Low-voltage outgoing line structure suitable for ultra-large-capacity distribution transformer
By adopting a low-voltage outlet structure on the ultra-large capacity distribution transformer, low-voltage current is drawn from the side wall of the fuel tank, the overheating problem caused by eddy current loss is solved, cost and volume saving is achieved, and the safety and service life of the transformer are improved.
Patent Information
- Application Number
- CN202421902714.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-08-07
AI Technical Summary
In the prior art, the eddy current loss generated by the low voltage and high current of the ultra-large capacity distribution transformer in the box wall and clamps leads to local overheating, affecting the service life and safe operation of the transformer, while increasing materials and costs.
The low-voltage outlet structure is adopted, and the outer side of the transformer main body is led out, including magnetic insulation steel plate, conductive discharge line terminals, protective cover and lead cables. The low-voltage outlet is changed to lead out of the side wall of the fuel tank, eliminating the width of the top copper bar and box cover, and adopting the box wall side exhaust structure to reduce the use of copper materials and insulating oil.
Reduces eddy current loss, avoids local overheating, saves material costs and transformer volume, and improves safety and service life.
Smart Images
Figure CN223123712U_ABST
Abstract
Description
Technical Field
[0001] This article belongs to the technical field of low-voltage outgoing lines of distribution transformers, and specifically relates to a low-voltage outgoing line structure suitable for extra-large-capacity distribution transformers. Background Art
[0002] For distribution transformers with extra-large capacity, low low-voltage voltage, and extra-large current, how to reduce the eddy current loss generated by such large low-voltage currents in iron parts such as the tank wall and clamping parts, and how to avoid local overheating caused by eddy current loss and high-temperature decomposition of the transformer insulating oil, which affect the service life and safe operation of the transformer, have become major problems plaguing the design industry.
[0003] Both the high voltage and the low voltage are equipped with closed covers, and it is for the high-voltage cable to enter from below and the low-voltage to exit from below. Therefore, the preliminary reference external shape diagram provided according to the conventional scheme is as Figure 3 shown:
[0004] A large amount of data shows that for such high-current transformers, copper shielding must be used and installed inside the tank wall through which the leads pass to avoid the risks of local overheating of the tank wall and increased stray losses. To meet the above two requirements, the width of the tank needs to be 300 mm more than the size of conventional products, resulting in the amount of insulating oil used being 36% higher than that of conventional products and the weight of the tank being 15% higher than that of conventional products.
[0005] In the original scheme, the amount of low-voltage copper busbars used is 10×120, totaling 175 kg, and the cost is about 13,475 yuan. The weight of the low-voltage stainless steel closed cover is 230 kg, and the cost is about 8,710 yuan. Content of the Utility Model
[0006] To solve the above problems, this article proposes a low-voltage outgoing line structure applicable to extra-large-capacity distribution transformers. The low-voltage outgoing line structure is externally led out on the outside of the transformer body. The low-voltage outgoing line structure includes a magnetic isolation steel plate, a conductive outgoing line terminal, a protective outer cover, an outgoing line outer cover, and a lead-out cable. One end of the protective outer cover is connected to the outside of the transformer body, and the inside of the protective outer cover is in communication with the inside of the transformer body. The magnetic isolation steel plate is embedded in the upper surface of the protective outer cover. The conductive outgoing line terminal is pluggably arranged at the other end of the protective outer cover. One end of the conductive outgoing line terminal is pluggably connected to the inside of the end of the protective outer cover. An outgoing line outer cover is arranged on the outside of the other end of the conductive outgoing line terminal. A lead-out cable is directly connected to the lower side of the other end of the conductive outgoing line terminal. The outgoing line outer cover is a right-angle connection cover. One side of the outgoing line outer cover is directly connected to the end face of the protective outer cover. The lead-out cable is led out from the inside of the other end of the outgoing line outer cover. The low voltage is no longer led out from the top cover of the transformer, but is led out in advance from the side wall of the fuel tank, saving a section of copper busbar from the coil to the top. There is no need to increase a magnetic isolation steel plate with a width of 500 mm on the cover, and it also avoids the phenomenon of the fuel tank being widened due to the widening of the cover and the increase in material cost. The length, width, and height of the fuel tank are the same as those of conventional products. The low-voltage bushing adopts a side-wall outgoing line structure, saving the internal connection copper busbar of the low-voltage closed cover and the complex-to-install copper shield on the box wall. At the same time, the weight of the low-voltage closed cover is only 70 kg.
