Single-phase autotransformer and voltage regulation method

Abstract

The application belongs to the field of transformer voltage regulation, and discloses a single-phase autotransformer and a voltage regulation method. The single-phase autotransformer comprises a first side column, a second side column, a main column arranged between the first side column and the second side column, a first tapping switch and a second tapping switch. A low-voltage coil, a common coil, a series coil and a first voltage regulation coil are sequentially arranged on the main column from inside to outside. A second voltage regulation coil is arranged on the first side column. The first tapping switch adjusts the number of turns of the first voltage regulation coil, and the second tapping switch adjusts the number of turns of the second voltage regulation coil. The first voltage regulation coil is arranged on the main column, and the second voltage regulation coil is arranged on the first side column. The first voltage regulation coil and the second voltage regulation coil are connected in series. The number of turns of the first voltage regulation coil and the second voltage regulation coil is set to control the accuracy of voltage regulation. The single-phase autotransformer can realize accurate voltage regulation at low cost without setting a large-capacity excitation coil. The copper consumption is reduced, and the cost is low in the same voltage regulation range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transformers, and particularly relates to a single-phase autotransformer and a voltage regulation method. BACKGROUND

[0002] Generally, a transformer has a plurality of taps led out from a coil on one side, and by means of on-load (or no-excitation) tap changers, the taps are switched from one to another to change the effective number of turns of the coil connected to the circuit, so as to adjust the turns ratio between the primary side and the secondary side of the transformer, and thus to regulate the voltage.

[0003] Generally, the voltage regulation coil of a transformer is wound on a side column. A single-phase transformer is disclosed in Chinese patent CN202405075U, in which a magnetizing coil and a voltage regulation coil are sequentially sleeved on a side column from inside to outside, and a low-voltage coil, a medium-voltage coil and a high-voltage coil are sequentially sleeved on a main column from inside to outside. However, in order to achieve the rated regulation range, the number of turns to be wound is large when the turn potential is constant, which consumes more materials and has a high cost. In addition, a large-capacity magnetizing coil is additionally provided, which increases the production cost.

[0004] In view of the above problems, a single-column sleeved single-phase autotransformer is disclosed in Chinese patent CN113871158A, in which a low-voltage coil, a common coil, a series coil and a voltage regulation coil are sequentially wound on the outer side of a main column from inside to outside, and no coil is provided on a side column. In this scheme, the voltage regulation coil is arranged on the main column, and the capacity of the magnetizing coil is reduced to 1 / N (where N is the number of voltage regulation taps) of the original capacity, thereby reducing the production cost. However, at the same time, since the cross-sectional area of the main column is larger than that of the side column, the turn potential of the voltage regulation coil wound on the main column is relatively large, and the regulation accuracy of the voltage regulation coil is less than that of the voltage regulation coil wound on the side column, which is difficult to meet the national standard ratio requirement.

[0005] In summary, the voltage regulation coil of a transformer consumes more materials and has a high cost when arranged on a side column, and the ratio error is unqualified when arranged on a main column. The present design scheme makes a trade-off and balance for this difficult problem. SUMMARY

[0006] The present application provides a single-phase autotransformer and a voltage regulation method, which solve the problems of the voltage regulation coil of a transformer consuming more materials and having a high cost when arranged on a side column, and the ratio error being unqualified when arranged on a main column.

[0007] In order to solve the above technical problems, the technical scheme of the present application is as follows: a single-phase autotransformer, comprising a first side column, a second side column, a main column arranged between the first side column and the second side column, a first tapping switch and a second tapping switch, wherein the main column is sequentially wound with a low-voltage coil, a common coil, a series coil and a first voltage regulating coil from inside to outside, and the first side column is wound with a second voltage regulating coil; the first tapping switch adjusts the number of turns of the first voltage regulating coil, and the second tapping switch adjusts the number of turns of the second voltage regulating coil.

[0008] In a preferred embodiment of the present application, the difference between the number of turns of the first voltage regulating coil corresponding to two adjacent levels of the first tapping switch is equal to the total number of turns of the second voltage regulating coil.

[0009] In a preferred embodiment of the present application, the tapping levels of the first tapping switch correspond to the tapping levels of the second tapping switch one by one.

[0010] In a preferred embodiment of the present application, the first voltage regulating coil comprises a first outgoing line end and a second outgoing line end, the first outgoing line end is connected with the series coil, and the second outgoing line end is connected with the first tapping switch.

