Compact phase-shift transformer and operating system
By using a special connection method and control switch of a compact phase-shifting transformer, the problems of complex structure, large size and high cost in the existing technology are solved, realizing small-angle phase shift and cost reduction, and suitable for live-loop operation of 10kV lines.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- WUJIANG TRANSFORMER CO LTD
- Filing Date
- 2025-04-09
- Publication Date
- 2026-06-04
AI Technical Summary
In existing technologies, the phase-shifting transformers of 10kV loop-closing devices are complex in structure, large in size, and expensive, and cannot effectively achieve small-angle phase shifting, thus failing to meet the actual operating conditions of distribution networks.
A compact phase-shifting transformer is used, and through a special connection method between the A-phase, B-phase, C-phase coils and the phase-shifting coil, combined with a polarity switching switch and a range switch, the phase-shifting angle adjustment from 0 to 12° can be achieved, simplifying the structure and reducing costs.
It achieves small-angle phase shift, simplifies transformer structure, reduces size, lowers production costs, and meets the actual operating conditions of power distribution networks.
Smart Images
Figure CN2025088160_04062026_PF_FP_ABST
Abstract
Description
A compact phase-shifting transformer and its operating system Technical Field
[0001] This invention belongs to the field of transformer phase-shifting technology, specifically relating to a compact phase-shifting transformer and its operating system. Background Technology
[0002] In order to achieve live loop closing operation of the line, a loop closing device is required to connect the two 10kV lines (the first line L1 and the second line L2) with different phase angles, so as to avoid additional power outages due to the inability to directly close the loop.
[0003] In existing technologies, 10kV loop closing devices mainly employ phase-shifting transformers. Referring to Figure 1, its main phase-shifting principle is as follows:
[0004] 1. When the angle difference between two voltage phasors U1 and U2 of equal magnitude is θ, and θ ≤ 12°, the voltage difference between them can be approximated by ΔU ≈ U1 * tgθ, with a theoretical value of 2 * U1 * SIN(θ / 2). When θ is at most 12°, the maximum error between them is (1 - 2 * Sin6 / tg12) * 100% = 1.65%. Furthermore, the smaller θ is, the smaller the error.
[0005] When θ = 12°, ΔU ≈ U1 * tan12 = 0.2126 * U1
[0006] 2. The orthogonal vector sum of U1 and ΔU is U1 / Cosθ. When θ = 12°, this value is greater than U1 by (1 - 1 / Cos12) * 100% = 2.23%. The smaller θ is, the smaller the increase. When θ = 6°, this value is only greater than U1 by (1 - 1 / Cos6) * 100% = 0.55%. That is, when θ ≤ 12°, the difference between the orthogonal vector sum of U1 and ΔU and U1 is very small.
[0007] Combining the above two points, when the angular difference between U1 and U2 is θ = 12°, the voltage difference between them is ΔU ≈ 0.213 * U1. If a phase-shifting vector U3 = ΔU, orthogonal to U1, is added, then the vector sum of U1 and U3, U1 + U3, will be in phase with U2, and the maximum voltage difference between them will only be 0.0223 * U1, a 90% reduction compared to the original ΔU = 0.213 * U1. Furthermore, the smaller θ is, the smaller the phase-shifting vector U3 is, and the smaller the voltage difference between it and U2.
[0008] Chinese patent CN114999782A discloses a phase-shifting transformer for closed-loop power supply. This transformer uses a zigzag connection for phase shifting and has three coils, making it difficult to achieve small-angle phase shifting and resulting in a relatively complex structure. Furthermore, Chinese patent CN215183483U discloses a phase-shifting transformer using a novel coil design. This coil employs a delta connection for phase shifting and also has three coils, but can only achieve a fixed-angle phase shift. Additionally, Chinese patent CN116526476A discloses a 10kV live-loop closing operation device, which uses a dual-body structure and is structurally complex.
[0009] In summary, the existing technology ignores the fact that the phase angle difference between the two lines is not large in actual operating conditions. The designed phase shift angle is too large, resulting in a complex transformer structure, large size, and high production cost. Summary of the Invention
[0010] This invention provides a compact phase-shifting transformer and its operating system to solve the problem that small-angle phase shifting is currently impossible.