[0007] The transformer body is a general-purpose transformer box body. Plate radiators are arranged on both sides of the transformer body, and a moisture absorber is arranged at the rear end of the transformer body. The other side of the plate radiator is provided with a low-voltage outgoing line structure. Conductive through holes are arranged on the outer wall surface of the transformer body, reducing the stray loss of the transformer caused by large current in iron parts from the structure, thereby saving the weight of copper used in the transformer, saving manufacturing costs, reducing the volume of the transformer from the structure, reducing the usage of the steel plates of the fuel tank and the closed cover, and reducing the usage of insulating oil, thereby saving manufacturing costs.
[0008] The conductive outgoing line terminal is a standard plug-in terminal. One end of the conductive outgoing line terminal is provided with an external outgoing line terminal, and the other end of the conductive outgoing line terminal is provided with a conducting terminal. The conducting terminal penetrates through the inside of the protective outer cover. The external outgoing line terminal is directly connected to the lead-out cable below.
[0009] The shape of the protective outer cover is a square frame with both ends conducting. Both ends of the outer frame of the protective outer cover are hermetically connected to the transformer body and the outgoing line outer cover. The magnetic isolation steel plate is embedded in the upper end face of the protective outer cover. The inside of the protective outer cover is in communication with the conductive outgoing line terminal and the inside of the transformer body through a conducting row. Through the optimization and improvement of the structure, the usage of low-voltage cables of on-site users is saved, which is shortened from 2.1 meters from the ground to 1.4 meters.
[0010] The shape of the outgoing line outer cover is a vertical square frame. There is a connection opening on the upper right side of the outgoing line outer cover, and an outgoing opening is provided at the lower end of the outgoing line outer cover. The connection opening is pluggably arranged outside the conductive discharge line terminal, and a connecting copper bar is arranged in an outgoing manner on the inner side of the outgoing opening.
[0011] Beneficial effects:
[0012] Low voltage is no longer led out from the top cover of the transformer, but is led out in advance from the side wall of the oil tank, saving a section of copper bar from the coil to the top. There is no need to add a magnetic isolation steel plate with a width of 500 mm to the cover, and it also avoids the phenomenon of the oil tank being widened due to the widening of the cover, resulting in an increase in material costs. The length, width, and height of the oil tank are the same as those of conventional products. The low-voltage bushing adopts a side-wall outgoing line structure, eliminating the internal connecting copper bar of the low-voltage closed cover and the complex copper shielding on the box wall. At the same time, the weight of the low-voltage closed cover is only 70 kg.
[0013] Structurally reduce the stray losses of the transformer caused by large current in iron parts, thereby saving the weight of copper materials used in the transformer and reducing the manufacturing cost.
[0014] Structurally reduce the volume of the transformer, reduce the usage of steel plates for the oil tank and the closed cover, and reduce the usage of insulating oil, thereby saving the manufacturing cost.
[0015] Avoid local overheating caused by large current, thereby decomposing the transformer oil and generating gases that affect the life and normal operation of the transformer.
