High-insulation neutral point grounding resistance box

Abstract

The utility model provides a high-insulation neutral point grounding resistance box, and the box comprises a side plate support which is provided with four folded edges; the two ends of the screw rod are respectively connected with the side plate brackets; the resistor disc is arranged on the screw rod; and the mica tube is sleeved on the screw rod and is arranged close to the side plate bracket. The four sides of the side plate bracket of the resistor are folded, so that an insulating washer is not required to be mounted on the side plate bracket, and the cost is saved and the strength of the bracket is improved on the premise of not influencing the insulating property; the side plate bracket is connected with the resistor disc through the screw, and the mica tube is additionally arranged outside the screw, so that the insulating strength of the resistor disc to the side plate bracket is improved, and the insulating property is improved.

Description

Technical Field

[0001] This application relates to the field of circuit protection technology, and more specifically, to a highly insulated neutral point grounding resistor box. Background Technology

[0002] A neutral point grounding resistor box is a protective electrical device used to connect the neutral point of a transformer or generator to the ground, limiting the grounding current or leakage current to a preset range. With the increasing capacity of urban power supply networks and the widespread use of cable lines, the single-phase short-circuit capacitive current of the system is becoming increasingly large. For power supply networks where most lines are buried underground, the probability of transient grounding faults caused by natural factors has significantly decreased, and low-resistance grounding methods are gradually increasing. Because the residual charge in the system's ground capacitance can be effectively released through the grounding resistor, no superimposed voltage will form after the arc reignites, thus effectively eliminating arc grounding overvoltage. Furthermore, the grounding resistor's connection to the zero-sequence network, with its damping characteristics, can also limit system resonant overvoltage. When a fault occurs in the power system, the neutral point of the distribution system will shift. At this time, the neutral point grounding resistor forces the neutral point of the distribution system to ground, limiting its fault current and allowing the power system time for detection, diagnosis, protection, and switching, thereby preventing potential damage to line equipment.

[0003] As the core equipment for low-resistance grounding, the neutral point grounding resistor box mainly consists of resistor elements, bolts and nuts, screws, ceramic components, mica tubes, side plate supports, etc. In recent years, with the increasing market demand for grounding resistors, the requirements for their application scenarios have also increased, especially in terms of size, insulation performance, corrosion resistance, flexibility, and simplicity. Small, lightweight, and high-performance neutral point grounding resistors can reduce the initial investment in site construction and costs. Therefore, the design of the grounding resistor's structural form is particularly important.

[0004] Currently, the main components of a neutral point grounding resistor consist of a side plate bracket with insulating washers, which are then directly inserted into a screw. This effectively secures the resistor elements, but also leads to cumbersome operation, poor insulation performance, and higher costs. In the assembly process, the resistor elements are stacked on ceramic interlayers. In this case, the insulation between the resistor elements and the side plate relies solely on the ceramic interlayers. If the ceramic interlayers are damaged, the insulation between the resistor elements and the side plate bracket is significantly reduced. In the welding process, the resistor elements are connected by argon arc welding using U-shaped connecting plates. Since argon arc welding is a manual operation, unstable operation can easily cause detachment, missed welds, or incomplete welds. If the resistor element itself short-circuits or opens, replacement is inconvenient and requires cutting with a cutting machine. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a highly insulated neutral point grounding resistor box, which optimizes the side plate support process, increases support strength, reduces the number of insulating washers for fixing the side plate support, and increases secondary insulation by adding mica tubes through screws, thereby improving the insulation capacity of the resistor.

[0006] One aspect of this application provides a highly insulated neutral point grounding resistor box, comprising:

[0007] Side plate bracket, wherein the side plate bracket is provided with four-sided folded edges for enhancing strength;

[0008] The screw is connected to the side plate brackets at both ends;

[0009] A resistor element is mounted on the screw.

[0010] The mica tube is sleeved on the screw and positioned near the side plate bracket.

[0011] Furthermore, the resistor sheet is of multiple sizes and is spaced apart on the screw.

[0012] Furthermore, the screw includes a first screw and a second screw, wherein the first screw and the second screw are arranged horizontally at the same level;

[0013] The two ends of the resistor are fixed to the first screw and the second screw, respectively.

