Compact phase-shifting transformer and working system

Abstract

The invention belongs to the field of transformer phase shifting, and particularly discloses a compact type phase-shifting transformer and a working system.The compact type phase-shifting transformer comprises an A-phase coil, a B-phase coil, a C-phase coil, 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; the C-phase phase-shifting coil is connected with a dotted terminal A1 of the A-phase coil through a polarity change-over switch K1a, the A-phase phase-shifting coil is connected with a dotted terminal B1 of the B-phase coil through a polarity change-over switch K1b, and the B-phase phase-shifting coil is connected with a dotted terminal C1 of the C-phase coil through a polarity change-over switch K1c. The phase-shifting angle range of the compact phase-shifting transformer is 0-12 degrees, and the compact phase-shifting transformer better conforms to the actual working condition of operation of a current power distribution network. The phase shifting angle range is 0-12 degrees, it is guaranteed that triangular connection orthogonal phase shifting can be adopted, the structure of the phase-shifting transformer is greatly simplified, the size of the phase-shifting transformer is reduced, and the manufacturing cost of the phase-shifting transformer is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer phase shifting, and in particular relates to a compact phase shifting transformer and a working system. Background Art

[0002] In order to realize the live closing operation of the line, a closing device is required to connect two 10kV lines (the first line L1 and the second line L2) with different phase angles to avoid additional power outages due to the inability to directly close the loop.

[0003] In the prior art, the 10kV ring closing device mainly uses a phase-shifting transformer. Figure 1 , its main phase shift 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, and its theoretical value is 2*U1*SIN(θ / 2). When θ is 12° at most, the maximum error between the two is (1-2*Sin6 / tg12)*100%=1.65%. And the smaller θ is, the smaller the error is.

[0005] When θ=12°, ΔU≈U1*tg12=0.2126*U1

[0006] 2. The orthogonal vector sum of U1 and ΔU is U1 / Cosθ. When θ=12°, the value is larger than U1 by (1-1 / Cos12)*100%=2.23%. And the smaller θ is, the smaller the increase is. When θ=6°, the value is only larger than U1 by (1-1 / Cos6)*100%=0.55%. That is to say, 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 angle difference between U1 and U2 is θ=12°, the voltage difference between them is ΔU≈0.213*U1. If a phase shift vector U3=ΔU orthogonal to U1 is added, then the vector sum U1+U3 of U1 and U3 will be in phase with U2, and the maximum voltage difference between them and U2 is only 0.0223*U1, which is 90% less than ΔU=0.213*U1 before the phase shift. And the smaller θ is, the smaller the phase shift vector U3 is, and the smaller the voltage difference between them and U2 is.

[0008] Chinese patent CN114999782A discloses a phase-shifting transformer for closed-loop power supply. The coil adopts a zigzag connection phase shifting and is equipped with three coils. It is difficult to achieve a small angle phase shift and the structure is relatively complex. In addition, Chinese patent CN215183483U discloses a phase-shifting transformer using a new type of coil. The coil adopts a triangle connection phase shifting and is also equipped with three coils. It can only achieve a fixed angle phase shift. And Chinese patent CN116526476A discloses a 10KV-level live closed-loop operation device, which adopts a double body structure and has a complex structure.

[0009] In summary, the prior art ignores the fact that the phase angle difference between the two lines in actual operating conditions is not large, and 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] The present invention provides a compact phase-shifting transformer and a working system, which are used to solve the problem that small-angle phase shifting cannot be achieved at present.

[0011] In order to solve the above technical problems, the technical solution of the present invention is: the compact phase-shifting transformer comprises: an A-phase iron core column, an A-phase coil wound on the A-phase iron core column, a B-phase iron core column, a B-phase coil wound on the B-phase iron core column, a C-phase iron core column, a C-phase coil wound outside the C-phase iron 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 same-name end A1 of the A-phase coil through a polarity conversion switch K1a, the A-phase phase-shifting coil is connected to the same-name end B1 of the B-phase coil through a polarity conversion switch K1b, and the B-phase phase-shifting coil is connected to the same-name end C1 of the C-phase coil through a polarity conversion 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 manner.

[0014] In a preferred embodiment of the present invention, a plurality of A-phase taps are provided on the A-phase phase shifting coil, and the A-phase taps are connected to the gear shifting switch K2a, and the output end of the gear shifting switch K2a is the terminal B2 of the B-phase coil after phase shifting;

[0015] The B-phase phase shifting coil is provided with a plurality of B-phase taps, and the B-phase taps are connected to the gear-shifting switch K2b, and the output end of the gear-shifting switch K2b is the terminal C2 after the C-phase coil is phase-shifted;

[0016] The C-phase phase-shifting coil is provided with a plurality of C-phase taps, and the C-phase taps are connected to the gear-shifting switch K2c, and the output end of the gear-shifting switch K2c is the terminal A2 after the A-phase coil is phase-shifted.

[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 triangle shape.