[0016] Through the optimization and improvement of the structure, save the usage of low-voltage cables for on-site users, which is shortened from the original 2.1 meters from the ground to 1.4 meters. Description of the drawings
[0017] Figure 1 It is a schematic structural diagram of a low-voltage outgoing line structure applicable to an extra-large capacity distribution transformer;
[0018] Figure 2 It is a comparison chart of the material costs of a low-voltage outgoing line structure applicable to an extra-large capacity distribution transformer and the original scheme;
[0019] Figure 3 It is the low-voltage outgoing line structure of the original scheme;
[0020] In the figure: 1. Transformer main body, 2. Magnetic isolation steel plate, 3. Conductive discharge line terminal, 4. Protective outer cover, 5. Outgoing line outer cover, 6. Outgoing cable, 7. Connecting copper bar. Specific implementation manners
[0021] To deepen the understanding of the present utility model, the present utility model will be further described in detail below in combination with embodiments and drawings. The embodiments are only used to explain the present utility model and do not limit the protection scope of the present utility model.
[0022] Transformer main body 1, magnetic isolation steel plate 2, conductive discharge line terminal 3, protective outer cover 4, outgoing line outer cover 5, outgoing cable 6, connecting copper bar 7.
[0023] Such as Figure 1 , 2 shown;
[0024] A low-voltage outgoing line structure applicable to an extra-large capacity distribution transformer. An externally derived low-voltage outgoing line structure is provided on the outside of the transformer main body 1. The low-voltage outgoing line structure includes a magnetic isolation steel plate 2, a conductive discharge line terminal 3, a protective outer cover 4, an outgoing line outer cover 5, and an outgoing cable 6. One end of the protective outer cover 4 is connected to the outside of the transformer main body 1, and the inside of the protective outer cover 4 is in mutual communication with the inside of the transformer main body 1. A magnetic isolation steel plate 2 is embedded in the upper surface of the protective outer cover 4, and a conductive discharge line terminal 3 is provided at the other end of the protective outer cover 4 in a pluggable manner. One middle part of one end of the conductive discharge line terminal 3 is provided in the inner side of the end of the protective outer cover 4 in a pluggable connection manner. An outgoing line outer cover 5 is provided on the outer side of the other end of the conductive discharge line terminal 3, and an outgoing cable 6 is directly connected to the lower side of the other end of the conductive discharge line terminal 3. The outgoing line outer cover 5 is a right-angle connection cover. One side of the outgoing line outer cover 5 is directly connected to the end face of the protective outer cover 4, and an outgoing cable 6 is externally derived from the inner side of the other end of the outgoing line outer cover 5. The transformer main body 1 is a general-purpose transformer box body. Plate radiators are provided on both sides of the transformer main body 1, and a moisture absorber is provided at the rear end of the transformer main body 1. The other side of the plate radiator is provided with a low-voltage outgoing line structure. A conduction outer hole is provided on the surface of the outer side wall of the transformer main body 1. The conductive discharge line terminal 3 is a standard pluggable terminal. One end of the conductive discharge line terminal 3 is provided with an external outgoing line terminal, and the other end of the conductive discharge line terminal 3 is provided with a conduction terminal. The conduction terminal penetrates through the inside of the protective outer cover 4. The external outgoing line terminal is directly connected to the outgoing cable 6 below. The protective outer cover 4 is in the shape of a square frame with both ends conducting. Both ends of the outer frame of the protective outer cover 4 are hermetically connected to the transformer main body 1 and the outgoing line outer cover 5. A magnetic isolation steel plate 2 is embedded in the upper end face of the protective outer cover 4. The inside of the protective outer cover 4 is in mutual communication with the conductive discharge line terminal 3 and the inside of the transformer main body 1 through a guide row. The outgoing line outer cover 5 is in the shape of a vertical square frame. A connection opening is provided on the upper right side of the outgoing line outer cover 5, and an outgoing opening is provided at the lower end of the outgoing line outer cover 5. The connection opening is provided in a pluggable manner on the outside of the conductive discharge line terminal 3, and a connecting copper bar 7 is externally derived from the inner side of the outgoing opening.
