Abstract: A method monitors gases produced in an insulating medium circuit. The insulating medium circuit is in contact with a transition resistor of an on-load tap-changer. The method includes: ascertaining a time profile of a resistor temperature of the transition resistor during a loading time period; and determining at least one characteristic value for characterizing the gases produced based upon the time profile of the resistor temperature.

Abstract: A method monitors gases produced in an insulating medium circuit. The insulating medium circuit is in contact with a transition resistor of an on-load tap-changer. The method includes: ascertaining a time profile of a resistor temperature of the transition resistor during a loading time period; and determining at least one characteristic value for characterizing the gases produced based upon the time profile of the resistor temperature.

Abstract: The invention relates to a tap changer having vacuum interrupters for switching over between winding taps of a tapped transformer without interruption. The tap changer according to the invention having vacuum interrupters is based on the general idea of combining the functionalities of at least one conventional vacuum switching contact which switches under load and a further mechanical switching means according to the prior art in just one single vacuum interrupter with two separately moving contact systems.

Abstract: Disclosed is an on-load tap changer comprising a connection to an insulating liquid of a transformer. The on-load tap changer in a housing (9) and the transformer are in the transformer tank (7) and are surrounded by insulating liquid (6). At least one opening (10) is formed in the housing base (9B) and/or housing cover (9M), said opening providing a fluidic connection between the insulating liquid in the transformer tank and the insulating liquid in the housing.

Abstract: The present invention relates to a method for quantitatively analyzing gases as a monitor for on-load tap changers. The general inventive concept lies in selecting particular characteristic gases allowing an indirect subsequent association and a dimension for aging effects, excessive discharge, and/or heating of the on-load tap changer; measuring said characteristic gases, formed during the operation of the tap changer in the insulating oil thereof, at particular time intervals; forming indicative quotients from the measured values of the defined gases, said quotients allowing direct conclusions about aging effects, excessive discharge, and/or heating; displaying trends from a comparison of the currently derived value of each quotient to the most recently derived value for the same quotient; and inferring warnings for aging effects, excessive discharge, and/or heating if the corresponding quotients tend to change significantly over time or in the course of the switch changes made.

Abstract: The present invention relates to a method for quantitatively analyzing gases as a monitor for on-load tap changers. The general inventive concept lies in selecting particular characteristic gases allowing an indirect subsequent association and a dimension for aging effects, excessive discharge, and/or heating of the on-load tap changer; measuring said characteristic gases, formed during the operation of the tap changer in the insulating oil thereof, at particular time intervals; forming indicative quotients from the measured values of the defined gases, said quotients allowing direct conclusions about aging effects, excessive discharge, and/or heating; displaying trends from a comparison of the currently derived value of each quotient to the most recently derived value for the same quotient; and inferring warnings for aging effects, excessive discharge, and/or heating if the corresponding quotients tend to change significantly over time or in the course of the switch changes made.

Abstract: The abstract relates to an arrangement of an oil-filled power transformer having an oil-filled stepping switch, wherein only a single oil expansion vessel is provided, this oil expansion vessel being connected both to the oil volume of the stepping switch and also to the transformer tank, which is likewise oil-filled, via corresponding flanges.

Abstract: The invention relates to a method for monitoring contact consumption in multiple contact switches of the load-switching type, wherein the selection and the switching is carried out in one step by the movement of switching contacts and which therefore do not have a separate diverter switch. Every time the multiple contact switch is actuated, the load current is measured. The corresponding, previously stored rated stage voltages for the current switching and information on whether it was shifted “up” or “down”, are used to calculate the switching currents of the breaking contacts, the consumption rates are determined on the basis thereof and the volume consumption is accumulated. Said accumulated value is compared with a previously determined threshold value; once this threshold value is reached, warning messages or other messages are generated.

Abstract: A method of monitoring contact burnoff in tap changers operating under load in which the load current is measured and for nominal variation of the voltage of the particular tap parameters are stored which are used to calculate the burnoff rate per contact per switching operation. From these values the cumulative burnoff rate of both the switching contact and resistance contact are determined and compared with limits or threshold values.

Abstract: A method of monitoring contact burnoff in tap changers operating under load in which the load current is measured and for nominal variation of the voltage of the particular tap parameters are stored which are used to calculate the burnoff rate per contact per switching operation. From these values the cumulative burnoff rate of both the switching contact and resistance contact are determined and compared with limits or threshold values.