[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-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1a is connected to the positive terminal or the negative terminal; one end of the B-phase phase-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1b is connected to the positive terminal or the negative terminal; one end of the C-phase phase-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1c is connected to the positive terminal or the negative terminal.

[0021] In a preferred embodiment of the present invention, the like-name end of the A-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1a, and the unlike-name end of the A-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1a; the like-name end of the B-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1b, and the unlike-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1b; the like-name end of the C-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1c, and the unlike-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1c.

[0022] In a preferred embodiment of the present invention, the connection polarities of the polarity conversion switch K1a, the polarity conversion switch K1b and the polarity conversion switch K1c are the same.

[0023] The present invention also discloses a working system of a transformer, which includes a compact phase-shifting transformer as described in any one of the items, a first line L1 and a second line L2; the output terminal A1 of the A-phase coil, the output terminal B1 of the B-phase coil and the output terminal C1 of the C-phase coil of the compact phase-shifting transformer are connected to the first line L1, and the output terminal of the A-phase phase-shifting coil, the output terminal of the B-phase phase-shifting coil and the output terminal of the C-phase phase-shifting coil are connected to the second line L2.

[0024] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0025] The compact phase-shifting transformer of the present invention has a phase-shifting angle range of 0 to 12°, which is more in line with the actual operating conditions of the current distribution network. The phase-shifting angle range of 0 to 12° ensures that a triangle-connected orthogonal phase shifting can be adopted, which greatly simplifies the structure of the phase-shifting transformer, reduces the volume of the phase-shifting transformer, and reduces the manufacturing cost of the phase-shifting transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is the phase shifting principle diagram;

[0028] Figure 2 is a coil connection principle diagram of a compact phase-shifting transformer described in one embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of coil arrangement and connection of a compact phase-shifting transformer and a working system described in one embodiment of the present invention. DETAILED DESCRIPTION

[0030] For ease of understanding, a compact phase-shifting transformer is described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0034] Reference Figure 2 and Figure 3 As shown, the present invention discloses a compact phase-shifting transformer, which includes: an A-phase iron core column, an A-phase coil wound on the A-phase iron core column, a B-phase iron core column, a B-phase coil wound on the B-phase iron core column, a C-phase iron core column, a C-phase coil wound outside the C-phase iron 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 phase-shifting coil is connected to the same-name end A1 of the A-phase coil through a polarity conversion switch K1a, the A-phase phase-shifting coil is connected to the same-name end B1 of the B-phase coil through a polarity conversion switch K1b, and the B-phase phase-shifting coil is connected to the same-name end C1 of the C-phase coil through a polarity conversion switch K1c.

[0036] Specifically, refer to Figure 2 and Figure 3 , the same-named ends of each coil in the figure are marked with dots.

[0037] The same-name end of the A-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1a, and the opposite-name end of the A-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1a; the same-name end of the B-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1b, and the opposite-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1b; the same-name end of the C-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1c, and the opposite-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1c. The connection polarities of the polarity conversion switch K1a, the polarity conversion switch K1b and the polarity conversion switch K1c are the same.

[0038] Here, polarity conversion switches K1a, K1b and K1c are set to connect the phase shift coil to the primary coil in two different vector directions. Taking the A-phase phase shift coil as an example, when the A-phase coil and the A-phase phase shift coil are connected at opposite ends, the phase shift angle is leading; when the A-phase coil and the A-phase phase shift coil are connected at the same end, the phase shift angle is lagging. In this way, the phase angle can be adjusted.

[0039] Specifically, the A-phase phase shift coil, the B-phase phase shift coil and the C-phase phase shift coil are arranged in the same manner. Furthermore, the A-phase coil, the B-phase coil and the C-phase coil are connected in a triangle shape.

[0040] The A-phase phase-shifting coil is provided with a plurality of A-phase taps, which are connected to the gear-adjusting switch K2a, and the output end of the gear-adjusting switch K2a is the terminal B2 of the B-phase coil after the phase shifting; the B-phase phase-shifting coil is provided with a plurality of B-phase taps, which are connected to the gear-adjusting switch K2b, and the output end of the gear-adjusting switch K2b is the terminal C2 of the C-phase coil after the phase shifting; the C-phase phase-shifting coil is provided with a plurality of C-phase taps, which are connected to the gear-adjusting switch K2c, and the output end of the gear-adjusting switch K2c is the terminal A2 of the A-phase coil after the phase shifting.

[0041] That is to say, the A-phase phase-shifting coil is used to set the shift switches K2a, K2b and K2c. Through the shift switches K2a, K2b and K2c, different taps on the A-phase phase-shifting coil can be selected, thereby achieving a phase shift of 2n different angles within the range of ±12°, with each level of 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 number of taps on the A-phase phase-shifting coil is 6. Taking the A-phase phase-shifting coil as an example, the A-phase phase-shifting coil is usually provided with n taps, and each tap corresponds to a phase shift angle of 12° / n. Different taps can be selected to achieve different phase shift angles. Where n is an integer and can be divided by 12, and n=6 is usually taken.

