JPH02192705A - Iron core type transformer - Google Patents

Abstract

PURPOSE:To easily manufacture a transformer of specified impedance by a method wherein a reactor core passing only leakage flux to a secondary winding is provided making gaps from a transformer iron core and then this reactor core is controlled. CONSTITUTION:A space to insert a reactor core 6 into a transformer iron core 1 is alloted to the title transformer as well as gaps 8 are made between the iron core 1 and a secondary winding 3. Then, cores 6a, 6b in required sectional spaces selected conforming to specified impedance are inserted covering the winding 3 while another gap 7 is adjusted for fixation. Accordingly, the leakage flux 4 in a primary winding 2 passes through the gap between outer space and the core 6 while the flux 4 is restrained from increasing so that the voltage induced in the winding 3 may be kept constant to control the leakage flux 5 passing through the core 6 at specified impedance by the gap 7. Through these procedures, a transformer at specified impedance can be easily manufactured by controlling the reactor 6 provided on the secondary winding 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a core type transformer that can adjust the leakage impedance of a secondary winding and can also be used as a reactor.

[Prior art] In conventional transformers, for example, the general 3 type shown in Fig.
As shown in one leg of a three-leg phase transformer, a primary winding 2 and three secondary windings (wound with the primary winding outside) are wound around each leg of a three-leg core 1. Therefore, the leakage magnetic flux 4 of the primary winding 2 passes between the windings and the outside of the primary winding, and the leakage magnetic flux 5 of the secondary winding 3 passes between the windings and through the core legs. Therefore, the leakage flux 4 of the primary winding is smaller than the leakage flux 5 of the secondary winding because the air gap is longer, but each leakage flux is The design values are selected, and the dimensions of each part are determined according to the design values.In addition, after the transformer is assembled, a core is inserted between the windings to reduce the magnetic resistance between the windings. It is known that the impedance changes depending on the

[Problems to be Solved by the Present Invention] As described above, the impedance of the transformer is selected at the time of design, and if it is desired to change it after design,
It is necessary to change the dimensions of each part and recreate it. Note that the impedance can be increased by inserting a core between the windings, but such a change in impedance also affects the leakage flux of both the primary and secondary windings, resulting in a decrease in impedance. The adjustment is qualitatively and quantitatively insufficient. Furthermore, if the primary winding 2 in FIG. 6 is placed inside and the secondary winding 3 is placed outside, the leakage flux of the primary winding increases, the exciting current increases, and the device becomes unusable.

In view of these points, the present invention makes it possible to adjust the leakage flux of the secondary winding without increasing the leakage flux of the primary winding, thereby adjusting the transformer impedance.

[Means for solving the problem] Therefore, by providing a closed-loop reactor core so as to link only to the secondary winding wound around the core leg, and changing its material, cross-sectional area, and gap length, two The leakage impedance of the secondary winding is changed, and if necessary, a tap winding is provided in the reactor core and connected in series with the secondary winding.

[Function] Therefore, even if the voltage ratio is the same, it is easy to create a transformer with the desired impedance by adjusting the reactor core provided in the secondary winding without increasing the leakage flux of the primary winding. can be obtained.

[Example] Figures 1 and 2 show examples of the present invention.
is the transformer core, 2 is the primary winding, 3 is the secondary winding, and 6 is the reactor core that surrounds the secondary winding. The cut cores 6a and 6b are formed into two halves (four pieces in the figure), and are inserted from both upper and lower sides of the secondary winding 3 wound around the core legs.
A reactor gap 7 is provided at the joint between a and 6b, and they are fixed by adhesive or other suitable fixing method. 8 is a gap provided to prevent the magnetic flux passing through the reactor core 6 from flowing into the transformer core.

The size and number of turns of the transformer core 1, primary winding 2, and secondary winding 3 are designed in the same way as before, depending on the desired voltage ratio and capacity, but the Sufficient space and clearance between the transformer core 1 and the secondary winding 3 are provided.

Cut cores 6a, eb with the necessary cross-sectional area according to the required impedance are added to the transformer assembled in this way.
are selected and inserted into the secondary winding 3 from above and below, and the reactor gap 7 is adjusted and fixed to obtain the desired impedance. This reactor gap 7 may sandwich a nonmagnetic material.

Therefore, the leakage magnetic flux 4 of the primary winding 2 passes between the outside space and the reactor core 6, and its increase is suppressed, the voltage induced in the secondary winding 3 is kept constant, and the reactor core 6
The leakage magnetic flux 5 passing through the reactor gap 7 can be adjusted to a required impedance.

