Single-phase transformer

Abstract

The utility model discloses a single-phase transformer, which relates to the technical field of transformers and comprises a rolled iron core, a coil group, a support plate, a fastening component and a clamping component. The rolled iron core comprises a core column, an upper iron yoke and a lower iron yoke, the upper iron yoke and the lower iron yoke are perpendicularly arranged at the two ends of the core column respectively, and the upper iron yoke is parallel to the lower iron yoke. The coil group is wound on the core column; the supporting plate is inserted between the core column and the coil assembly; the fastening assembly comprises a contraction band and a plurality of clamping plates, the clamping plates abut against the peripheral face of the coil assembly, and the contraction band is wound around the oppositely-arranged clamping plates so that the clamping plates can provide clamping force for the coil assembly; the clamping assembly comprises a top plate, a base and two clamping plates installed on the two sides of the base respectively, a clamping area is defined by the top plate, the base and the clamping plates, the rolled iron core is installed in the clamping area, the base is attached to the lower iron yoke, and the top plate is attached to the upper iron yoke. Therefore, the strength of the coil assembly and the rolled iron core is improved, so that the single-phase transformer has the advantages of being stable in structure and high in short circuit resistance.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and in particular to a single-phase transformer. Background Technology

[0002] In power transmission and transformation projects, transformers are essential key equipment. With the continuous development of the power industry, the market demand for single-phase transformers is showing an increasing trend. However, traditional single-phase transformers are prone to problems such as core loosening, displacement, and coil displacement when encountering sudden short circuits, resulting in insufficient resistance to sudden short circuits. Utility Model Content

[0003] The main purpose of this utility model is to propose a single-phase transformer, which aims to solve the technical problems of insufficient resistance to sudden short circuits and poor structural stability of single-phase transformers.

[0004] To achieve the above objectives, this utility model proposes a single-phase transformer, comprising:

[0005] A rolled iron core, the rolled iron core including a core column and an upper iron yoke and a lower iron yoke respectively perpendicularly disposed at both ends of the core column, the upper iron yoke and the lower iron yoke being parallel;

[0006] A coil assembly, wherein the coil assembly is wound around the core column;

[0007] A support plate, which is inserted between the core column and the coil assembly;

[0008] A fastening assembly, comprising a shrink band and multiple clamping plates, wherein the clamping plates abut against the outer peripheral surface of the coil assembly, and the shrink band is wound around the oppositely arranged clamping plates to provide a clamping force to the coil assembly;

[0009] A clamping assembly includes a top plate, a base, and two clamping plates respectively installed on both sides of the base. The top plate, the base, and the clamping plates enclose a clamping area. The rolled iron core is installed in the clamping area. The base is in contact with the lower yoke, and the top plate is in contact with the upper yoke.

[0010] In one embodiment, the rolled iron core includes two sets of single-frame iron cores, each single-frame iron core including two iron core columns. The two sets of single-frame iron cores are arranged side by side to form the rolled iron core. The rolled iron core has a two-frame three-column structure, and the two adjacent iron core columns of the two sets of single-frame iron cores are combined to form the core column.

[0011] In one embodiment, the single-phase transformer further includes multiple fastening straps, which are sleeved on the outer circumferential surface of the single-frame iron core. The single-frame iron core comprises multiple layers of silicon steel sheets, and the fastening straps are parallel to the silicon steel sheets.

[0012] In one embodiment, the coil assembly includes a first low-voltage winding, a high-voltage winding, and a second low-voltage winding wound sequentially around the outside of the core column. The support plate is inserted between the first low-voltage winding and the core column, and the clamping plate abuts against the outer peripheral surface of the second low-voltage winding.

[0013] In one embodiment, an insulating layer is provided on both the inner and outer sides of the high-voltage winding.

[0014] In one embodiment, the base includes a base plate and two bottom flanges, the bottom flanges being perpendicular to the base plate, the two bottom flanges and the base plate forming a bottom abutment groove, the inner wall of the bottom abutment groove abutting against the lower yoke;

[0015] The top plate includes a main body and two top flanges. The top flanges are perpendicular to the main body. The two top flanges and the main body enclose a top pressing groove. The inner wall of the top pressing groove abuts against the upper yoke.