[0011] To solve the above-mentioned technical problems, the technical solution of the present invention is: a compact phase-shifting transformer, comprising: an A-phase core column, an A-phase coil wound on the A-phase core column, a B-phase core column, a B-phase coil wound on the B-phase core column, a C-phase core column, a C-phase coil wound outside the C-phase core column, an A-phase phase-shifting coil wound outside the A-phase coil, a B-phase phase-shifting coil wound outside the B-phase coil, and a C-phase phase-shifting coil wound outside the C-phase coil;
[0012] The C-phase phase shifting coil is connected to the A-phase coil at its corresponding terminal A1 via a polarity switch K1a; the A-phase phase shifting coil is connected to the B-phase coil at its corresponding terminal B1 via a polarity switch K1b; and the B-phase phase shifting coil is connected to the C-phase coil at its corresponding terminal C1 via a polarity switch K1c.
[0013] In a preferred embodiment of the present invention, the A-phase phase shifting coil, the B-phase phase shifting coil, and the C-phase phase shifting coil are arranged in the same way.
[0014] In a preferred embodiment of the present invention, the A-phase phase shifting coil is provided with a plurality of A-phase taps, the A-phase taps are connected to the adjustment switch K2a, and the output terminal of the adjustment switch K2a is the terminal B2 of the B-phase coil after phase shifting;
[0015] The B-phase phase-shifting coil is provided with multiple B-phase taps, which are connected to the adjustment switch K2b. The output terminal of the adjustment switch K2b is the terminal C2 of the C-phase coil after phase shifting.
[0016] The C-phase phase-shifting coil is provided with multiple C-phase taps. The C-phase taps are connected to the adjustment switch K2c. The output terminal of the adjustment switch K2c is the terminal A2 of the A-phase coil after phase shifting.
[0017] In a preferred embodiment of the present invention, the A-phase coil, the B-phase coil, and the C-phase coil are connected in a delta configuration.
[0018] In a preferred embodiment of the present invention, the number of taps on the A-phase phase shifting coil is a factor of 12.
[0019] In a preferred embodiment of the present invention, the number of taps on the A-phase phase shifting coil is 6.
[0020] In a preferred embodiment of the present invention, one end of the A-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1a is connected to the positive terminal or the negative terminal; one end of the B-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1b is connected to the positive terminal or the negative terminal; one end of the C-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1c is connected to the positive terminal or the negative terminal.
[0021] In a preferred embodiment of the present invention, the same-name terminal of the A-phase phase shifting coil is connected to the negative terminal of the polarity reversing switch K1a, and the opposite-name terminal of the A-phase phase shifting coil is connected to the positive terminal of the polarity reversing switch K1a; the same-name terminal of the B-phase phase shifting coil is connected to the negative terminal of the polarity reversing switch K1b, and the opposite-name terminal of the B-phase phase shifting coil is connected to the positive terminal of the polarity reversing switch K1b; the same-name terminal of the C-phase phase shifting coil is connected to the negative terminal of the polarity reversing switch K1c, and the opposite-name terminal of the B-phase phase shifting coil is connected to the positive terminal of the polarity reversing switch K1c.
[0022] In a preferred embodiment of the present invention, the polarity switching switches K1a, K1b, and K1c are connected with the same polarity.
[0023] The present invention also discloses a transformer operating system, comprising a compact phase-shifting transformer as described in any one of the claims, a first line L1, and a second line L2; the output terminals A1 of the A-phase coil, B1 of the B-phase coil, and C1 of the C-phase coil of the compact phase-shifting transformer are connected to the first line L1, and the output terminals of the A-phase coil, the B-phase coil, and the C-phase coil are connected to the second line L2.
[0024] The technical solution provided by this invention has the following advantages compared with the prior art:
[0025] The compact phase-shifting transformer in this invention has a phase-shifting angle range of 0–12°, which better suits the actual operating conditions of current power distribution networks. This 0–12° phase-shifting angle range ensures that orthogonal phase shifting with delta connections can be used, greatly simplifying the transformer structure, reducing its size, and lowering its manufacturing cost. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.
[0027] Figure 1 is a schematic diagram of the phase shifting principle;
[0028] Figure 2 is a schematic diagram of the coil connection principle of a compact phase-shifting transformer according to an embodiment of the present invention;
[0029] Figure 3 is a schematic diagram of the coil arrangement and connection of a compact phase-shifting transformer and its working system according to an embodiment of the present invention. Detailed Implementation
[0030] For ease of understanding, the following embodiments illustrate a compact phase-shifting transformer. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.
