JP6915347B2 - How to adjust the transformer and the winding position of the transformer - Google Patents

Description

The present invention relates to a transformer and a winding position adjusting method of a transformer, and more particularly to a transformer and a winding position adjusting method of a transformer in which an inner winding is arranged inside an outer winding.

A transformer is a device that converts the voltage of AC power by using electromagnetic induction, and includes an iron core that constitutes a magnetic circuit and a winding that constitutes an electric circuit. In the winding of a transformer, when a large current flows in the event of a short circuit, an excessive electromagnetic force is generated and acts in the direction of axially compressing and expanding the winding. When a winding is composed of an outer winding and an inner winding and arranged around an iron core, if the outer winding and the inner winding are in different axial positions, their axial electromagnetic forces are symmetrical. Will not be. Therefore, an upward or downward external force called an external thrust appears in the winding.

The external thrust can be suppressed by making the magnetic center positions of the outer winding and the inner winding the same in the axial direction. For example, when the current density of the winding is constant, if the axial positions of the inner winding and the outer winding are the same, the magnetic center position is also the same, and no external thrust is generated. Since each winding is supported by a support structure such as a coil receiver with an insulator interposed between the upper and lower windings, external thrust is generated if the axial position of each winding is made the same by dimensional control and dimensional adjustment of the insulator. Will not be.

However, even if an attempt is made to suppress the external thrust as described above, it is difficult to completely control and grasp the dimensions of the insulation due to reasons such as the insulation used shrinking due to a load or moisture in the manufacture of a transformer. There is a problem that it is. Further, since the inner winding is arranged inside the outer winding, it is difficult to visually recognize the inner winding from the outside after assembly, and the relative position of the outer winding and the inner winding in the axial direction can be grasped. There is also the problem that it becomes difficult.

Here, as disclosed in Patent Document 1, a method is known in which a winding is divided into upper and lower parts, and an upper winding and a lower winding are configured as a parallel circuit. In this method, the current is distributed according to the magnetic flux interlinking between the upper winding and the lower winding due to the relationship between the magnetic flux density distribution and the current. be able to.

Japanese Unexamined Patent Publication No. 57-109313

However, in the method of Patent Document 1, when the magnetic flux density is symmetrical at the center in the axial direction, the external thrust becomes almost zero, but in the actual winding configuration, the magnetic flux density becomes high due to the convenience of insulation, tap extraction, etc. It may be asymmetric. In this case, the magnetic center positions of the outer winding and the inner winding are not the same, and an external thrust is generated. Therefore, it is necessary to provide a winding support structure capable of withstanding external thrust, and there is a problem that the dimensions of the structure and the housing of the transformer become large and the cost of the transformer as a whole increases. ..

By the way, in a winding support structure, it is indispensable to stably support the weight of the winding itself for a long period of time, so that the structure that supports the winding from below has high rigidity and strength. Become. In other words, the structure that supports the winding from above has relatively lower rigidity and strength, and can be simplified and reduced in weight for reasons such as cost reduction. However, in consideration of the durability against the external thrust described above, it is required to increase the rigidity and strength of the upper support structure, and there is a problem that the upper support structure becomes heavier and more complicated.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a transformer and a method for adjusting the winding position of the transformer, which can simplify the structure supporting the winding. Make one.

One aspect of the transformer in the present invention is a transformer having an inner winding and an outer winding concentrically arranged around an iron core extending in the vertical direction, and a support portion for supporting the outer winding from the axial direction. The outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit, and the support portion is the outer side with respect to the center position of the inner winding in the axial direction. wherein the center position of the winding to support the outer winding to be located below side. Further, the transformer of one aspect of the present invention is a transformer having an inner winding and an outer winding concentrically arranged around an iron core extending in the vertical direction, and a support portion for supporting the outer winding from the axial direction. In the instrument, the outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit, and the support portion adjusts the position of the outer winding in the axial direction. The outer winding is supported so that the center position of the outer winding is aligned with or below the center position of the inner winding in the axial direction. It is characterized in that the position of the outer winding in the axial direction can be adjusted according to the current values of the upper coil group and the lower coil group.