[0014] Furthermore, it also includes ceramic parts, which are multiple and spaced apart and sleeved on the screw;

[0015] A resistor is provided between two adjacent ceramic pieces.

[0016] Furthermore, it also includes multiple mica sheets, which are respectively disposed between adjacent ceramic pieces and resistive sheets.

[0017] Furthermore, adjacent resistors are secured together by bolts, flat washers, and nuts.

[0018] Furthermore, there are multiple mica tubes, which are respectively sleeved on the two ends of the first screw and the second screw near the side plate bracket;

[0019] One end of the mica tube abuts against the ceramic piece near the side plate bracket.

[0020] Furthermore, the height of the ceramic piece is 20mm.

[0021] Furthermore, the four-sided folded edge structure is a wedge-shaped structure.

[0022] Compared with the prior art, this application has at least one of the following beneficial effects:

[0023] 1. Compared with conventional configurations, this application uses bolts to fix the resistor elements together, eliminating the need for argon arc welding, making maintenance easier and the resistor body free of arc residue, resulting in a cleaner and tidier appearance. The addition of a mica tube to the screw increases the insulation strength between the resistor elements and the side plate bracket, improving insulation performance. The side plate bracket eliminates the need for insulating washers, saving costs. The addition of the mica sheet reduces the occurrence of friction damage between the ceramic parts and the resistor elements.

[0024] 2. This application adds secondary insulation by setting mica tubes on the screw, resulting in better insulation performance and a higher withstand voltage of the resistor sheet to the side plate bracket; in addition, the bolted connection of the resistor sheet makes maintenance and replacement more convenient, and the appearance is more beautiful and aesthetically pleasing. Attached Figure Description

[0025] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a front view of a highly insulated neutral point grounding resistor box according to an embodiment of this application.

[0027] Figure 2 This is a side view of a highly insulated neutral point grounding resistor box according to an embodiment of this application.

[0028] Figure 3 This is a top view of a highly insulated neutral point grounding resistor box according to an embodiment of this application.

[0029] In the diagram: 1. Side plate bracket; 2. Resistor element; 3. Screw; 31. First screw; 32. Second screw; 4. Mica tube; 5. Ceramic component; 6. Mica sheet;

[0030] 7. Nut; 8. Flat washer; 9. Bolt. Detailed Implementation

[0031] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application. These all fall within the protection scope of the present application.

[0032] It should be understood that the terms "first," "second," etc., in the following embodiments are used to distinguish different objects, not to describe a specific order. The terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets thereof. In the description of this specification, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for ease of description and simplification, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0033] Reference Figure 1 As shown, an embodiment of this application provides a highly insulated neutral point grounding resistor box, comprising: a side plate bracket 1, the side plate bracket 1 having four folded edges for enhancing strength; a screw 3, with both ends connected to the side plate bracket 1; a resistor sheet 2, disposed on the screw 3; and a mica tube 4, sleeved on the screw 3 and disposed close to the side plate bracket 1.

[0034] This application eliminates the need for insulating washers on the side plate bracket 1 of the resistor by folding the four sides, thus saving costs and increasing the strength of the bracket without affecting the insulation performance, especially when there is an insulator support. The side plate bracket 1 and the resistor piece 2 are connected by a screw 3, and the screw 3 is equipped with a mica tube 4 to increase the insulation strength of the resistor piece 2 to the side plate bracket 1 and improve the insulation performance.

[0035] The four-sided folded edge structure is a wedge-shaped structure, which is used to enhance the strength of the side plate bracket 1 and make transportation more reliable. The resistor sheet 2 is supported and fixed by the connection between the screw 3 and the side plate bracket 1.

[0036] In some specific embodiments, there are multiple resistors 2, which are spaced apart on the screw 3.

[0037] Specifically, the screw 3 includes a first screw 31 and a second screw 32, which are arranged horizontally at the same level; the two ends of the resistor 2 are respectively fixed to the first screw 31 and the second screw 32.

[0038] By fixing the two ends of multiple resistor pieces 2 to the first screw 31 and the second screw 32 respectively, the stability of the resistor pieces 2 on the screw 3 is improved.

