JP4897949B2 - Transformer winding - Google Patents

Description

  The present invention relates to a transformer winding dislocation structure having a multiple cylindrical winding structure in which a plurality of conductors are wound in parallel.

  Conventionally, when a transformer winding is formed by winding a plurality of conductors in parallel, the impedance of each conductor may be different. In such a case, load currents of different sizes (hereinafter referred to as unbalanced currents) flow in each conductor, and as a result, the generated load loss is increased compared to the case where the current flows uniformly in each conductor. become.

  In order to reduce the load loss, there is a so-called dislocation method in which the conductors wound in parallel cross each other at a predetermined position and the positions of the conductors are switched. That is, by shifting the conductor at a predetermined position, the impedance of each conductor is made equal, and the current value flowing through each conductor is made equal, thereby reducing the load loss.

  The windings used in power transformers have various structures, especially the multi-cylindrical winding has a large opposing area between the conductor layers and a large series capacitance of the windings, so when lightning impulse voltage is applied It is widely used as a winding for power transformers because of its good potential distribution.

And when performing the said dislocation in the said multiple cylindrical winding, as shown in FIG. 6 of the following patent document 1, near the center of conductor layer 11 ', 12', 13 ', 14', 15 '. Conductor dislocation by reversing the order of arrangement of the conductors in the winding radial direction, or the problem of the dislocation method shown in FIG. 6 described in Patent Document 1, that is, the number of dislocations of the conductor is large. The winding structure shown in FIGS. 1 to 5 described in Patent Document 1 has been proposed in order to solve the problem of poor workability caused by the above-described problem and the increase in processing man-hours.
Japanese Patent Laid-Open No. 2000-21625

  According to the winding structure shown in FIGS. 1 to 4 of Patent Document 1, the dislocation of the conductor is performed at the end of the conductor layer, and the same winding in the winding structure shown in FIG. 6 described above. Since the number of shifts is reduced compared to the number of transformer windings, the workability can be improved and the number of processing steps can be reliably reduced.

  Further, according to the winding structure shown in FIG. 5 described in Patent Document 1, the dislocation of the conductor is performed at the central portion of the conductor layer, and is the same as the winding structure shown in FIG. For example, the number of turns can be reduced as compared with the transformer winding having the same number of turns, and improvement in workability and reduction in the number of processing steps can be achieved satisfactorily.

  However, in any of the conventional techniques shown in FIGS. 1 to 5 described in Patent Document 1, it is common that dislocations are required for each conductor layer, and the conductor layers shown in FIGS. In the structure, four dislocations are required.

  Further, in the winding structure shown in FIG. 3 described in Patent Document 1, the number of times of dislocation is required two times, and in the winding structure shown in FIG. 4, two times of dislocation are required.

  Further, according to the winding structure shown in FIG. 5 described in Patent Document 1, in addition to the necessity of one dislocation every 18 turns of the transformer winding, the plurality of conductors 52a and 52b are arranged in the winding radial direction. In the winding work of the conductor layers wound side by side, it is necessary to dispose the conductors near the center of each of the conductor layers 52, 54, and 56. Therefore, it is described in Patent Document 1 that the winding work must be temporarily interrupted. 6, and it was difficult to say that the problem of the winding structure shown in FIG. 6 described in Patent Document 1, which is poor workability and increased man-hours, could be solved satisfactorily.

  Therefore, the present invention eliminates the above-mentioned problems as much as possible, and improves the workability in the winding work of the transformer winding and realizes the reduction of the processing man-hours. The purpose is to provide a structure.

Invention of claim 1, wherein, in a multi-cylinder winding having a plurality of conductor layers formed by winding side by side a plurality of conductors in the windings radially by utilizing the circuit equations representing an equivalent circuit of the transformer windings, low-voltage Wire and high voltage winding
After calculating the body's self-inductance and mutual inductance, create an inductance matrix,
By designating the dislocation position of the conductor, this is converted into an impedance matrix, and the impedance
Unbalance of currents flowing through each conductor at the same current flowing through the conductors
As a dislocation position that eliminates the above, a transformer winding is configured by providing one location for one winding.

