Low-voltage voltage transformer and manufacturing method thereof

Abstract

The invention discloses a low-voltage voltage transformer and a manufacturing method thereof, and relates to the technical field of power transmission and transformation equipment and peripheral supporting facilities thereof. A low-voltage voltage transformer comprises a protective shell used for providing protection; the protection layer is filled in the protection shell; the iron core is arranged in the protective layer, the coil comprises a primary coil and a secondary coil, and the primary coil and the secondary coil are both wound on the iron core; the primary connecting terminal is mounted on the protective shell and is connected with a primary coil of the coil; and the secondary connecting terminal is arranged on the protective shell and is connected with the secondary coil of the coil. According to the invention, the problems of easy wetting and rusting, accelerated equipment aging and reduced insulating property are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation equipment and peripheral supporting facilities thereof, and in particular to a low-voltage voltage transformer and a manufacturing method thereof. Background Art

[0002] In photovoltaic and wind power generation systems, high-voltage switchgear, as the core power distribution and protection device, ensures the effective transmission of electric energy and the safe operation of the system. Among them, the low-voltage voltage transformer plays a vital role. It not only provides the necessary voltage signal for the monitoring system for measurement and control, but also powers measuring equipment such as relays and instruments to ensure the accuracy and reliability of system operation. Traditionally, these voltage transformers use laminated silicon steel sheets as the core. Although this design is cost-effective, it has significant limitations in practical applications. Since the silicon steel sheets are directly exposed to the environment, they are prone to moisture after long-term operation, especially under high humidity conditions, which leads to rust of the core. Rust not only increases the loss of the magnetic circuit and affects the measurement accuracy, but also causes short-circuit failures in severe cases, threatening the stability and safety of the entire power generation system.

[0003] In addition, when not in use for a long time, the problem of moisture penetration is more prominent, which accelerates the aging process of the equipment, shortens the maintenance cycle and service life, increases maintenance costs and potential power outage risks. Therefore, for power generation systems such as photovoltaic and wind power that rely on outdoor environments and require long-term stable operation, the existing protection measures for low-voltage voltage transformers are insufficient, and there is an urgent need for a new design that can effectively prevent moisture and improve insulation performance and reliability. Now there is an improvement that is to put the voltage wire package into a specific mold, pour a specific material, and remove the mold after solidification. However, this method has the problems of long curing time, low production efficiency, and requires a lot of money to open the mold in practice.

[0004] In view of the above problems, the present invention proposes an innovative low-voltage voltage transformer design, aiming to overcome the defects of traditional designs and improve the durability of the equipment and the reliability of the entire system through improvements in structure and materials. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the existing low-voltage voltage transformer is prone to moisture, which accelerates equipment aging and reduces insulation performance.

[0006] One of the purposes is to provide a low voltage voltage transformer to solve the problems of easy moisture corrosion, accelerated equipment aging and reduced insulation performance.

[0007] The second purpose is to provide a method for manufacturing a low-voltage voltage transformer, which solves the problems of low production efficiency and high production cost.

[0008] The present invention is achieved through the following technical solutions:

[0009] The present invention provides a low voltage voltage transformer, comprising

[0010] A protective case, used to provide protection;

[0011] A protective layer filled in the protective shell;

[0012] The iron core is arranged in the protective layer.

[0013] The wire package includes a primary coil and a secondary coil, and both the primary coil and the secondary coil are wound on the iron core;

[0014] The primary connection terminal is installed on the protective shell and connected to the primary coil of the coil;

[0015] The secondary connection terminal is installed on the protective shell and connected to the secondary coil of the wire package.

[0016] As a possible design, the low-voltage voltage transformer further includes a heat dissipation hole, and there are multiple heat dissipation holes, which are evenly opened on the protective shell.

[0017] As a possible design, the protective layer includes epoxy resin, silicone rubber, polyurethane, organic silicone resin, polyester resin, phenolic resin and / or mica-based resin.

[0018] As a possible design, the iron core is a ring-shaped iron core or a C-shaped iron core with a cutout.

[0019] As a possible design, the low-voltage voltage transformer further includes a tripod, which is installed at one end of the protective shell away from the primary connection end and the secondary connection end to provide stable support.

