric field relaxation cover 9 may be provided on the axial side of the bushing 2 .

[0042] The electric field relaxation shield 9 made of conductive resin is provided with an annular recess 10 with respect to the central axis of the solid insulating busbar 3. The function of the annular recess 10 will be described later.

[0043] Figure 2 This is a cross-sectional view of a mold 40 used to illustrate a method for molding a conductive resin electric field relaxation shield 19 according to a comparative example. Furthermore, the conductive resin electric field relaxation shield 19 according to the comparative example does not include the recess 10 provided in the conductive resin electric field relaxation shield 9 that constitutes a portion of the busbar connection device 100 according to the first embodiment.

[0044] First, a mold 40 corresponding to the shape of the conductive resin electric field relaxation shield 19 of the comparative example is prepared. The mold 40 can be divided into three parts to facilitate removal of the conductive resin electric field relaxation shield 19 after molding.

[0045] That is, the mold 40 of the comparative example is as follows Figure 2 As shown in A, it is composed of three parts: the first mold part 40a, the second mold part 40b, and the third mold part 40c. Among them, the first mold part 40a forms one end side of the electric field relaxation protective cover 19 made of conductive resin, the second mold part 40b is provided with an introduction port 35 for introducing the conductive resin 13, and the third mold part 40c forms the other end side of the electric field relaxation protective cover 19 made of conductive resin. Figure 2 The mold 40 is shown in cross-section including the introduction port 35 .

[0046] First, the molten conductive resin 13 is poured into the mold 40 formed by combining three parts through the inlet 35 while applying pressure. Figure 2 The cross-sectional view of B shows the mold 40 after the conductive resin 13 is introduced.

[0047] The conductive resin 13 poured into the mold 40 is cooled under pressure until it solidifies. After the conductive resin 13 inside the mold 40 is completely solidified, the mold 40 is opened and the electric field relaxation shield 19 made of the conductive resin inside is removed.

[0048] In the molding method of the electric field relaxation cover 19 made of conductive resin according to the comparative example, burrs 20 as protrusions are generated between divided dies, that is, burrs 20 are generated on the outer surface of the electric field relaxation cover 19 .

[0049] That is to say, if Figure 2 As shown in C, when the first mold part 40a is separated from the second mold part 40b, a protrusion, that is, a minute burr 20 is generated at the boundary between the first mold part 40a and the second mold part 40b.

[0050] In addition, when the third mold part 40c is separated and the electric field mitigation protective cover 19 made of conductive resin is completely removed, the following state is achieved: in addition to the boundary between the first mold part 40a and the second mold part 40b, a protrusion, i.e., a tiny burr 20, is also generated at the boundary between the second mold part 40b and the third mold part 40c.

[0051] Here, the causes of burrs 20 will be described. When a resin product is molded using a mold, resin intrudes into the gaps between the divided surfaces of the mold, thereby generating burrs 20. The causes of burrs 20 can be divided into two categories.

[0052] The first type of burr 20 is caused by the resin flowing into the gaps formed between the divided surfaces of the mold from the very beginning due to low machining accuracy of the mold.

[0053] The second type of burr 20 is caused by the mold being deformed by high resin pressure during the resin molding process, thereby creating a gap into which the resin is pressed.

[0054] According to the above, the burrs 20 generated due to either or both of the above two causes may constitute the starting point of flashover, and therefore need to be removed after resin molding.

[0055] When the electric field relaxation cover 19 made of conductive resin is further molded into a shape corresponding to the busbar insulating adapter 1 , the burrs 20 are basically removed. However, they may not be completely removed, and some burrs 20 may remain that cannot be removed.

[0056] When the conductive resin electric field relaxation shield 19 is provided in the busbar insulation adapter 1 and the busbar insulation adapter 1 is molded without completely removing the burrs 20, the burrs 20 may become starting points for flashover when the busbar connection devices 100 and 110 are operated.

