Distribution transformer for voltage regulation of local distribution networks

Patent metadata

Field	Value
Publication number	US-9406434-B2
Application number	US-201314379955-A
Country	US
Kind code	B2
Filing date	Mar 25, 2013
Priority date	Apr 20, 2012
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

The invention relates to a distribution transformer having a tap-changing device for no-break switching between different winding taps of a distribution transformer. The general inventive concept consists in actuating both the selector contact unit and the switching means for no-break load switching by means of a common motor drive without interposition of an energy store.

First claim

The invention claimed is:

1. A distributing transformer for voltage regulation of local mains, comprising
a main winding and a regulating winding with a plurality of winding taps,
a tap regulating device for uninterrupted switching between different winding taps of the distributing transformer, wherein
at least one selector contact with a respective plurality of fixed selector contacts respectively electrically connected with the individual winding taps is arranged along a line,
the fixed selector contacts are actuatable by two longitudinally displaceable movable selector contacts,
for the uninterrupted switching two vacuum interrupters are provided for each phase,
a motor drive for introducing a drive movement into the tap regulating device is provided, and
the at least one selector contact unit and the switching means for the uninterrupted switching are so directly actuatable by means of the common motor drive that the introduction of the drive movement of the motor drive into the at least one selector contact unit and the switching means for the uninterrupted switching takes place without interposition of a force-storing device.

2. The distributing transformer according to claim 1 , wherein
rotation generated by the motor drive is transmissible by means of a transmission module to a threaded spindle engaged with a spindle nut provided at a center slide carriage so that a longitudinal displacement of the center slide carriage along guide rods can thereby be produced, and
the remaining slide carriages are operatively connected with the center slide carriage by way of a similarly longitudinally displaceable guide link that is mechanically coupled with the center slide carriage, so that the remaining slide carriages in turn are so mechanically coupled with the center slide carriage by way of the guide link that not only the selector contact units, but also the switching means for the uninterrupted load switching are thereby simultaneously actuatable.

3. The distributing transformer according to claim 1 , wherein the entire step regulating device is arranged by means of a transmission module at the underside of a transformer cover.

4. The distributing transformer according to claim 1 , wherein the transmission module comprises a flange-like sealing module.

5. The distributing transformer according to any claim 1 , further comprising:
a support plate of a dielectric material, at the first side of which the at least one selector contact unit and at the second side of which switching means for the uninterrupted switching are arranged, is provided.

6. The distributing transformer according to claim 1 , wherein the at least one selector contact unit comprises a respective slide carriage, a respective contact support and respective movable selector contacts that co-operate with at least one fixed selector contact.

7. The distributing transformer according to claim 1 , wherein the slide carriage is received by two parallel arranged guide rods that are in turn arranged at the support plate by means of cross members.

8. The distributing transformer according to claim 1 , wherein the movable selector contacts are each received in a contact support and co-operate with fixed selector contacts arranged at the support plate.

9. The distributing transformer according to claim 1 , wherein the at least one selector contact unit is arranged to be so displaceable along the guide rods by means of the respective slide carriage that it is thereby possible to run through the regulating range of the step regulating device.

10. The distributing transformer according to claim 1 , wherein the plurality of cross-members forms a mechanical abutment for the at least one selector contact unit that is displaceable along the guide rods, in such a way that the regulating range of the step regulating device is mechanically limited.

11. The distributing transformer according to claim 1 , wherein the movable selector contacts of a phase in each stationary operational setting connect at least one fixed selector contact of the same phase of the step regulating device.

12. The distributing transformer according to claim 1 , wherein in each instance two movable selector contacts are received in a contact support to be resiliently mounted.

13. The distributing transformer according to claim 1 , wherein
the movable switch contact of the corresponding vacuum interrupter is respectively pivotably and mechanically operatively connected with a coupling element and a control lever, and
provided at the pivotable connection between the corresponding support element and the control lever on the side facing the support plate is a roller that rolls along a profiled upper side of the guide link under partially maintained contact so that the respective vacuum interrupter is connectable by a longitudinal displacement of the guide link in dependence on the profiling of the upper side thereof.

14. The distributing transformer according to claim 1 , wherein the fixed selector contacts are arranged at a contact strip, which contact strips are in turn fastened to the support plate by means of respective spacers.

15. The distributing transformer according to claim 1 , wherein the contact strip has at its longitudinal side a control link at which several lobes are arranged on both sides.

16. The distributing transformer according to claim 1 , wherein the profile of the lobes is so dimensioned that the movable selector contacts of the corresponding selector contact unit between two adjacent fixed selector contacts lift off the currently connected fixed selector contact, since the movable selector contacts again connect the next fixed selector contact after switching has been completed.

17. The distributing transformer according to claim 1 , wherein
two respective vacuum interrupters per phase are directly arranged at the corresponding slide carriage of the respective selector contact unit,
the motor drive drives a central threaded spindle by means of an angle transmission,
each slide carriage has a separate spindle nut, and
the threaded spindle co-operates with the spindle nut of each slide carriage and the rotation can be converted into a synchronous longitudinal displacement of the plurality of slide carriages in such a manner that not only the movable selector contacts but also the vacuum interrupters are thereby actuatable.

18. The distributing transformer according to claim 1 , wherein the motor drive drives not only a threaded spindle that in turn is operatively connected with the selector contact unit but also a camshaft, by way of which the switching means for the uninterrupted switching are actuatable, in such a manner that both the movable switching contacts and the switching means for the uninterrupted switching are thereby actuatable.

Assignees

• Bieringer Alfred
• Hammer Christian
• Pankofer Martin
• Strempel Rolf
• Stocker Andreas
• Reinhausen Maschf Scheubeck

Inventors

• Bieringer Alfred
• Hammer Christian
• Pankofer Martin
• Strempel Rolf
• Stocker Andreas

Classifications

• H01H9/0044

  Casings; Mountings; Disposition in transformer housing · CPC title

• H01F29/04 Primary

  having provision for tap-changing without interrupting the load current · CPC title

• H01H9/0027

  Operating mechanisms · CPC title

• H01H9/0011

  Voltage selector switches · CPC title

• H02P13/06

  by tap-changing; by rearranging interconnections of windings · CPC title