[0020] The present invention also provides a method for manufacturing a low-voltage voltage transformer, comprising the following steps:

[0021] S1, winding wire package;

[0022] S2, assemble the core and wire package;

[0023] S3. Weld the primary nut and the secondary nut on the wire package;

[0024] S4, wrap the iron core and wire package;

[0025] S5. Open the protective shell, put the wrapped iron core and wire package into the protective shell, connect the primary nut and the secondary nut to the primary connection end mark and the secondary connection end mark of the protective shell with screws respectively, and close the protective shell;

[0026] S6. Pour the molten protective layer material into the protective shell and solidify it.

[0027] As a possible design, the above step S1 includes:

[0028] S11, putting an epoxy cylinder on the secondary wire core mold, winding the enameled wire on the epoxy cylinder by a parallel winding machine, winding the first winding, wrapping the first winding with insulating paper, and then repeatedly winding the second winding on the first winding. After winding the two windings, respectively put silicone tubes on the wire ends of the first winding and the wire ends of the second winding to obtain a secondary coil;

[0029] S12. Wrap insulating paper around the secondary coil and fix it, prepare the primary coil according to the method of the secondary coil, then remove the primary coil and the secondary coil together with the epoxy tube respectively, and remove the paint from the primary coil wire ends and the secondary coil wire ends.

[0030] As a possible design, the above step S2 includes:

[0031] Put the primary coil and secondary coil together with the epoxy tube into the long end of the iron core, fit the short end of the iron core tightly with the long end, and use a stainless steel belt to tightly close and tighten the iron core along the outer circumference of the iron core.

[0032] As a possible design, after the iron core and the coil are assembled, the further step includes: performing error detection on the assembled iron core and the coil on a low voltage voltage transformer testing device, and then proceeding to step S3 if the error detection is qualified;

[0033] Step S3 includes:

[0034] Put silicone tubes on the primary and secondary windings, and weld primary nuts on the wire ends of the primary winding and secondary nuts on the wire ends of the secondary winding.

[0035] As a possible design, the above step S4 includes:

[0036] S41. Place insulating paper on both sides of the core and the long side of the core, and use cardboard to secure the core and the wire package.

[0037] S42. Place a cushioning cardboard on the outside of the iron core and wrap the cushioning cardboard tightly;

[0038] Step S5 includes:

[0039] S51. Open the protective shell, put four nuts at the bottom of the protective shell, and fix the two mounting plates on the nuts with screws;

[0040] S52. Place the wrapped iron core and wire package into the protective shell with the iron core facing downward and the wire package facing upward and fix them. Outside the protective shell, connect the primary nut and the secondary nut to the primary connection end mark and the secondary connection end mark respectively with screws, and finally close the protective shell.

[0041] As a possible design, the above step S6 includes:

[0042] S61. Place the protective shell on the casting platform with the core facing upward and the wire package facing downward;

[0043] S62, pouring the molten protective layer material into the protective shell along the pouring port of the protective shell until the liquid on the surface of the pouring port is flat and solidified.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0045] The present invention places the iron core and the wire package in a protective shell, and insulates and wraps the internal iron core and the wire package with a protective layer, thereby preventing moisture and rust, slowing down the aging speed of the equipment, and improving the insulation performance.

[0046] The present invention also provides a manufacturing method for the low-voltage voltage transformer, by installing a protective shell outside the iron core and filling the protective shell with resin to form a protective layer. Compared with the prior art of placing the transformer in a specific mold and then pouring protective material into the mold, not only is there no need to wait for the material in the mold to solidify, thereby improving production efficiency, but also the low-cost protective shell can be directly used as the solidification shell, greatly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0048] Figure 1 is a cross-sectional view of a low voltage voltage transformer of the present invention;

[0049] Figure 2 A side view of a low voltage voltage transformer of the present invention;

[0050] Figure 3 The figure is a top view of a low voltage voltage transformer of the present invention.

[0051] Marks and corresponding parts names in the attached drawings:

[0052] 1-protective shell; 2-protective layer; 3-iron core; 4-wire package; 5-primary connection terminal; 6-secondary connection terminal; 7-heat dissipation hole; 8-tripod. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the examples and drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention. If no specific conditions are specified in the examples, the conventional conditions or the conditions recommended by the manufacturer shall be followed.