[0011] The second voltage regulating coil comprises a third outgoing line end and a fourth outgoing line end, the third outgoing line end is connected with the first voltage regulating coil, and the fourth outgoing line end is connected with the second tapping switch.

[0012] In a preferred embodiment of the present application, the first voltage regulating coil comprises a power-on coil connected with a working circuit and a power-off coil not connected with the working circuit, and one outgoing line end of the second voltage regulating coil is connected with the power-on coil.

[0013] In a preferred embodiment of the present application, the second tapping switch comprises a common lead-out point and a plurality of tapping contact points, and adjacent two tapping contact points are one conductive contact point and the other is an insulating contact point.

[0014] In a preferred embodiment of the present application, the side wall of the first side column is sleeved with an annular iron yoke pad.

[0015] In a preferred embodiment of the present application, the iron yoke pad is provided with an annular groove in the cross section, and the second voltage regulating coil is wound in the annular groove.

[0016] The present application further discloses a voltage regulating method of a single-phase autotransformer, comprising the following steps:

[0017] The common coil and the first voltage regulating coil are connected in series to form a secondary side winding;

[0018] The number of tapping levels of the first tapping switch is adjusted to change the number of turns of the first voltage regulating coil connected with the secondary side winding.

[0019] adjusting the second tap switch to control the second voltage regulating coil to be connected to the secondary winding or not to be connected to the secondary winding;

[0020] One tap level corresponds to one voltage value, and the first tap switch and the second tap switch are adjusted to the corresponding tap level.

[0021] In a preferred embodiment of the present application, when the second voltage regulating coil is not connected to the secondary winding, one output terminal of the second regulating coil is disconnected, and the other output terminal is connected to the secondary winding.

[0022] Compared with the prior art, the technical solution provided by the present application has the following advantages:

[0023] The present application sets the first voltage regulating coil on the main column and the second voltage regulating coil on the first side column, and cooperates the first voltage regulating coil and the second voltage regulating coil in series to realize high-precision voltage regulation, and controls the precision of voltage regulation by setting the turns ratio of the first voltage regulating coil and the second voltage regulating coil. Thus, precise voltage regulation can be realized, the ratio error is small, the cost is low, a large-capacity excitation coil does not need to be set, the copper consumption is reduced for the same voltage regulation range, and the cost is lower. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain the drawings of other embodiments according to these drawings without any creative effort.

[0025] Figure 1 is a schematic diagram of the inside of a single-phase autotransformer described in an embodiment of the present application;

[0026] Figure 2 is a structural schematic diagram of a single-phase autotransformer described in an embodiment of the present application;

[0027] Figure 3 is a first tap level wiring schematic diagram of a single-phase autotransformer described in an embodiment of the present application;

[0028] Figure 4 is a second tap level wiring schematic diagram of a single-phase autotransformer described in an embodiment of the present application;

[0029] Figure 5 is a third tap level wiring schematic diagram of a single-phase autotransformer described in an embodiment of the present application;

[0030] Figure 6is a fourth tap connection schematic diagram of a single-phase autotransformer according to an embodiment of the present application;

[0031] Figure 7 is a fifth tap connection schematic diagram of a single-phase autotransformer according to an embodiment of the present application.

[0032] shown in the figure:

[0033] 101 - first side column; 102 - second side column; 103 - main column; 201 - low-voltage coil; 202 - common coil; 203 - series coil; 204 - first voltage regulating coil; 301 - second voltage regulating coil; 301 - iron yoke pad; 303 - groove. DETAILED DESCRIPTION

[0034] For the purpose of facilitating understanding, the single-phase autotransformer and the voltage regulating method will be described below in conjunction with the embodiments, and it should be understood that these embodiments are only used for illustrating the present application and are not used for limiting the scope of the present application.

[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation and position relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application 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 application more thorough and comprehensive.

[0038] As Figure 1As shown, a single-phase autotransformer, comprising: a first side column 101, a second side column 102, a main column 103 arranged between the first side column 101 and the second side column 102, a first tapping switch and a second tapping switch, the main column 103 is sequentially wound with a low-voltage coil 201, a common coil 202, a series coil 203 and a first voltage regulating coil 204 from inside to outside, and the first side column 101 is wound with a second voltage regulating coil 301; the first tapping switch adjusts the number of turns of the first voltage regulating coil 204, and the second tapping switch adjusts the number of turns of the second voltage regulating coil 301.

