A transformer configured to receive a primary incoming voltage and provide at least two secondary output voltages. The transformer includes at least one secondary output assembly which includes at least two secondary voltage stabs, the number of voltage stabs being the same as the number of secondary output voltages, connected and configured to provide access to a respective secondary output voltage. The chosen secondary output voltage is connected by coupling a tap change link between a lug landing and either of the at least two secondary voltage stabs. Another of the secondary output voltages is provided by connecting coupling the tap change link between the lug landing and the other of the at least two secondary voltage stabs.

A transformer configured to receive a primary incoming voltage and provide at least two secondary output voltages. The transformer includes at least one secondary output assembly which includes at least two secondary voltage stabs, the number of voltage stabs being the same as the number of secondary output voltages, connected and configured to provide access to a respective secondary output voltage. The chosen secondary output voltage is connected by coupling a tap change link between a lug landing and either of the at least two secondary voltage stabs. Another of the secondary output voltages is provided by connecting coupling the tap change link between the lug landing and the other of the at least two secondary voltage stabs.

A phase shifting transformer for poly-phase alternating current includes source side terminals, load side terminals, an exciting unit, and a series unit. The exciting unit includes further coils that are magnetically coupled to primary coils and to the secondary coils of the exciting unit to provide further voltages. The further coils are connected in series between the source side terminals and the series unit, so that the voltages at the load terminals are combinations of the quadrature voltages and the further voltages with the source voltages, thus modifying the voltage phase displacement between the source side terminals and the load side terminals.

A phase shifting transformer for poly-phase alternating current includes source side terminals, load side terminals, an exciting unit, and a series unit. The exciting unit includes further coils that are magnetically coupled to primary coils and to the secondary coils of the exciting unit to provide further voltages. The further coils are connected in series between the source side terminals and the series unit, so that the voltages at the load terminals are combinations of the quadrature voltages and the further voltages with the source voltages, thus modifying the voltage phase displacement between the source side terminals and the load side terminals.

The present disclosure relates to a method of monitoring switching by an on-load tap changer (OLTC) 1 from a first contact 3a to a second contact 3b of a transformer winding 2. The method includes measuring a voltage of the transformer. The method also includes measuring a temperature of the OLTC. The method also includes, based on the measured voltage and temperature, determining whether the switching from the first contact to the second contact has been successful.

The present disclosure relates to a method of monitoring switching by an on-load tap changer (OLTC) 1 from a first contact 3a to a second contact 3b of a transformer winding 2. The method includes measuring a voltage of the transformer. The method also includes measuring a temperature of the OLTC. The method also includes, based on the measured voltage and temperature, determining whether the switching from the first contact to the second contact has been successful.

A method of controlling at least one switching module having commutation cells which are associated with a regulating winding of a regulating transformer, the commutation cells including: a first and second switching element each having two thyristors in antiparallel connection.

A method of controlling at least one switching module having commutation cells which are associated with a regulating winding of a regulating transformer, the commutation cells including: a first and second switching element each having two thyristors in antiparallel connection.

This consists of a system capable of integrating all the control, supervision and monitoring functions of power transformers (2) equipped with on-load tap changers bringing benefits such as design simplifications, manufacturing simplifications, reductions in manufacturing costs, optimization and reduction of maintenance costs, and increased reliability of the transformer, which is promoted to the category of intelligent transformer, ready for the Industrial Internet of Things (IIoT) and Smart Grids.

The invention relates to a switch assembly (1), in particular a preselector, for a variable transformer (4) having a first winding (2) and a second winding (3) with a first and a second tap (3.3, 3.4), said switch assembly comprising: a first connection terminal (2.1) that can be connected to the first winding (2); a second connection terminal (3.1) that can be connected to the first tap (3.3); a third connection terminal (3.2) that can be connected to the second tap (3.4); a first, second, third and fourth fixed contact (5.1, 5.2, 5.3, 5.4); a vacuum interrupter (6); a first moving contact (7) that can be contacted selectively with the first or second fixed contact (5.1, 5.2); a second moving contact (8) that can be contacted selectively with the third or fourth fixed contact (5.3, 5.4), wherein the second and the fourth fixed contact (5.2, 5.4) are connected to the second connection terminal (3.1), the first and the third fixed contact (5.1, 5.3) are connected to the third connection terminal (32) the first moving contact (7) is connected to the first connection terminal (2.1) via the vacuum interrupter (6), and the second moving contact (8) is connected to the first connection terminal (2.1).