According to such a configuration, the external thrust generated in the outer winding can be stably maintained downward. As a result, the external thrust applied to the support structure above the winding can be suppressed or eliminated, and the support structure above can be simplified and the manufacturing cost can be reduced. Here, in general, the support structure below the winding adopts a robust support structure in advance so as to support the weight of the winding itself, and also supports using the support force from the ground or the like as the installation surface. The structure is adopted. Therefore, even if the external thrust is allowed to be applied to the support structure below the winding, the outer winding is stably supported without the need for reinforcement for the external thrust or by adding a slight reinforcement. be able to. As a result, it is possible to suppress the complexity and weight increase of the lower support structure, and it is also possible to suppress the manufacturing cost.

One aspect of the transformer winding position adjusting method in the present invention is a winding position adjusting method for a transformer having an inner winding and an outer winding concentrically arranged around an iron core extending in the vertical direction. The outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit, and a measurement step for measuring the current value of each of the upper coil group and the lower coil group, and the measurement step. The ratio of the current values of the upper coil group and the lower coil group measured in 1 is calculated, and the deviation direction of the center position of the outer winding with respect to the center position of the inner winding in the axial direction is calculated using the ratio. The adjustment step of adjusting the center position of the outer winding to coincide with or lower than the center position of the inner winding in the axial direction according to the calculation step to be performed and the deviation direction calculated in the calculation step. It is characterized by having.

According to such a method, since the axial position of the outer winding is adjusted as described above, the external thrust of the outer winding can be reduced. As a result, the support structure of the winding can be simplified and downsized, and an inexpensive transformer can be provided.

According to the present invention, at least the external thrust applied to the supporting structure above the winding can be suppressed, and the structure supporting the winding can be simplified.

It is sectional drawing which shows typically the schematic structure of the transformer which concerns on embodiment. It is a circuit block diagram of the said transformer. It is explanatory cross-sectional view of the state which the position in the axial direction of the outer winding is deviated. It is a graph which shows an example of the relationship between the axial deviation amount of an outer winding, and an external thrust. It is a graph which shows an example of the relationship between the axial deviation amount of the outer winding, and the ratio of the current values of the upper coil group and the lower coil group.

Hereinafter, the transformer according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following, a case where the transformer according to the present invention is applied to an oil-immersed transformer will be described. However, the application target of the present invention is not limited to the oil-immersed transformer, and can be changed as appropriate. For example, it can be applied to a dry transformer or a gas isolation transformer.

FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a transformer according to an embodiment. As shown in FIG. 1, the transformer 1 includes an iron core 2 extending in the vertical direction, an inner winding 3 and an outer winding 4 wound around the iron core 2, and an inner winding 3 and an outer winding. It is provided with a support portion 5 that supports the wire 4 from the axial direction. The transformer 1 of the present embodiment is an oil-filled transformer in which a tank (not shown) is filled with insulating oil, and the iron core 2, each winding 3, 4 and the support portion 5 are impregnated with insulating oil in the tank. It is in a state.

The inner winding 3 and the outer winding 4 are arranged concentrically with the iron core 2 as the axial position. The inner winding 3 and the outer winding 4 are formed by coating a conductor such as copper or aluminum with a sheet-shaped insulating material and then winding a plurality of loops in a coil shape. Here, the axial direction in each of the windings 3 and 4 is the direction in which the central axial position of each of the windings 3 and 4 having a cylindrical shape extends, and the axial direction in each of the windings 3 and 4 in FIG. 1 is the vertical direction. The outer winding 4 is divided in the axial direction and is formed so as to include the upper coil group 4a and the lower coil group 4b. Here, the center position C3 of the inner winding 3 and the center position C4 of the outer winding 4 are illustrated by a alternate long and short dash line, and these center positions C3 and C4 are dimensional in the axial direction of the inner winding 3 and the outer winding 4. It becomes the center position in.

