Abstract
The invention relates to an on-load tap changer (2) according to the reactor switching principle for uninterrupted load switching between different tap windings of a tapped transformer (1), comprising: an inductor (3) which is designed as an inductive transition reactance; the inductor (3) being part of the on-load tap changer (2).
Claims
1. In an on-load tap changer according to the reactor switching principle for uninterrupted load switching of a phase between different winding taps of a tapped transformer, the improvement comprising: a choke constructed as an inductive switching inductance for the phase, mounted on the on-load tap changer, and connected to and having the same voltage potential relative to ground as the on-load tap changer, the on-load tap changer being either a load selector or the combination of a tap selector with a load-changeover switch.
2. The on-load tap changer defined in claim 1, wherein, when the on-load tap changer is a load selector, the choke is mounted to an upper end or to a lower end of the load selector.
3. The on-load tap changer defined in claim 1, further comprising, when the on-load tap changer is a load-changeover switch and a tap selector, the choke is mounted to an upper end or to a lower end of the load-changeover switch or to an upper end or to a lower end of the tap selector.
4. The on-load tap changer defined in claim 3, further comprising: an iron core extending through and between the load-changeover switch and the tap selector, the choke being mounted on the iron core between the load-changeover switch and the tap selector.
5. The on-load tap changer defined in claim 2, wherein the on-load tap changer is at an upper part of a transformer housing.
6. The on-load tap changer defined in claim 2, further comprising an insulating foot at a lower part of a transformer housing and carrying the choke and the load selector.
Description
BRIEF DESCRIPTION OF THE DRAWING
(1) The invention and advantages thereof are described in more detail in the following with reference to the accompanying drawings, in which:
(2) FIG. 1 shows a first embodiment of a tapped transformer with an on-load tap changer;
(3) FIG. 2 shows a second embodiment of a tapped transformer with an on-load tap changer;
(4) FIG. 3 shows a third embodiment of a tapped transformer with an on-load tap changer;
(5) FIG. 4 shows a fourth embodiment of a tapped transformer with an on-load tap changer;
(6) FIG. 5 shows a fifth embodiment of a tapped transformer with an on-load tap changer;
(7) FIG. 6 shows a sixth embodiment of a tapped transformer with an on-load tap changer;
(8) FIG. 7 shows a seventh embodiment of a tapped transformer with an on-load tap changer;
(9) FIG. 8 shows an eighth embodiment of a tapped transformer with an on-load tap changer;
(10) FIG. 9 shows a ninth embodiment of a tapped transformer with an on-load tap changer;
(11) FIG. 10 shows a tenth embodiment of a tapped transformer with an on-load tap changer;
(12) FIG. 11 shows an eleventh embodiment of a tapped transformer with an on-load tap changer;
(13) FIG. 12 shows a twelfth embodiment of a tapped transformer with an on-load tap changer; and
(14) FIG. 13 shows a thirteenth embodiment of a tapped transformer with an on-load tap changer.
(15) Identical reference numerals are used for the same or equivalent elements of the invention. Moreover, for the sake of clarity only those reference numerals are illustrated in the individual figures that are required for description of the respective figure. The illustrated embodiments represent merely examples of how the on-load tap changer according to the invention and in accordance with the reactor switching principle can be constructed and thus do not represent a definitive limitation of the invention.
SPECIFIC DESCRIPTION OF THE INVENTION
(16) FIG. 1 shows a tapped transformer 1 with an on-load tap changer 2, which is in the interior thereof, for uninterrupted load changeover between different winding taps. The on-load tap changer 2 comprises a load-changeover switch 5 and a selector 6. Three windings 10, which are fastened to a transformer yoke 11, are in the interior of the tapped transformer 1, thus in the transformer housing 8. The windings are connected with the on-load tap changer 2 by individual lines 12. The on-load tap changer 2 is fastened to the cover or upper part 81 of the transformer housing 8. In the embodiment illustrated here, the on-load tap changer 2 is operated by a motor drive 13 arranged externally on the transformer housing 8. An insulating liquid such as, for example, oil or ester is present in the interior of the tapped transformer 1. However, the tapped transformer 1 can also be constructed as a so-called dry transformer in which air serves as insulating medium.