According to a second aspect of the present invention, in the transformer winding according to the first aspect , the axial height of the conductor layer subjected to the dislocation is configured by the number of turns equal to the axial height of the other conductor layers. did

  According to the first aspect of the present invention, since the dislocation for changing the position of the conductor in the middle of the winding in order to eliminate the imbalance of the current flowing through each conductor may be at one place with respect to one winding, It is very effective because it reduces the number of man-hours required for revolving work, shortens the work period, and can dramatically improve workability.

According to the first aspect of the present invention, in the circuit equation representing the equivalent circuit of the transformer winding, the optimum position can be easily obtained by adjusting the dislocation position so that the impedances of the plurality of conductors are the same. The dislocation position can be specified.

According to the invention of claim 2, the conductor layer subjected to the dislocation with the number of windings in which the height in the axial direction of the conductor layer subjected to the dislocation is the same as the height in the axial direction of the other conductor layer not subjected to the dislocation. For example, it is possible to reliably prevent the occurrence of problems such as an increase in the electric field at the winding end during a withstanding voltage test, and to take special measures such as increasing insulation reinforcement and insulation distance. It can eliminate the need to take and is very effective.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 is a partial side sectional view showing a transformer winding of the present invention. In FIG. 1, 1 is an iron core, 2 is a low-voltage winding wound around the iron core 1, and 3 is concentric with the low-voltage winding 2. A high-voltage winding wound around the iron core 1 is shown.

The low-voltage winding 2 is composed of four conductor layers 2a to 2d, in which a single insulated conductor ₁₅ is wound spirally around the iron core 1 by winding it in a spiral manner in the winding axis direction. On the other hand, the high-voltage winding ₃ is composed of _three conductors l _{1 to} l ₃ arranged in the winding radial direction to form one set, and the one set of conductors in the axial direction of the winding. The main winding 3A comprising six conductor layers 3a to 3f wound concentrically on the outer periphery of the low-voltage winding 2 by being wound spirally around the prescribed number of turns, and the main winding 3A A laminated conductor portion composed of a tap winding 3B provided with two conductor layers 3g and 3h formed by spirally winding a single conductor l ₄ connected to the winding in the axial direction of the winding a prescribed number of times Yes.

FIG. 2 shows an equivalent circuit of the transformer winding shown in FIG. In FIG. 2, L ₅ is the self-inductance of the conductor l ₅ constituting the low-voltage winding 2, R ₅ is the resistance of the conductor l ₅ , and i ₅ is the current flowing through the conductor l ₅ . .

L _{1 to} L ₃ are self-inductances of the _three conductors l _{1 to} l 3 arranged in parallel in the radial direction of the main winding 3A of the high-voltage winding, and R _{1 to} R ₃ are the conductors Resistance of l _{1 to} l ₃ is shown.

i _{1 to} i ₃ are currents flowing through the conductors l _{1 to} l ₃ , and i ₄ is a current flowing through the conductor l ₄ constituting the tap winding 4. L ₄ indicates the self-inductance of the conductor l ₄ , and R ₄ indicates the resistance of the conductor l ₄ .

Also, V is an AC power source for supplying power to the high-voltage winding 3, M ₁₅ is the mutual inductance relative to the conductor l ₅ of the low voltage winding 2 conductors l ₁ of high voltage winding 3. M ₂₅ indicates the mutual inductance of the conductor l ₂ of the high voltage winding 3 with respect to the conductor l ₅ of the low voltage winding 2, and M ₃₅ indicates the mutual inductance of the conductor l ₃ of the high voltage winding ₃ with respect to the conductor l ₅ of the low voltage winding 2. ing.

M ₂₃ is the mutual inductance of the conductor l ₂ of the high voltage winding _{3 with} respect to the conductor l ₃ , M ₁₂ is the mutual inductance of the conductor l ₁ of the high voltage winding 3 with respect to the conductor l ₂ , and M ₁₃ is the high voltage winding 3. The mutual inductance of the conductor l ₁ with respect to the conductor l ₃ is shown.

Furthermore, M ₁₄ mutual inductance for the mutual inductance relative to the conductor l ₄ taps winding 3B conductors l ₁ of high voltage winding 3, M ₂₄ is conductive l ₄ taps winding 3B of conductor l ₂ of the high-voltage winding 3 in and, M ₃₄ represents a mutual inductance with respect to the conductor l ₄ taps winding 3B of conductor l ₃ of the high voltage winding.