[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation and positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0033] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0034] Referring to Figures 2 and 3, the present invention discloses a compact phase-shifting transformer, which includes: an A-phase core column, an A-phase coil wound on the A-phase core column, a B-phase core column, a B-phase coil wound on the B-phase core column, a C-phase core column, a C-phase coil wound outside the C-phase core column, an A-phase phase-shifting coil wound outside the A-phase coil, a B-phase phase-shifting coil wound outside the B-phase coil, and a C-phase phase-shifting coil wound outside the C-phase coil.
[0035] The C-phase shifting coil and the A-phase coil's corresponding terminal A1 are connected through a polarity switch K1a; the A-phase shifting coil and the B-phase coil's corresponding terminal B1 are connected through a polarity switch K1b; and the B-phase shifting coil and the C-phase coil's corresponding terminal C1 are connected through a polarity switch K1c.
[0036] Specifically, referring to Figures 2 and 3, the corresponding ends of each coil in the figures are marked with dots.
[0037] The same-name terminal of phase A shift coil is connected to the negative terminal of polarity changeover switch K1a, and the opposite-name terminal of phase A shift coil is connected to the positive terminal of polarity changeover switch K1a; the same-name terminal of phase B shift coil is connected to the negative terminal of polarity changeover switch K1b, and the opposite-name terminal of phase B shift coil is connected to the positive terminal of polarity changeover switch K1b; the same-name terminal of phase C shift coil is connected to the negative terminal of polarity changeover switch K1c, and the opposite-name terminal of phase B shift coil is connected to the positive terminal of polarity changeover switch K1c. The polarity of polarity changeover switches K1a, K1b, and K1c is the same.
[0038] Here, polarity reversal switches K1a, K1b, and K1c are used to connect the phase-shifting coil to the primary coil in two different vector directions. Taking the A-phase phase-shifting coil as an example, when the opposite-named terminals of the A-phase coil and the A-phase phase-shifting coil are connected, the phase shift angle is leading; when the same-named terminals of the A-phase coil and the A-phase phase-shifting coil are connected, the phase shift angle is lagging. This achieves phase angle adjustment.
[0039] Specifically, the A-phase phase shifting coil, B-phase phase shifting coil, and C-phase phase shifting coil are configured in the same way. Furthermore, the A-phase coil, B-phase coil, and C-phase coil are connected in a delta configuration.
[0040] The A-phase phase shifting coil has multiple A-phase taps, which are connected to the adjustment switch K2a. The output of the adjustment switch K2a is the terminal B2 of the B-phase coil after phase shifting. The B-phase phase shifting coil has multiple B-phase taps, which are connected to the adjustment switch K2b. The output of the adjustment switch K2b is the terminal C2 of the C-phase coil after phase shifting. The C-phase phase shifting coil has multiple C-phase taps, which are connected to the adjustment switch K2c. The output of the adjustment switch K2c is the terminal A2 of the A-phase coil after phase shifting.
[0041] In other words, by setting adjustment switches K2a, K2b and K2c on the phase shifting coil of phase A, different taps on the phase shifting coil of phase A can be selected through adjustment switches K2a, K2b and K2c, thereby achieving phase shifting of 2n different angles within a range of ±12°, with each stage being 12° / n.
[0042] The number of taps on the A-phase phase shifting coil is a factor of 12. In a preferred embodiment of the present invention, the A-phase phase shifting coil has 6 taps. Taking the A-phase phase shifting coil as an example, the A-phase phase shifting coil is usually equipped with n taps, and the phase shift angle corresponding to each tap is 12° / n. Different taps can be selected to achieve different phase shift angles. Here, n is an integer and divisible by 12, and is usually taken as n = 6.
[0043] One end of the phase shifter coil in phase A is the positive terminal and the other end is the negative terminal. The polarity switch K1a is connected to either the positive or negative terminal. One end of the phase shifter coil in phase B is the positive terminal and the other end is the negative terminal. The polarity switch K1b is connected to either the positive or negative terminal. One end of the phase shifter coil in phase C is the positive terminal and the other end is the negative terminal. The polarity switch K1c is connected to either the positive or negative terminal.
[0044] Referring to Figure 3, a transformer operating system includes a compact phase-shifting transformer, a first line L1, and a second line L2. The output terminals A1, B1, and C1 of the A-phase coil, B1, and C1 of the compact phase-shifting transformer are connected to the first line L1. The output terminals B2, C2, and A2 of the A-phase, B-phase, and C-phase coils are connected to the second line L2. By selecting an appropriate gear using a gear selector switch, the closed-loop operation of lines L1 and L2 can be achieved.