[0054] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In a first aspect, a low voltage voltage transformer, referring to Figures 1 to 3, including a protective shell 1, a protective layer 2, an iron core 3, a wire package 4, a primary connection end 5 and a secondary connection end 6. The protective shell 1 is preferably made of insulating resin and is shaped as two hollow half shells spliced ​​together. The protective shell 1 can provide protection for the internal iron core 3 and the wire package 4 to avoid external impact, and can also provide space for pouring the protective layer 2, so that the poured resin can be arranged around the iron core 3 and the wire package 4. The protective layer 2 is filled in the protective shell 1 around the iron core 3 and the wire package 4. On the one hand, it has an excellent insulation effect after solidification, isolating the low-voltage voltage transformer from the external environment and ensuring electrical safety; on the other hand, the filling of the protective layer 2 strengthens the overall structure of the voltage transformer, making it more solid and able to resist external physical impact and vibration; on the other hand, it has good thermal conductivity and heat resistance, which can help the internal components dissipate heat, keep the operating temperature within a safe range, prevent overheating, and effectively prevent fire accidents. The iron core 3 is arranged in the protective layer 2, and the wire package 4 is wrapped around the surface. The coil 4 includes a primary coil and a secondary coil, both of which are wound on the iron core 3, the primary coil is electrically connected to the primary connection terminal 5, and the secondary coil is electrically connected to the secondary connection terminal 6; the primary connection terminal 5 is installed on the protective shell 1 and connected to the primary coil of the coil 4, which is used for high voltage input, electrical isolation, and improved connection stability. The secondary connection terminal 6 is installed on the protective shell 1 and connected to the secondary coil of the coil 4, which is used for low voltage output, safe measurement, standardized interface, protective grounding, and flexible configuration.

[0058] In some embodiments of the present invention, the above further includes heat dissipation holes 7, and there are multiple heat dissipation holes 7, and the multiple heat dissipation holes 7 are evenly opened on the protective shell 1. The number of heat dissipation holes can be 2, 5, 8 or any number, and they are preferably opened on the side, front and rear sides and / or bottom side of the protective shell 1.

[0059] In some embodiments of the present invention, the protective layer 2 comprises epoxy resin, silicone rubber, polyurethane, silicone resin, polyester resin, phenolic resin and / or mica-based resin. The above resins all have excellent high temperature resistance, chemical stability and electrical insulation. More preferably, the protective layer 2 is epoxy resin.

[0060] In some embodiments of the present invention, the iron core 3 is a ring-shaped iron core or a C-shaped iron core with a cutout.

[0061] In some embodiments of the present invention, the low voltage voltage transformer further comprises a tripod 8, which is mounted at one end of the protective shell 1 away from the primary connection terminal 5 and the secondary connection terminal 6, and is used to provide stable support. The tripod 8 is connected to the bottom of the protective shell 1 by screws, clamping or other fixing methods, and is used to provide support and fixation, avoid wear on the protective shell 1 and facilitate installation and fixation. The shape is preferably that the two sides extend in parallel and the middle bulges upward, the front of the bulge is fixed to the protective shell 1, and holes are opened on both sides so that it can be fixed with screws.

[0062] In a second aspect, a method for manufacturing a low voltage voltage transformer comprises the following steps:

[0063] S1, winding wire package 4.

[0064] In some embodiments of the present invention, the above step S1 includes:

[0065] S11, putting an epoxy tube on the secondary wire core mold, winding the enameled wire on the epoxy tube sleeve by a parallel winding machine, winding the first winding, wrapping the first winding with insulating paper, and then repeatedly winding the second winding on the first winding. After winding the two windings, respectively put silicone tubes on the wire ends of the first winding and the wire ends of the second winding to obtain a secondary coil;

[0066] S12. Wrap the insulating paper PMP on the secondary coil and fix it, prepare the primary coil according to the method of the secondary coil, then remove the primary coil and the secondary coil together with the epoxy tube, and remove the paint from the primary coil wire ends and the secondary coil wire ends.

[0067] S2. Assemble the iron core 3 and the coil 4.

