US 11,749,453 B2
Assembly for automatic tap adjustment of a power transformer using load tap changer and a method and support assembly for mounting the same
Shamaun Hakim, Washington, MO (US); Jesus Antonio Herrera Juarez, Washington, MO (US); and Azam Ali R. Shaikh, Washington, MO (US)
Assigned to WEG TRANSFORMERS USA LLC, Washington, MO (US)
Appl. No. 18/9,593
Filed by WEG TRANSFORMERS USA LLC, Washington, MO (US)
PCT Filed Apr. 4, 2022, PCT No. PCT/US2022/023306
§ 371(c)(1), (2) Date Dec. 9, 2022,
PCT Pub. No. WO2022/216605, PCT Pub. Date Oct. 13, 2022.
Claims priority of provisional application 63/171,899, filed on Apr. 7, 2021.
Prior Publication US 2023/0197335 A1, Jun. 22, 2023
Int. Cl. H01F 29/04 (2006.01); H01F 29/02 (2006.01); H01F 27/04 (2006.01); H01H 9/00 (2006.01); H01F 27/12 (2006.01)
CPC H01F 29/04 (2013.01) [H01F 27/04 (2013.01); H01F 29/025 (2013.01); H01H 9/0027 (2013.01); H01F 27/12 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A power transformer assembly configured for supplying electrical power to at least one consumer, comprising:
a power transformer having an input terminal configured to connect to and receive alternating electrical current from an external source;
a principal housing having a main chamber and a rear chamber, with the main chamber configured for receiving at least one high voltage coil and retaining oil surrounding the at least one high voltage coil, an auxiliary housing configured on an outer portion of the principal housing defining a cavity that is fluidly connected to the main chamber via a passageway that is configured for receiving electrical wiring, the at least one high voltage coil having a plurality of taps associated with a range of winding ratios, the at least one high voltage coil connected to the external source through the input terminal, at least one low voltage coil positioned adjacent to the at least one high voltage coil and connected to an output terminal of the power transformer to be capable of supplying electrical power to at least one customer, where an electrical current can be induced in the at least one low voltage coil from a magnetic coupling with the ratio of windings associated with a selected tap from said plurality of taps of the at least one high voltage coil when the external source supplies alternating current to the input of the power transformer:
a potential transformer configured for connection to the output terminal of the power transformer to measure an electrical potential on the at least one low voltage coil, the potential transformer configured to generate a measured value indicative of the electrical potential across the at least one low voltage coil;
a load tap changer having a controller, a motor and a plurality of switches each with one or more connectors/terminals configured to connect to electrical wiring connected to each of the plurality of taps on the at least one high voltage coil of the power transformer, the plurality of the switches being positioned within the auxiliary housing cavity to be submerged by the oil in the main housing chamber, the load tap changer configured to adjust the connected tap associated with a ratio of total windings in the at least one high voltage coil to be included in magnetic coupling;
a load tap change controller having at least one input configured to electrically couple to the potential transformer, wherein the load tap changer is configured to determine the electrical potential across the at least one low voltage coil based upon the measured value from the potential transformer and upon detecting an unacceptable electrical potential across the at least one low voltage coil, is configured to adjust the ratio of total windings in the at least one high voltage coil available for magnetic coupling with the at least one low voltage coil of the power transformer, and configured to adjust the electrical potential induced in the at least one low voltage coil;
wherein the load tap change controller is configured to adjust the connected tap associated with the ratio of windings available for magnetic coupling such that during adjustment, the switches and electrical connections of the tap electrical wiring are submerged in the oil of the main chamber and the auxiliary housing cavity, the magnetic coupling can be shifted and simultaneously provide a continuous supply of electrical power to the consumer.