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 transformer apparatus for a charging station for electrically charging vehicles. The charging station includes at least two charging points. The transformer apparatus includes an input connection for electrical connection to an electrical power source. The transformer apparatus further includes at least one primary winding, and connected downstream electrically in series, at least three electrically parallel secondary windings that are DC-isolated from one another. The secondary windings are configured to be connected to at least two output connections of the at least two charging points of the charging station by switching logic. The switching logic connects at least two secondary windings electrically in parallel with a respective output connection of a respective charging point.

A device for connecting to a high-voltage grid carrying an AC voltage and having a plurality of phases, includes an active part having at least one phase connection for connecting to a phase of the high-voltage grid, at least one step winding connected downstream of one of the phase connections and having a plurality of taps, a tap changer having, for each step winding, a selector for currentlessly switching over from a current to a desired tap of the step winding, and a load changeover switch connected downstream of the selector in series for commutating the current from the current to the desired tap, for avoiding a high short-circuit current in the step winding or in the tap changer. An impedance unit, having an impedance to be switched between a low impedance and a high impedance, is disposed between each selector and each load changeover switch.

A transformer includes a transformer housing, a stationary contact, a load break rotary switchand a magnetically sensitive indicator component. The load break rotary switch comprises a shaft, comprising a shaft portion which is disposed in an inner housing area and a shaft contact attached to the shaft portion. The load break rotary switch comprises a lever connected to the shaft portion with respect to a rotary axis in a rotationally fixed manner, wherein the lever comprises a lever portion having a radial distance from the rotary axis. The lever portion comprises a lever magnet. A magnetically sensitive indicator component is switched from its first state into its second state by the lever magnet when the shaft is rotated from the first position to the second position or vice versa. Thus, an operator can ensure that the shaft contact is disconnected from the stationary contact before performing a maintenance work.

An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.

An on-load tap changing apparatus includes a first switching unit connected to a first tap of a transformer provided in a power system and switching power supplied from the first tap, a first impedance changing unit connected in series with the first switching unit and increasing an impedance when the first switching unit executes a switching operation, a second switching unit connected to a second tap of the transformer and switching power supplied from the second tap, and a second impedance changing unit connected in series with the second switching unit and increasing an impedance when the second switching unit executes a switching operation. The on-load tap changing apparatus can suppress an arc at the time of switching, reduce deterioration of a switching unit, and have excellent durability.

A tap changing regulator with at least one regulator stage that has a set of input taps and a set of switches in a switching matrix. The have respective on-off modes to connect one or more of the taps to an output voltage to effect a number of regulation steps, where the ratio of the number of regulation steps to the number of taps is always greater than 1:1. The regulator taps are spaced between sets of windings having a progressive windings ratio of 1 to 3 to 2, or integer multiples of that ratio. Series connected additional regulator stages have an input tap with a windings ratio that is twice the sum of the first stage regulation steps, plus 1.

An on-load tap changer that includes an actuator configured to adjust a turn ratio of the transformer, and a processing unit configured to control the actuator and to communicate with a control device via a digital signal connection. The processing unit is further configured to receive a status detected by a sensor. A method of manufacturing the on-load tap changer is also disclosed. Embodiments according to the present disclosure provide a digitalized on-load tap changer that allows various statuses to be monitored or controlled, by which various advantages can be achieved. For example, the life of a contact of the transformer can be predicted. Other data can be used to determine whether it is safe to adjust the contact of the transformer. Moreover, the optical fibers between the on-load tap changer and an external device enable an isolated transmission of control and data signals that almost eliminates interferences.

A load stepping switch (1) for uninterrupted changeover between winding taps (n, n+1) on a control winding (20) comprises a changeover switch (2) that comprises a first, second and third changeover contact (2.1, 2.2, 2.3) and can adopt a first position, in which the first and third changeover contacts are connected, a second position, in which the second and third changeover contacts are connected, and a bridge position, in which the changeover contacts are connected; a first fixed contact (4) that can be connected to a first winding tap; a second fixed contact (5) that can be connected to a second winding tap; a first moving contact (6) that can optionally make contact with each of the fixed contacts; a second moving contact (7) that can optionally make contact with each of the fixed contacts; a main path (8) that connects the first moving contact to the first changeover contact; an auxiliary path (9) that connects the second moving contact to the second changeover contact via a current-limiting element (10); a switching element (11) that is connected between the main path and the second changeover contact.

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.