[0068] In some embodiments of the present invention, the above step S2 includes:

[0069] Put the primary coil and the secondary coil together with the epoxy tube into the long end of the iron core, fit the short end of the iron core tightly with the long end, and use a stainless steel belt to tightly close and tighten the iron core along the outer circumference of the iron core.

[0070] In some embodiments of the present invention, after the iron core 3 and the coil 4 are assembled, the method further includes: performing error detection on the assembled iron core 3 and the coil 4 on a low voltage voltage transformer inspection device, and performing step S3 if the error detection is qualified;

[0071] S3. Weld the primary nut and the secondary nut on the wire package 4.

[0072] In some embodiments of the present invention, the above step S3 includes:

[0073] Put silicone tubes on the primary and secondary windings, and weld primary nuts on the wire ends of the primary winding and secondary nuts on the wire ends of the secondary winding.

[0074] S4, wrap the iron core 3 and the wire package 4.

[0075] In some embodiments of the present invention, the above step S4 includes:

[0076] Place insulating paper on both sides of the core and the long side of the core, and use cardboard to secure the core and wire package.

[0077] Place buffer cardboard on the outside of the iron core and wrap the buffer cardboard tightly.

[0078] S5. Open the protective shell 1, put the wrapped iron core 3 and wire package 4 into the protective shell 1, connect the primary nut and the secondary nut to the primary connection end 5 and the secondary connection end 6 of the protective shell with screws respectively, and close the protective shell 1.

[0079] In some embodiments of the present invention, the above step S5 includes:

[0080] S51, open the protective shell 1, put four nuts at the bottom of the protective shell 1, and fix the two mounting plates on the nuts with screws;

[0081] S52. Place the wrapped iron core and wire package into the protective shell 1 with the iron core facing downward and the wire package facing upward and fix them. Outside the protective shell 1, connect the primary nut and the secondary nut to the primary connection terminal 5 mark and the secondary connection terminal 6 mark respectively with screws, and close the protective shell 1.

[0082] Preferably, the above step S5 further includes S53, performing error detection on the iron core and the wire wrap of the closed protective shell 1 on a low-voltage voltage transformer testing device, checking the wiring and performing a withstand voltage test.

[0083] S6, pouring the molten protective layer material into the protective shell 1 and solidifying it.

[0084] In some embodiments of the present invention, the above step S6 includes:

[0085] S61, placing the protective shell 1 on the casting platform with the core facing upward and the wire package facing downward;

[0086] S62, pouring the molten protective layer material into the protective shell 1 along the pouring port of the protective shell until the liquid on the surface of the pouring port is flat and solidified.

[0087] Preferably, the above method also includes step S7, installing the solidified low-voltage voltage transformer on a tripod, performing an appearance inspection, measuring the DC resistance of the primary winding and the secondary winding respectively with a digital bridge, performing a volt-ampere characteristic test with a volt-ampere characteristic tester, performing a power frequency withstand voltage test with a withstand voltage test bench, and measuring the error with a low-voltage transformer error measuring device. After all inspections are qualified, it is put into storage.

[0088] Example 1

[0089] A method for manufacturing a low voltage voltage transformer comprises the following steps:

[0090] S1, winding package 4:

[0091] S10. Prepare enameled wire, PMP insulating paper, epoxy tube, silicone tube and other auxiliary materials.

[0092] S11. The epoxy cylinder is put on the secondary wire core mold, and then the winding core mold is installed on the automatic parallel winding machine and tightened. The enameled wire is placed on the winding machine's wire storage disk, and the wire head is pulled out and inserted into the winding machine's wire pulley to prepare for winding; the technical parameters are set on the display screen for winding the first winding and the second winding on the automatic parallel winding machine, leaving a wire head length of 150mm, inserting the wire head into the outside of the winding mold baffle, and sticking the wire head with adhesive tape to start winding. After winding a full layer, wrap it with 0.1×80mm PMP insulation paper, with an overlap greater than 30mm, and then wind the second layer, third layer, fourth layer... (The number of layers is set as needed, which can be 4 layers, 6 layers, 8 layers, 10 layers or any layers). After each layer is wound, a layer of 0.1×80mm PMP paper is placed until the required number of turns is wound, leaving a wire head length of 150mm. After winding the first winding, wrap the first winding with 2 layers of 0.1x80mm PMP insulation paper, with the overlap greater than 30mm. Repeat the winding of the second winding on the first winding. After winding the two windings, wrap the ends of the first winding and the second winding with the insulation paper. The silicone tube is used to obtain the secondary coil, in which the first winding has yellow and green ends, and the second winding has red and black ends.