[0057] However, if the burrs 20 are to be completely removed, the process of removing the burrs 20 takes time. In addition, the burr removal inspection to confirm whether the burrs 20 have been completely removed also takes a lot of time and labor. Therefore, the structure of the electric field relaxation protective cover that allows a certain degree of burrs 20 to exist and avoids the adverse conditions caused by the burrs 20 can also achieve the overall low cost of the busbar connection devices 100, 110.

[0058] Taking into account the potential problems caused by the conductive resin electric field relaxation shield 19 of the comparative example, the conductive resin electric field relaxation shield 9 of the first embodiment, which constitutes a portion of the busbar connection devices 100 and 110, is configured such that a protrusion 14 for forming the annular recess 10 is pre-formed at the mold segment, i.e., at the boundary between the mold segments where burrs 20 may be generated. In other words, the burrs 20 that may be generated remain only within the recess 10, thereby being shielded by the recess 10.

[0059] In order to achieve the above-mentioned shielding effect, the depth d of the recess 10 is set to be greater than the height h of the burr 20 , that is, to satisfy the relationship d>h.

[0060] Furthermore, since the height h of the burr 20 is generally about 0.1 to 1 mm, the depth d of the recess 10 relative to the outer surface of the electric field relaxation cover 9 made of conductive resin needs to be set to at least greater than 0.1 mm.

[0061] Figure 3 This is a cross-sectional view of a mold 30 for illustrating a method for molding the electric field relaxation cover 9 made of conductive resin, which constitutes a part of the busbar connection devices 100 and 110 according to the first embodiment.

[0062] First, a mold 30 is prepared that corresponds to the shape of the conductive resin electric field relaxation shield 9. The mold 30 can be divided into three parts to facilitate removal of the conductive resin electric field relaxation shield 9 after molding.

[0063] That is, the mold 30 is as Figure 3 As shown in A, it is composed of three parts: the first mold part 30a, the second mold part 30b, and the third mold part 30c. Among them, the first mold part 30a forms one end side of the electric field relaxation protective cover 9 made of conductive resin, the second mold part 30b is provided with an introduction port 35 for introducing the conductive resin 13, and the third mold part 30c forms the other end side of the electric field relaxation protective cover 9 made of conductive resin. Figure 3 The mold 30 is shown in cross-section including the introduction port 35 .

[0064] Furthermore, at the boundary between the first mold section 30a and the second mold section 30b, a projection 14 is provided in each of the first mold section 30a and the second mold section 30b. These projections 14 form a recess 10 centered on the boundary when molding the electric field relaxation shield 9. The following describes a method for molding the electric field relaxation shield 9 made of conductive resin using the mold 30.

[0065] First, while applying pressure inside the mold 30 formed by combining three parts, the molten conductive resin 13 is flowed into the mold 30 through the inlet 35 . Figure 3 The cross-sectional view of B shows the mold 30 after the conductive resin 13 is introduced.

[0066] The conductive resin 13 that has flowed into the mold 30 is cooled while being pressurized until it solidifies.

[0067] After the conductive resin 13 inside is completely solidified, Figure 3 As shown in C, the mold 30 is opened and the electric field relaxation shield 9 made of conductive resin inside is taken out.

[0068] Since the annular recess 10 provided on the outer surface of the electric field relaxation cover 9 made of conductive resin is located exactly at the boundary between the divided first mold portion 30 a and the second mold portion 30 b , a burr 20 remains at the center of the bottom of the recess 10 .

[0069] The electric field relaxation shield 9 made of conductive resin is further molded into a shape corresponding to the insulating adapter 1 for the busbar. Figure 4 In the shape shown in the schematic diagram of , the burrs 20 are basically removed, but not completely removed, and a certain amount of burrs 20 remain at the bottom of the recess 10.

[0070] Figure 5 The figure shows the cross-sectional shape of a recessed portion 10 including burrs 20 formed of protrusions formed on the flat surface of the bottom of an electric field relaxation cover 9 made of conductive resin. The cross-sectional shape of the recessed portion 10 is an inverted trapezoid.