[0016] In one embodiment, the two clamping plates are arranged opposite to each other, and the clamping plates are perpendicular to the base plate. The clamping plates include side plates and two side flanges. The side flanges are perpendicular to the side plates. The two side flanges and the side plates enclose each other to form a side abutment groove. The openings of the two side abutment grooves are arranged opposite to each other. The rolled iron core also includes a side yoke parallel to the core column. The inner wall of the side abutment groove abuts against the side yoke.

[0017] In one embodiment, the top plate is detachably connected to the clamping plate.

[0018] In one embodiment, the single-phase transformer further includes an oil tank, a bushing, lead cables, and a cable fixing bracket. The oil tank includes a side panel with a through hole. The bushing passes through the through hole. The lead end of the coil group is connected to the input end of the bushing. The lead cable is connected to the output end of the bushing. The cable fixing bracket is installed on the side panel and is used to clamp the lead cable.

[0019] In one embodiment, the fuel tank further includes a lifting plate and a top sealing plate. The top sealing plate is used to seal the top of the side enclosure. The lifting plate is installed on the side enclosure and has a lifting hole in the vertical direction. The height of the lifting hole is greater than the height of the top surface of the top sealing plate.

[0020] According to the technical solution of this utility model, a single-phase transformer includes a wound iron core, a coil assembly, a support plate, a fastening assembly, and a clamping assembly. The wound iron core includes a core column and an upper yoke and a lower yoke respectively vertically disposed at both ends of the core column, with the upper and lower yokes parallel to each other. The coil assembly is wound around the core column. The support plate is inserted between the core column and the coil assembly. The fastening assembly includes a shrink band and multiple clamping plates, with the clamping plates abutting against the outer circumference of the coil assembly. The shrink band is wrapped around the oppositely disposed clamping plates to provide clamping force to the coil assembly. The clamping assembly includes a top plate, a base, and two clamping plates respectively installed on both sides of the base. The top plate, base, and clamping plates enclose a clamping area, where the wound iron core is installed. The base is in contact with the lower yoke, and the top plate is in contact with the upper yoke. This design allows the support plate to radially secure the coil assembly through structural support, while the shrink band clamps the coil assembly, making it more secure and improving the overall strength of the coil assembly. In the event of a sudden short circuit, this reduces the probability of the coil assembly shifting, thus improving the short-circuit withstand capability of the single-phase transformer. Furthermore, by clamping the wound core with the clamping assembly, the overall strength and structural stability of the wound core are improved, thereby reducing the probability of the wound core loosening in the event of a sudden short circuit and further enhancing the short-circuit withstand capability of the single-phase transformer. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 A partial structural schematic diagram of an embodiment of the single-phase transformer provided by this utility model;

[0023] Figure 2 A front structural schematic diagram of an embodiment of the rolled iron core provided by this utility model;

[0024] Figure 3 for Figure 1 Side structural perspective view;

[0025] Figure 4 for Figure 1 A top-view structural diagram;

[0026] Figure 5 A schematic diagram of another part of the structure of an embodiment of the single-phase transformer provided by this utility model;

[0027] Figure 6 for Figure 5 A top view of the central section of the structure.

[0028] Explanation of icon numbers:

[0029] 1. Rolled iron core; 11. Single-frame iron core; 111. Core column; 112. Upper yoke; 113. Lower yoke; 114. Side yoke;

[0030] 2. Coil group; 21. First low-voltage winding; 22. High-voltage winding; 23. Second low-voltage winding;

[0031] 3. Support plate;

[0032] 4. Plywood;

[0033] 5. Clamping assembly; 51. Top plate; 511. Main body; 512. Top folded edge; 52. Base; 521. Bottom plate; 522. Bottom folded edge; 53. Clamping plate; 531. Side plate; 532. Side folded edge;

[0034] 6. Fastening straps;

[0035] 7. Fuel tank; 71. Side panel; 72. Hanging plate; 721. Lifting hole; 73. Top sealing plate;

[0036] 8. Sleeve;

[0037] 9. Cable mounting bracket;

[0038] Y, vertical direction.

[0039] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0041] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0042] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0043] In recent years, the construction of global power infrastructure has continued to advance, and the demand for upgrading single-phase transformers in overseas markets has become increasingly urgent. With the deepening of smart grid construction and the widespread integration of distributed energy resources, higher requirements have been placed on both the quantity and quality of single-phase transformers, resulting in a sustained growth in market demand. The working principle of a single-phase transformer is based on the principle of electromagnetic induction. Its core transformer component consists of windings and an iron core. The iron core has a magnetic conductivity, used to form a closed magnetic circuit to constrain magnetic lines of force, while the windings are used to achieve electromagnetic coupling, realizing the transfer of electrical energy.

