A switch assembly includes a switch and a servo drive system. The drive system includes: a drive shaft connecting the drive system to the switch; a motor driving the switch; a power section supplying power to the motor; a feedback system; and a programmable safety controller. The feedback system determines at least two values for an absolute position of the drive shaft; and generates a feedback signal on the basis of the values. The controller controls the power section depending on at least one desired value; influences an operation of the motor depending on the feedback signal; and identifies the presence of at least one safety-relevant event, and based thereon, transmits a control signal to the power section. The power section is initiates/carries-out at a safety measure depending on the control signal.

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.

An electrical device (10, 13), in particular a power transformer (13), a shunt reactor, or an on-load tap changer (10), comprises a housing (101, 131) that is filled or fillable with insulation oil (11, 11); and a sensor (12) that comprises a piezo element (16) in the housing (101, 131) on a level with a minimum fill level (19, 19) of the insulation oil (11, 11); and an evaluation device (18) that is connected to the piezo element (16); wherein the evaluation device (18) is formed such that it can induce an oscillation of the piezo element (16); and it can determine the fill level from a measurement of a characteristic of the oscillation, in particular the half-life period of the amplitude of the oscillation.

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 switch assembly including a switch and a drive system for the switch. The drive system includes a motor for driving the switch, a control device with a power section for supplying power to the motor, a controller for initiating a switching operation of the switch by control of the power section, and a protection circuit. The protection circuit is configured to detect a first error signal via a state contact of the controller in the event of a malfunction of the controller, detect a second error signal via a state contact of the power section in the event of a malfunction of the power section, and initiate a safety measure depending on the first and the second error signal. The control device is configured to activate the protection circuit prior to the switching operation being initiated and to deactivate it following successful execution of the switching operation.

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.

Disclosed is an on-load voltage regulation tap switch for a transformer, comprising a main switch group, a switch contact protection branch and a switch control circuit, wherein the main switch group comprises a plurality of switch contacts, one end of the switch group is connected to a corresponding transformer winding tap, and the other end of the switch group is connected in parallel and is then connected to a power source; the switch contact protection branch is a series circuit formed by a plurality of groups of diodes and auxiliary switch contacts, and is respectively connected to both ends of a corresponding main switch in parallel; and the switch control circuit is composed of a power source, a single chip microcomputer and a peripheral circuit, and controls all of the main switches and auxiliary switches to act in a certain time sequence to complete the switching of the transformer windings.

A method for carrying out a switchover of a switch from a current switching position to a target switching position by means of a drive system. The method includes receiving, by the drive system, a switching signal from a control device, determining, via a feedback signal of a feedback system, at least one value for a first position of a drive shaft of the drive system, determining, by the control device, a value for a second position of the drive shaft on the basis of the target switching position, to be moved to, of the switch, and ascertaining, by the control device, a difference between the value for the first position and the value for the second position of the drive shaft. The control device, depending on the feedback signal, acts on a motor until the value for the second position of the drive shaft is reached.

A method of pressure-filling a container includes placing its opening tightly against a filling element, extending a return gas tube into the container, causing and measuring a progression of pressures in the container's interior, thereby generating a measured progression of pressures, generating a signal indicative of the measured progression of pressures, recording it, monitoring it for information indicative of a pressure peak, identifying such information, comparing a measured value of the pressure peak with a reference value, measuring an absolute pressure at a point in time at which the pressure peak is measured, based at least in part this measurement, determining that the pressure peak is caused by the filling-material level having reached the return gas tube, and upon making the determination, transmitting closing the filling element.

A switch apparatus (10) for a measuring device (30) for a transformer comprises controllable switch means (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) comprising 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 of the invention, the work effort, time expenditure and errors and inaccuracies can be reduced through an automated testing of transformers.