(17) The iron core 7 is between the load-changeover switch 5 and the selector 6, thus at the lower end of the load-changeover switch 52. The iron core 7 connects the load-changeover switch 52 and the selector 6. A choke 3 constructed as a coil is on this iron core 7. This choke 3 serves as inductive switching inductance for the on-load tap changer 2, in this embodiment the load-changeover switch 5. Depending on the requirements of the on-load tap changer 2, the choke 3 can comprise one, two or three windings fastened to the iron core 7 that is adapted to that purpose.
(18) FIG. 2 shows a second embodiment in which the choke 3 and the iron core 7 are directly at a lower end 62 of the selector 6. However, the choke 3 can also be fastened to an upper end 51 of the load-changeover switch 5 (not illustrated here).
(19) FIG. 3 shows a third embodiment in which the choke 3 and the yoke 7 are mounted laterally on the on-load tap changer 2 by a support bracket 14.
(20) FIG. 4 shows a fourth embodiment in which the on-load tap changer 2 is a load selector 4. The load selector 4 is fastened to the upper part or cover 81 of the transformer housing 8. The choke 3 is at the lower end 42 of the load selector 4.
(21) FIG. 5 shows a fifth embodiment in which a three-phase choke 3 is mounted laterally on the on-load tap changer 2, here constructed as a load selector 4, by a support bracket 14. However, the choke 3 can also be fastened at the upper end 41 of the load selector 4 (not illustrated here).
(22) FIG. 6 shows a sixth embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part 82 (base) of the transformer housing 8. In that case the choke 3 is between the load-changeover switch 5 and the selector 6. Since the on-load tap changer 2 is no longer fastened by the load-changeover switch 5 to the upper part 81 of the transformer housing 8, which lies at ground potential, and thus no longer has to be insulated relative thereto, the load-changeover switch 5 can be of particularly short construction.
(23) FIG. 7 shows a seventh embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part (base) of the transformer housing 8. In that case, the choke 3 is between the selector 6 and the insulating foot 9. Since the on-load tap changer 2 is no longer fastened by the load-changeover switch 5 to the upper part 81 of the transformer housing 8, this load-changeover switch 5 can be of particularly short construction.
(24) FIG. 8 shows an eighth embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part 82 (base) of the transformer housing 8. In that case, the choke 3 is on the load-changeover switch 5. Since the on-load tap changer 2 is no longer fastened by the load-changeover switch 5 to the upper part 81 of the transformer housing 8, this load-changeover switch 5 can be of particularly short construction.
(25) FIG. 9 shows a ninth embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part 82 (base) of the transformer housing 8. In that case the choke 3 is laterally by a support bracket 14 near the on-load tap changer 2. Since the on-load tap changer 2 is no longer fastened by the load-changeover switch 5 to the upper part 81 of the transformer housing 8, this load-changeover switch 5 can be of particularly short construction.
(26) FIG. 10 shows a tenth embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part 82 (base) of the transformer housing 8. This is a load selector 4. In that case the choke 3 is between the load selector 4 and the insulating foot 9. However, this choke 3 can also be arranged at the upper end 41 of the load selector 4 (not illustrated here). Since the load selector 4 is no longer fastened to the upper part 81 of the transformer housing 8, the upper end 41 of the load selector 4 can be of particularly short construction.
(27) FIG. 11 shows an eleventh embodiment in which the on-load tap changer 2 stands on an insulating foot 9 arranged at the lower part 82 (base) of the transformer housing 8. This is a load selector 4. In that case the choke 3 (in this instance three-phase) is laterally near the load selector 4 by a support bracket 14. Since the load selector 4 is no longer fastened to the upper part 81 of the transformer housing 8, the upper end 41 of the load selector 4 can be of particularly short construction.
(28) FIG. 12 shows a twelfth embodiment in which the choke 3 comprises three separate (single-phase) windings and iron cores 7 that are directly on or by a respective support bracket 14 mounted laterally on the on-load tap changer 2. Since the load selector 4 is no longer fastened to the upper part 81 of the transformer housing 8, the upper end 41 of the load selector 4 can be of particularly short construction.
(29) FIG. 13 shows a thirteenth embodiment in which three separate single-phase chokes 3 are directly on or by the respective support bracket 14 mounted laterally on the on-load tap changer 2.