[0071] like Figure 5As shown, the height h of the burr 20 remaining at the bottom of the recess 10 is lower than the depth d from the outer surface to the bottom of the recess 10. Therefore, the protrusion, or burr 20, is formed inside the recess 10. Consequently, the electric field at the tip of the burr 20 is mitigated by the shielding provided by the recess 10. This prevents the problem of flashover, which could occur if the burr 20 remains on the outer surface of the conductive resin electric field mitigation shield 9, where the burr 20 serves as a starting point. Consequently, even if the burr 20 remains, it does not adversely affect the performance of the conductive resin electric field mitigation shield 9.

[0072] In addition, the above description shows an example in which the recess 10 is located at the boundary between the divided first mold part 30a and the second mold part 30b. However, regarding the position of the recess 10, if the electric field relaxation protective cover 9 is cylindrical and the mold is bowl-shaped, it can also be located at the root of the chamfered corner (R part) or on the circumference of the cylindrical part as described above. If the mold is a shape that covers the cylindrical part up and down with the central axis of the cylinder set horizontally, it can also be located on the side of the cylinder.

[0073] In addition, examples of the conductive resin mentioned here include conductive silicone resin and the like.

[0074] As described above, according to the busbar connection device of the first embodiment, since an annular recess 10 for accommodating a protrusion such as a burr 20 is provided on the outer surface of the electric field relaxation shield 9 made of conductive resin, which constitutes a part of the busbar connection device, it is possible to prevent local flashover starting from the burr 20. Therefore, it is possible to improve the insulation resistance of the busbar insulating adapter and maintain the high voltage resistance of the busbar connection device.

[0075] Implementation Method 2

[0076] In the busbar connection devices 100 and 110 of the second embodiment, the cross section of the recessed portion 10a of the electric field relaxation cover 9a made of conductive resin is set to be Figure 6 Hereinafter, a characteristic part of the method for manufacturing the electric field relaxation cover 9a made of conductive resin will be described.

[0077] First, a mold 30 corresponding to the curved shape of the conductive resin electric field relaxation shield 9a is prepared. The mold 30 can be divided into three parts to facilitate removal of the conductive resin electric field relaxation shield 9a after molding.

[0078] That is, the mold 30 is composed of three parts: a first mold part 30a, a second mold part 30b, and a third mold part 30c. The first mold part 30a forms one end side of the electric field relaxation protective cover 9a made of conductive resin, the second mold part 30b is provided with an inlet 35 for introducing the conductive resin 13, and the third mold part 30c forms the other end side of the electric field relaxation protective cover 9a made of conductive resin.

[0079] Furthermore, at the boundary between the first mold portion 30a and the second mold portion 30b, a convex portion 14 is provided in each of the first mold portion 30a and the second mold portion 30b, and the convex portion 14 forms a concave portion 10a centered on the boundary into a curved shape when molding the electric field relaxation protective cover 9a made of conductive resin.

[0080] According to the busbar connection devices 100 and 110 of the second embodiment, since the outer surface of the conductive resin electric field relaxation shield 9a constituting a portion of the busbar connection devices 100 and 110 is provided with an annular recess 10a having a curved cross-section for accommodating a protrusion such as the burr 20, local flashover originating from the burr 20 can be prevented. This has the effect of improving the insulation resistance of the busbar insulation adapter 1 and, further, maintaining the high voltage resistance of the busbar connection devices 100 and 110.

[0081] Furthermore, since the cross-section of recess 10a is curved, the width of the opening of recess 10a relative to the outer surface can be further narrowed compared to the inverted trapezoidal cross-section of recess 10 in the first embodiment. This narrowing of the opening further enhances the shielding effect against burrs 20 formed at the bottom of recess 10a. Consequently, the withstand voltage performance of the busbar connection device is further improved.

