Dry-type transformer for variable-flux multi-voltage output test

Abstract

The utility model relates to a dry-type transformer for a variable-flux multi-voltage output test, which comprises an iron core, a primary winding, a secondary winding and a tertiary winding are sequentially arranged on each phase core column of the iron core from outside to inside, the primary winding comprises a plurality of primary winding sections which are connected in parallel, and the secondary winding comprises a plurality of secondary winding sections which are connected in parallel. A segment head end joint of the primary winding segment is connected with a primary winding busbar through a convergence cable, a segment tail end joint is connected with a corresponding segment tail end joint on an adjacent phase core column through a zero sealing copper bar, and tapping joints of the primary winding segment are connected through tapping sheets; the lower side of the primary winding is provided with an excitation winding which is sleeved on the corresponding core column. According to the utility model, the primary winding is divided into a plurality of groups which are connected in parallel, so that the impact resistance of the winding is improved, and meanwhile, the tapping joint is adjusted to the primary winding from the original secondary winding and the tertiary winding, so that the potential safety hazard in the winding process of the secondary winding and the tertiary winding is reduced; and meanwhile, the process of repeatedly exchanging the secondary winding cable and the tertiary winding cable during use is avoided.

Description

Technical Field

[0001] This utility model relates to the field of transformers, specifically a dry-type transformer for testing variable flux and multi-voltage output. Background Technology

[0002] In recent years, new energy sources have developed rapidly, especially photovoltaic, wind power, and energy storage. The transformers supplied to these manufacturers are generally low-voltage, high-current products, and the required voltage and current vary depending on the application. To meet the factory testing requirements of these devices, multiple transformers capable of outputting different voltages are typically required. However, configuring multiple transformers significantly increases investment costs and the floor space required for the equipment.

[0003] With technological advancements, to address the aforementioned issues, existing technologies have developed transformers that input one voltage on the high-voltage side and output multiple voltages on the low-voltage side. These transformers typically employ constant flux voltage regulation, using different taps on the low-voltage side to correspond different voltages to different equipment. However, this multi-voltage constant flux dry-type transformer has certain structural design flaws. Specifically, the output voltage of multi-voltage output transformers is generally below 1kV, while the capacity is generally above 2500kVA. Therefore, the low-voltage current is usually quite large. The low-voltage coil is typically wound with foil, and different taps are led out using copper busbars. If a voltage change is required during use, multiple cables connected to the copper busbars must be disassembled and installed on other voltage taps. Given the large low-voltage current and the numerous cables, this operation is very cumbersome. Furthermore, the cable lengths used for different taps are generally inconsistent, and changing taps increases or decreases the cable bending, posing safety hazards during operation. Furthermore, the input voltage of most multi-voltage output transformers is currently 0.4kV, resulting in a large primary current. Since the primary coil is wound with foil without casting, the inrush current on the primary side will be relatively large when the transformer is closed under no-load conditions. The electromagnetic force will have a significant impact on the coil, posing a safety hazard to the non-cast coil. Additionally, the transformer protection may trip due to excessive inrush current.

[0004] Patent CN205452004U discloses a multi-voltage output dry-type transformer, which includes an iron core, a low-voltage coil I, a low-voltage coil II, and a high-voltage coil. The low-voltage coils I and II are arranged vertically around the iron core, and the high-voltage coil is arranged around the low-voltage coils I and II. The transformer connects the low-voltage coils I and II together as the secondary coils. Patent CN207367763U discloses a 6-10kV dual-voltage conversion input multi-winding dry-type transformer for offshore platforms. In this transformer, the high-voltage winding, two medium-voltage windings, and the low-voltage winding are arranged concentrically. The high-voltage winding includes three asymmetrical sub-windings from top to bottom. This transformer achieves the conversion between 10kV and 6kV power receiving modes through the aforementioned asymmetrical sub-winding structure. Utility Model Content

[0005] The purpose of this utility model is to provide a dry-type transformer for testing variable flux and multi-voltage output. By dividing the primary winding into multiple groups connected in parallel, the shock resistance of the winding is improved. At the same time, the tap joint is adjusted from the original secondary and tertiary windings to the primary winding, reducing the safety hazards during the winding process of the secondary and tertiary windings. It also avoids the process of repeatedly changing the cables of the secondary and tertiary windings during use.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A dry-type transformer for testing variable flux and multi-voltage output includes an iron core, and each phase core column of the iron core is provided with a primary winding, a secondary winding and a tertiary winding from the outside to the inside. The primary winding includes multiple parallel primary winding segments, and the first end of each segment is connected to the primary winding busbar through a busbar cable, and the last end of each segment is connected to the corresponding last end of the segment on the adjacent phase core column through a neutral copper busbar. The tap joints of the primary winding segments are connected by tap joints, and an excitation winding is provided on the lower side of the primary winding and fitted onto the corresponding core column.