Next, the dislocation position of the transformer winding of the present invention will be described. When determining the dislocation position of the transformer winding shown in FIG. 1, the currents flowing in the conductors l _{1 to} l ₅ of the equivalent circuit shown in FIG.

Therefore, if the dislocations of the conductors l _{1 to} l ₃ are performed at positions where the values of the currents i _{1 to} i ₃ flowing in the conductors l _{1 to} l 3 of the high-voltage winding ₃ are the same according to the formula [1], the current i _The imbalance of _{1 to} i ₃ is eliminated, and an increase in load loss can be prevented.

Therefore, when the values of the currents i _{1 to} i ₃ flowing in the conductors l _{1 to} l ₃ are calculated by the above [Equation 1], first, the self-inductance for each turn of each of the conductors l _{1 to} l ₅ and the mutual Calculate the inductance.

  The self and mutual inductances are calculated as the self and mutual inductance of the air-core coil since the inductance is a tightly coupled leakage (leakage) with little influence of the iron core 1. That is, the self inductance L and the mutual inductance M are expressed by the following equations.

In the above [Expression 2], μ ₀ = 4π × 10 ⁻⁷ (H / m), and N represents the number of turns of each of the conductors l _{1 to} l ₅ . D _{0 to} D ₂ and ac represent the dimensions shown in FIG. Here, FIG. 3 (a) represents the size of each conductor of said conductor l ₁ to l _5, D ₀ is wound radius when wound each conductor l ₁ to l ₅ around the iron core 1 Yes, a represents the height of each of the conductors l _{1 to} l ₅ , and b represents the width of each of the conductors l _{1 to} l ₅ .

On the other hand, FIG. 3B is a diagram showing the positional relationship of two of the conductors l _{1 to} l ₅ , and D ₁ and D ₂ are the results when the two conductors are wound around the iron core 1. Each of the winding radii, c indicates the distance between the two conductors.

That is, by inputting the respective dimensions (ac to c, D _{0 to} D ₂ ), the constant μ _0, and the number of turns N of the conductors l _{1 to} l ₅ shown in FIG. The self inductance and the mutual inductance of l _{1 to} l ₅ can be calculated. In the example of the calculation result, an inductance matrix of 1938 × 1938 is created.

  Then, by changing the dislocation position, the elements of the inductance matrix are replaced, and then converted into a 5 × 5 impedance matrix Z as shown below.

Then, the current i ₁ through i ₃ flowing through each conductor l ₁ to l ₃ by the Expression 1 is calculated by the impedance matrix of the converted 5 × 5 is calculated. Therefore, in order to eliminate the imbalance of the current i ₁ through i ₃ flowing to the each conductor l ₁ to l ₃ is unbalance current i ₁ through i ₃ calculated by the Expression 1 is eliminated What is necessary is just to find the position where the impedance between the conductors l _{1 to} l ₃ is the same by adjusting the dislocation position variously.

In this way, the searched dislocation position (for example, the position shown in FIG. 4) is an optimum position where the unbalance of the currents i _{1 to} i ₃ flowing through the conductors l _{1 to} l ₃ is eliminated. It is possible to surely avoid the increase.

  Moreover, since the dislocation position can be limited to one place, it is very effective for improving workability during the winding work of the transformer winding and reducing the number of processing steps.

  Moreover, according to the winding structure of the transformer winding of the present invention, the length of the winding axis direction (the height of the conductor layer) differs from the other conductor layers due to the dislocation of the dislocated conductor layer. For example, in the withstand voltage test, in order to prevent the occurrence of problems such as an increase in the electric field at the end of the winding, in the conductor layer that has been displaced, by reducing the number of turns, The height of the dislocated conductor layer is configured to be the same as that of other conductor layers that are not dislocated.

  As a result, it is not necessary to take special measures such as insulation reinforcement and increase of the insulation distance against the harmful effects caused by the electric field at the winding end being increased, and the structure can be simplified. At the same time, an increase in electromagnetic force generated in the transformer winding can be satisfactorily prevented even when an external short circuit failure occurs.

FIG. 5A is a graph showing calculated values of the currents i _{1 to} i ₃ flowing in the conductors l _{1 to} l ₃ when the conductor is transposed at the position specified as described above (see FIG. 4). Yes, by adjusting the dislocation position, the position where the amplitudes of the currents i _{1 to} i ₃ (sinusoidal waveforms) flowing in the conductors l _{1 to} l ₃ are equal can be specified as the optimum dislocation position.