[0039] In some possible embodiments, a plurality of ceramic parts 5 are also included, which are spaced apart and sleeved on the screw 2; a resistor 2 is provided between two adjacent ceramic parts 5.

[0040] By setting a resistor sheet between two adjacent ceramic parts 5 and fitting the screw 2 into the mica tube 4, the secondary insulation capability between the resistor sheet 2 and the side plate support 1 is increased compared with the conventional resistor box structure. The resistor sheet 2 first insulates the ceramic part 5 and then insulates the mica tube 4, thereby improving the insulation capability.

[0041] In some specific embodiments, two adjacent resistor pieces 2 are fixed together by bolts 9, flat washers 8 and nuts 7.

[0042] The connection between adjacent resistors 2 is fixed by bolts 9, flat washers 8, and nuts 7, eliminating the spring washers in the conventional structure, increasing the contact area between bolts 9 and resistors 2, and improving the current overload capacity.

[0043] Specifically, the mica tube 4 is located at both ends of the ceramic part 5.

[0044] In some possible embodiments, a plurality of mica sheets 6 are also included, which are disposed between adjacent ceramic pieces 5 and resistive pieces 2.

[0045] This application adds a mica sheet 6 to the front end of each ceramic component 5 during the stacking process of installing the resistor sheet 2 between two ceramic components 5. This creates an additional mica sheet 6 between each resistor sheet 2 and ceramic component 5, preventing direct contact between the resistor sheet 2 and ceramic component 5. This effectively prevents damage to the ceramic component 5 caused by hard collisions during transportation vibration, reduces friction damage between the ceramic component 5 and the resistor sheet 2, and improves service life.

[0046] Specifically, the height of ceramic component 5 is 20mm. The increase in the height of ceramic component 5 from the previous 16mm to 20mm increases the creepage distance and improves the insulation between the resistor 2 and the side plate bracket 1.

[0047] The conventional structure of a neutral point grounding resistor box is as follows: the screw 3 is directly inserted into the side plate bracket 1, and the resistor piece 2 is connected by argon arc welding. According to the national standard JB / T 10777-2018 Neutral Point Grounding Resistor, Section 6.2.3 specifies the insulation level, "When the resistor element of the resistor is a multi-unit structure, the external voltage that can be withstood between adjacent units is: external voltage (kV) = rated voltage of each unit (kV) × 2.5 + 2kV." According to the design scheme proposed in this application, compared with the conventional resistor box structure, the screw 3 is fitted into the mica tube 4, and the resistor piece 2 is first insulated from the ceramic part 5, and then from the mica tube 4, which improves the insulation capacity and results in a higher withstand voltage value, especially the insulation value of the resistor piece 2 to the side plate bracket 1.

[0048] The specific embodiments of this application have been described above. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A high insulation neutral grounding resistor box, characterized by, include: Side plate bracket, wherein the side plate bracket is provided with four-sided folded edges for enhancing strength; The screw is connected to the side plate brackets at both ends; A resistor element is mounted on the screw. A mica tube is sleeved on the screw and positioned near the side plate bracket; The screw includes a first screw and a second screw, which are arranged horizontally at the same level; the two ends of the resistor are respectively fixed to the first screw and the second screw. It also includes ceramic parts and mica sheets, and there are multiple ceramic parts, with the ceramic parts spaced apart on the screw; a resistor sheet is provided between two adjacent ceramic parts; the mica sheets are respectively disposed between adjacent ceramic parts and resistor sheets.

2. The highly insulated neutral point grounding resistor box according to claim 1, characterized in that, The resistor element is a plurality of those arranged at intervals on the screw.

3. The high insulation neutral grounding resistor box according to claim 1, characterized in that, The two adjacent resistors are fixed together by bolts, flat washers and nuts.

4. The highly insulated neutral grounding resistor box of claim 1, wherein, The mica tubes are multiple and are respectively sleeved on both ends of the first screw and the second screw near the side plate bracket; One end of the mica tube abuts against the ceramic piece near the side plate bracket.

5. The highly insulated neutral grounding resistor box of claim 1, wherein, The height of the ceramic piece is 20mm.

6. The highly insulated neutral grounding resistor box of claim 1, wherein, The four-sided folded edge structure is a wedge-shaped structure.

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