Maschinenfabrik Reinhausen Gmbh

Siemens Aktiengesellschaft

Pharmacia & Upjohn Company

Rainer Frotscher

Andreas Sachsenhauser

Wolfgang Albrecht

Dieter Dohnal

Werner Hartmann

Roman Renz

Christian Hammer

Sylvio Kosse

Christian Pircher

Andreas Stelzer

Joerg Teichmann

Andreas Lawall

Christian Kotz

Norbert Wenzel

Klaus Schlepp

Jörg Teichmann

Christoph Heynen

Ralf Hartwig

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.

Monitoring of gases produced in an insulating-means circuit

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.

Tap changer with vacuum interrupters

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.

Method for gas analysis of on-load tap changers

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.

Method of monitoring the contact burnoff in tap changers

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Regenstauf, Germany

Rainer Frotscher