[0082] Furthermore, since the cross-section of recess 10a is curved, its corners disappear. On the other hand, the recess 10 of the conductive resin electric field mitigation shield 9a of the first embodiment has corners despite its inverted trapezoidal cross-section. Since recess 10a lacks corners, after the conductive resin 13 solidifies within mold 30 and the first mold section 30a is separated from the second mold section 30b, this also contributes to the manufacturing process, resulting in a lower resistance compared to the first embodiment.

[0083] As described above, in the busbar connection device of the second embodiment, since the recess 10a having a curved cross-section is provided in the electric field relaxation shield 9a made of conductive resin that constitutes a part of the busbar connection device, the opening width at the outer surface of the recess 10a can be narrowed compared to the case of the inverted trapezoidal cross-section of the first embodiment. As a result, as a result of further increasing the degree of shielding of the burrs 20, the insulation resistance of the busbar insulating adapter is further improved, and the voltage resistance performance of the busbar connection device is further improved.

[0084] Implementation Method 3

[0085] In the busbar connection devices 100 and 110 of the third embodiment, the cross section of the recessed portion 10b of the electric field relaxation shield 9b made of conductive resin is set to be Figure 7 The shape of the inverted triangle shown.

[0086] Hereinafter, a characteristic part of the method for manufacturing the electric field relaxation cover 9b made of conductive resin will be described.

[0087] First, a mold 30 is prepared that corresponds to the concave portion 10b of the inverted triangular cross section of the conductive resin electric field relaxation shield 9b. The mold 30 can be divided into three parts to facilitate removal of the conductive resin electric field relaxation shield 9b after molding.

[0088] That is, the mold 30 is composed of three parts: a first mold part 30a, a second mold part 30b, and a third mold part 30c. The first mold part 30a forms one end side of the electric field relaxation protective cover 9b made of conductive resin, the second mold part 30b is provided with an inlet 35 for introducing the conductive resin 13, and the third mold part 30c forms the other end side of the electric field relaxation protective cover 9b made of conductive resin.

[0089] In addition, at the boundary between the first mold part 30a and the second mold part 30b, a protrusion 14 is provided in each of the first mold part 30a and the second mold part 30b, and the protrusion 14 forms a concave part 10b centered on the boundary into an inverted triangular shape when the electric field relaxation protective cover 9b made of conductive resin is molded.

[0090] According to the busbar connection devices 100 and 110 of the third embodiment, since the outer surface of the conductive resin electric field relaxation protective cover 9b constituting a part of the busbar connection devices 100 and 110 is provided with a recess 10b having an inverted triangular cross-section and accommodating a protrusion such as the burr 20, local flashover starting from the burr 20 can be prevented. Therefore, the insulation resistance of the busbar insulating adapter 1 can be improved, and further, the high voltage resistance of the busbar connection devices 100 and 110 can be maintained.

[0091] Furthermore, in busbar connection devices 100 and 110 according to the third embodiment, the recess 10b of the conductive resin electric field mitigation shield 9b has an inverted triangular cross-section. This allows the opening width of the outer surface of recess 10b to be further narrowed compared to the inverted trapezoidal cross-section of recess 10 in the first embodiment or the curved cross-section of recess 10a in the second embodiment. This narrowing of the recess 10b further enhances the shielding effect against burrs 20 formed at the bottom of recess 10b. Consequently, the withstand voltage performance of busbar connection devices 100 and 110 is further improved.

[0092] Furthermore, compared to the inverted trapezoidal cross-section of the recess 10 of the conductive resin electric field mitigation shield 9 in the first embodiment, the corners of the recess 10b are reduced. This reduction in the corners of the recess 10b has the following effect in terms of the manufacturing method: after the conductive resin 13 solidifies within the mold 30, when the first mold section 30a is separated from the second mold section 30b, the electrical resistance is reduced compared to the case of the first embodiment.