[0045] In operation, this invention first obtains the working phase angles of the first line L1 and the second line L2, and calculates the difference between them. Based on the requirements for leading or lagging, the adjustment switches K2a, K2b, and K2c are adjusted to make the first line L1 and the second line L2 operate in a closed loop.
[0046] The compact phase-shifting transformer in this invention has a phase-shifting angle range of 0–12°, which better suits the actual operating conditions of current power distribution networks. This 0–12° phase-shifting angle range ensures that orthogonal phase shifting with delta connections can be used, greatly simplifying the transformer structure, reducing its size, and lowering its manufacturing cost.
[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A compact phase-shifting transformer, characterized in that, include: A-phase core column, A-phase coil wound on the A-phase core column, B-phase core column, B-phase coil wound on the B-phase core column, C-phase core column, C-phase coil wound outside the C-phase core column, A-phase phase-shifting coil wound outside the A-phase coil, B-phase phase-shifting coil wound outside the B-phase coil, and C-phase phase-shifting coil wound outside the C-phase coil; The C-phase phase shifting coil is connected to the A-phase coil at its corresponding terminal A1 via a polarity switch K1a; the A-phase phase shifting coil is connected to the B-phase coil at its corresponding terminal B1 via a polarity switch K1b; and the B-phase phase shifting coil is connected to the C-phase coil at its corresponding terminal C1 via a polarity switch K1c.
2. A compact phase-shifting transformer according to claim 1, characterized in that: The A-phase phase shifting coil, the B-phase phase shifting coil, and the C-phase phase shifting coil are configured in the same way.
3. A compact phase-shifting transformer according to claim 1, characterized in that: The phase-shifting coil of phase A is provided with multiple phase A taps. The phase A taps are connected to the adjustment switch K2a. The output terminal of the adjustment switch K2a is the terminal B2 of the phase-shifted coil of phase B. The B-phase phase-shifting coil is provided with multiple B-phase taps, which are connected to the adjustment switch K2b. The output terminal of the adjustment switch K2b is the terminal C2 of the C-phase coil after phase shifting. The C-phase phase-shifting coil is provided with multiple C-phase taps. The C-phase taps are connected to the adjustment switch K2c. The output terminal of the adjustment switch K2c is the terminal A2 of the A-phase coil after phase shifting.
4. A compact phase-shifting transformer according to claim 1, characterized in that: The A-phase coil, the B-phase coil, and the C-phase coil are connected in a delta configuration.
5. A compact phase-shifting transformer according to claim 1, characterized in that: The number of taps on the phase-shifting coil of phase A is a factor of 12.
6. A compact phase-shifting transformer according to claim 5, characterized in that: The A-phase phase shifting coil has 6 taps.
7. A compact phase-shifting transformer according to claim 1, characterized in that: One end of the A-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1a is connected to the positive terminal or the negative terminal; one end of the B-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1b is connected to the positive terminal or the negative terminal; one end of the C-phase phase shifting coil is the positive terminal and the other end is the negative terminal, and the polarity reversing switch K1c is connected to the positive terminal or the negative terminal.
8. A compact phase-shifting transformer according to claim 1, characterized in that: The same-name terminal of phase A shift coil is connected to the negative terminal of polarity reversing switch K1a, and the opposite-name terminal of phase A shift coil is connected to the positive terminal of polarity reversing switch K1a; the same-name terminal of phase B shift coil is connected to the negative terminal of polarity reversing switch K1b, and the opposite-name terminal of phase B shift coil is connected to the positive terminal of polarity reversing switch K1b; the same-name terminal of phase C shift coil is connected to the negative terminal of polarity reversing switch K1c, and the opposite-name terminal of phase B shift coil is connected to the positive terminal of polarity reversing switch K1c.
9. A compact phase-shifting transformer according to claim 8, characterized in that: The polarity switching switches K1a, K1b, and K1c have the same connection polarity.
10. A transformer operating system, characterized in that, The system includes a compact phase-shifting transformer as described in any one of claims 1-9, a first line L1, and a second line L2; the output terminals A1 of the A-phase coil, B1 of the B-phase coil, and C1 of the C-phase coil of the compact phase-shifting transformer are connected to the first line L1, and the output terminals of the A-phase coil, the B-phase coil, and the C-phase coil are connected to the second line L2.