In addition, the reactor core 6 is made by dividing cut cores 6a and 6b formed into arc shapes into four parts and inserting them from above and below into the secondary winding 3 in FIG. 2, but as shown in the embodiment shown in FIG. The winding 3 is formed into a polygonal shape, and the required number of reactor cores 6 are
The cut core can also be constructed from a laminated core by providing it in the straight section of the next winding to adjust the reactor.

FIG. 4 shows an embodiment in which the impedance of a single-phase transformer formed by two cores is adjusted.
A primary winding 2 is wound around one leg of the transformer core 11, and a secondary winding 3 is wound around the other leg, and a reactor core 6 selected according to the required impedance is inserted into the secondary winding. A gap 8 larger than the reactor gap 7 is provided between the transformer core ti and the reactor core 6 so that the leakage magnetic flux 5 flowing through the reactor core 6 does not flow into the transformer core 11. Note that 12 is a primary winding terminal, and 13 is a secondary winding terminal.

Further, FIG. 5 shows an embodiment in which it is necessary to further adjust the adjustment value by the reactor core 6, in which a tap winding 14 is provided in the reactor core 6, and a secondary winding terminal 13 is provided in the reactor core 6.
One of the terminals is connected to the middle of the tap winding, and an appropriate tap and the other terminal are connected to a load.

Note that even in a transformer having a tertiary winding, by providing a reactor core in each of the secondary winding and the tertiary winding, the impedance of each can be adjusted separately.

[Effects of the present invention] As described above, the present invention provides a reactor core for passing only the leakage flux of the secondary winding in the secondary winding of a core type transformer, and connects this reactor core and the transformer iron core to the reactor core. A gap is provided to prevent the magnetic flux passing through the core from flowing into the transformer core over a large distance, and the impedance of the transformer can be adjusted by selecting the reactor core material, cross-sectional area, and reactor gap. The impedance of the transformer can be adjusted by manufacturing the transformer according to a standard design with a large gap between the transformer core and the secondary winding, and inserting the necessary reactor core according to the required impedance after assembly. This has the effect of standardizing transformer manufacturing.

Furthermore, if the gap between the transformer core and reactor core is made larger than the reactor gap, the transformer core and reactor core can be designed while ignoring each other.
The reactor made by the reactor core of the secondary winding can be considered as N, /N, times on the primary side, which makes it easy to match the design value and the measured value, simplifying the design.

Also, since it is possible to obtain a high impedance transformer, the secondary winding can be shorted and used as a reactor. For example, when connecting a shunt reactor directly to a power transmission line, it is the most economical method Although it was not possible to select a suitable voltage, by configuring the configuration as shown in Figure 4, the transformer core transforms the voltage, and the secondary winding is shared as the primary winding of the reactor, and the reactor core is Depending on the selection, an economical accelerator effect can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a partial side sectional view showing an embodiment of a three-phase transformer according to the present invention, FIG. 2 is a plan view taken along line A-A in FIG. 1, and FIG. Figure 2 is a diagram equivalent to Figure 4. Figure 4 is a side view showing an embodiment of a single-phase transformer. Figure 5 is a side view showing another embodiment of a single-phase transformer. Figure 6 is a leakage flux of a conventional transformer. FIG. 1 is the transformer core, 2 is the primary winding, 3 is the secondary winding, 4 is 1
Leakage flux of the next winding, 5 is the leakage flux of the secondary winding, 6 is the reactor core, 6a, 6b are the cut cores, 7 is the reactor gap, 8 is the gap, 11 is the transformer core, 12 is the primary winding Terminal I3 is a secondary winding terminal. Figure Figure Figure 2゜Figure Figure

Claims (1)

[Scope of Claims] 1. In a core type transformer equipped with a primary winding and a secondary winding, a reactor core that interlinks only with the secondary winding and passes only the leakage flux of the secondary winding is provided. An appropriate gap is provided between the reactor core and the transformer core so that the magnetic flux flowing through the reactor core does not flow into the transformer core, and impedance is adjusted by adjusting the material, cross-sectional area, and reactor gap of the reactor core. A core type transformer characterized by: 2. The core type transformer according to claim 1, wherein the reactor core is formed of a cut core and is attached to the secondary winding after the transformer is assembled. 3. Wrap the primary winding around one leg of the two-leg iron core, and wind the primary winding around the other leg.
2. The core type transformer according to claim 1, further comprising a secondary winding and a reactor core inserted between the secondary winding and the transformer core with a suitable gap therebetween. 4. The inner iron type transformer according to claim 3, wherein a tap winding is wound around the reactor core inserted through the secondary winding, and one terminal of the secondary winding is led out through the tap winding. vessel. 5. The core type transformer according to claim 1, wherein the secondary winding is short-circuited to function as a reactor.