[0093] As described above, in the busbar connection device of the third embodiment, since the recess 10b with an inverted triangular cross-section is provided in the electric field relaxation protective cover 9b made of conductive resin that constitutes a part of the busbar connection device, the opening width at the outer surface of the recess 10b can be further narrowed compared with the case of the inverted trapezoidal cross-section of the first embodiment and the case of the curved cross-section of the second embodiment. Therefore, as a result of further increasing the shielding degree of the burr 20, the insulation resistance of the busbar insulating adapter is further improved, and further, the voltage resistance performance of the busbar connection device is further improved.

[0094] Implementation Method 4

[0095] In the busbar connection devices 100 and 110 of the fourth embodiment, the depth d of the recess 10 of the electric field relaxation cover 9 made of conductive resin is set to be greater than twice the height h of the burr 20 formed on the bottom. In other words, the depth d is set so that d>2h holds.

[0096] In the busbar connection device of the fourth embodiment, by setting the depth d of the recess 10 relative to the height h of the burr 20 so that d>2h, local flashover originating from the burr 20 can be more reliably prevented. This has the effect of stably improving the insulation resistance of the busbar insulating adapter and further stably maintaining the high voltage resistance of the busbar connection device.

[0097] This disclosure describes various exemplary embodiments and examples, but various features, modes, and functions described in one or more embodiments are not limited to application to specific embodiments and can be applied to the embodiments alone or in various combinations.

[0098] Therefore, numerous modifications not shown are contemplated within the technical scope disclosed in this specification. For example, these include modifying, adding, or omitting at least one component, and also include extracting at least one component and combining it with components from other embodiments.

[0099] Explanation of symbols

[0100] 1Insulation adapter for busbar

[0101] 2 bushings

[0102] 2a Current-carrying conductor

[0103] 2b Bushing molding

[0104] 2c Bushing mounting hole

[0105] 3 Solid insulated busbar

[0106] 3a Busbar conductor

[0107] 3b Insulation protective cover

[0108] 4 Insulation plug

[0109] 5 stud bolts

[0110] 6 Fixed conductor components

[0111] 7 Nut

[0112] 8 Anti-tilt conductor components

[0113] 9, 9a, 9b, 11, 19 electric field mitigation shields

[0114] 10, 10a, 10b concave parts

[0115] 13 Conductive resin

[0116] 14 convex part

[0117] 15 Busbar mounting hole

[0118] 18 through holes

[0119] 20 Burrs (protrusions)

[0120] 30, 40 molds

[0121] 30a, 40a first mold part

[0122] 30b, 40b second mold part

[0123] 30c, 40c third mold part

[0124] 35 import port

[0125] 100, 110 busbar connection device

Claims

1. A busbar connection device for connecting a solid insulated busbar consisting of a busbar conductor and an insulating protective cover covering the busbar conductor, characterized in that: include: A busbar insulating adapter having a through hole and a busbar mounting hole intersecting each other, wherein the through hole is vertical and the busbar mounting hole is for inserting the solid insulated busbar horizontally; a stud bolt installed on one side of the through hole of the busbar insulating adapter to fix the solid insulated busbar via a fixing conductor member; and a bushing composed of a current-carrying conductor and a bushing molding, wherein the current-carrying conductor is connected to the stud bolt and the bushing molding covers the current-carrying conductor; The busbar insulating adapter includes an electric field relaxation shield, which is configured to cover the periphery of the inserted solid insulating busbar and has an annular recessed portion on its outer surface, and a protrusion on at least a portion of the bottom of the recessed portion. The concave portion is formed by pre-arranging a convex portion at the boundary portion between the divided dies where burrs may be generated. The protrusion is the burr generated at the boundary portion between the dies.

2. The busbar connection device according to claim 1, characterized in that: The electric field relaxation shield is made of conductive resin.

3. The busbar connection device according to claim 1, characterized in that: The cross section of the recess has any of the following shapes: The two side surfaces of the recess are formed by flat inclined surfaces, the bottom is formed by a flat surface, and the opening is gradually narrowed toward the bottom; The two side surfaces of the recess are formed of flat inclined surfaces, and the opening gradually narrows toward the bottom and intersects at the bottom; and The two side surfaces and the bottom of the recess are formed of curved surfaces, and the opening is gradually narrowed toward the bottom.