[0044] According to the applicant's observations and research, conventional single-phase transformers, when operating, may experience loosening of the core due to insufficient mechanical strength under electromagnetic forces in the event of a sudden short circuit. Furthermore, the windings have poor resistance to deformation and may also shift under short-circuit conditions. Therefore, conventional single-phase transformers suffer from insufficient resistance to sudden short circuits and poor structural stability.

[0045] In view of the above, this utility model proposes a single-phase transformer to solve or at least alleviate the above problems.

[0046] Please see Figures 1 to 4In one embodiment of this utility model, the single-phase transformer includes a wound iron core 1, a coil group 2, a support plate 3, a fastening assembly and a clamping assembly 5. The coiled iron core 1 includes a core column 111 and an upper yoke 112 and a lower yoke 113 respectively vertically arranged at both ends of the core column 111, with the upper yoke 112 and the lower yoke 113 being parallel; a coil group 2 is wound around the core column 111; a support plate 3 is inserted between the core column 111 and the coil group 2; a fastening assembly includes a shrink band and multiple clamping plates 4, with the clamping plates 4 abutting against the outer circumferential surface of the coil group 2, and the shrink band being wound around the oppositely arranged clamping plates 4 so that the clamping plates 4 provide clamping force to the coil group 2; a clamping assembly 5 includes a top plate 51, a base 52, and two clamping plates 53 respectively installed on both sides of the base 52, with the top plate 51, the base 52, and the clamping plates 53 forming a clamping area, with the coiled iron core 1 installed in the clamping area, the base 52 fitting against the lower yoke 113, and the top plate 51 fitting against the upper yoke 112.

[0047] Specifically, the coiled iron core 1 includes either a shell-type iron core or a core-type iron core. After the coil assembly 2 is wound, it is press-dried. Then, a support plate 3 is inserted into the inner circumference of the coil assembly 2, and a clamping plate 4 is placed on the outer side of the coil assembly 2. The clamping plate 4 is then bound with shrink tape to improve the overall strength of the coil assembly 2. Subsequently, the coiled iron core 1 is installed into the coil assembly 2 on the operating table, so that the core column 111 passes through the coil assembly 2. Finally, the coiled iron core 1 with the coil assembly 2 is installed on the clamping assembly 5, so that the clamping assembly 5 clamps the coiled iron core 1 around its perimeter, thereby improving the overall strength of the coiled iron core 1. The support plate 3 includes either an epoxy board or a high-voltage board. In this embodiment, the support plate 3 is a 2 to 4 mm thick FR4 epoxy board. The clamping plate 4 includes either a stainless steel plate or an aluminum alloy plate. In this embodiment, the clamping plate 4 is a 2 mm thick stainless steel plate. An insulating cardboard is placed between the clamping plate 4 and the coil assembly 2 for isolation. The shrink tape needs to provide a certain tension to the clamping plate 4. The shrink tape includes one of semi-dry non-woven tape and carbon fiber non-woven tape. In this embodiment, the clamping plate 4 is bound with multiple layers of semi-dry non-woven tape so that the clamping plate 4 can hold the coil group 2. It should be noted that the shape of the coil group 2 projected onto the horizontal plane is a rectangular frame with rounded corners. It has an outer frame and an inner frame. The outer frame and the inner frame have the same length direction. The support plate 3 is inserted into the inner frame of the rectangular frame and is set parallel to the length direction. The clamping plate 4 is set parallel to the length direction on the outside of the outer frame. There are two clamping plates 4. The two clamping plates 4 are set opposite each other and are bound with shrink tape to improve the strength of the coil group 2 while reducing costs.

[0048] Through the technical solution of this embodiment, the support plate 3 can achieve radial fastening of the coil group 2 through structural support. At the same time, the shrink band can make the clamping plate 4 clamp the coil group 2, making the coil group 2 more secure, thereby improving the overall strength of the coil group 2. In the event of a sudden short circuit, the probability of the coil group 2 shifting is reduced, and the short-circuit withstand capability of the single-phase transformer is improved. On this basis, the clamping component 5 clamps the wound iron core 1, which improves the overall strength and structural stability of the wound iron core 1. Thus, in the event of a sudden short circuit, the probability of the wound iron core 1 loosening is reduced, and the short-circuit withstand capability of the single-phase transformer is further improved.