On the other hand, FIG. 6B shows the current i ₁ that actually flows in each of the conductors l _{1 to} l ₃ when the conductors are transposed at the optimum dislocation position specified by using the formula [1]. It is a graph which shows the result of measuring i ₃ , and is in good agreement with the calculated value shown in FIG. 5 (a). From this, the accuracy, validity and validity of the above-mentioned method for specifying the dislocation position Can be confirmed.

  Next, another embodiment of the present invention will be described with reference to FIGS. The winding structure of the power transformer shown in FIG. 6 is a set of a plurality of low-voltage windings 4 and high-voltage windings 5 arranged in parallel in the radial direction of the conductor windings (three in this embodiment). By winding the low-voltage winding 4 around the iron core 1 in a spiral manner in the winding axis direction, four conductor layers 4a to 4d are formed, and then the high-voltage winding 5 is connected to the low-voltage winding 5 Four conductor layers 5a to 5d are formed on the outside of the wire 4 by being spirally wound with a predetermined number of turns concentrically therewith.

FIG. 7 shows an equivalent circuit of the transformer winding of FIG. In FIG. 7, L4 to L6 are each a self-inductance of the conductor l ₄ to l ₆ constituting the low-voltage winding _4, R 4 ~R ₆ shows the resistance of each conductor l ₄ to l _6.

I _{4 to} i ₆ are currents flowing through the conductors l _{4 to} l ₆ , and L _{1 to} L ₃ are the self-inductances of the conductors l ₁ to l ₃ constituting the high-voltage winding 5, and R _{1 to} R _3. Indicates the resistance of each of the conductors l _{1 to} l ₃ .

i _{1 to} i ₃ are currents flowing through the conductors l _{1 to} l ₃ , and V denotes an AC power supply that supplies power to the high-voltage winding 5. M ₄₆ is a mutual inductance between the conductors l ₄ and l ₆ of the low-voltage winding 4, and M ₅₆ is a mutual inductance between the conductors l ₅ and l ₆ of the low-voltage winding 4.

M ₄₅ is a mutual inductance between the conductors l ₄ and l ₅ of the low voltage winding 4, and M ₁₃ is a mutual inductance between the conductors l ₁ and l ₃ of the high voltage winding 5. M ₂₃ is the mutual inductance between the conductors l ₂ and l ₃ of the high voltage winding 5, and M ₁₂ is the mutual inductance between the conductors l ₁ and l ₂ of the high voltage winding 5.

M ₁₄ , M ₁₅ , and M ₁₆ are mutual inductances between the conductor l ₁ of the high-voltage winding 5 and the conductors l ₄ , l ₅ , and l _{6 of the} low-voltage winding 4, and M ₂₄ , M ₂₅ , M ₂₆ is the mutual inductance between the conductor l ₂ of the high voltage winding 5 and the conductors l ₄ , l ₅ and l _{6 of the} low voltage winding ₄ , and M ₃₄ , M ₃₅ and M ₃₆ are the conductors l of the high voltage winding 5. ₃ and the mutual inductances between the conductors l ₄ , l ₅ and l _{6 of the} low-voltage winding 4 are shown.

Current l ₁ to l ₃ flowing through the conductor l _1, l _2, l ₃ of thus constituted transformer winding, like the transformer winding as shown in FIG. 1, represented by the Expression 1 The transformer winding shown in FIG. 6 is dislocated at a position where the impedances between the conductors l _{1 to} l ₆ are the same, thereby eliminating the unbalance of the current flowing through the conductors l _{1 to} l _6. Thus, an increase in load loss can be prevented.

In the same way as the transformer winding shown in FIG. 1, the method for specifying the dislocation position is first of all of the conductors l _{4 to} l ₆ of the low voltage winding ₄ and the conductors l _{1 to} l ₃ of the high voltage winding 5. Calculate self-inductance and mutual inductance.

The calculation of the self-inductance and the mutual inductance is obtained by the above [Equation 2], where μ ₀ = 4π × 10 ⁻⁷ [H / m] in the above [Equation 2], and N is each conductor l _1. the number of turns of to l _5, also, a to c and D ₀ to D ₂ may be calculated by substituting the dimensions of the conductor l ₁ to l ₅ shown in FIG.

