A power electronic tap changer module for transformer, the power electronic tap changer module comprising a plurality of tap lines, each tap line of the plurality of tap lines including: - a first terminal (a1 '....aN') for connecting the power electronic tap changer module (1 ') to a voltage source; - a second terminal (b1 '....bN') for connecting the power electronic tap changer module (1 ') to a tap section of a winding of the transformer; and - a valve (V1 '...VN'); wherein each valve comprises: - a pair of thyristors; - a transient voltage suppressor device for basic short-term overvoltage protection; - a triggering circuit; and - a control signal receiver; wherein the pair of thyristors of each valve is connected in antiparallel to each other and in parallel to the transient voltage suppressor device; wherein the pair of a thyristors of each valve is adapted to be connected with a controller through its respective triggering circuit and control signal receiver; characterized in that the power electronic tap changer module (1 ') further comprises: - a plurality of fuses (FT...FN) connected in series respectively with each of the valves in the plurality of valves; and - an additional oversized tap line; wherein the additional oversized tap line comprises: - a third terminal (aX) for connecting the power electronic tap changer module (1 ') to the voltage source; - a fourth terminal (bX) for connecting the power electronic tap changer module (1 ') to a tap section of a winding of the transformer; and - an oversized valve; wherein the oversized valve comprises: - a pair of thyristor or transistors (SCRX); - a thermally protected voltage suppressing device; - an overvoltage triggering circuit; - a triggering circuit; and - a control signal receiver; wherein the overvoltage triggering circuit is connected in parallel between the third (aX) and fourth (bX) terminals; wherein the overvoltage triggering circuit is connected in parallel with the pair of thyristors or transistors (SCRX) of the oversized valve; wherein the pair of thyristors (SCRX) of the oversized valve is connected in antiparallel to each other and in parallel with the thermally protected voltage suppressing device; wherein the pair of a thyristors or transistors (SCRX) of the oversized valve is adapted to be connected with the controller through its triggering circuit and control signal receiver; and wherein the oversized valve is rated for short-circuit current whereas each valve of each tap line of the plurality of tap lines is rated for nominal current. - a first terminal (a1 '....aN') for connecting the power electronic tap changer module (1 ') to a voltage source; - a second terminal (b1 '....bN') for connecting the power electronic tap changer module (1 ') to a tap section of a winding of the transformer; and - a valve (V1 '...VN'); - a pair of thyristors; - a transient voltage suppressor device for basic short-term overvoltage protection; - a triggering circuit; and - a control signal receiver; wherein the pair of thyristors of each valve is connected in antiparallel to each other and in parallel to the transient voltage suppressor device; wherein the pair of a thyristors of each valve is adapted to be connected with a controller through its respective triggering circuit and control signal receiver; characterized in that the power electronic tap changer module (1 ') further comprises: - a plurality of fuses (FT...FN) connected in series respectively with each of the valves in the plurality of valves; and - an additional oversized tap line; - a plurality of fuses (FT...FN) connected in series respectively with each of the valves in the plurality of valves; and - an additional oversized tap line; wherein the additional oversized tap line comprises: - a third terminal (aX) for connecting the power electronic tap changer module (1 ') to the voltage source; - a fourth terminal (bX) for connecting the power electronic tap changer module (1 ') to a tap section of a winding of the transformer; and - an oversized valve; - a third terminal (aX) for connecting the power electronic tap changer module (1 ') to the voltage source; - a fourth terminal (bX) for connecting the power electronic tap changer module (1 ') to a tap section of a winding of the transformer; and - an oversized valve; wherein the oversized valve comprises: - a pair of thyristor or transistors (SCRX); - a thermally protected voltage suppressing device; - an overvoltage triggering circuit; - a triggering circuit; and - a control signal receiver; - a pair of thyristor or transistors (SCRX); - a thermally protected voltage suppressing device; - an overvoltage triggering circuit; - a triggering circuit; and - a control signal receiver; wherein the overvoltage triggering circuit is connected in parallel between the third (aX) and fourth (bX) terminals; wherein the overvoltage triggering circuit is connected in parallel with the pair of thyristors or transistors (SCRX) of the oversized valve; wherein the pair of thyristors (SCRX) of the oversized valve is connected in antiparallel to each other and in parallel with the thermally protected voltage suppressing device; wherein the pair of a thyristors or transistors (SCRX) of the oversized valve is adapted to be connected with the controller through its triggering circuit and control signal receiver; and wherein the oversized valve is rated for short-circuit current whereas each valve of each tap line of the plurality of tap lines is rated for nominal current.