Combined converter transformer bank
By setting up two converter transformer bodies in the same oil tank and sharing the grid-side bushings and cooling system, the problems of fault risk and high cost caused by complex wiring in the existing technology are solved, and the effects of simplified wiring, reduced energy consumption and cost are achieved.
Patent Information
- Application Number
- CN202422754905.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-12
AI Technical Summary
The existing dual-winding converter transformers have complex wiring, which increases the risk of system failure and results in high footprint and investment costs.
A combined converter transformer group is adopted, in which the transformer bodies of the two converter transformers are placed in the same oil tank, the electrical connection of the grid-side windings shares a set of bushings, the valve-side windings are led out independently, and they share a cooling and protection system, simplifying the wiring and sharing the cooling equipment.
It reduces the probability of failure, saves weight and floor space, reduces investment costs and energy consumption of the converter system, and improves operational economic efficiency.
Smart Images
Figure CN223513750U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of converter transformer technology, specifically relating to a combined converter transformer group. Background Technology
[0002] The basic working principle of a DC transmission system is to convert alternating current (AC) energy into direct current (DC) energy for transmission, and then convert the DC energy back into AC energy to supply users. The power transformer used in the converter of a DC transmission system is called a converter transformer, and it is one of the key pieces of equipment in the system. On the rectifier side, the converter transformer provides AC energy to the converter equipment, which converts the AC energy into DC energy for transmission through DC transmission lines. On the inverter side, the converter transformer receives the DC energy from the inverter, converts it back into AC energy, and sends it to other power grids.
[0003] There are four main structural types of converter transformers: three-phase three-winding, three-phase two-winding, single-phase two-winding, and single-phase three-winding. Currently, existing two-winding converter transformers have one grid-side winding and one valve-side winding. The grid-side winding is connected to the power grid, and the valve-side winding is connected to the valve chamber. The grid-side winding and the valve-side winding are located within the same transformer body. When a converter station requires two converter transformers, two sets of grid-side bushings are needed, connected to the power grid via two sets of overhead lines. This increases the complexity of the wiring, and with the increase in wiring complexity, the risk of system failure also increases accordingly. Summary of the Invention
[0004] This invention provides a combined converter transformer group to solve the problem of increased system failures caused by complex wiring.
[0005] To achieve the above objectives, this utility model provides a combined converter transformer group, including an oil tank, a first converter transformer body, and a second converter transformer body. Both the first and second converter transformer bodies are located inside the oil tank. The grid-side windings of the first and second converter transformer bodies are electrically connected and share a set of grid-side bushings and grid-side neutral point bushings. The valve-side windings of the first and second converter transformer bodies are independent of each other and are each led out from the tank wall to the valve-side bushing.
[0006] Furthermore, both the first converter transformer body and the second converter transformer body are three-phase dual-winding converter transformer bodies. The three-phase valve-side winding of the first converter transformer body is delta-connected, and the three-phase valve-side winding of the second converter transformer body is Y-connected.
[0007] Furthermore, the starting ends of the grid-side windings of the first and second converter transformer bodies that are in phase are respectively connected to the same grid-side bushing through grid-side leads, and there are a total of three grid-side bushings for the three phases of the first and second converter transformer bodies.
[0008] Furthermore, the wires on the mesh side are stranded wires.
[0009] Furthermore, the ends of the grid-side windings of each phase of the first and second converter transformer bodies are led out from the bottom of the transformer body and connected together via stranded wires. The three-phase leads are gathered on a single stranded wire and connected to a grid-side neutral point bushing.
[0010] Furthermore, the first converter transformer body and the second converter transformer body are arranged side by side.
[0011] Furthermore, the grid-side windings of the first converter transformer and the grid-side windings of the second converter transformer are arranged in the middle of the oil tank, while the grid-side windings of the first converter transformer and the valve-side windings of the second converter transformer are arranged on both sides of the oil tank.
[0012] Furthermore, a maintenance passage and electrical distance are provided between the first converter transformer body and the second converter transformer body.
[0013] Furthermore, the first converter transformer body and the second converter transformer body share a cooling system.
[0014] Furthermore, the first converter transformer body and the second converter transformer body share a common protection system.
[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects:
[0016] This utility model provides a combined converter transformer group, which sets up two converter transformer bodies in the same oil tank, and the grid-side windings of the two converter transformer bodies are electrically connected, sharing a set of grid-side bushings and grid-side neutral point bushings. Only one set of overhead lines is needed, simplifying the external system wiring, reducing on-site installation workload, and reducing the probability of failure. At the same time, it saves one oil tank, reducing weight, saving the footprint of the converter system, and reducing the investment cost of the converter system.