The support portion 5 includes an upper support member 5a provided above the inner winding 3 and the outer winding 4, and a lower support member 5b provided below. Although the specific shapes of the support members 5a and 5b are not shown, they are composed of a frame member or the like having a substantially constant cross section. The cross-sectional shape is not particularly limited, but is formed in a U-shape or a B-shape, for example.

In the support portion 5, the inner upper insulating material 6a is arranged between the upper supporting member 5a and the inner winding 3, and the inner lower insulating material 6b is arranged between the lower supporting member 5b and the inner winding 3. ing. Further, an outer upper insulator 7a is arranged between the upper support member 5a and the outer winding 4, and an outer lower insulator 7b is arranged between the lower support member 5b and the outer winding 4. The total thickness of each of the insulators 6a, 6b, 7a, and 7b can be changed by preparing a plurality of types of thicknesses and selectively using them, or by changing the number of intervening insulators.

By changing the total thickness in this way, the axial positions of the windings 3 and 4 can be adjusted between the support members 5a and 5b, and the outer upper insulator that adjusts the axial position of the outer winding 4 The position adjusting portion is composed of 7a and the outer lower insulating material 7b. In addition to these insulators 7a and 7b, a bolt or the like screwed to the support members 5a and 5b is provided as a position adjusting portion, and the bolt is rotated to move forward and backward in the axial direction to move the outer winding 4 in the axial direction. The position may be adjusted.

FIG. 2 is a circuit configuration diagram of the transformer. As shown in FIG. 2, in the outer winding 4, the winding directions are opposite in the upper coil group 4a and the lower coil group 4b, and the upper coil group 4a and the upper coil group 4a and the central portion in the axial direction of the outer winding 4 The lower coil group 4b is connected. As a result, the connecting portion of the outer winding 4 at the central portion in the axial direction becomes one terminal, and both ends of the outer winding 4 in the axial direction become another terminal. In the present embodiment, currents Ia and Ib in the directions indicated by arrows flow from the connection portion at the central portion in the axial direction toward both ends in the axial direction, and the upper coil group 4a and the lower coil group 4b are configured as a parallel circuit. NS. Since the winding directions of the upper coil group 4a and the lower coil group 4b are opposite to each other, the induced voltages do not cancel each other out.

Current measuring means 8a and 8b including an ammeter and a sensor for measuring the respective current values Ia and Ib are connected to the upper coil group 4a and the lower coil group 4b. The current measuring means 8a and 8b may be removed after the position adjustment of the outer winding 4 described later is completed.

Subsequently, a case where the position of the outer winding 4 in the axial direction is deviated will be described with reference to FIG. FIG. 3 is a cross-sectional view for explanation of a state in which the positions of the outer windings in the axial direction are deviated. In FIG. 3, it is assumed that the center position C4 of the outer winding 4 in the axial direction is displaced upward with respect to the center position C3 of the inner winding 3 in the axial direction. In this case, among the elements of the axial electromagnetic force acting on the outer winding 4, the radial component of the outer winding 4 acts on the magnetic field from the inner winding 3. This magnetic field is in the direction indicated by the arrow in FIG. 3, and a radial magnetic field Ba is applied to the upper coil group 4a and a radial magnetic field Bb is applied to the lower coil group 4b. The radial magnetic field generated by the inner winding 3 becomes maximum at both ends in the axial direction of the inner winding 3, and gradually decreases toward the central portion in the axial direction. Therefore, when the axial position of the outer winding 4 shifts upward, the relationship between the magnitudes of the magnetic fields Ba and Bb becomes Ba> Bb. Correspondingly, the relationship between the currents Ia and Ib flowing in the upper coil group 4a and the lower coil group 4b is Ia <Ib. Ideally, the axial force of the upper coil group 4a and the axial force of the lower coil group 4b are the same, and the external thrust of the outer winding 4 is zero.