[0039] The first voltage regulating coil 204 is arranged at the outermost side, which is convenient for tapping the lead. The first voltage regulating coil 204 is arranged on the main column 103, and the second voltage regulating coil 301 is arranged on the first side column 101. The first voltage regulating coil 204 and the second voltage regulating coil 301 are connected in series to realize high-precision voltage regulation. The number of turns of the first voltage regulating coil 204 and the second voltage regulating coil 301 is arranged to control the precision of voltage regulation. Thus, accurate voltage regulation can be realized, the ratio error is small, the cost is low, a large-capacity excitation coil does not need to be arranged, the copper consumption is reduced, and the cost is lower.

[0040] As shown in the figure, in an embodiment of the present application, the number of turns of the corresponding first voltage regulating coil 204 between the adjacent two levels of the first tapping switch is equal to the total number of turns of the second voltage regulating coil 301, and the tapping levels of the first tapping switch correspond to the tapping levels of the second tapping switch one by one.

[0041] Since the cross-sectional area of the first side column 101 is half of that of the main column 103, the turn potential of the coil wound on the first side column 101 is half of that of the main column 103. Since the number of turns of the first voltage regulating coil 204 between the adjacent two levels is equal to the total number of turns of the second voltage regulating coil 301, the total voltage on the second voltage regulating coil 301 is half of the voltage between the adjacent two levels of the first voltage regulating coil 204. Therefore, the voltage regulation level of the transformer can be half of that when the voltage regulating coil is arranged only on the main column 103, and only one voltage level coil is wound on the first side column 101, which has a cost much lower than that when the voltage regulating coil is arranged only on one side column in the prior art.

[0042] In addition, the number of turns of the second voltage regulating coil 301 corresponds to the number of turns of the first tapping switch, and the number of turns between the adjacent two levels of the first voltage regulating coil 204 is an integer multiple of the number of turns between the adjacent two levels of the second voltage regulating coil 301. The number of turns of the second voltage regulating coil 301 is controlled, and the voltage regulation precision is higher.

[0043] In an embodiment of the present application, the second tapping switch comprises a common lead-out point and a plurality of tapping contact points. Among the adjacent two tapping contact points, one is a conductive contact point, and the other is an insulating contact point.

[0044] In the present application, during the voltage regulation of the transformer, the second regulating coil 301 is connected to the circuit by setting the conductive contact and the insulating contact on the second tapping switch at intervals, that is, the second regulating coil 301 is connected in series at the even-numbered taps, and the second regulating coil is disconnected from the first regulating coil at the odd-numbered taps; or the second regulating coil 301 is connected in series at the odd-numbered taps, and the second regulating coil is disconnected from the first regulating coil at the even-numbered taps. In this way, the second regulating coil 301 is connected to the circuit by the interval conductive contact of the second tapping switch, so that the first regulating coil 204 is connected to the circuit at intervals of half a tap between two adjacent taps of the transformer, that is, the function of regulating the voltage of the main column 103 by 0.5 taps is realized.

[0045] The first regulating coil 204 comprises a first outgoing line end and a second outgoing line end, the first outgoing line end is connected with the series coil 203, and the second outgoing line end is connected with the first tapping switch. The second regulating coil 301 comprises a third outgoing line end and a fourth outgoing line end, the third outgoing line end is connected with the first regulating coil 204, and the fourth outgoing line end is connected with the second tapping switch.

[0046] The first regulating coil 204 comprises a power-on coil connected to the working circuit and a circuit-breaking coil not connected to the working circuit, and one outgoing line end of the second regulating coil 301 is connected with the power-on coil.

[0047] When the second regulating coil 301 is not connected to the coil but is in the magnetic field of the first regulating coil 204, because the second regulating coil 301 is not grounded, a potential suspension will be generated. The suspended potential is high in voltage and concentrated in field strength, which generally causes the surrounding solid dielectric to be burned or carbonized, and also causes a large amount of characteristic gas to be decomposed from the insulating oil under the action of the suspended potential, so that the chromatographic analysis result of the insulating oil exceeds the standard. When the suspended potential is large, partial discharge will be generated. Therefore, in the present application, the second regulating coil 301 is electrically connected with the power-on part of the first regulating coil 204, which is simple and convenient, so that the potential at each point of the second regulating coil 301 is equal to that of the first regulating coil 204, and the product structure is flexible, convenient and simplified.

