JPH0419992Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention is directed to a transformer for a 12-phase rectifier, particularly for a rectifier with a phase shift winding that can be applied to a 24-phase rectifier by using two such transformers. Concerning the winding structure of transformers.

[Prior art and its problems]

For a 12-phase rectifier transformer, there is an electrical angle of 30° between each phase terminal of two sets of DC side windings connected in a double star shape.
In order to obtain a 24-phase output voltage using two 12-phase rectifier transformers, a phase difference of 15 degrees electrical angle is required between the DC side windings of the two transformers. Requires phase difference.

FIG. 3 is a wiring diagram showing a conventional transformer winding for a 12-phase rectifier, in which a DC side winding 3 consisting of star-connected windings 3A and 3B, which are supposed to be double star-connected; In addition, the main winding 5A is triangularly connected, and 4U, 4V, 4W are connected to each phase line end U, V, W side.
A first winding set 1 includes an AC side winding 5 consisting of a phase shift winding 4, a DC side winding 3 formed in the same manner as described above, and a star-connected main winding 7.
A and a second winding set 2 having a phase shift winding 6 consisting of 6U, 6V, and 6W on the line end side are wound around the legs of a two-story iron core having an intermediate yoke. At the same time, a triangularly connected stable winding 8 is provided in the second winding set 2 which does not have a triangularly connected winding, so that the zero-sequence magnetic flux generated in the iron core is controlled by the circulating current flowing through the stable winding 8. It is configured to cancel. In addition, the AC side windings 5 and 7 of the first and second winding sets 1 and 2 are phase shift windings 4 so as to rotate the induced voltage vector by 7.5 electrical degrees in the same direction, either clockwise or counterclockwise. , 6, the main windings 5A and 5B are triangularly connected and star-shapedly connected between the output voltages of the DC side windings of the first and second winding sets. As a result, a phase difference of 30 degrees electrical angle is maintained, and by setting the phase shift angles of the two transformers to rotate 7.5 degrees in opposite directions, the DC windings of the two transformers are Electrical angle 15° between lines
It is possible to obtain a phase difference of .

FIG. 4 is a schematic side sectional view of the winding portion of the transformer connected as described above, and the upper leg 9A of the two-story core 9 having the intermediate yoke 9C has a first winding set. 1, a second winding set 2 is wound around each of the lower leg parts 9B, and the magnetic flux generated in the iron core by both winding sets passes through the intermediate yoke 9C in opposite directions to the core. In addition to being lighter in weight, it also has the advantage of simplifying the tank, radiator, conservator, etc. compared to the case where both winding sets are formed separately into two transformers. By the way, since only the second winding set 2 is provided with the stable winding 8, the space factor of the windings in the core windows 10A and 10B, which are formed to have approximately the same dimensions, is higher than that of the second winding set. high on the 2nd side;
A low unbalance occurs on the first winding set 1 side, e.g. the required insulation distance between the main winding and the DC side winding.
There is a drawback that an insulating space d1, which is much larger than d2, is generated on the first winding group side compared to d2, resulting in an extremely uneconomical configuration.

[Purpose of invention]

This idea was created in view of the above-mentioned situation.
It is an object of the present invention to provide a rectifier transformer with a phase shift winding which is lightweight and compact by eliminating a stabilizing winding by improving the alternating current side winding, thereby eliminating wasted insulation distance.

[Key points of the idea]

In the present invention, the AC side winding of the second winding set in the prior art is formed of a triangularly connected main winding with a small number of turns and a phase shift winding with a large number of turns, and the phase shift angle 22.5° in the opposite direction of rotation from that of the first winding set.
By configuring the configuration to set a deep phase angle, the triangularly connected main winding also functions as a stable winding, eliminating the need for a stable winding, and the second winding set is connected to the first winding. By reducing the size of the transformer to the same extent as the two winding sets, the transformer can be made smaller and lighter, and a phase difference of 30° can be ensured between the DC side winding sets of both winding sets. By setting the phase shift angles in opposite rotation directions between the two, it is possible to secure a phase difference of 15° necessary for 24-phase rectification.

[Example of idea]

The present invention will be explained below based on one embodiment.

FIG. 1 is a schematic connection diagram of the winding portion of a transformer according to an embodiment of the present invention, and the same components as in the conventional device are given the same reference numerals and detailed explanations are omitted. In the figure, the AC winding 17 of the second winding set 12 includes a triangularly connected main winding 17A, and phase shift windings 16U, 16V provided at the ends of each line of U, V, and W.
It is composed of a phase shift winding 16 of 16W. By the way, since the main windings 5A and 17A of the AC side windings 5 and 17 of the first and second winding sets are both triangularly connected, the first and second windings necessary for 12-phase rectification are Phase difference between sets 11 and 12
It becomes necessary to implement the 30° shift by means of phase shift windings 4 and 16.

The phase shift angle Θ of the AC side windings 5 and 17 configured as shown in FIG.
Equivalent number of turns between each phase (for example, between U-V phases)
When Nt, it can be expressed by the following formula.

