Pouring type semi-insulating structure and manufacturing process thereof

Abstract

The invention provides a pouring type semi-insulating structure and a manufacturing process thereof. The manufacturing process comprises the following steps: step 1, pre-drying semiconductor crepe paper and insulating crepe paper; 2, sanding the surface of the conductor, and wiping with alcohol; 3, wrapping a zero screen on the conductor by adopting semiconductor crepe paper; 4, wrapping an insulating layer on the zero screen by adopting insulating crepe paper; 5, sleeving the insulating layer, the feeding end flange terminal plate and the discharging end flange terminal plate with a heat-shrinkable tube; 6, baking the heat-shrinkable tube to enable the heat-shrinkable tube to shrink and hoop the bus; 7, wrapping the outer side of the heat-shrinkable tube with a contraction band; 8, epoxy resin is poured into the feeding through hole of the feeding end flange terminal plate; ninthly, after the epoxy resin is solidified, the contraction band is taken down; epoxy resin can be injected outside the conductor, a shielding layer is omitted, the production period is short, interphase short circuit risks are shielded, the production period is shortened, the cable is suitable for extra-urgent engineering projects, and operation safety is guaranteed as much as possible under the condition that the full-insulation period cannot meet the construction period.

Description

Technical Field

[0001] The invention belongs to the technical field of semi-insulating tubular busbars, in particular to a cast semi-insulating structure. Background Art

[0002] During use, busbars often experience single-phase grounding and phase-to-phase short circuit accidents, and their reliability is poor. Fully insulated busbars have complex processes and long production cycles, and they have high requirements for product processes. During operation, insulation breakdown, joint dampness and discharge are common accidents, and the repair and replacement cycle is long. Existing semi-insulated tubular busbars are similar to busbars, except that a heat shrink sheath is added to the conductor. If there is contact with foreign objects, single-phase grounding and phase-to-phase short circuit accidents are inevitable.

[0003] Fully insulated tubular busbars need to completely isolate the conductors from the external environment to avoid any risk of leakage or discharge; the core goal of fully insulated tubular busbars is to achieve a defect-free uniform insulation layer to ensure absolute insulation reliability under high voltage. Semi-insulated tubular busbars, on the other hand, allow some conductors to be exposed (such as connection ends or contact parts), and only require insulation of specific areas; the insulation layer does not need to be completely sealed, and even needs to retain the heat dissipation or grounding function of the conductor; the application of full insulation technology destroys the design intent of semi-insulation, and how to improve the insulation performance of semi-insulation is a problem to be solved. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide a semi-insulated tubular busbar which is safe and reliable, has a simple process and a short production cycle.

[0005] In order to achieve some or all of the above-mentioned purposes or other purposes, the present application provides the following technical solutions: a cast semi-insulating structure, including a conductor, an epoxy resin casting layer, a heat shrink sleeve, a feed end flange terminal board, a discharge end flange terminal board, terminal No. 1 and terminal No. 2; one end of the conductor is connected to the end face of the feed end flange terminal board, and the other end of the conductor is connected to the end face of the discharge end flange terminal board; the outer diameter of the conductor, the outer diameter of the feed end flange terminal board and the outer diameter of the discharge end flange terminal board are covered with a heat shrink sleeve, and the space formed between the conductor and the heat shrink tube is the epoxy resin casting layer; a feed through hole is provided on the feed end flange terminal board, and the feed through hole is connected to the epoxy resin casting layer; a discharge through hole is provided on the discharge end flange terminal board, and the discharge through hole is connected to the epoxy resin casting layer; one end of the conductor is connected to terminal No. 2 through the feed end flange terminal board, and the other end of the conductor is connected to terminal No. 1 through the discharge end flange terminal board.

[0006] Furthermore, the conductor is a copper tube.

[0007] Furthermore, semiconductor crepe paper and insulating crepe paper are evenly arranged in sequence on the outer peripheral surface of the conductor.

[0008] Furthermore, there are two No. 1 through holes and two No. 2 through holes.

[0009] Furthermore, the diameter of the No. 1 flange terminal board is larger than the diameter of the conductor, and the diameter of the No. 2 flange terminal board is larger than the diameter of the conductor.