[0008] The first and last joints of each primary winding segment are located on one side of the transformer body, while the tap joints of each primary winding segment are located on the other side of the transformer body.

[0009] The secondary winding output terminal of the secondary winding is located at the upper part of the transformer body, away from the primary winding busbar, and the tertiary winding output terminal of the tertiary winding is located at the lower part of the transformer body, away from the primary winding busbar.

[0010] The primary winding busbar is connected to an external input power supply.

[0011] The transformer body has an upper clamp on the upper side and a lower clamp on the lower side, and the lower clamp has a pad on the lower side.

[0012] The advantages and positive effects of this utility model are as follows:

[0013] 1. This utility model divides the primary winding into multiple groups connected in parallel, and makes the segmented current of each group of primary windings reach the level that can be used for winding. In this way, the primary winding can be cast, which improves the winding's impact resistance.

[0014] 2. Each primary winding of this utility model is equipped with a tap joint in each segment. At the same time, the low-voltage side is divided into inner and outer windings, which can be set to output the same voltage or different voltages. The output voltage of the low-voltage side can be changed by adjusting the tap joint connection of the primary winding, which can meet the needs of different occasions.

[0015] 3. This utility model adjusts the tap joint from the secondary and tertiary windings to the primary winding, so that the secondary and tertiary windings no longer need to use multiple copper busbars as taps, which greatly reduces the safety hazards caused by copper busbar welding during the winding process of the secondary and tertiary windings, and avoids the process of repeatedly changing the cables of the secondary and tertiary windings during the use of the transformer.

[0016] 4. This utility model places the excitation winding at the bottom of the transformer body, which can significantly reduce the inrush current when the transformer is closed under no-load conditions. Attached Figure Description

[0017] Figure 1 This is the front view of the present invention.

[0018] Figure 2 This is the left view of the present invention.

[0019] Figure 3 This is a rear view of the present invention.

[0020] Figure 4 This is a schematic diagram of the winding arrangement on the single-phase iron core column of this utility model.

[0021] Figure 5 This is a schematic diagram showing the connection relationship of the primary windings of each phase of this utility model.

[0022] Figure 6 This is a schematic diagram showing the connection relationship of the secondary windings of each phase of this utility model.

[0023] Figure 7 This is a schematic diagram showing the connection relationship of the three-phase windings of this utility model.

[0024] Figure 8 This is a schematic diagram showing the connection relationship of the excitation windings of each phase of this utility model.

[0025] Among them, 1 is the upper clamp, 2 is the lower clamp, 3 is the pad, 4 is the primary winding, 401 is the primary winding segment, 5 is the segment start connector, 6 is the segment end connector, 7 is the zero-sealing copper busbar, 8 is the tertiary winding, 801 is the tertiary winding output terminal, 9 is the secondary winding, 901 is the secondary winding output terminal, 10 is the excitation winding, 11 is the busbar cable, 12 is the primary winding busbar, 13 is the core, 14 is the tap joint, and 15 is the tap piece. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings.

[0027] like Figures 1-8 As shown, this utility model includes an iron core 13, and each phase column of the iron core 13 is provided with a primary winding 4, a secondary winding 9, and a tertiary winding 8 sequentially from the outside to the inside. The primary winding 4 includes multiple parallel primary winding segments 401, and as shown... Figure 1 As shown, the segment start connector 5 and segment end connector 6 of each primary winding segment 401 are located on one side of the transformer body, as follows: Figure 3 As shown, the tap joints 14 of each primary winding segment 401 are all located on the other side of the transformer body, such as... Figure 2 As shown, the segmented first-end connector 5 is connected to the primary winding busbar 12 via a busbar cable 11. The primary winding busbar 12 is connected to an external power supply, such as... Figure 1 As shown, the segmented end connector 6 is connected to the corresponding segmented end connector 6 on the adjacent phase core column via a sealing copper busbar 7, thereby achieving a short circuit, as shown. Figure 3 As shown, the tap joint 14 is connected via the tap piece 15, and additionally as... Figure 1 and Figure 4 As shown, the primary winding 4 has an excitation winding 10 mounted on the core column of the corresponding phase.

