High-voltage 400Hz double-split isolation transformer

Abstract

The invention discloses a high-voltage 400Hz double-split isolation transformer, and relates to the field of isolation transformers, the high-voltage 400Hz double-split isolation transformer comprises an isolation transformer, the isolation transformer is provided with a high-voltage winding, a first low-voltage winding and a second low-voltage winding, and the high-voltage winding, the first low-voltage winding and the second low-voltage winding all adopt an upper and lower end outgoing line terminal mode. According to the invention, two kinds of voltage and more than two grades of lines can be flexibly interconnected, and meanwhile, the low-voltage side adopts a split-type technology, so that two-path low-voltage safe output is realized, short-circuit current is effectively limited, and the sudden short-circuit resistance of the isolation transformer is improved; according to the high-voltage 400Hz double-split isolation transformer provided by the invention, the purpose of reducing the size and weight of the transformer is achieved, and multi-path power supply is also achieved.

Description

Technical Field

[0001] This invention relates to the field of isolation transformers, and particularly to a high-voltage 400Hz double-split isolation transformer. Background Technology

[0002] With the vigorous development of new power systems, photovoltaic and wind power, as renewable and clean energy sources, possess advantages such as stability and abundance, high power generation utilization hours, and suitability for large-scale development. Their application value will bring development opportunities to the power transmission and transformation industry. According to the theory of electromagnetic induction, increasing the operating frequency of power transmission and transformation equipment can effectively achieve equipment miniaturization and weight reduction. Furthermore, since offshore wind farms use medium-frequency (typically 400Hz-1000Hz) transmission technology to achieve asynchronous interconnection with the onshore power grid, the independence of the system's operating frequency provides theoretical feasibility for medium-frequency design.

[0003] With the increasing requirements for transmission voltage and transmission distance in wind farms, the operation scheme of medium frequency systems needs a lightweight isolation transformer that can interconnect two or more voltage level lines. Traditional transformers have problems such as large size, heavy weight, and insufficient short-circuit withstand capability under high voltage and high frequency conditions.

[0004] Therefore, it is necessary to propose a high-voltage 400Hz double-split isolation transformer to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a high-voltage 400Hz double-split isolation transformer, which provides a lightweight isolation transformer capable of interconnecting two or more voltage level lines.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a high-voltage 400Hz double-split isolation transformer, comprising an isolation transformer, wherein the isolation transformer is provided with a high-voltage winding, a first low-voltage winding, and a second low-voltage winding, and the high-voltage winding, the first low-voltage winding, and the second low-voltage winding all adopt the method of upper and lower end terminal output, with a total of 6 terminals, the first and the second low-voltage transmission systems being connected to the high-voltage transmission system, the first low-voltage transmission system, and the second low-voltage transmission system, respectively; The 6 terminals are divided into: The high-voltage transmission system inlet terminal and high-voltage transmission system outlet terminal are provided on the high-voltage winding, the first low-voltage transmission system inlet terminal and the first low-voltage transmission system outlet terminal are provided on the first low-voltage winding, and the second low-voltage transmission system inlet terminal and the second low-voltage transmission system outlet terminal are provided on the second low-voltage winding. The high-voltage transmission system's incoming and outgoing terminals are connected to the high-voltage transmission system; the first low-voltage transmission system's incoming and outgoing terminals are connected to the first low-voltage transmission system; and the second low-voltage transmission system's incoming and outgoing terminals are connected to the second low-voltage transmission system.

[0007] Preferably, it also includes an iron core, which adopts a single-phase double-frame laminated iron core structure with a circular cross-section of the main column. The iron core is used to house the high-voltage winding, the first low-voltage winding, and the second low-voltage winding. The windings are arranged in the following order from the iron core outward: first low-voltage winding, high-voltage winding, and second low-voltage winding. The cross-sections of the two side posts and the upper and lower yokes on the iron core are half the cross-section of the main post, forming a closed magnetic circuit.

[0008] Preferably, the first low-voltage winding and the second low-voltage winding are arranged in a radial split manner.