However, in reality, the external thrust may not become zero due to factors such as the conductor cross-sectional dimensions of the windings 3 and 4, the winding cross-sectional dimensions, and the leakage flux. Therefore, the present inventor made measurements to verify such external thrust. In this measurement, a measuring transformer having a partially simplified configuration was manufactured with respect to the transformer 1 of the above-described embodiment. The main specifications of the measuring transformer are the height of the inner winding 850 mm, the height of the outer winding 810 mm, the thickness of each winding 51 mm, the inner diameter of the inner winding φ538 mm, the inner diameter of the outer winding φ760 mm, and each winding. The number of turns was 82, and it was an air-core transformer. The outer winding was divided into two at the central portion in the axial direction to form an upper coil group and a lower coil group, and the external thrusts when they were connected in parallel and when they were connected in series were measured. The results are shown in the graph of FIG.

FIG. 4 is a graph showing an example of the relationship between the amount of axial deviation of the outer winding and the external thrust. Looking at the graph of FIG. 4, when there is an axial deviation in the outer winding, the parallel connection has a smaller external thrust than the series connection, but it is not zero. Therefore, in order to further reduce the external thrust, it can be understood that it is necessary to reduce the amount of axial deviation of the outer winding.

Further, the present inventor measured the currents Ia and Ib flowing in the upper coil group and the lower coil group with a measuring transformer, and analytically calculated the relationship between the ratio and the amount of axial deviation of the outer winding. .. Also in this calculation, it is assumed that the center position of the outer winding is shifted upward with respect to the center position of the inner winding in the axial direction in the measuring transformer. The results are shown in the graph of FIG.

FIG. 5 is a graph showing an example of the relationship between the amount of axial deviation of the outer winding and the ratio of the current values of the upper coil group and the lower coil group. Here, the ratio of the current values is obtained by dividing the value of the current Ia of the upper coil group by the value of the current Ib of the lower coil group to obtain a percentage. As shown in the graph of FIG. 5, as the amount of displacement of the outer winding in the axial direction increases, the ratio of the current values (current Ia / current Ib) decreases due to the above-mentioned radial magnetic field distribution. There is. This relationship is common not only to the measuring transformer but also to the transformer 1 in which the windings 3 and 4 are arranged as in the above embodiment. Since the relationship of FIG. 5 can be obtained analytically, the currents Ia and Ib flowing in the upper coil group 4a and the lower coil group 4b in the above embodiment are measured, and the ratio thereof is obtained and the graph of FIG. 5 is referred to. Therefore, the amount of axial deviation of the outer winding 4 can be obtained. Although omitted in the graph of FIG. 5, when the ratio of the current values (current Ia / current Ib) is larger than 100%, it is understood that the deviation amount is negative, that is, the outer winding 4 is displaced downward. It is possible, and the deviation direction of the outer winding 4 can also be obtained. When the ratio of the current values (current Ia / current Ib) is smaller than 100%, it can be understood that the deviation amount is positive, that is, the outer winding 4 is displaced upward.

In this way, from the ratio of the current values of the upper coil group and the lower coil group, the deviation amount and the deviation direction of the center position C4 of the outer winding 4 with respect to the center position C3 of the inner winding 3 can be obtained in the axial direction. The position of the outer winding 4 can be adjusted. Hereinafter, a method of adjusting the position of the outer winding 4 will be described with reference to FIG.

First, a predetermined power is supplied to the transformer 1, and the current values Ia and Ib of the upper coil group 4a and the lower coil group 4b are measured by the current measuring means 8a and 8b (see FIG. 2) (measurement step). .. After that, the ratio of the measured current values Ia and Ib (current Ia / current Ib) is calculated, and the outer winding 4 with respect to the center position C3 of the inner winding 3 in the axial direction is used with the calculated ratio and the graph of FIG. The deviation direction and the deviation amount of the center position C4 of the above are calculated (calculation step). To give a specific example, assuming that the ratio of current Ia / current Ib is 96%, the axial center position C4 of the outer winding 4 is the axial center position of the inner winding 3 from the relationship of the graph of FIG. It can be calculated that it is 9 mm above C3.

