Power transformer with five-column unequal yoke iron core structure
By optimizing the five-column unequal yoke core structure, the problems of large weight, high loss, poor heat dissipation and high operational danger in the existing technology have been solved, achieving the effects of material saving, weight reduction, loss reduction and structural miniaturization.
Patent Information
- Application Number
- CN202422987750.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-04
AI Technical Summary
Existing large three-phase oil-immersed power transformers with five-column equal-yoke core structures suffer from problems such as large weight, high material consumption, high no-load loss, large structural size, poor heat dissipation, and high operational risks.
The core adopts a five-column unequal yoke core structure, with the core column cross-sectional area larger than the main yoke, the main yoke larger than the side yoke, and the side yoke and side column areas equal. The core oil channel is set inside the core, and the outer end has a smooth structure. It is fixed with insulating pads and binding straps, thus optimizing the core design.
It achieves material savings, weight reduction, reduced no-load loss, smaller structural size, reduced hot spot temperature rise, and improved operational safety, and is easy to manufacture and install.
Smart Images
Figure CN223665292U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power transformers, and in particular relates to a power transformer with a five-column unequal yoke core structure. Background Technology
[0002] Large three-phase oil-immersed power transformers are generally quite tall, which is not conducive to transportation, and some are even too tall to be transported. The height of a five-column core transformer of the same model is much lower than that of a three-column core transformer, which makes it easier to transport. Therefore, large three-phase oil-immersed power transformers usually adopt a five-column core structure.
[0003] Currently, large three-phase oil-immersed power transformers all adopt a five-column equal-yoke core structure, such as Figure 1 As shown, a typical five-post equal-yoke iron core consists of a core post, main yoke, side yoke, side post, core oil ducts, binding straps, tie plates, and tie plate insulation. See... Figures 2-4 The effective cross-sectional area of the core column is greater than that of the main yoke, side yoke, and side column, and the effective cross-sectional areas of the main yoke, side yoke, and side column are equal. Typically, the effective cross-sectional area of the main yoke, side yoke, and side column is 0.577 times that of the core column. The core oil channel is located in the middle of the main core stage, and the last stage of the core column is a single piece structure. Binding straps are used for binding and fixing the core to the tie plate and the tie plate insulation.
[0004] The five-limb equal-yoke core structure is relatively heavy, consuming more effective silicon steel sheets. Since the no-load loss of the core is related to the core weight and the grade of silicon steel sheets, increasing the amount of silicon steel sheets leads to increased no-load loss. As long as the transformer is in operation, no-load loss persists, resulting in higher energy consumption and hindering environmental protection and energy conservation. The large dimensions of the main yoke, side yoke, and side columns in the five-limb equal-yoke core structure inevitably lead to a larger transformer structure. Although the height is reduced compared to a three-limb core, the overall size is still large, and the height reduction effect is not satisfactory. The side yokes and side columns of the five-limb equal-yoke core structure have pointed ends, as shown in [the original text]. Figure 5 The sharp corners are prone to scratching and injuring workers, requiring proper protection during construction and increasing operational difficulty. Furthermore, these artificially created sharp corners should be avoided as much as possible for high-voltage, high-capacity products. The final stage of the five-column equal-yoke core structure is a single piece, resulting in significant eddy current losses and increased overall losses. The core oil channels are only located in the main core stage, leading to inadequate heat dissipation and high temperature rise in localized hot spots, which is detrimental to the safe and reliable operation of the transformer. Summary of the Invention
[0005] The purpose of this invention is to provide a power transformer with a five-column unequal yoke core structure, which saves materials, reduces no-load loss, reduces the temperature rise of hot spots inside the core, and reduces the size of the transformer structure.
[0006] To achieve the above objectives, this utility model employs the following technical solution:
[0007] A power transformer with a five-column unequal yoke core structure includes a core column, a main yoke, a side yoke, and a side column; the cross-sectional area of the core column is larger than that of the main yoke, the cross-sectional area of the main yoke is larger than that of the side yoke, and the cross-sectional area of the side yoke is equal to that of the side column.
[0008] The cross-sectional area of the main yoke is 0.53 ± 0.01 times that of the core column; the cross-sectional area of the side yoke is 0.47 ± 0.01 times that of the core column.
[0009] The cross-section of the core column is circular; the cross-sections of the main yoke, the side yoke, and the side column are oblong or oval.
[0010] The upper part of the main yoke is higher than the upper part of the side yoke; the lower part of the main yoke is lower than the lower part of the side yoke.