[0048] Referring to Figure 1 As shown in the figure, the side wall of the first side column 101 is sleeved with an annular iron yoke pad 301.

[0049] Because the voltage on the side column of the high-voltage and extra-high-voltage transformer is large, the magnetic field is strong, and the insulation performance is poor, in the present application, the iron yoke pad 301 is arranged for magnetic conduction and insulation, so as to improve the safety and reliability of the overall operation of the transformer.

[0050] Referring to Figure 2 As shown in the figure, an annular groove 303 is arranged on the cross section of the iron yoke pad 301, and the second regulating coil 301 is arranged in the annular groove 303.

[0051] The second voltage regulating coil 301 is arranged in the groove 303 of the iron yoke pad 301, which can support and limit the second voltage regulating coil 301 to prevent the second voltage regulating coil 301 from falling off, facilitate insulation between the first side column 101 and the second voltage regulating coil 301 to avoid safety hazards during the operation of the transformer, and completely surround the second voltage regulating coil 301 to have an attractive appearance and facilitate assembly.

[0052] When the transformer works, the voltage regulating method mainly includes the following steps:

[0053] The common coil 202 and the first voltage regulating coil 204 are connected in series to form a secondary winding;

[0054] The tap number of the first tap switch is adjusted to change the number of turns of the first voltage regulating coil 204 connected to the secondary winding;

[0055] The second tap switch is adjusted to control whether the second voltage regulating coil 301 is connected to the secondary winding or not;

[0056] One tap level corresponds to one voltage value, and the first tap switch and the second tap switch are adjusted to the corresponding tap level.

[0057] That is, the voltage value of the output is controlled by controlling the number of turns of the secondary winding connected. In the present application, each tap level corresponds to an output voltage, the closest tap level is selected according to the target voltage, and the tap levels of the first tap switch and the second tap switch are adjusted to be equal to the target tap level. The tap level of the first tap switch is adjusted to determine the number of turns and the connection position of the first voltage regulating coil 204, and the tap level of the second tap switch is adjusted to control whether the second voltage regulating coil 301 is connected to the secondary winding.

[0058] Taking the number of turns of the first voltage regulating coil 204 at the first tap position as N turns (which is actually the number of turns of the common coil), and taking the number of turns of the adjacent two levels as an example, the number of turns of the second voltage regulating coil 301 is n turns, and the n-turn second voltage regulating coil 301 is equivalent to 0.5n-turn first voltage regulating coil 204.

[0059] Referring to FIG. 1, Figure 3 When the first tap switch and the second tap switch of the transformer are both at the first tap level, the first voltage regulating coil 204 is fully connected to the secondary winding, and the second voltage regulating coil 301 is not connected, so the total number of turns of the voltage regulating coil is N turns.

[0060] Referring to FIG. 1, Figure 4As shown, when the first tap switch and the second tap switch of the transformer are both in the second tap level, the first voltage regulating coil 204 is connected with (N-n) turns, and the second voltage regulating coil 301 is connected, so that the total turns of the voltage regulating coil is (N-0.5n) turns.

[0061] Referring to Figure 5 As shown, when the first tap switch and the second tap switch of the transformer are both in the third tap level, the first voltage regulating coil 204 is connected with (N-n) turns, and the second voltage regulating coil 301 is not connected, so that the total turns of the voltage regulating coil is (N-n) turns.

[0062] Referring to Figure 6 As shown, when the first tap switch and the second tap switch of the transformer are both in the fourth tap level, the first voltage regulating coil 204 is connected with (N-2n) turns, and the second voltage regulating coil 301 is connected, so that the total turns of the voltage regulating coil is (N-1.5n) turns.

[0063] Referring to Figure 7 As shown, when the first tap switch and the second tap switch of the transformer are both in the fifth tap level, the first voltage regulating coil 204 is connected with (N-2n) turns, and the second voltage regulating coil 301 is not connected, so that the total turns of the voltage regulating coil is (N-2n) turns.