[0049] Further, please refer to Figure 2 In one embodiment of this utility model, the wound iron core 1 includes two sets of single-frame iron cores 11, each single-frame iron core 11 including two iron core columns. The two sets of single-frame iron cores 11 are arranged side by side to form the wound iron core 1. The wound iron core 1 has a two-frame, three-column structure, and the two adjacent iron core columns of the two sets of single-frame iron cores 11 are combined to form a core column 111. In this embodiment, the wound iron core 1 adopts a shell-type iron core form, which is composed of two single-frame iron cores 11 (or C-type iron cores) assembled together. The two-frame, three-column wound iron core 1 has the advantages of low leakage flux and lower hysteresis loss, which is beneficial to the compact design of single-phase transformers.

[0050] Furthermore, please refer to Figures 1 to 3 In one embodiment of this utility model, the single-phase transformer further includes multiple fastening straps 6. The fastening straps 6 are sleeved on the outer circumference of the single-frame iron core 11. The single-frame iron core 11 includes multiple layers of silicon steel sheets, and the fastening straps 6 are parallel to the silicon steel sheets. At least two fastening straps 6 are tied to the side of each single-frame iron core 11, and the overlap of the fastening straps 6 is located at the rounded corner of the single-frame iron core 11. The fastening straps 6 include one of steel strips and stainless steel flexible strips. In this embodiment, steel strips are used to fasten and bind the single-frame iron core 11. The ends of the steel strips are provided with snap buckles to facilitate the overlap of the steel strips. After the coiled iron core 1 and the coil group 2 are assembled, the steel strips are tied to the outside of the coiled iron core 1. The tension of the steel strips is maintained at 300 to 400 kgf during binding. By setting fastening bands 6 parallel to the silicon steel sheets, the overall strength of the single-frame core 11 is improved, thereby further reducing the probability of the rolled core 1 loosening when the single-phase transformer encounters a sudden short circuit, and improving the short-circuit resistance of the single-phase transformer.

[0051] In one embodiment of this utility model, please refer to Figure 3 and Figure 4The coil group 2 includes a first low-voltage winding 21, a high-voltage winding 22, and a second low-voltage winding 23 sequentially wound around the outside of the core column 111. A support plate 3 is inserted between the first low-voltage winding 21 and the core column 111, and a clamping plate 4 abuts against the outer peripheral surface of the second low-voltage winding 23. The first low-voltage winding 21 and the second low-voltage winding 23 can be independently connected to an external circuit. Compared to using multiple coil groups 2, the scheme of one coil group 2 including two low-voltage windings reduces the winding time of the coil group 2 and facilitates the mutual cancellation of the electromagnetic forces generated by the first low-voltage winding 21, the second low-voltage winding 23, and the high-voltage winding 22 in the coil group 2, reducing the probability of axial displacement of the coil group 2 during a sudden short circuit.

[0052] Furthermore, in one embodiment of this utility model, insulating layers are provided on both the inner and outer sides of the high-voltage winding 22. In this embodiment, the first low-voltage winding 21 and the second low-voltage winding 23 are made of copper / aluminum foil, and the high-voltage winding 22 is made of copper / aluminum enameled wire. A 0.08mm / 0.13mm large diamond-patterned adhesive insulating paper is provided between the high-voltage winding 22 and the low-voltage winding as an insulating layer to improve the insulation effect. The insulating layer, together with the transformer oil, forms an oil-paper composite insulating layer, which can avoid breakdown or partial discharge caused by electric field concentration and improve the stability of single-phase transformer operation.

[0053] In one embodiment of this utility model, please refer to Figure 1 , Figure 3 and Figure 4 The base 52 includes a base plate 521 and two bottom flanges 522. The bottom flanges 522 are perpendicular to the base plate 521. The two bottom flanges 522 and the base plate 521 enclose a bottom abutment groove, and the inner wall of the bottom abutment groove abuts against the lower yoke 113. The top plate 51 includes a main body 511 and two top flanges 512. The top flanges 512 are perpendicular to the main body 511. The two top flanges 512 and the main body 511 enclose a top pressing groove, and the inner wall of the top pressing groove abuts against the upper yoke 112. The bottom fold 522 extends a distance toward the top plate 51, and the top fold 512 extends a distance toward the bottom, so that part of the upper yoke 112 is covered in the top pressing groove, and part of the lower yoke 113 is covered in the bottom abutment groove, thereby increasing the contact area between the rolled iron core 1 and the clamping assembly 5, preventing the rolled iron core 1 from loosening along its height direction (the direction from the base 52 to the top plate 51), and thus improving the stability and overall strength of the rolled iron core 1 installation.