[0010] Furthermore, two ends of the epoxy resin casting layer are arranged to be sloped.

[0011] Compared with the prior art, the invention has the following beneficial effects: the invention adds epoxy resin to the outside of the conductor, eliminates the shielding layer, shortens the production period, and shields the risk of phase-to-phase short circuit. It shortens the production period. The purpose is to be suitable for urgent engineering projects, and to ensure operation safety as much as possible when the full insulation period cannot meet the period.

[0012] The epoxy resin cast semi-insulated tubular busbar of the present invention adopts a T2Y copper tube as the conductor, which has low skin effect and high strength; flange terminal plates are welded at both ends of the copper tube to ensure that the contact area meets the standard requirements when two busbars or terminals are connected; semiconductor crepe paper is evenly wound on the copper tube, and then insulating crepe paper is evenly wound to ensure that the epoxy resin does not crack during operation and is resistant to aging; a heat shrinkable sheath is put on the outer side of the crepe paper to have a protective effect, and an epoxy resin mixture that meets the process requirements is impregnated (cast) between the heat shrinkable sheath and the copper tube to form a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the cast-type semi-insulating structure of the present invention; Figure 2 for Figure 1 AA section view in; Figure 3 for Figure 1 BB section view in; Figure 4 This is a schematic diagram of the structure of the furnace of the present invention; Figure 5 It is a structural schematic diagram of step three; Figure 6 It is a structural diagram of step 4; Figure 7 This is a schematic diagram of the structure of step seven; Figure 8 It is a structural schematic diagram of placing the wrapped U-shaped insulated busbar on the bracket in step eight; Fig. 9 It is a structural schematic diagram of placing the wrapped straight insulated busbar on the bracket in step eight; Fig.10 It is a structural schematic diagram of the pipeline connection in step eight; Fig.11 It is a structural schematic diagram of the cast semi-insulating structure in step five; Fig.12 It is a structural schematic diagram of the cast semi-insulating structure in step seven; Fig.13 It is a structural schematic diagram of the cast semi-insulating structure in step eight; In the figure: 1, conductor, 2, semiconductor crepe paper, 3, insulating crepe paper, 4, epoxy resin casting layer, 5, heat shrink sleeve, 6, discharge end flange terminal board, 601, discharge through hole, 7, feed end flange terminal board, 701, feed through hole, 8, terminal No. 2, 9, terminal No. 1, 10, furnace, 11, pressure mixing tank, 12, observation cup, 13, vacuum pump, 14, shrink belt, 15, pipe clamp. DETAILED DESCRIPTION

[0014] In order to make the structure and function of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0015] See attached Figure 1-13 , a cast semi-insulated structure, comprising a conductor 1, an epoxy resin casting layer 4, a heat shrinkable sheath 5, a feed end flange terminal board 7, a discharge end flange terminal board 6, a first terminal 9 and a second terminal 8; one end of the conductor 1 is connected to the end face of the feed end flange terminal board 7, and the other end of the conductor 1 is connected to the end face of the discharge end flange terminal board 6; the outer diameter of the conductor 1, the outer diameter of the feed end flange terminal board 7 and the outer diameter of the discharge end flange terminal board 6 are sleeved with a heat shrinkable sheath 5, and the space formed between the conductor 1 and the heat shrinkable tube is the epoxy resin casting layer 4; the feed end flange terminal board 7 is provided with a feed through hole 701, and the feed through hole 701 is connected to the epoxy resin casting layer 4; the discharge A discharge through hole 601 is provided on the feed end flange terminal board 6, and the discharge through hole 601 is connected to the epoxy resin casting layer 4; one end of the conductor 1 is connected to the No. 2 terminal 8 through the feed end flange terminal board 7, and the other end of the conductor 1 is connected to the No. 1 terminal 9 through the discharge end flange terminal board 6; the conductor 1 is a copper tube; semiconductor corrugated paper 2 and insulating corrugated paper 3 are uniformly arranged on the outer peripheral surface of the conductor 1 in sequence; there are two feed through holes 701 and two discharge through holes 601; the diameter of the feed end flange terminal board 7 is larger than the diameter of the conductor 1, and the diameter of the discharge end flange terminal board 6 is larger than the diameter of the conductor 1; the two ends of the epoxy resin casting layer 4 are set to be sloped.