[0093] S12. Wrap three layers of 0.1×80mm PMP insulating paper on the secondary coil and fix them. Prepare the primary coil according to the method of the secondary coil, leaving a wire end length of 150mm, and then wrap it with 3 layers of 0.1×80mm PMP paper and stick it with double-sided tape; then remove the primary and secondary coils together with the epoxy tube, and remove the paint on the primary and secondary coil wire ends. Specifically, soak each wire end with a length of 15-20mm in a paint stripper. After the paint layer of the wire end bubbles, wipe off the paint layer with cotton cloth.

[0094] S13. Use a turns meter to measure the number of turns of each winding, and proceed to the next process after it is accurate.

[0095] S2, assemble the core 3 and the coil 4:

[0096] S20, grinding the cut end surface of the core 3 flat and smooth using a disc grinder;

[0097] S21. Put the epoxy tube with the primary coil and the secondary coil into the long end of the iron core, fit the short end of the iron core tightly with the long end, and use a stainless steel belt to tightly close the iron core along the outer circumference of the iron core.

[0098] S22, performing error detection on the assembled iron core 3 and the coil 4 on a low voltage voltage transformer testing device;

[0099] S3. Weld the primary nut and secondary nut on the wire package 4: Put them on the primary winding. The A end of the silicone tube is white and the N (B) end is blue. Use an electric soldering iron to weld a special primary nut of M6×12mm on the wire end of the primary winding, and a special secondary nut of M6×12mm on the wire end of the secondary winding.

[0100] S4. Wrap the iron core 3 and the wire package 4:

[0101] S41. Place three layers of 0.1×80mm insulating paper on both sides of the core and the long sides of the core, and use cardboard to secure the core and wire package.

[0102] S42. Place a 2-3mm thick buffer cardboard on the outside of the iron core, and then wrap the buffer cardboard tightly and completely with 25mm wide adhesive tape.

[0103] S5. Open the protective shell 1, put the wrapped iron core 3 and wire package 4 into the protective shell 1, connect the primary connection terminal 5 and the secondary connection terminal 6 with the primary nut and the secondary nut respectively, and close the protective shell 1:

[0104] S51. Open the protective shell 1, put four M8×20mm nuts on the bottom of the protective shell 1, and fix the two mounting plates on the nuts with M8×20mm screws.

[0105] S52. Place the wrapped iron core and wire package in the protective shell 1 with the iron core facing downward and the wire package facing upward, and fix them. Outside the protective shell 1, connect the primary nut and the secondary nut to the A-BN), 1a-1n, and 2a-2n identification holes of the protective shell 1 respectively. When wiring, place a pad on the M6 ​​nut mouth. Flat washers are installed and screws are tightened; the wire ends are arranged, leaving a distance of 20 mm between the wire ends to ensure that the wire ends do not short-circuit, and then the protective shell 1 is closed; adhesive tape is wrapped around the seam of the shell for one week, and then the protective shell 1 is tied tightly with heat shrink tape;

[0106] S53, the iron core and the wire package of the closed protective shell 1 are subjected to error detection on a low-voltage voltage transformer testing device, and the wiring is checked and a withstand voltage test is performed.

[0107] S6, pouring the molten protective layer material into the protective shell 1 and solidifying it:

[0108] S61, placing the protective shell 1 on the casting platform with the core facing upward and the wire package facing downward;

[0109] S62, pouring the molten protective layer material into the protective shell 1 along the pouring port of the protective shell until the liquid on the surface of the pouring port is flat and solidified.

[0110] S7. Check the appearance to confirm that it is intact, without defects, and the markings are correct and clear; use a digital bridge to measure the DC resistance of the primary and secondary windings respectively, use a volt-ampere characteristic tester to perform volt-ampere characteristic test, use a withstand voltage test bench to perform power frequency withstand voltage test, and use a low-voltage transformer error measurement device to measure the error. After all inspections are passed, it can be put into storage.

