A switch device includes an operation unit to receive an operation performed by a user, a movable contact that is connected to a ground circuit and moves according to an operation performed on the operation unit, plural fixed contacts whose state of connection to the movable contact is switched according to an operation position of the operation unit, plural resistors connected in series in such a manner that one end is connected to a power supply, another end is connected to one of the plural fixed contacts, and a node formed by connecting in series is connected to the remaining of the plural fixed contacts, and a control unit that includes an input terminal connected to a first node between the fixed contact connected closest to the power supply and the resistor and determines the operation position of the operation unit based on voltage detected through the input terminal.

The present disclosure provides a degassing membrane tube module and an online gas-in-oil monitoring apparatus for a vacuum on-load tap changer (OLTC). The online gas-in-oil monitoring apparatus includes an online monitoring housing, an oil inlet tube, a gas monitoring device, an oil tank, and an oil diffusing screen, where one end of the oil inlet tube extends through an inner wall at one side of the online monitoring housing; the gas monitoring device is located on a top inner wall of the online monitoring housing; and a front end of the oil inlet tube is provided with the degassing membrane tube module for online preliminary degassing on insulating oil. With the degassing membrane tube module, the online gas-in-oil monitoring apparatus can increase removal rates for gases in the insulating oil within a short time, and can perform degassing on various gases in the insulating oil.

A method for actuating an on-load tap-changer using a control device, a sensor, and a drive is provided. The control device receives a switching command for actuating the on-load tap-changer. The sensor detects a current profile. The control device determines multiple consecutive times for current zero crossings of the current profile and multiple intervals between the multiple consecutive times of the current zero crossings. The control device derives a characteristic variable from the multiple intervals and compares the characteristic variable with a limit value. The control device terminates or pauses the actuation based on determining that the characteristic variable exceeds the limit value and performs the actuation by controlling the drive based on determining that the characteristic variable satisfies or falls below the limit value.

An on-load tap-changer for switching, without interruption, between winding taps of a tap-changing transformer, including a diverter switch for performing a switch-over from a first to a second fixed contact, a selector for preselecting, without power, the first and second fixed contact, and a first controller, wherein the diverter switch has a plurality of semiconductor and mechanical switching elements, the selector has a first and second selector arm, which are actuatable independently of one another and can contact each of the fixed contacts, and the first controller is configured to trigger a switch command and to actuate the first and second selector arm and the plurality of mechanical switching elements by a motor drive, wherein the on-load tap changer includes a second controller to actuate the plurality of semiconductor switching elements, and wherein during the switch-over the first controller actuates the motor drive depending on the second controller.

The disclosure relates to a method for monitoring a vacuum on-load tap changer including determining a total main vacuum interrupter opening time as a time elapsed between a first point in time and a second point in time, a total resistor vacuum interrupter opening time as a time elapsed between the third point in time and the fourth point in time, a circulating current time as a time elapsed between the second point in time and the third point in time, and/or a switch time as the sum of the total main vacuum interrupter opening time, the total resistor vacuum interrupter opening time and the circulating current time.

A vacuum interrupter for an on-load tap changer comprising a cylindrical housing arranged on an axis including a wall enclosing a hermetically sealed inner volume and a ceramic bottom part extending perpendicularly to the axis, the wall comprising a first optical interface between the inner volume and an outer environment, the first optical interface being configured to be transparent to at least one optical wavelength, the inner volume comprising an optical guide open to an environment of the inner volume, a switch coaxially arranged with the housing on the axis within the inner volume of the housing, the vacuum interrupter further comprising a shield element coaxially arranged with the switch, characterised in that the optical guide is arranged recessed in relation to an inner surface of the ceramic bottom part of the wall and in that the shield element is arranged between the switch and the optical guide.

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.