[0011] The last stage of the core column consists of insulating pads and broken silicon steel sheets, with multiple insulating pads between the broken silicon steel sheets.
[0012] The outer ends of the side pillars and side yokes are not sharp-angled structures.
[0013] The core column, main yoke, side yoke, and side column are provided with a core oil channel in the third stage from the inner center outward.
[0014] It also includes binding straps, pull plates, and pull plate insulation. The pull plates are set on the outside of the iron core of the side column and the core column. Pull plate insulation is provided on both sides of the pull plate. The iron core, pull plate, and pull plate insulation are fixed by binding straps.
[0015] Compared with the prior art, the beneficial effects of this utility model are:
[0016] This utility model has a reasonable structure, adopting a five-column unequal yoke core structure, which saves materials, reduces weight, reduces no-load loss, shrinks the transformer structure size, reduces the temperature rise of hot spots inside the core, and is easier to manufacture, install and use. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the original five-column equal-yoke core structure of a power transformer.
[0018] Figure 2 yes Figure 1 A sectional view along line AA.
[0019] Figure 3 yes Figure 1 Sectional view along line BB.
[0020] Figure 4 yes Figure 1 A sectional view along line CC.
[0021] Figure 5 yes Figure 1 Enlarged view of part I.
[0022] Figure 6 This is a schematic diagram of a power transformer with a five-column unequal yoke core structure.
[0023] Figure 7 yes Figure 6 A cross-sectional view along DD.
[0024] Figure 8 yes Figure 6 A sectional view along EE.
[0025] Figure 9 yes Figure 6 A cross-sectional view along FF.
[0026] Figure 10 yes Figure 6 A cross-sectional view along GG.
[0027] Figure 11 This is a schematic diagram of the structure of the final layer of the cardiac column.
[0028] Figure 12 (a) is a schematic diagram of the silicon steel sheet structure of the side yoke and side pillar; (b) is a schematic diagram of the silicon steel sheet structure of the main yoke, side yoke, and side pillar; (c) is a schematic diagram of the silicon steel sheet structure of the main yoke; and (d) is a schematic diagram of the silicon steel sheet structure of the core pillar.
[0029] In the diagram: 1-core column, 2-main yoke, 3-side yoke, 4-side column, 5-silicon steel sheet, 6-iron core oil channel, 7-binding strap, 8-pull plate, 9-pull plate insulation, 10-insulation pad, 11-broken silicon steel sheet. Detailed Implementation
[0030] The present invention will now be described in detail with reference to the accompanying drawings. However, it should be noted that the implementation of the present invention is not limited to the following embodiments.
[0031] See Figures 6-10A power transformer with a five-column unequal yoke core structure includes a core column 1, a main yoke 2, a side yoke 3, and a side column 4. The cross-sectional area of the core column 1 is larger than that of the main yoke 2, the cross-sectional area of the main yoke 2 is larger than that of the side yoke 3, and the cross-sectional area of the side yoke 3 is equal to that of the side column 4. The cross-sectional area of the main yoke 2 is 0.53 ± 0.01 times the cross-sectional area of the core column 1; the cross-sectional area of the side yoke 3 is 0.47 ± 0.01 times the cross-sectional area of the core column 1. The cross-sectional area of the main yoke 2 is approximately 92% of that of the five-column equal yoke core structure, while the cross-sectional areas of the side yokes 3 and 4 are approximately 81% of those of the side yokes 3 and 4 of the five-column equal yoke core structure. It is evident that the cross-sectional areas of the main yoke 2, side yokes 3, and 4 are much smaller than those of the five-column equal yoke core structure. Furthermore, since the weight of the core is related to the density of the silicon steel sheet 5, the length of each part, and the cross-sectional area, under the same conditions, the weight of the five-column unequal yoke core structure is lighter than that of the five-column equal yoke core structure, consuming less effective silicon steel sheet 5 material, resulting in lower no-load losses and lower electrical energy consumption.
[0032] The cross-section of the central pillar 1 is circular. The cross-sections of the main yoke 2, the side yoke 3, and the side pillar 4 are oblong or similar to oblong. The cross-sections of the main yoke 2 and the side yoke 3 can be similar to oblong with one side relatively flat, see... Figure 7 , Figure 8 The core column 1, main yoke 2, side yoke 3, and side column 4 are all made of cut silicon steel sheets 5 stacked in stages, with each stage in a stepped shape. Generally, the larger the diameter of the core, the more stages there are.