[0009] Preferably, an electrostatic ring is provided at both ends of the first low-voltage winding and the second low-voltage winding, and an electrostatic ring is provided at both ends of the high-voltage winding; one positive angle ring and one negative angle ring are provided in the insulation of the transformer body at the ends of the first low-voltage winding and the second low-voltage winding, and two positive angle rings and two negative angle rings are provided in the insulation of the transformer body at the ends of the high-voltage winding.

[0010] Preferably, the isolation transformer adopts a single-body structure and is installed in a single oil tank.

[0011] The technical effects and advantages of this invention are as follows: Using this invention, two or more voltage levels of lines can be flexibly interconnected. At the same time, the low-voltage side adopts a split technology to achieve two safe low-voltage outputs, effectively limit short-circuit current, and improve the isolation transformer's ability to resist sudden short circuits.

[0012] The present invention proposes a high-voltage 400Hz double-split isolation transformer, which not only reduces the size and weight of the transformer, but also enables multi-source power supply. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the high-voltage 400Hz double-split isolation transformer of the present invention.

[0014] Figure 2 This is a schematic diagram of the core and winding arrangement of the present invention.

[0015] Figure 3 This is a schematic diagram of the insulation structure of the device body of the present invention.

[0016] Figure 4 This is a schematic diagram of the high-voltage 400Hz double-split isolation transformer of the present invention.

[0017] Figure 5 This is a side view of the high-voltage 400Hz double-split isolation transformer of the present invention.

[0018] Figure 6 This is a top view of the high-voltage 400Hz double-split isolation transformer of the present invention.

[0019] In the diagram: 1. Isolation transformer; 2. High-voltage winding; 3. First low-voltage winding; 4. Second low-voltage winding; 5. High-voltage transmission system incoming terminal; 6. High-voltage transmission system outgoing terminal; 7. Second low-voltage transmission system incoming terminal; 8. Second low-voltage transmission system outgoing terminal; 9. First low-voltage transmission system incoming terminal; 10. Iron core; 11. Detailed Implementation

[0020] This invention provides, for example Figures 1-6 The high-voltage 400Hz double-split isolation transformer shown not only reduces the size and weight of the transformer, but also enables multiple power supplies. By adopting the split technology, the isolation transformer proposed in this invention not only achieves two safe low-voltage outputs, but also effectively limits the short-circuit current and improves the isolation transformer's ability to resist sudden short circuits.

[0021] The core 11 of the high-voltage 400Hz double-split isolation transformer adopts a single-phase double-frame laminated core structure. The main column has a circular cross-section and houses all windings. This structure can effectively reduce the volume and weight of the core. The cross-sections of the two side columns and the upper and lower yokes are half the cross-section of the main column, forming a closed magnetic circuit, which improves the magnetic circuit efficiency and reduces the amount of material used.

[0022] When implementing the transformer, silicon steel sheets with high magnetic permeability and low loss should be given priority as the core material to further reduce the volume and weight of the core and improve the efficiency of the transformer.

[0023] The main core assembly houses all windings, arranged outwards from core 11 in the following order: first low-voltage winding 3, high-voltage winding 2, second low-voltage winding 4. The rated voltages of the first low-voltage winding 3 and the second low-voltage winding 4 can be the same or different. The first low-voltage winding 3 and the second low-voltage winding 4 employ a radial splitting method. This structure ensures a splitting coefficient of not less than 5.0, effectively improving the transformer's resistance to sudden short circuits. Specifically: The insulation level requirements for the high-voltage winding 2, the first low-voltage winding 3, and the second low-voltage winding 4 on the isolation transformer 1 are full insulation level. The high-voltage winding 2 meets the insulation level requirements for the 400kV voltage level, and the first low-voltage winding 3 and the second low-voltage winding 4 meet the insulation level requirements for the 35kV voltage level. One electrostatic ring is provided at both ends of the first low-voltage winding 3 and the second low-voltage winding 4, and one electrostatic ring is provided at both ends of the high-voltage winding 2. One positive angle ring and one negative angle ring are provided in the insulation of the transformer body at the ends of the first low-voltage winding 3 and the second low-voltage winding 4, and two positive angle rings and two negative angle rings are provided in the insulation of the transformer body at the ends of the high-voltage winding 2.