[0111] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low voltage voltage transformer, characterized in that: include A protective case, used to provide protection; A protective layer filled in the protective shell; An iron core is disposed in the protective layer, A coil package, the coil package comprising a primary coil and a secondary coil, the primary coil and the secondary coil are both wound on an iron core; A primary connection terminal is mounted on the protective shell and connected to the primary coil of the coil; The secondary connection terminal is installed on the protective shell and connected to the secondary coil of the wire package.

2. A low voltage voltage transformer according to claim 1, characterized in that: It also includes heat dissipation holes, and there are multiple heat dissipation holes, which are evenly opened on the protective shell.

3. A low voltage voltage transformer according to claim 1, characterized in that: The protective layer includes epoxy resin, silicone rubber, polyurethane, silicone resin, polyester resin, phenolic resin and / or mica-based resin.

4. A low voltage voltage transformer according to claim 1, characterized in that: The iron core is a ring-shaped iron core or a C-shaped iron core with a cutout.

5. A low voltage voltage transformer according to claim 1, characterized in that: A tripod is also included, which is installed at one end of the protective shell away from the primary connection end and the secondary connection end to provide stable support.

6. A method for manufacturing a low voltage voltage transformer according to any one of claims 1 to 5, characterized in that: The steps include: S1, winding package; S2, assemble the core and the wire package; S3. Weld the primary nut and the secondary nut on the wire package; S4, wrap the iron core and wire package; S5. Open the protective shell, put the wrapped iron core and wire package into the protective shell, connect the primary nut and the secondary nut to the primary connection end mark and the secondary connection end mark of the protective shell with screws respectively, and close the protective shell; S6. Pour the molten protective layer material into the protective shell and solidify it.

7. The method for manufacturing a low voltage voltage transformer according to claim 6, characterized in that: The step S1 comprises: S11, putting an epoxy cylinder on the secondary wire core mold, winding the enameled wire on the epoxy cylinder by a parallel winding machine, winding the first winding, wrapping the first winding with insulating paper, and then repeatedly winding the second winding on the first winding. After winding the two windings, respectively put silicone tubes on the wire ends of the first winding and the wire ends of the second winding to obtain a secondary winding; S12. Wrap insulating paper on the secondary winding and fix it, prepare the primary winding according to the secondary winding method, then remove the primary coil and the secondary coil together with the epoxy tube respectively, and remove the paint from the primary coil wire end and the secondary coil wire end.

8. The method for manufacturing a low voltage voltage transformer according to claim 6, characterized in that: The step S2 comprises: Put the epoxy tube with the primary coil and the secondary coil wound on it into the long end of the iron core, fit the short end of the iron core tightly with the long end, and use a stainless steel belt to tightly close and tighten the iron core along the outer circumference of the iron core.

9. The method for manufacturing a low voltage voltage transformer according to claim 6, characterized in that: After the core and the coil are assembled, the method further includes: performing error detection on the assembled core and the coil on a low voltage voltage transformer inspection device, and performing step S3 if the detection is qualified; The step S3 comprises: Put silicone tubes on the primary and secondary windings, and weld primary nuts on the wire ends of the primary winding and secondary nuts on the wire ends of the secondary winding.

10. The method for manufacturing a low voltage voltage transformer according to claim 6, characterized in that: The step S4 comprises: S41. Place insulating paper on both sides of the core and the long side of the core, and use cardboard to secure the core and the wire package. S42. Place a cushioning cardboard on the outside of the iron core and wrap the cushioning cardboard tightly; The step S5 comprises: S51. Open the protective shell, put four nuts at the bottom of the protective shell, and fix the two mounting plates on the nuts with screws; S52. Place the wrapped iron core and wire package into the protective shell with the iron core facing downward and the wire package facing upward and fix them. Outside the protective shell, connect the primary nut and the secondary nut to the primary connection end mark and the secondary connection end mark with screws respectively, and finally close the protective shell.

11. The method for manufacturing a low voltage voltage transformer according to claim 6, characterized in that: The step S6 comprises: S61. Place the protective shell on the casting platform with the core facing upward and the wire package facing downward; S62, pouring the molten protective layer material into the protective shell along the pouring port of the protective shell until the liquid on the surface of the pouring port is flat and solidified.

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