[0017] Furthermore, the first and second converter transformer bodies share a cooling system, which allows for more efficient use of the cooling system, reduces the number of cooling equipment and components, thereby reducing energy consumption, and also reduces the footprint of the converter transformer group.
[0018] Furthermore, the first and second converter transformer bodies share a common protection system, which can make more effective use of protection equipment resources, avoid redundant configuration, reduce the overall cost of the power system, and improve the economic efficiency of converter transformer operation. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of a shared-enclosure combined converter transformer unit;
[0020] Figure 2 A schematic diagram of the transformer body layout for a common-enclosure combined converter transformer unit;
[0021] Figure 3 This is a schematic diagram of the internal electrical connections of a common-enclosure combined converter transformer group.
[0022] Figure 4 A schematic diagram of a non-common-enclosure combined converter transformer unit;
[0023] Figure 5 This is a wiring diagram of a common-enclosure combined converter transformer group.
[0024] In the attached diagram: 1. Oil tank; 2. First converter transformer body; 3. Second converter transformer body; 4. Valve side lead; 5. Grid side lead; 6. Grid side neutral point lead; 7. Valve side Δ bushing; 8. Valve side Y bushing; 9. Grid side bushing; 10. Grid side neutral point bushing; 11. Cooler. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0026] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.
[0027] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or may be interposed with another element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or may be interposed with another element. The terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., used herein to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0029] This utility model provides a combined converter transformer group, which includes: two three-phase double-winding converter transformer bodies, a common oil tank, a cooling system and a protection system. The grid-side head-end outputs of the two converter transformer bodies are connected together inside the oil tank. The grid-side neutral point outputs of the two converter transformer bodies are connected together inside the oil tank. Three grid-side bushings 9 and one grid-side neutral point bushing 10 extend directly from the oil tank cover and are connected to the power grid. The valve-side outputs of the two converter transformer bodies extend obliquely from the tank walls on both sides and are connected to the valve hall and valve tower.
[0030] The following are specific embodiments. It should be noted that these embodiments are preferred examples of the present invention and are intended for those skilled in the art to understand the present invention. However, the present invention is not limited to these embodiments.
[0031] Example 1
[0032] Reference Figures 1 to 4 A combined converter transformer group includes an oil tank 1, a first converter transformer body 2, and a second converter transformer body 3. The Y-connected converter transformer body includes a first A-phase valve-side winding, a first B-phase valve-side winding, a first C-phase valve-side winding, a first A-phase grid-side winding, a first B-phase grid-side winding, and a first C-phase grid-side winding. The Δ-connected converter transformer body includes a second A-phase valve-side winding, a second B-phase valve-side winding, a second C-phase valve-side winding, a second A-phase grid-side winding, a second B-phase grid-side winding, and a second C-phase grid-side winding.
[0033] All grid-side winding leads are located in the middle of tank 1, and all valve-side winding leads are located on both sides of tank 1. A maintenance passage and sufficient electrical clearance are provided between the first converter transformer body 2 and the second converter transformer body 3.
[0034] Among them, the first converter transformer body 2 is a delta-connected converter transformer body (also known as an angle-connected converter transformer body), and the second converter transformer body 3 is a Y-connected converter transformer body.
[0035] The Y-connected converter transformer body and the Δ-connected converter transformer body are electrically connected on the grid side inside tank 1, sharing a common set of grid-side bushings and grid-side neutral point bushings, which are led out from the tank cover of tank 1 and connected to the AC power grid; the valve sides are independent of each other, with leads led out separately from the two side walls of tank 1 and connected to the two valve chambers. The specific structure is as follows:
[0036] Reference Figure 5 The first A-phase valve-side winding, the first B-phase valve-side winding, and the first C-phase valve-side winding are Y-connected; the first A-phase grid-side winding, the first B-phase grid-side winding, and the first C-phase grid-side winding are Y-connected; the second A-phase valve-side winding, the second B-phase valve-side winding, and the second C-phase valve-side winding are Δ-connected; the second A-phase grid-side winding, the second B-phase grid-side winding, and the second C-phase grid-side winding are Δ-connected.
[0037] The three-phase grid-side windings and grid-side neutral points of the Y-connected converter transformer body and the Δ-connected converter transformer body are connected together inside the oil tank 1 and connected to the grid-side bushing 9 on the tank cover of the oil tank 1. The valve-side windings of the Y-connected converter transformer body and the Δ-connected converter transformer body are not connected. They are connected to the valve hall from both sides of the oil tank 1 through valve-side bushings via valve-side leads 4. Specifically, the Δ-connected converter transformer body is connected to the valve hall from one side of the oil tank 1 through the valve-side Δ-connection bushing 7, and the Y-connected converter transformer body is connected to the valve hall from the other side of the oil tank 1 through the valve-side Y-connection bushing 8.