[0016] The manufacturing process of cast semi-insulated structure includes the following steps: Step 1: Pre-dry the semiconductor crepe paper 2 and the insulating crepe paper 3: put the semiconductor crepe paper 2 and the insulating crepe paper 3 into a drying oven for drying at a temperature of 70±5°C for a period of not less than 5 hours; Step 2: Use fine sandpaper and a grinder to sand the surface of the conductor 1, and then wipe it clean with alcohol; Step 3, use semiconductor crepe paper 2 to wrap the zero screen on the conductor 1: use 40mm wide semiconductor crepe paper 2 with 1 / 3 fold for wrapping, leave 20mm at the two ends of the zero screen unwrapped to form the end of the zero screen, and the epoxy resin casting layer between the end of the zero screen and the heat shrink tube is sloped; leave 20mm unwrapped for easier wrapping, if it is attached to the root, it is easy to get edges, the ends should be aligned, the ends of the semiconductor crepe paper 2 should be cut into semicircular arcs, and the wrinkles of the crepe paper can be slightly spread out when wrapping; Step 4: Use insulating crepe paper 3 to wrap the insulation layer on the zero screen: The insulation layer is wrapped with insulating crepe paper 3 with a thickness of 0.05mm and a width of 40mm. The thickness of the insulation layer wrapped on the zero screen is 2mm. The 2mm thick insulation layer is wrapped with 2 layers of insulating crepe paper 3. The insulating crepe paper 3 is wrapped at 2 / 3-4 / 5. In general, the first layer can be slightly denser and the second layer can be slightly sparser to align the size. When wrapping the insulating crepe paper 3, do not pull the wrinkles completely open, just open the wrinkles to make it easier for the epoxy resin to penetrate. Wrap the insulating crepe paper 3 evenly on the copper tube to ensure that the epoxy resin does not crack during operation and is resistant to aging. The crepe paper is wrapped with 2mm, and finally the epoxy resin is impregnated to form a 2mm insulation layer.

[0017] Step 5, set heat shrink tubes on the insulation layer, the feed end flange terminal board 7 and the discharge end flange terminal board 6: select heat shrink tubes of appropriate size according to the outer diameter of the busbar and set them on the busbar. Since the heat shrink tube will extend to both ends when shrinking, the two ends should be appropriately shorter when cutting, generally about 300mm shorter, and then use a spray gun to bake from the middle section of the busbar to both sides to shrink the heat shrink tube and tighten the busbar. During baking, bake evenly along the circumferential direction, and another person will straighten the heat shrink tube; when baking the arc part, first bake the outer cylindrical surface, and then bake the inner cylindrical surface; Step 6, use a spray gun to bake from the middle section of the busbar to both sides, so that the heat shrink tube shrinks and tightens the busbar, the feed end flange terminal board and the discharge end flange terminal board; bake evenly along the circumferential direction during baking, and straighten the heat shrink tube at the same time; when baking the arc part, bake the outer cylindrical surface first, and then bake the inner cylindrical surface; the heat shrink tube, the feed end flange terminal board, the conductor, the semiconductor crepe paper end face, and the insulating crepe paper end face form a first cavity; the heat shrink tube, the discharge end flange terminal board, the conductor, the semiconductor crepe paper end face, and the insulating crepe paper end face form a second cavity; Step 7: Wrap the shrink tape 14 outside the heat shrink tube: Wrap a layer (1 / 3 fold) of shrink tape 14 outside the heat shrink tube to protect the heat shrink tube and prevent the heat shrink tube from deforming during the drying and impregnation resin process (pressurization) in the drying oven 10. Wrap several layers of shrink tape 14 at the beginning and end, and clamp the color rubber tape with a tube hoop 15 to ensure that it is sealed and leak-proof. Step 8: pouring epoxy resin into the feed through hole 701 of the feed end flange terminal plate 7; the specific steps are as follows: a. Preparation before the product enters the furnace 10: clean the drying furnace 10, clean the injection cup, injection pipe joint, and resin stirring tank joint with a cleaning agent, and place the corresponding observation cup 12 and storage cup on the furnace 10 according to the number of products entering the furnace 10; b. Product entering furnace 10: Place the wrapped insulating busbar on the bracket, and push the insulating busbar into the drying furnace 10 in sequence. Since there are many shapes of closed insulating busbars, there are straight insulating busbars, right-angle insulating busbars, and U-shaped insulating busbars; when the product enters the furnace 10, the long side of the busbar is close to the bottom of the furnace 10, and the short side is against the wall of the furnace 10; the straight insulating busbar that has been wrapped is padded higher at the discharge end (the busbar should be padded with arc-shaped pads such as busbar clamps, and the zero-screen end part is not allowed to be padded), which will be conducive to the impregnation of resin; special-shaped busbars (such as right-angle insulating busbars and U-shaped insulating busbars) are limited in space in the furnace 10 and cannot be padded; padded is not necessary, but it will be better if space permits, and normal pouring can be performed without padded; c. Pipeline connection: connect the products in the furnace 10 one by one, connect the upper end of the busbar outlet to the lower end of the observation cup 12 with a silicone tube, connect the lower end inlet of the busbar to the pressure mixing tank 11 communication vessel, mark the busbar number at the outlet valve of the communication vessel, connect the upper end of the observation cup 12 to the evacuation valve of the vacuum pipeline, and connect the front end valve of the communication vessel to the storage cup; d. Injecting epoxy resin: For straight insulated busbars, the feeding end (the lower end) is injected with resin, and the discharging end (the higher end) is evacuated by a vacuum pump 13; e. Pipeline removal; f. Cast-type semi-insulated structure comes out of the furnace 10.