[0064] In summary, by adjusting the series connection or non-series connection between the first voltage regulating coil 204 and the second voltage regulating coil 301, 0.5-level main column 103 voltage regulation is realized, so that the high-voltage large-capacity transformer is more flexible and convenient in electromagnetic scheme design, and has reasonable structure, flexible design and strong practicability. It is suitable for single-phase autotransformer with super-high voltage, extra-high voltage and large capacity with side column, and also suitable for single-phase converter transformer with side column. When the number of tap levels of the converter is too large, it is not convenient to arrange the tap winding, the number of tap leads of the converter transformer can be reduced to about half, so that the structure of the multi-tap on-load voltage regulating converter transformer is simplified.

[0065] When the second voltage regulating coil 301 is connected to the secondary winding, the common coil 202, the first voltage regulating coil 204 and the second voltage regulating coil 301 are connected in series to form the secondary winding.

[0066] When the second voltage regulating coil 301 is not connected to the secondary winding, one of the two output terminals of the second regulating coil is disconnected, and the other output terminal is connected to the secondary winding. At this time, the second voltage regulating coil 301 does not participate in the current-carrying work, does not change the number of turns of the secondary winding, and does not cause potential suspension.

[0067] It should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing examples, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing examples can be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements 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 application.

Claims

1. A single phase autotransformer, characterized by The application relates to a transformer, which comprises a first side column, a second side column, a main column arranged between the first side column and the second side column, a first tapping switch and a second tapping switch, wherein the main column is sequentially provided with a low-voltage coil, a common coil, a series coil and a first voltage regulating coil from inside to outside, and the first side column is provided with a second voltage regulating coil; the first tapping switch adjusts the number of turns of the first voltage regulating coil, and the second tapping switch adjusts the number of turns of the second voltage regulating coil. The first voltage regulating coil comprises a first outgoing line and a second outgoing line, the first outgoing line is connected with the series coil, and the second outgoing line is connected with the first tapping switch. The second voltage regulating coil comprises a third outgoing line and a fourth outgoing line, the third outgoing line is connected with the first voltage regulating coil, and the fourth outgoing line is connected with the second tapping switch. The common coil and the first voltage regulating coil are connected in series to form a secondary side winding. The number of turns of the first voltage regulating coil connected with the secondary side winding is changed by adjusting the tapping level of the first tapping switch. The second voltage regulating coil is connected with or not connected with the secondary side winding by adjusting the second tapping switch. One tapping level corresponds to one voltage value, and the first tapping switch and the second tapping switch are adjusted to the corresponding tapping level. The difference between the number of turns of the first voltage regulating coil in the adjacent two levels of the first tapping switch is equal to the total number of turns of the second voltage regulating coil.

2. A single-phase autotransformer according to claim 1, characterized in that: The tapping level of the first tapping switch corresponds to the tapping level of the second tapping switch.

3. A single-phase autotransformer according to claim 1, characterized in that The first voltage regulating coil comprises a current coil connected with the working circuit and a break coil not connected with the working circuit, and one outgoing line of the second voltage regulating coil is connected with the current coil.

4. A single-phase autotransformer according to claim 1, characterized in that: The second tapping switch comprises a common outgoing point and a plurality of tapping contact points, and one of the adjacent two tapping contact points is a conductive contact point and the other is an insulating contact point.

5. A single-phase autotransformer according to claim 1, characterized in that: The side wall of the first side column is provided with an annular iron yoke pad.

6. A single-phase autotransformer according to claim 1, characterized in that: The cross section of the iron yoke pad is provided with an annular groove, and the second voltage regulating coil is arranged in the annular groove.

7. A single-phase autotransformer according to claim 6, characterized in that: The application further discloses a method for adjusting the voltage of the transformer, which comprises the following steps:

8. A method of regulating the voltage of a single-phase autotransformer according to any one of claims 1-7, characterized in that, The common coil and the first voltage regulating coil are connected in series to form a secondary side winding. The number of turns of the first voltage regulating coil connected with the secondary side winding is changed by adjusting the tapping level of the first tapping switch. The second voltage regulating coil is connected with or not connected with the secondary side winding by adjusting the second tapping switch. One tapping level corresponds to one voltage value, and the first tapping switch and the second tapping switch are adjusted to the corresponding tapping level. When the second voltage regulating coil is not connected with the secondary side winding, one outgoing line of the second voltage regulating coil is disconnected and the other outgoing line is connected with the secondary side winding.

9. A method of regulating the voltage of a single-phase autotransformer according to claim 8, characterized in that: ​

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