4. A busbar connection device for connecting a solid insulated busbar consisting of a busbar conductor and an insulating protective cover covering the busbar conductor, characterized in that: include: A busbar insulating adapter having a through hole and a busbar mounting hole intersecting each other, wherein the through hole is vertical and the busbar mounting hole is for inserting the solid insulated busbar horizontally; a stud bolt installed on one side of the through hole of the busbar insulating adapter to fix the solid insulated busbar via a fixing conductor member; and a bushing composed of a current-carrying conductor and a bushing molding, wherein the current-carrying conductor is connected to the stud bolt and the bushing molding covers the current-carrying conductor; The busbar insulating adapter includes an electric field relaxation shield, which is configured to cover the periphery of the inserted solid insulating busbar and has an annular recess on its outer surface. The electric field relaxation shield is made of a conductive resin. The concave portion is formed by providing a convex portion in advance at the divided portion of the mold, that is, at the boundary portion between the divided molds where burrs may be generated.

5. The busbar connection device according to claim 4, characterized in that: The recess has a protrusion on at least a portion of a bottom.

6. The busbar connection device according to claim 5, characterized in that: The depth d of the recess and the height h of the protrusion from the bottom have a relationship of d>h.

7. The busbar connection device according to claim 5, characterized in that: The depth d of the recess and the height h of the protrusion from the bottom have a relationship of d>2h.

8. The busbar connection device according to claim 4, characterized in that: The cross section of the recess has any of the following shapes: The two side surfaces of the recess are formed by flat inclined surfaces, the bottom is formed by a flat surface, and the opening is gradually narrowed toward the bottom; The two side surfaces of the recess are formed of flat inclined surfaces, and the opening gradually narrows toward the bottom and intersects at the bottom; and The two side surfaces and the bottom of the recess are formed of curved surfaces, and the opening is gradually narrowed toward the bottom.

9. A busbar connection device for connecting a solid insulated busbar consisting of a busbar conductor and an insulating protective cover covering the busbar conductor, characterized in that: include: A busbar insulating adapter having a through hole and a busbar mounting hole intersecting each other, wherein the through hole is vertical and the busbar mounting hole is for inserting the solid insulated busbar horizontally; a stud bolt installed on one side of the through hole of the busbar insulating adapter to fix the solid insulated busbar via a fixing conductor member; and a bushing composed of a current-carrying conductor and a bushing molding, wherein the current-carrying conductor is connected to the stud bolt and the bushing molding covers the current-carrying conductor; The busbar insulating adapter includes an electric field relaxation shield, which is configured to cover the periphery of the inserted solid insulating busbar and has an annular recess on its outer surface. The cross section of the recess has any of the following shapes: The two side surfaces of the recess are formed by flat inclined surfaces, the bottom is formed by a flat surface, and the opening is gradually narrowed toward the bottom; The two side surfaces of the recess are formed of flat inclined surfaces, and the opening gradually narrows toward the bottom and intersects at the bottom; and The two side surfaces and the bottom of the recess are formed of curved surfaces, and the opening is gradually narrowed toward the bottom. The concave portion is formed by providing a convex portion in advance at the divided portion of the mold, that is, at the boundary portion between the divided molds where burrs may be generated.

10. The busbar connection device according to claim 9, characterized in that: The recess has a protrusion on at least a portion of a bottom.

11. The busbar connection device according to claim 10, characterized in that: The depth d of the recess and the height h of the protrusion from the bottom have a relationship of d>h.

12. The busbar connection device according to claim 10, characterized in that: The depth d of the recess and the height h of the protrusion from the bottom have a relationship of d>2h.

13. The busbar connection device according to claim 9, characterized in that: The electric field relaxation shield is made of conductive resin.

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