After obtaining the deviation amount of the outer winding 4 as described above, the adjustment amount of the outer winding 4 is determined according to the deviation amount, and the outer winding is relative to the center position C3 of the inner winding 3 in the axial direction. Adjust so that the center position C4 of 4 is located at the same position or below (adjustment step). For example, when the outer winding 4 is 9 mm above as described above, the outer winding 4 may be lowered by 9 mm or more as an adjustment amount, so that the total thickness of the outer lower insulating material 7b is reduced by 9 mm or more to make it thinner. Therefore, the total thickness of the outer upper insulating material 7a is increased. As a result, the center position C4 of the outer winding 4 coincides with or downwards with respect to the center position C3 of the inner winding 3 via the respective insulators 6a, 6b, 7a, 7b, the upper support member 5a, and the lower support member 5b. Each winding 3, 4 is supported so that it is located.

By implementing the above position adjusting method, when the center position C4 of the outer winding 4 coincides with the center position C3 of the inner winding 3 in the axial direction, the external thrust acting on the outer winding 4 becomes almost zero. More preferably, when the magnetic center position of the outer winding 4 coincides with the magnetic center position of the inner winding 3 in the axial direction, the external thrust of the outer winding 4 can be further brought closer to zero. By suppressing the external thrust in this way, the load applied to the upper support member 5a and the lower support member 5b can be reduced, the structures thereof can be simplified and the weight can be reduced, and the manufacturing cost can be reduced. can.

Further, by implementing the above position adjusting method, as shown in FIG. 1, when the center position C4 of the outer winding 4 is supported so as to be located below the center position C3 of the inner winding 3 in the axial direction, the outer winding 3 is supported. The external thrust generated in the winding 4 can be kept downward. As a result, the external thrust applied from the outer winding 4 to the upper support member 5a can be suppressed or eliminated, and the structure of the upper support member 5a can be simplified and reduced in weight.

Here, when the center position C4 of the outer winding 4 is lower than the center position C3 of the inner winding 3, the external thrust applied from the outer winding 4 to the lower support member 5b is larger than when they match. Become. However, the lower support member 5b is generally designed to have durability, strength, and the like that can support the windings 3 and 4 from below even when the transformer 1 is transported or used for a long period of time. Further, although not shown, the lower support member 5b often adopts a structure in which the supporting force from the ground or the like, which is the installation surface, directly acts to support the windings 3 and 4. Therefore, even if an external thrust is applied to the lower support member 5b, it is possible to maintain good support of the outer winding 4 by eliminating the need for reinforcement of the lower support member 5b or by adding a slight reinforcement. can. As a result, it is possible to avoid complicating the structure of the lower support member 5b and increasing the weight, and it is possible to simplify the structure of the entire support portion 5 together with the upper support member 5a.

Even if the magnetic center position of the outer winding 4 is supported so as to be located below the magnetic center position of the inner winding 3 in the axial direction, the same action and effect can be obtained.

Further, when the center position C4 of the outer winding 4 is adjusted downward from the center position C3 of the inner winding 3, the magnitude of the external thrust is assumed to be due to various reasons such as aging and tolerance of the windings 3 and 4. Is changed, the direction of the external thrust from the outer winding 4 does not change, and it becomes easy to maintain the direction downward. As a result, the structure of the upper support member 5a can be designed under the condition that no external thrust is applied, and the structure of the upper support member 5a can be simplified and reduced in weight.

Further, the adjustment of the axial positions of the windings 3 and 4 can be handled by changing the thickness of the intervening insulators 6a, 6b, 7a, 7b, thereby shortening the working time and reducing the work load. Can be done.

Further, the currents Ia and Ib flowing through the upper coil group 4a and the lower coil group 4b are measured, and the axial deviation amount and the deviation direction of the outer winding 4 are determined by the ratio thereof, and the position adjustment is performed. It is possible to omit measuring the actual position of the wire 4. As a result, even if the windings 3 and 4 are arranged in the tank or the housing and are difficult to see, or if the windings 3 and 4 become large and the position measurement becomes difficult, the position of the outer winding 4 is adjusted. The amount can be easily grasped.