[0054] Furthermore, in one embodiment of the present invention, two clamping plates 53 are arranged opposite to each other, and the clamping plates 53 are perpendicular to the bottom plate 521. The clamping plates 53 include side plates 531 and two side folded edges 532. The side folded edges 532 are perpendicular to the side plates 531. The two side folded edges 532 and the side plates 531 enclose each other to form a side abutment groove. The openings of the two side abutment grooves are arranged opposite to each other. The rolled iron core 1 also includes a side yoke 114 parallel to the core column 111. The inner groove wall of the side abutment groove abuts against the side yoke 114. Two clamping plates 53 are fixedly installed on both sides of the base plate 521. The side plates 531 are parallel to the silicon steel sheets of the rolled core 1, and the side folded edges 532 are perpendicular to the silicon steel sheets. The two sides of the rolled core 1 are clamped between the two clamping plates 53, which can restrict the rolled core 1 from loosening along its length (the direction in which one clamping plate 53 points to the other clamping plate 53), thereby further improving the stability and overall strength of the rolled core 1 installation. By setting the base 52, the top plate 51, and the clamping plates 53, the rolled core 1 is covered and fixed on all sides, restricting the movement and deformation of the rolled core 1. Thus, under short-circuit conditions, the rolled core 1 is prevented from loosening due to the impact of electromagnetic force, improving the short-circuit withstand capability of the single-phase transformer.

[0055] In one embodiment of this utility model, the top plate 51 and the clamping plate 53 are detachably connected. During assembly, after the coil group 2 and the wound iron core 1 are assembled to form the core substation structure, the core substation structure is installed in the clamping assembly 5. Before installation, the top plate 51 is not connected to the clamping plate 53 to reserve an installation channel for the core substation structure. After the core substation structure is in contact with the base 52 and the two clamping plates 53, the top plate 51 is then installed on the clamping plate 53, so that the top plate 51 presses against the upper yoke 112, thereby completing the installation of the core substation structure and the clamping assembly 5. In this embodiment, the top plate 51 and the clamping plate 53 are connected by four bolts. The main body 511 of the top plate 51 is provided with connecting plates on both sides. The connecting plates are attached to the side plates 531 of the clamping plate 53. The bolts pass through the connecting plates and the side plates 531, which can fix the top plate 51 to the clamping plate 53. During installation, the bolts are 8.8 grade M12 high-strength bolts, and the preload torque is set to 45~55 N·m.

[0056] In one embodiment of this utility model, please refer to Figure 5 and Figure 6The single-phase transformer also includes an oil tank 7, bushings 8, lead cables, and a cable holder 9. The oil tank 7 includes a side panel 71 with a through hole through which the bushing 8 passes. The lead end of the coil group 2 is connected to the input end of the bushing 8, and the lead cable is connected to the output end of the bushing 8. The cable holder 9 is installed on the side panel 71 and is used to hold the lead cable. Specifically, the lead ends of the first low-voltage winding 21 and the second low-voltage winding 23 in the coil group 2 are connected to the input end of the bushing 8, and the lead cable is connected to the output end of the bushing 8 so that the bushing 8 can be connected to an external load. However, the lead cable has a certain weight, and the bushing 8 may sag and deform due to bearing the weight of the lead cable for a long time, which may affect the sealing of the bushing 8 and even cause oil leakage in the single-phase transformer. Therefore, in this embodiment, a set of cable fixing brackets 9 is provided on the outside of the side circumference 71 of the oil tank 7, and below the sleeve 8. The cable fixing brackets 9 can support the lead-out cables, thereby avoiding the sleeve 8 bearing the weight of the lead-out cables for a long time, and thus solving the problem of poor sealing performance caused by deformation of the sleeve 8. Since the cable fixing brackets 9 are existing technology, their structure will not be described in detail here.