A predetermined inductance matrix is created by substituting the above numerical values into the [Equation 2] and calculating, so that the inductance is determined by designating the dislocation positions of the conductors l _{1 to} l _5. After replacing the elements of the matrix, the inductance matrix is converted into a 6 × 6 impedance matrix Z shown in the following equation.

Therefore, by specifying the [number 4] The impedance matrix Z of the formula are substituted into the Expression 1, the dislocation position current i ₁ through i ₃ flowing through each conductor l ₁ to l ₃ are the same in its impedance between the dislocation position each conductor l ₁ to l ₃ is the same, imbalance of current i ₁ through i ₃ flowing through the conductor l ₁ to l ₃ is the optimum dislocation position is eliminated.

If dislocations of the conductors l _{1 to} l ₆ are performed at the dislocation positions specified in this way (see FIG. 8), naturally, there is no imbalance between the currents i _{1 to} i ₃ flowing in the conductors l _{1 to} l ₃ . It is possible to provide a transformer winding having a winding structure that does not increase loss due to current imbalance.

  Even in this case, the dislocated conductor layer has a problem in that the height in the winding axis direction differs from that of the conductor layer that has not been dislocated. Therefore, the dislocation was performed to eliminate this problem. By reducing the number of turns in the conductor layer, the electric field at the end of the winding becomes high during a withstand voltage test, etc., with the same height in the winding axis direction of the other conductor layers that are not displaced. In the same manner as the winding structure shown in FIG.

  As described above, according to the winding structure of the transformer winding of the present invention, the dislocation position that can eliminate the imbalance of the current flowing through each conductor constituting the transformer winding is equivalent to the equivalent circuit of the transformer winding. Therefore, it is possible to provide a winding structure that can reliably prevent the occurrence of loss, and the dislocation position may be one in one winding. It is possible to satisfactorily improve workability and reduce processing man-hours during turning operations.

  Further, by reducing the number of turns of the dislocated conductor layer compared to the number of turns of the conductor layer that has not been dislocated, the height in the winding axis direction of all the conductor layers is made the same, and the winding in the withstand voltage test is performed. It is possible to reliably prevent an increase in the electric field at the line end and the same magnitude of electromagnetic force at the time of external short circuit failure.

  According to the present invention, one dislocation point (for one winding) that can be easily identified by an equivalent circuit of the transformer winding and that can eliminate the imbalance of the current flowing through the conductors constituting the transformer winding. ), It is possible to provide transformer windings that have been displaced.

It is a fragmentary sectional side view which shows the winding structure of the transformer winding of this invention. It is an equivalent circuit of the transformer winding. It is a longitudinal cross-sectional view which shows the dimension of the conductor which comprises the said transformer winding, and the positional relationship between each conductor. It is a fragmentary sectional side view which shows the dislocation position of the said transformer winding. It is a wave form diagram of the electric current which flows into each conductor at the time of making it transfer at an optimal dislocation position. It is a fragmentary sectional side view which shows the winding structure of the transformer winding in the other Example of this invention. It is an equivalent circuit of the transformer winding in another Example. It is a fragmentary sectional side view which shows the optimal dislocation position of the transformer winding in another Example.

Explanation of symbols

1 core 2,4 low voltage winding 3,5 high voltage winding 2a~2d, 3a~3h, 4a~4d, 5a~5d conductive layer 3A main winding 3B tap winding i ₁ through i ₆ current L ₁ ~L ₆ self-inductance R ₁ to R ₆ resistor V AC power source M mutual inductance

Claims (2)

In multi-cylinder winding having a plurality a plurality of conductor layers wound side by winding radially conductors, transformers using the circuit equations representing the equivalent circuit of the winding, the low voltage winding and high voltage winding of the conductor Self-inductance
After calculating the mutual inductance, create an inductance matrix and specify the dislocation position of the conductor.
This is converted into an impedance matrix, and the impedance matrix is used to convert the derived
The position where the current flowing through the body is the same as the dislocation position where the unbalance of the current flowing through each conductor is eliminated
The transformer winding is characterized by being configured to have one location in one winding.
2. The conductor layer in which the dislocation of the conductor is performed with the number of turns so that the axial height of the conductor layer in which the dislocation has been performed is the same as the axial height of another conductor layer is configured. The described transformer winding.

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