The embodiments of the present invention are not limited to the above embodiments, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of technology or another technology derived from it, it may be carried out by using that method. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

Further, in the present embodiment, the configuration in which the present invention is applied to a transformer has been described, but it is also possible to apply the present invention to other electric power stationary devices as long as the above-mentioned effects can be obtained.

The contents illustrated in each of the above embodiments are schematically shown for explanation, and if the above-mentioned effects can be exhibited, the support portion 5 and the insulators 6a, 6b, 7a, and 7b are used. The configuration of the position adjusting unit may be changed. For example, in the support portion 5, both the windings 3 and 4 are supported by the upper support member 5a and the lower support member 5b, but a support portion may be provided for each of the windings 3 and 4. Further, when it is possible to adjust the position of the outer winding 4 by using bolts or the like from above and below instead of the insulators 6a, 6b, 7a, 7b, the outer winding 4 is located at the center position C3 of the inner winding 3. When the center position C4 is above, that is, when the ratio of the current values (current Ia / current Ib) is less than 100%, adjustments such as increasing the bolt tightening amount from the upper portion may be performed. In this case, it is possible to prevent an external thrust from being applied to the upper support member 5a by a simple method without creating a graph as shown in FIG. 5 in advance.

1 Transformer 2 Iron core 3 Inner winding 4 Outer winding 4a Upper coil group 4b Lower coil group 5 Support part 7a Outer upper upper insulation (position adjustment part)
7b Outer lower insulation (position adjustment part)
8a Current measuring means 8b Current measuring means C3 Center position C4 Center position

Claims (7)

With the inner and outer windings arranged concentrically around the vertically extending iron core,
A transformer having a support portion that supports the outer winding from the axial direction.
The outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit.
The support portion is a transformer that supports the outer winding so that the center position of the outer winding is located below the center position of the inner winding in the axial direction. The support includes a position adjuster for adjusting the position of the outer winding in the axial direction.
The first aspect of the present invention, wherein the position adjusting unit is provided so that the axial position of the outer winding can be adjusted according to the current values of the upper coil group and the lower coil group, respectively. Transformer. With the inner and outer windings arranged concentrically around the vertically extending iron core,
A transformer having a support portion that supports the outer winding from the axial direction.
The outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit.
The support portion includes a position adjusting portion for adjusting the position of the outer winding in the axial direction, and the center position of the outer winding coincides with or downwards with respect to the center position of the inner winding in the axial direction. Support the outer winding so that it is located
The position adjusting unit is a transformer characterized in that the position of the outer winding in the axial direction can be adjusted according to the current values of the upper coil group and the lower coil group. The claim is characterized in that the support portion supports the outer winding so that the magnetic center position of the outer winding coincides with or is located below the magnetic center position of the inner winding in the axial direction. The transformer according to any one of 1 to 3. A current measuring means for measuring the current value of each of the upper coil group and the lower coil group is included.
The position adjusting unit adjusts the axial position of the outer winding according to the ratio of the current value of the upper coil group to the current value of the lower coil group measured by the current measuring means. The transformer according to claim 2 or 3. A method of adjusting the winding position of a transformer having an inner winding and an outer winding concentrically arranged around an iron core extending in the vertical direction.
The outer winding includes an upper coil group and a lower coil group which are divided in the axial direction to form a parallel circuit.
A measurement step for measuring the current values of the upper coil group and the lower coil group, respectively.
The ratio of the current values of the upper coil group and the lower coil group measured in the measurement step is calculated, and the ratio is used to shift the center position of the outer winding with respect to the center position of the inner winding in the axial direction. Calculation steps to calculate the direction and
It is provided with an adjustment step for adjusting the center position of the outer winding to coincide with or lower than the center position of the inner winding in the axial direction according to the deviation direction calculated in the calculation step. A method of adjusting the winding position of a transformer, which is characterized by this. In the calculation step, the deviation amount of the center position of the outer winding with respect to the center position of the inner winding in the axial direction is further calculated, and in the adjustment step, the adjustment amount of the outer winding is adjusted according to the deviation amount. The method for adjusting a winding position of a transformer according to claim 6, wherein the method is determined.

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