[0043] One end of the A-phase phase-shift coil is the positive terminal, and the other end is the negative terminal, and the polarity conversion switch K1a is connected to the positive terminal or the negative terminal; one end of the B-phase phase-shift coil is the positive terminal, and the other end is the negative terminal, and the polarity conversion switch K1b is connected to the positive terminal or the negative terminal; one end of the C-phase phase-shift coil is the positive terminal, and the other end is the negative terminal, and the polarity conversion switch K1c is connected to the positive terminal or the negative terminal.

[0044] Reference Figure 3As shown, a transformer working system includes a compact phase-shifting transformer, a first line L1 and a second line L2; an output terminal A1 of an A-phase coil, an output terminal B1 of a B-phase coil and an output terminal C1 of a C-phase coil of the compact phase-shifting transformer are connected to the first line L1, an output terminal B2 of an A-phase phase-shifting coil, an output terminal C2 of a B-phase phase-shifting coil and an output terminal A2 of a C-phase phase-shifting coil are connected to the second line L2, and a closed-loop operation of lines L1 and L2 can be realized by selecting a suitable gear position of a gear-shifting switch.

[0045] When the present invention is working, the working phase angles of the first line L1 and the second line L2 are first obtained, and the difference between the two is calculated. According to the requirements of leading or lagging, the shift switches K2a, K2b and K2c are adjusted to make the first line L1 and the second line L2 run in a closed loop.

[0046] The compact phase-shifting transformer of the present invention has a phase-shifting angle range of 0 to 12°, which is more in line with the actual operating conditions of the current distribution network. The phase-shifting angle range of 0 to 12° ensures that a triangle-connected orthogonal phase shifting can be adopted, which greatly simplifies the structure of the phase-shifting transformer, reduces the volume of the phase-shifting transformer, and reduces the manufacturing cost of the phase-shifting transformer.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions 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: An A-phase iron core column, an A-phase coil wound on the A-phase iron core column, a B-phase iron core column, a B-phase coil wound on the B-phase iron core column, a C-phase iron core column, a C-phase coil wound outside the C-phase iron 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; The C-phase phase-shifting coil is connected to the same-name end A1 of the A-phase coil through a polarity conversion switch K1a, the A-phase phase-shifting coil is connected to the same-name end B1 of the B-phase coil through a polarity conversion switch K1b, and the B-phase phase-shifting coil is connected to the same-name end C1 of the C-phase coil through a polarity conversion 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 arranged in the same manner.

3. A compact phase-shifting transformer according to claim 1, characterized in that: The A-phase phase shifting coil is provided with a plurality of A-phase taps, and the A-phase taps are connected to the gear-shifting switch K2a, and the output end of the gear-shifting switch K2a is the terminal B2 of the B-phase coil after phase shifting; The B-phase phase shifting coil is provided with a plurality of B-phase taps, and the B-phase taps are connected to the gear-shifting switch K2b, and the output end of the gear-shifting switch K2b is the terminal C2 after the C-phase coil is phase-shifted; The C-phase phase-shifting coil is provided with a plurality of C-phase taps, and the C-phase taps are connected to the gear-shifting switch K2c, and the output end of the gear-shifting switch K2c is the terminal A2 after the A-phase coil is phase-shifted.

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 shape.

5. A compact phase-shifting transformer according to claim 1, characterized in that: The number of taps on the A-phase phase-shifting coil is a factor of 12.

6. A compact phase-shifting transformer according to claim 5, characterized in that: The number of taps on the A-phase phase-shifting coil is 6.

7. A compact phase-shifting transformer according to claim 1, characterized in that: One end of the A-phase phase-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1a is connected to the positive terminal or the negative terminal; one end of the B-phase phase-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1b is connected to the positive terminal or the negative terminal; one end of the C-phase phase-shift coil is a positive terminal, and the other end is a negative terminal, and the polarity conversion switch K1c is connected to the positive terminal or the negative terminal.

8. The compact phase-shifting transformer according to claim 1, characterized in that: The like-name end of the A-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1a, and the unlike-name end of the A-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1a; the like-name end of the B-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1b, and the unlike-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1b; the like-name end of the C-phase phase-shift coil is connected to the negative pole of the polarity conversion switch K1c, and the unlike-name end of the B-phase phase-shift coil is connected to the positive pole of the polarity conversion switch K1c.

9. A compact phase-shifting transformer according to claim 8, characterized in that: The connection polarities of the polarity conversion switch K1a, the polarity conversion switch K1b, and the polarity conversion switch K1c are the same.

10. A transformer working system, characterized in that: The invention comprises a compact phase-shifting transformer according to any one of claims 1 to 9, a first line L1 and a second line L2; an output terminal A1 of an A-phase coil of the compact phase-shifting transformer, an output terminal B1 of the B-phase coil and an output terminal C The output terminal C1 of the phase coil is connected to the first line L1, and the output terminal of the A-phase phase-shifting coil, the output terminal of the B-phase phase-shifting coil, and the output terminal of the C-phase phase-shifting coil are connected to the second line L2.

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