[0024] The high-voltage winding 2, the first low-voltage winding 3, and the second low-voltage winding 4 on the isolation transformer 1 all adopt the upper and lower end terminal method, with a total of 6 terminals. The first and second ends are respectively connected to three external voltage transmission systems (high-voltage transmission system, first low-voltage transmission system, and second low-voltage transmission system). Among them, the high-voltage transmission system input terminal 5 and high-voltage transmission system output terminal 6 on the high-voltage winding 2 are connected to the high-voltage transmission system. The first low-voltage transmission system input terminal 9 and first low-voltage transmission system output terminal 10 on the first low-voltage winding 3 are connected to the first low-voltage transmission system. The second low-voltage transmission system input terminal 7 and second low-voltage transmission system output terminal 8 on the second low-voltage winding 4 are connected to the second low-voltage transmission system. The voltages of the first low-voltage transmission system and the second low-voltage transmission system can be the same or different.

[0025] The isolation transformer 1 adopts a single-body structure and is housed in a single oil tank, which further improves its insulation performance and short-circuit withstand capability.

[0026] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A high-voltage 400Hz double-split isolation transformer, comprising an isolation transformer (1), characterized in that: The isolation transformer (1) is equipped with a high voltage winding (2), a first low voltage winding (3), and a second low voltage winding (4). The high voltage winding (2), the first low voltage winding (3), and the second low voltage winding (4) all adopt the method of upper and lower end terminal output, with a total of 6 terminals. The first and second ends are respectively connected to the high voltage transmission system, the first low voltage transmission system, and the second low voltage transmission system. The 6 terminals are divided into: The high voltage transmission system inlet terminal (5) and high voltage transmission system outlet terminal (6) are provided on the high voltage winding (2), the first low voltage transmission system inlet terminal (9) and first low voltage transmission system outlet terminal (10) are provided on the first low voltage winding (3), and the second low voltage transmission system inlet terminal (7) and second low voltage transmission system outlet terminal (8) are provided on the second low voltage winding (4). Among them, the high voltage transmission system incoming terminal (5) and the high voltage transmission system outgoing terminal (6) are connected to the high voltage transmission system; the first low voltage transmission system incoming terminal (9) and the first low voltage transmission system outgoing terminal (10) are connected to the first low voltage transmission system; the second low voltage transmission system incoming terminal (7) and the second low voltage transmission system outgoing terminal (8) are connected to the second low voltage transmission system.

2. The high-voltage 400Hz double-split isolation transformer according to claim 1, characterized in that: It also includes an iron core (11), which adopts a single-phase double-frame laminated iron core structure. The main column cross section is circular. The iron core (11) is used to house the high voltage winding (2), the first low voltage winding (3), and the second low voltage winding (4). The windings are arranged in the following order from the iron core (11) outward: the first low voltage winding (3), the high voltage winding (2), and the second low voltage winding (4). The cross-sections of the two side posts and the upper and lower yokes on the iron core (11) are half of the cross-section of the main post, forming a closed magnetic circuit.

3. A high-voltage 400Hz double-split isolation transformer according to claim 1, characterized in that: The first low-voltage winding (3) and the second low-voltage winding (4) are set in a radial split manner.

4. A high-voltage 400Hz double-split isolation transformer according to claim 1, characterized in that: One electrostatic ring is provided at both ends of the first low-voltage winding (3) and the second low-voltage winding (4), and one electrostatic ring is provided at both ends of the high-voltage winding (2); one positive angle ring and one negative angle ring are provided at the insulation of the transformer body at the ends of the first low-voltage winding (3) and the second low-voltage winding (4), and two positive angle rings and two negative angle rings are provided at the insulation of the transformer body at the ends of the high-voltage winding (2).

5. A high-voltage 400Hz double-split isolation transformer according to claim 1, characterized in that: The isolation transformer (1) adopts a single-body structure and is installed in an oil tank.

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