[0028] This invention divides the primary winding 4 on the high-voltage side into multiple parallel groups, and makes the current of each group's primary winding segment 401 reach a level suitable for winding. In this way, the primary winding 4 can be cast, improving the winding's impact resistance. In addition, each group of primary winding segments 401 in this invention is equipped with a tap joint 14. At the same time, the low-voltage side is divided into inner and outer windings, which can be set to output the same voltage or different voltages. The output voltage of the low-voltage side can be changed by adjusting the connection of the tap joint 14 of the primary winding 4. Moreover, this invention adjusts the tap joint 14 from the original secondary winding 9 and tertiary winding 8 to the primary winding 4, so that the secondary winding 9 and tertiary winding 8 no longer use multiple copper busbars as taps, greatly reducing the safety hazards caused by copper busbar welding during the winding process of the secondary winding 9 and tertiary winding 8, and avoiding the process of repeatedly swapping the cables of the secondary winding 9 and tertiary winding 8 during the operation of the transformer. In addition, this invention places the excitation winding 8 at the bottom of the transformer body, which can significantly reduce the inrush current when the transformer is closed under no-load.

[0029] like Figure 2 As shown, in this embodiment, the secondary winding output terminal 901 of the secondary winding 9 is located on the upper part of the transformer body away from the primary winding busbar 12, and the tertiary winding output terminal 801 of the tertiary winding 8 is located on the lower part of the transformer body away from the primary winding busbar 12.

[0030] like Figure 1 As shown, in this embodiment, the transformer body is provided with an upper clamp 1 on the upper side and a lower clamp 2 on the lower side. The lower clamp 2 is provided with a pad 3 on the lower side. The upper clamp 1 and the lower clamp 2 are used to fix the transformer body. This is a well-known technology in the art.

[0031] The working principle of this utility model is as follows:

[0032] When this utility model is in operation, before the transformer is running, the tap 14 of the primary winding 4 is first connected and adjusted to the corresponding working position. Then, the power supply of the excitation winding 8 is turned on to excite the transformer. After the excitation set time (10 seconds in this embodiment), the primary winding bus 12 is connected to the power supply of the primary winding 4. After the set time (5 to 7 seconds in this embodiment), the power supply of the excitation winding 8 is turned off. At this time, the secondary winding 9 and the tertiary winding 8 of the transformer can output the required voltage. If the output voltage of the secondary winding 9 and the tertiary winding 8 is changed, the tap 14 of the primary winding 4 can be readjusted after the power is turned off. After the adjustment is completed, the above process is repeated.

Claims

1. A variable flux dry-type test transformer with multiple voltage outputs, characterized by: The system includes an iron core (13), and each phase core column of the iron core (13) is provided with a primary winding (4), a secondary winding (9) and a tertiary winding (8) from the outside to the inside. The primary winding (4) includes multiple parallel primary winding segments (401), and the segment head connector (5) of the primary winding segment (401) is connected to the primary winding busbar (12) through a busbar cable (11), and the segment end connector (6) is connected to the corresponding segment end connector (6) on the adjacent phase core column through a zero-sealing copper busbar (7). The tap connector (14) of the primary winding segment (401) is connected through a tap piece (15). The excitation winding (10) is provided on the lower side of the primary winding (4) and fitted onto the corresponding core column.

2. The dry-type transformer for multi-voltage output testing with variable flux as described in claim 1, characterized in that: The segment start joint (5) and segment end joint (6) of each primary winding segment (401) are located on one side of the transformer body, and the tap joint (14) of each primary winding segment (401) is located on the other side of the transformer body.

3. The dry-type transformer for multi-voltage output testing with variable flux as described in claim 1, characterized in that: The secondary winding output terminal (901) of the secondary winding (9) is located on the upper part of the transformer body away from the primary winding busbar (12), and the tertiary winding output terminal (801) of the tertiary winding (8) is located on the lower part of the transformer body away from the primary winding busbar (12).

4. The dry-type transformer for multi-voltage output testing with variable flux as described in claim 1, characterized in that: The primary winding bus (12) is connected to an external power supply.

5. The dry-type transformer for multi-voltage output testing with variable flux as described in claim 1, characterized in that: The transformer body is provided with an upper clamp (1) on the upper side and a lower clamp (2) on the lower side, and the lower clamp (2) is provided with a pad (3) on the lower side.

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