[0057] Please see Figure 5 In one embodiment of this utility model, the fuel tank 7 further includes a lifting plate 72 and a top sealing plate 73. The top sealing plate 73 is used to seal the top of the side enclosure 71. The lifting plate 72 is installed on the side enclosure 71 and has a lifting hole 721 along the vertical direction Y ( Figure 5 (In the direction indicated by the middle arrow Y), the height of the lifting hole 721 is greater than the height of the top surface of the top sealing plate 73. During the installation of a single-phase transformer, a winch or crane hook must be used to connect to the lifting hole 721 to lift the transformer and place it in the designated position. Normally, the outside of the oil tank 7 is coated with anti-corrosion paint to reduce the rate of rust and improve its service life. In this embodiment, the height of the lifting hole 721 is 50 to 80 millimeters higher than the top surface of the top sealing plate 73. This design prevents the hook and cable from rubbing against the surface of the oil tank 7 during lifting, thus avoiding damage to the paint film and preventing rusting of the oil tank 7 due to paint film damage.

[0058] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A single-phase transformer, characterized in that, include: A rolled iron core, the rolled iron core including a core column and an upper iron yoke and a lower iron yoke respectively perpendicularly disposed at both ends of the core column, the upper iron yoke and the lower iron yoke being parallel; A coil assembly, wherein the coil assembly is wound around the core column; A support plate, which is inserted between the core column and the coil assembly; A fastening assembly, comprising a shrink band and multiple clamping plates, wherein the clamping plates abut against the outer peripheral surface of the coil assembly, and the shrink band is wound around the oppositely arranged clamping plates to provide a clamping force to the coil assembly; A clamping assembly includes a top plate, a base, and two clamping plates respectively installed on both sides of the base. The top plate, the base, and the clamping plates enclose a clamping area. The rolled iron core is installed in the clamping area. The base is in contact with the lower yoke, and the top plate is in contact with the upper yoke.

2. The single-phase transformer as described in claim 1, characterized in that, The rolled iron core includes two sets of single-frame iron cores, each single-frame iron core including two iron core columns. The two sets of single-frame iron cores are arranged side by side to form the rolled iron core. The rolled iron core has a two-frame three-column structure. The two adjacent iron core columns of the two sets of single-frame iron cores are combined to form the core column.

3. The single-phase transformer as described in claim 2, characterized in that, The single-phase transformer also includes multiple fastening straps, which are sleeved on the outer circumference of the single-frame iron core. The single-frame iron core includes multiple layers of silicon steel sheets, and the fastening straps are parallel to the silicon steel sheets.

4. The single-phase transformer as described in claim 2, characterized in that, The coil assembly includes a first low-voltage winding, a high-voltage winding, and a second low-voltage winding wound sequentially around the outside of the core column. The support plate is inserted between the first low-voltage winding and the core column, and the clamping plate abuts against the outer peripheral surface of the second low-voltage winding.

5. The single-phase transformer as described in claim 4, characterized in that, Insulating layers are provided on both the inner and outer sides of the high-voltage winding.

6. The single-phase transformer as described in claim 1, characterized in that, The base includes a base plate and two bottom folded edges. The bottom folded edges are perpendicular to the base plate. The two bottom folded edges and the base plate enclose a bottom abutment groove. The inner wall of the bottom abutment groove abuts against the lower yoke. The top plate includes a main body and two top flanges. The top flanges are perpendicular to the main body. The two top flanges and the main body enclose a top pressing groove. The inner wall of the top pressing groove abuts against the upper yoke.

7. The single-phase transformer as described in claim 6, characterized in that, The two clamping plates are arranged opposite each other and the clamping plates are perpendicular to the base plate. The clamping plates include side plates and two side flanges. The side flanges are perpendicular to the side plates. The two side flanges and the side plates enclose each other to form a side abutment groove. The openings of the two side abutment grooves are arranged opposite each other. The rolled iron core also includes a side yoke parallel to the core column. The inner wall of the side abutment groove abuts against the side yoke.

8. The single-phase transformer as described in claim 1, characterized in that, The top plate and the clamping plate are detachably connected.

9. The single-phase transformer as described in any one of claims 1 to 8, characterized in that, The single-phase transformer also includes an oil tank, a bushing, lead cables, and a cable fixing bracket. The oil tank includes a side panel with a through hole. The bushing passes through the through hole. The lead end of the coil group is connected to the input end of the bushing. The lead cable is connected to the output end of the bushing. The cable fixing bracket is installed on the side panel and is used to clamp the lead cable.

10. The single-phase transformer as described in claim 9, characterized in that, The fuel tank also includes a lifting plate and a top sealing plate. The top sealing plate is used to seal the top of the side enclosure. The lifting plate is installed on the side enclosure. The lifting plate has a lifting hole in the vertical direction. The height of the lifting hole is greater than the height of the top surface of the top sealing plate.

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