[0025] Implementation example;
[0026] The low voltage is no longer led out from the top cover of the transformer, but is led out in advance from the side wall of the oil tank, saving a section of copper busbar from the coil to the top. There is no need to add a magnetic isolation steel plate 2 with a width of 500 mm to the cover, and it also avoids the phenomenon of the oil tank becoming wider due to the widened cover and the increase in material costs. The length, width and height of the oil tank are the same as those of the conventional products. The low-voltage bushing adopts a side-wall outlet structure, eliminating the internal connecting copper busbar 7 in the low-voltage hermetic cover and the complex copper shielding on the box wall. At the same time, the weight of the low-voltage hermetic cover is only 70 kg.
[0027] Before the finished product is subjected to the temperature rise test, the optical fiber probes are respectively buried in the low-voltage abc flexible connection and the high- and low-voltage coils. The measured temperature rise of the copper busbar to the top layer of oil is 17K, and the top layer of oil is 45K, which is very close to the design value. The temperature rises of the high- and low-voltage windings are 52 and 54.5K respectively, which are lower than the design value. There is no phenomenon of local overheating or excessive temperature rise in the transformer.
[0028] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A low-voltage outgoing line structure suitable for ultra-large capacity distribution transformers, wherein the low-voltage outgoing line structure is provided on the outer side of the transformer body, and the low-voltage outgoing line structure comprises a magnetic isolation steel plate, a conductive outgoing line terminal, a protective cover, an outgoing line cover and an outgoing cable, characterized in that: One end of the described protective cover is connected to the outside of the transformer body. The inside of the protective cover is in communication with the inside of the transformer body. A magnetic isolation steel plate is embedded in the upper surface of the protective cover. A conductive discharge line terminal is provided at the other end of the protective cover in a plug-in manner. The middle of one end of the conductive discharge line terminal is connected in a plug-in manner to the inner side of the end of the protective cover. An outlet outer cover is provided on the outer side of the other end of the conductive discharge line terminal. A lead cable is directly connected to the lower side of the other end of the conductive discharge line terminal. The outlet outer cover is a right-angle connection cover. One side of the outlet outer cover is directly connected to the end face of the protective cover. A lead cable is led out from the inner side of the other end of the outlet outer cover.
2. The low-voltage outgoing line structure for an extra-large capacity distribution transformer according to claim 1, characterized in that, The described transformer body is a general-purpose transformer box body. Plate radiators are provided on both sides of the transformer body. A moisture absorber is provided at the rear end of the transformer body. A low-voltage outlet structure is provided on the other side of the plate radiator. Conductive outer holes are provided on the surface of the outer side wall of the transformer body.
3. The low-voltage outgoing line structure for an extra-large capacity distribution transformer according to claim 1, characterized in that, The described conductive discharge line terminal is a standard plug-in terminal. An external outlet terminal is provided at one end of the conductive discharge line terminal. A conductive connection terminal is provided at the other end of the conductive discharge line terminal. The conductive connection terminal penetrates through the inside of the protective cover. The lead cable is directly connected to the lower side of the external outlet terminal.
4. The low-voltage outgoing line structure for an extra-large capacity distribution transformer according to claim 1, characterized in that, The shape of the described protective cover is a square frame with both ends in communication. Both ends of the outer frame of the protective cover are hermetically connected to the transformer body and the outlet outer cover. A magnetic isolation steel plate is embedded in the upper end face of the protective cover. The inside of the protective cover is in communication with the conductive discharge line terminal and the inside of the transformer body through a conductive row.
5. The low-voltage outgoing line structure for an extra-large capacity distribution transformer according to claim 1, characterized in that, The shape of the described outlet outer cover is a vertical square frame. A connection opening is provided on the upper right side of the outlet outer cover. An outlet opening is provided at the lower end of the outlet outer cover. The connection opening is provided in a plug-in manner on the outside of the conductive discharge line terminal. A connection copper bar is led out from the inner side of the outlet opening.