[0033] Because the effective cross-sectional area of each part is related to the width Bzz (Bpz, Bze, Bpe) of the silicon steel sheet 5 and the core stacking thickness Td, and because the core stacking thickness Td is the same, the width of the core column 1 in the five-column unequal yoke core structure is greater than the width of the main yoke 2, the side yoke 3, and the side column 4. The width of the main yoke 2 is greater than the width of the side yoke 3, and the width of the side column 4 is equal to the width of the side yoke 3. To ensure that the core window height Hw is consistent, the upper part of the upper yoke of the main yoke 2 is higher than the upper part of the upper yoke of the side yoke 3; the lower part of the lower yoke of the main yoke 2 is lower than the lower part of the lower yoke of the side yoke 3, that is... Figure 1 H1 is less than H.
[0034] Under the same conditions of core diameter, window height Hw, column center distance Mo, and side column distance Mp. Figure 6 The H and L dimensions of the five-column unequal yoke core structure are respectively smaller than Figure 1 The dimensions of H and L in the five-column equal-yoke core structure show that the core structure size is reduced, which in turn reduces the transformer structure size. This not only reduces the transportation height but also saves materials such as insulating oil and steel, further reducing the total weight of the transformer.
[0035] See Figure 11The last stage of the core column 1 is composed of insulating pads 10 and broken silicon steel sheets 11. Multiple insulating pads 10 are provided between the broken silicon steel sheets 11. The insulating pads 10 are arranged in parallel to each other to reduce eddy current losses and reduce the risk of local overheating.
[0036] See Figure 6 The outer ends of the side pillar 4 and the side yoke 3 are not sharp-angled structures, and the silicon steel sheets 5 of the side pillar 4 and the side yoke 3 are cut into... Figure 12 The structural forms in (a) and (b) are characterized by a smooth right-angle structure at the outer end of the five-column unequal yoke core structure, eliminating the risk of scratching or puncturing workers. During construction, no sharp corner protection is required, reducing working hours and avoiding the adverse effects of sharp corners on high-voltage, high-capacity products.
[0037] See Figures 7-10 The third stage, extending outward from the center of the core column 1, main yoke 2, side yoke 3, and side column 4, is equipped with core oil channels 6, which increases the heat dissipation area of the core, reduces the temperature rise of hot spots inside the core, and extends the service life of the transformer.
[0038] The power transformer with a five-column unequal yoke core structure also includes binding straps 7, pull plates 8, and pull plate insulation 9. The pull plates 8 are set outside the core of the side column 4 and the core column 1. Pull plate insulation 9 is provided on both sides of the pull plates 8. The core, pull plates 8, and pull plate insulation 9 are bound and fixed by binding straps 7.
[0039] This utility model is applied to large three-phase oil-immersed power transformers. Compared with the traditional five-column equal yoke core structure, this structure saves materials, is lighter, reduces no-load loss, reduces the temperature rise of hot spots inside the core, extends the service life of the transformer, reduces the structural size of the transformer, is easy to manufacture, and is convenient to install and use.
Claims
1. A power transformer with a five-column unequal yoke core structure, characterized in that, It includes a core column, a main yoke, a side yoke, and a side column; the cross-sectional area of the core column is larger than that of the main yoke, the cross-sectional area of the main yoke is larger than that of the side yoke, and the cross-sectional area of the side yoke is equal to that of the side column; the last stage of the core column is composed of insulating pads and broken silicon steel sheets, with multiple insulating pads between the broken silicon steel sheets.
2. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, The cross-sectional area of the main yoke is 0.53 ± 0.01 times that of the core column; the cross-sectional area of the side yoke is 0.47 ± 0.01 times that of the core column.
3. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, The cross-section of the core column is circular; the cross-sections of the main yoke, the side yoke, and the side column are oblong or oval.
4. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, The upper part of the main yoke is higher than the upper part of the side yoke; the lower part of the main yoke is lower than the lower part of the side yoke.
5. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, The outer ends of the side pillars and side yokes are not sharp-angled structures.
6. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, The core column, main yoke, side yoke, and side column are provided with a core oil channel in the third stage from the inner center outward.
7. A power transformer with a five-column unequal yoke core structure according to claim 1, characterized in that, It also includes binding straps, pull plates, and pull plate insulation. The pull plates are set on the outside of the iron core of the side column and the core column. Pull plate insulation is provided on both sides of the pull plate. The iron core, pull plate, and pull plate insulation are fixed by binding straps.