A switch apparatus (10) for a measuring device (30) for a transformer includes controllable switch device (14) which are configured to short-circuit respectively assigned terminals (11) of one of a plurality of windings of the transformer. A test apparatus (40) including the switch apparatus (10) and a method (50) for operating the switch apparatus (10) are also disclosed. With apparatuses (10, 40) and methods (50) according to the exemplary embodiments, the work effort, time expenditure and errors and inaccuracies can be reduced through an automated testing of transformers.

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 following steps are performed in order to test a tap changer (20) of a transformer (5; 6) which tap changer is designed to change a transmission ratio of the transformer (5; 6): generating a test signal which is supplied to a winding (1-3; 10) of the transformer (5; 6) and to the tap changer (20). Repeatedly actuating the tap changer (20) in order to change the transmission ratio with each actuation. Determining a curve of an electrical measurement variable (I; I.sub.1; I.sub.2) of the transformer (5; 6) over time (t) respectively during the step of actuating the tap changer (20) depending on the test signal. automatically illustrating the curves (41, 42) in a temporally-superimposed manner.

A tester for testing a transformer is provided. The tester comprises a primary voltmeter and a plurality of secondary voltmeters. The tester may also comprise an ammeter in series with a voltage source configured to apply voltage to the transformer. The primary voltmeter is configured to measure voltage induced across a primary winding of the transformer, while the secondary voltmeters may simultaneously measure voltage outputs at secondary windings of the transformer. The tester is configured to calculate ratios, saturation curves, and knee points for multiple winding combinations based on the measurements simultaneously obtained by the ammeter and the primary and secondary voltmeters.

In a method for cleaning an on-load tap changer (19) in a regulating transformer (20), provision is made for the on-load tap changer (19) to comprise a moving contact (11) and a fixed contact (12); for a cleaning signal to be generated; for the moving contact (11) to be frictionally moved relative to the fixed contact (12) on the basis of the cleaning signal. An on-load tap changer (19) in a regulating transformer (20) comprises: a moving contact (11) and a fixed contact (12); a contact drive (17) which is coupled to the moving contact (11); a control device (18) which is connected to the contact drive (17) and is designed in such a manner that the control device can generate a cleaning signal and can transmit said signal to the contact drive (17); wherein the contact drive (17) is designed in such a manner that the contact drive can frictionally move the moving contact (11) relative to the fixed contact (12) on the basis of the cleaning signal.

A transformer arrangement includes a transformer, a transformer tank and at least one tap changer that is arranged to be connected to said transformer. The transformer arrangement further includes at least one support structure which is arranged to be connected to the tap changer and to extend between the tap changer and at least two support members located between the tap changer and at least two points on an inner surface of the transformer tank. The at least one support structure is arranged to reduce pendular movement of the tap changer.

A switch assembly has an on-load tap changer and a drive system for the on-load tap changer. The drive system has: a stepper motor having a motor shaft, the motor shaft being connected to and configured to actuate the on-load tap changer; a feedback system, which is configured: to determine at least one value for a position of the motor shaft; and to generate a feedback signal based on the at least one value; and a control device, which is configured to influence the operation of the switch assembly depending on the feedback signal.

A drive system drives a switch. The drive system includes: a drive shaft connecting the drive system to the switch; a motor configured to drive the drive shaft; a feedback system; and a controller. The feedback system is configured to: determine at least one value for a position of the drive shaft; and generate a feedback signal based on the at least one value. The controller acts on an operation of the motor depending on the feedback signal.

A method carries out a switchover of a first switch or at least one second switch for equipment. The method includes receiving, by a controller, a switching signal; selecting, by the controller, the first switch or at least the second switch for switchover on the basis of the switching signal; querying, by the controller, at least one parameter of the first switch or the at least second switch; checking a locking condition on the basis of the at least one queried parameter for the first switch or a locking condition for the at least second switch; and carrying out the switchover by the selected first switch or the at least second switch based upon the corresponding locking condition being met.

An adapter device transmits tap positions of an on-load tap-changer from a control device to a secondary device. The adapter device has: an input configured to receive at least one tap position from the control device of the on-load tap-changer; an output configured to output the tap position of the on-load tap-changer to the secondary device; and at least one resistor and at least one switch, which are connected in parallel with one another. The adapter devices is configured such that: depending on the tap position of the on-load tap-changer, the at least one switch is actuated by the control device and the at least one resistor is connected or disconnected, and the output tap position of the on-load tap-changer at the output corresponds to the resistance value of the at least one resistor that has been connected or disconnected.