[0038] In both the Y-connected and Δ-connected converter transformer bodies, the start ends of each phase's grid-side winding are led out from the upper part of the transformer body via grid-side leads 5. The two grid-side leads are connected to the same grid-side bushing 9. The three phases of the first converter transformer body 2 and the second converter transformer body 3 share three grid-side bushings 9. The end of each column's grid-side winding is led out from the lower part of the transformer body via grid-side neutral point leads 6. The three-phase grid-side neutral point leads 6 converge on a stranded wire and are connected to a grid-side neutral point bushing 10. Both grid-side leads 5 and grid-side neutral point leads 6 are stranded wires.
[0039] In one embodiment, the Y-connected converter transformer body and the Δ-connected converter transformer body share a common oil tank 1, cooling system and protection system, and common protection components such as: oil conservator, cooler 11, pressure relief valve, gas relay, etc. All protection components are set up in the same way as conventional transformers.
[0040] Example 2
[0041] Reference Figure 4 If the converter transformer capacity is large and transportation limitations apply, the Y-connected and Δ-connected converter transformer bodies can be designed as two independent converter transformers, according to... Figure 4 The two converter transformers are arranged to form a combined converter transformer group. There is a maintenance passage and sufficient electrical distance between the two converter transformers. The two independent converter transformers are not electrically connected in tank 1 and have independent cooling and protection systems.
[0042] according to Figure 4 The Y-connected converter transformer and the Δ-connected converter transformer can be operated as two independent converter transformers, or the grid-side bushings 9 of the two converter transformers can be connected to operate as a converter transformer group.
[0043] The term "constituting of" in describing a combination should include the identified elements, components, parts, or steps, as well as other elements, components, parts, or steps that do not substantially affect the essential novel features of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, parts, or steps herein also contemplates embodiments that are essentially composed of such elements, components, parts, or steps. The use of the term "may" herein is intended to indicate that any described attribute included by "may" is optional.
[0044] Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The use of "a" or "an" to describe an element, component, part, or step does not imply the exclusion of other elements, components, parts, or steps.
[0045] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed utility model subject matter.
Claims
1. A combined converter transformer group, characterized in that, It includes an oil tank (1), a first converter transformer body (2) and a second converter transformer body (3). The first converter transformer body (2) and the second converter transformer body (3) are both located inside the oil tank (1). The grid-side winding of the first converter transformer body (2) and the grid-side winding of the second converter transformer body (3) are electrically connected and share a set of grid-side bushings and grid-side neutral point bushings (10). The valve-side winding of the first converter transformer body (2) and the valve-side winding of the second converter transformer body (3) are independent of each other and are each led out from the tank wall of the oil tank (1) to the valve-side bushing.
2. A combined converter transformer group according to claim 1, characterized in that, The first converter transformer body (2) and the second converter transformer body (3) are both three-phase double-winding converter transformer bodies. The three-phase valve side winding of the first converter transformer body is angled \, and the three-phase valve side winding of the second converter transformer body is Y-connected.
3. A combined converter transformer group according to claim 1 or 2, characterized in that, The first phase of the grid-side winding of the first converter transformer body (2) and the second converter transformer body (3) is connected to the same grid-side bushing (9) through grid-side lead wire (5). The three phases of the first converter transformer body (2) and the second converter transformer body (3) have a total of three grid-side bushings (9).
4. A combined converter transformer group according to claim 3, characterized in that, The wire (5) on the mesh side is a stranded wire.
5. A combined converter transformer group according to claim 3, characterized in that, The ends of the grid-side windings of each phase of the first converter transformer body (2) and the second converter transformer body (3) are led out from the bottom of the body and connected together by stranded wires. The three-phase leads are gathered on a stranded wire and connected to a grid-side neutral point bushing (10).
6. A combined converter transformer group according to claim 1, characterized in that, The first converter transformer body (2) and the second converter transformer body (3) are arranged side by side.
7. A combined converter transformer group according to claim 1, characterized in that, The grid-side winding of the first converter transformer body (2) and the grid-side winding of the second converter transformer body (3) are arranged in the middle of the oil tank (1), and the valve-side winding of the first converter transformer body (2) and the valve-side winding of the second converter transformer body (3) are arranged on both sides of the oil tank (1).
8. A combined converter transformer group according to claim 1, characterized in that, There is a maintenance passage and electrical distance between the first converter transformer body (2) and the second converter transformer body (3).
9. A combined converter transformer group according to claim 1, characterized in that, The first converter transformer body (2) and the second converter transformer body (3) share a cooling system.
10. A combined converter transformer group according to claim 1, characterized in that, The first converter transformer body (2) and the second converter transformer body (3) share a protection system.