Prüfung zu Umgebungsbedingungen bis zu 70 kV für IEC 60060-1
Prof. Stefan Kornhuber studierte elektrische Energietechnik an der Technischen Universität Graz. Er erhielt sein Diplom 2005 und promovierte 2007. Bis 2006 arbeitete er an der Versuchsanstalt für Hochspannungstechnik Graz GmbH an der Technischen Universität Graz im Bereich von Hochspannungsprüfungen, Berechnung und Untersuchung transienter Vorgänge in der Energietechnik. Zwischen 2006 und 2013 arbeitete er für Lemke Diagnostics GmbH und Doble Lemke GmbH in verschiedenen Bereichen. Ab Februar 2013 war er für ABB AG im Transformatorwerk in Halle tätig und leitet den Bereich Zustandsbeurteilung von Transformatoren und ab März 2014 die Prüffelder im Bereich Engineering Solutions. Im Oktober 2014 folgte er dem Ruf an die Hochschule Zittau/Görlitz - Professur für Hochspannungstechnik/ Theoretische Elektrotechnik. Die Forschungsschwerpunkte setzt er auf äußeren und inneren Grenzflächen von polymeren Isolierstoffen, deren Prüf- und Messmethoden und deren technischen Diagnostik. Er ist Mitglied von verschiedenen Arbeitsgruppen bei der CIGRE, IEC und dem DKE und leitet die Arbeitsgruppe CIGRE D1.58 und IEC TC 112 WG 3.
Contribution to the behavior of the breakdown voltage in air as a function of humidity and temperature for small electrode distances (< 20 cm)
Currently the climate correction of IEC 60060:2010 is under consideration of the CIGRE WG D1.50 as well also the IEC 60071 is updated with an adapted climate correction. Anyhow, the available corrections either do not cover the voltage range (IEC 60060-1:2010) below a system voltage of 72.5 kV or are considered to have too small reproduceable data base (IEC 62271-1:2017). Additional in connection with the investigations for alternatives for the insulating gas SF6, air-insulated switchgear in the medium voltage range is again interest. In order to keep these switchgear systems as small as possible and still usable in climatically difficult areas, a suitable climate correction is required for the voltage range up to 72.5 kV and strike distances smaller than 20 cm. The insulating behavior of air gaps depends on several factors, beside the electrode configuration. These include, among other things as pressure and ion density, the temperature and the humidity. The aim of the project is to create a climate correction on a sufficiently reproducible broad database for system voltages up to 72.5 kV and a climate range of 5 to 40 °C and 1 to 40 g/m3 absolute humidity. It is intended for future use in IEC 60060-1:2010 and may be suitable for converting measurements and results from high voltage tests to standard atmospheric conditions. In order to investigate the temperature and humidity behavior, a climate chamber was designed and set up in the high voltage laboratory. The special climate chamber was built up by using a pressure vessel, a customized temperature and humidity preparation system and an electrode fixing system with precise distance setting. The chamber has an air volume of about 1.2 m3 and can be used for alternating and direct voltages up to 100 kV as well as lightning impulse voltages up to about 300 kV. The air conditioner is able to provide temperatures of -20...+ 80 °C in the test room, with variable air humidity above 0 °C. The climate (temperature, humidity, air pressure) is measured close to the discharge area. As spark gaps as ball-ball electrodes are used. The impact widths are initially 5 to 50 mm, which covers the range up to 90 kV AC and 250 kV lightning impulse voltage. In this paper the measurement setup and results are provided and compared with existing models.