Supplementary transformer winding

A transformer winding, comprising:

• a main transformer winding;
• and
• a supplementary transformer winding configured to be electrically connected in series with the main transformer winding, the supplementary transformer winding comprising:
• a first winding module, a second winding module, and a third winding module, each of the winding modules having at least a first, a second and a third winding segment, and wherein each of the winding segments has a plurality of taps;
• an on-load tap changer configured to be connected to the taps of the second winding module, and wherein the second winding module is configured to be electrically connected in series to at least one winding segment of the first winding module and the third winding module;
• and
• at least one selector switch, wherein the at least one selector switch is connected to at least one of the plurality of taps of the first winding module and at least one of the plurality of taps the third winding module.