[0018] Step 9: After the epoxy resin solidifies, remove the shrink tape 14.

[0019] Semi-insulated tubular busbar, the insulation layer only covers the busbar body, and the ends or joints are exposed. The material and manufacturing costs are low. The insulation of the semi-insulated tubular busbar is formed into a skeleton by crepe paper, then shrunk into heat shrink tube, and impregnated with epoxy resin to form a whole.

[0020] The 1 / 3, 2 / 3, and 4 / 5 fold wrapping mentioned above refers to wrapping the semiconductor crepe paper 2 / insulating crepe paper 3 around the wrapped object, and the width of each overlap is 1 / 3, 2 / 3, and 4 / 5 of the width of the semiconductor crepe paper 2 / insulating crepe paper 3. During the wrapping process, the tension of the semiconductor crepe paper 2 / insulating crepe paper 3 should be uniform to avoid looseness or wrinkles; according to the above method, the semiconductor crepe paper 2 / insulating crepe paper 3 is continuously wrapped until the required wrapping length or number of layers is reached, and the overlapping parts between each circle should be tightly fitted without gaps.

[0021] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. The manufacturing process of the cast semi-insulated structure is characterized by: The steps include: Step 1, pre-drying the semiconductor crepe paper and the insulating crepe paper; Step 2: Sand the surface of the conductor and clean it with alcohol; Step 3: Use semiconductor crepe paper to wrap the zero screen on the conductor; Step 4: Use insulating crepe paper to wrap the insulation layer on the zero screen; Step 5, a heat shrink tube is sleeved on the insulating layer, the feed end flange terminal board and the discharge end flange terminal board; the space formed between the conductor and the heat shrink tube is the epoxy resin casting layer; one end of the conductor is connected to the end face of the feed end flange terminal board, and the feed end flange terminal board is provided with a feed through hole, and the feed through hole is connected to the epoxy resin casting layer; the other end of the conductor is connected to the end face of the discharge end flange terminal board, and the discharge end flange terminal board is provided with a discharge through hole, and the discharge through hole is connected to the epoxy resin casting layer; Step 6, baking the heat shrinkable tube to shrink the heat shrinkable tube and tighten the busbar, the feed end flange terminal board and the discharge end flange terminal board; the heat shrinkable tube, the feed end flange terminal board, the conductor, the semiconductor crepe paper end face, and the insulating crepe paper end face form a first cavity; the heat shrinkable tube, the discharge end flange terminal board, the conductor, the semiconductor crepe paper end face, and the insulating crepe paper end face form a second cavity; Step 7: Wrap the outside of the heat shrink tube with shrink tape; Step 8: pouring epoxy resin into the feed through hole of the feed end flange terminal plate; Step 9: After the epoxy resin solidifies, remove the shrink tape to form a cast semi-insulating structure without a shielding layer.

2. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: In the step 1, the semiconductor crepe paper and the insulating crepe paper are placed in a drying oven for drying at a temperature of 70±5° C. for a time of not less than 5 hours.

3. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: In the step 3: use 1 / 3 of the 40mm wide semiconductor crepe paper for wrapping, and leave 20mm at the two ends of the conductor unwrapped for zero screen.

4. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: In the step 4: the insulating layer is wrapped with insulating crepe paper with a thickness of 0.05mm and a width of 40mm, and the thickness of the insulating layer wrapped on the zero screen is 2mm; the 2mm thick insulating layer is wrapped with 2 layers of insulating crepe paper, and the insulating crepe paper is wrapped at 2 / 3-4 / 5 folds.

5. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: In the step 5: a heat shrink tube 300 mm shorter than the busbar is selected, and the diameter of the heat shrink tube is larger than the diameter of the busbar.

6. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: In the step seven: use a spray gun to bake from the middle section of the busbar to both sides, so that the heat shrink tube shrinks and tightens the busbar, bakes evenly along the circumferential direction during baking, and straightens the heat shrink tube at the same time; when baking the arc part, bake the outer cylindrical surface first, and then bake the inner cylindrical surface.

7. The manufacturing process of the cast semi-insulating structure according to claim 1, characterized in that: The pouring of epoxy resin in step eight comprises the following steps: a. Preparation before pouring semi-insulated structure into the furnace: clean the drying furnace, clean the injection cup, injection pipe joint, and resin stirring tank joint with a cleaning agent, and place the corresponding observation cup and storage cup on the furnace according to the number of products entering the furnace; b. Casting type semi-insulated structure into the furnace: Place the wrapped insulated busbar on the bracket and push it into the drying furnace in sequence, with the long side of the busbar close to the bottom of the furnace and the short side against the furnace wall; c. Pipeline connection: Connect the cast-in-furnace semi-insulated structures one by one, connect the discharge through-hole on the flange terminal board at the discharge end of the busbar to the lower end nozzle of the observation cup with a silicone tube, and connect the upper end nozzle of the observation cup to the vacuum pipeline evacuation valve; connect the feed through-hole on the flange terminal board at the feed end of the busbar to the pressure mixing tank connecting pipe with a silicone tube, mark the busbar number at the outlet valve of the connecting pipe, and connect the valve nozzle at the front end of the connecting pipe to the storage cup; d. Inject epoxy resin: For straight insulated busbars, inject resin into the feed end and evacuate the discharge end; e. Pipeline removal; f. The cast-type semi-insulated structure comes out of the furnace.

8. The manufacturing process of the cast semi-insulating structure according to claim 7, characterized in that: In the step b, the discharge end of the wrapped insulated busbar is padded.

9. A cast-type semi-insulating structure manufactured by the manufacturing process of cast-type semi-insulating structure according to claim 1, characterized in that: It includes a conductor, an epoxy resin casting layer, a heat shrink sleeve, a feed end flange terminal board, a discharge end flange terminal board, a No. 1 terminal and a No. 2 terminal; one end of the conductor is connected to the No. 1 terminal through the feed end flange terminal board, and the other end of the conductor is connected to the No. 2 terminal through the discharge end flange terminal board; the outer diameters of the conductor, the feed end flange terminal board and the discharge end flange terminal board are covered with heat shrink sleeves; the conductor is a copper tube; semiconductor crepe paper and insulating crepe paper are uniformly arranged on the outer circumference of the conductor in sequence; there are two feed through holes and two discharge through holes; the diameter of the feed end flange terminal board is larger than the diameter of the conductor, and the diameter of the discharge end flange terminal board is larger than the diameter of the conductor; the two ends of the epoxy resin casting layer are arranged to be sloped.

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