Θ=sin ^-1 (√3/2×Nh/Nt) Therefore, in order to ensure a phase difference of 30° between the winding sets, Θ=+7 for the AC side winding 5 as in the conventional device. .5°, and for the AC side winding 17, the number of turns Nh of the phase shift winding relative to the equivalent number of turns Nt is increased to Θ = 22.5°, and the main winding 5A,
The connection position of each phase shift winding for 17A is 4U,
By making 4V, 4W and 16U, 16V, 16W in opposite positions, the phase shift angle Θ in the AC side winding 17 is set to -22.5°. To explain this state by regarding the connection diagram in Figure 1 as equivalent to a vector diagram, for the power supply voltage vector triangles U, V, and W shown by chain lines in Figure 1, the AC side winding 5 has the main The vector triangle of the winding is counterclockwise (positive)
The AC side winding 17 is rotated 22.5 degrees clockwise (negative direction), and as a result, there is a gap between the DC side windings of the first and second winding sets 11 and 12. A phase difference of 30° required for 12-phase rectification can be obtained. In addition, the transformer 2 configured as described above
When attempting to perform 24-phase rectification using a transformer, the phase shift angle Θ of the other transformer is set to Θ on the AC side winding 5 side.
= -7.5°, Θ = + on the AC side winding 17 side
By configuring the phase shift angle to be 22.5°, which is opposite to that shown in Fig. 1, it is possible to obtain a phase difference of 15° between the two transformers, which is necessary for 24-phase rectification.

FIG. 2 is a cross-sectional view of the winding side of the main part of the transformer of the above-described embodiment, and since the stable winding of the second winding set 2 is no longer necessary, Groups 11 and 12 both include phase shift windings 4 and 16, and main winding 5.
A, 17A, a three-winding configuration consisting of a DC side winding 3, and a phase shift winding 1 of the second winding set.
6 is larger than that of the main winding 17A, so the main winding 17A is opposite to the first winding group.
By arranging the phase shift winding 16 on the side of the core leg 9B and the phase shift winding 16 on the outside thereof, both winding sets having approximately the same number of equivalent turns can be formed to have approximately the same size. Therefore, the iron core window portions 10A and 10B created by providing a stable winding in the prior art
This makes it possible to almost completely eliminate the increase in the dimensions of the transformer and the weight of the windings, iron core, insulation materials, etc., making it possible to make the transformer smaller and lighter.

Conventionally, the maximum phase shift angle Θ in a rectifier transformer with a phase shift winding is 15 degrees in electrical angle, and if a larger phase shift angle is required, the star connection should be changed to a triangular connection.
Alternatively, by switching from a triangular connection to a star connection, measures are taken to compress the phase shift angle Θ as much as possible by utilizing the 30° phase difference between both windings, and as a result, a stable winding is created. There was no great interest in whether something was possible or not. The present invention was achieved by breaking away from such conventional design concepts, and achieved great rationalization results by changing the way of thinking.

[Effect of idea]

As mentioned above, the present invention consists of a main winding and a phase shift winding that are both triangularly connected in the AC side winding of a 12-phase rectifier transformer having first and second winding sets, and The phase shift angle on the first winding group side was 7.5°, and the phase shift angle on the second winding group side was 22.5°, which is the opposite direction to the first winding group side. As a result, the weight of the stable winding can be reduced by the triangularly connected main winding serving as the stable winding required in the conventional technology, and by providing the stable winding on one side of the winding group. The winding, core, and insulation are significantly smaller, including wasted insulation space on the other side of the winding assembly.
A lightweight rectifier transformer with a phase shift winding can be economically advantageously provided. In addition, the phase difference of 30° between both winding sets required for 12-phase rectification can be obtained by using phase shift angles of +7.5° and -22.5° that are opposite to each other.
By making the phase shift angles of the two transformers opposite to each other, the phase difference of 15° between the two transformers required for 24-phase rectification is reduced and the phase shift winding is reduced in size and weight. It can be obtained by using a rectifier transformer.

[Brief explanation of the drawing]

Fig. 1 is a winding wiring diagram showing a transformer according to an embodiment of the present invention, Fig. 2 is a schematic side sectional view of the main parts in the embodiment, Fig. 3 is a wiring diagram showing a conventional technique, and Fig. 4 is a conventional one. It is a schematic side sectional view of the important part in a technique. 1, 11...first winding set, 2,12...second
Winding set, 3...DC side winding, 4, 6, 16...
Phase shift winding, 5, 7... AC side winding (phase shift angle +
7.5°), 5A, 17A...Main winding (triangular connection), 7
A... Main winding (star connection), 8... Stable winding, 9
...Two-story iron core, 9A, 9B...Legs, 9C...
Intermediate yoke, 17... AC side winding (phase shift angle -
22.5°).

Claims (1)

[Scope of utility model registration request] The first and second windings consist of an AC side winding consisting of a main winding and a phase shift winding, and a DC winding connected in a double star shape.
The upper and lower main legs of a two-story core having a common intermediate yoke are
The winding set consists of a triangularly connected main winding and a phase shift winding formed to maintain a phase shift angle of 7.5 electrical degrees with respect to the main winding. the first having an AC side winding;
A winding set of
A transformer for a rectifier with a phase shift winding, characterized in that the second winding set includes an AC side winding made of a phase shift winding formed to maintain a phase shift angle of 22.5 degrees. vessel.