Zusammenfassung
Im vorliegenden Beitrag wird zuerst auf historische Aspekte und Grundsätzliches bezüglich der Herstellung von Isolierstoffen aus Zellulose, d. h. Papier und Pressspan, eingegangen. Weiterführend werden Grundlagen der elektrischen Dimensionierung der Isolierung von Leistungstransformatoren beschrieben. Im Speziellen werden die Besonderheiten bei Gleichspannungsbelastung der Isolierung sowie die Anforderungen an Entwicklungsversuche von Isolierkomponenten und –Systemen erläutert. Stabile, gut gepresste Wicklungen sind wichtig, um die gewaltigen oszillierenden Kräfte bei Kurzschluss im Netz zu beherrschen. Die Einflüsse der Materialwahl sowie der Trocknungs- und Ölimprägnierungsprozesse werden anhand von Versuchsergebnissen mit kleinen Scheibenspulenmodellen erklärt. Den Abschluss bildet eine Auflistung von praktischen Hinweisen, die zur Verbesserung der Betriebssicherheit und zur erhöhten Betriebsdauer von Leistungstransformatoren beitragen.
Abstract
This article first reports on the history and fundamentals regarding the manufacturing of insulation products made from cellulose, i.e. presspaper and pressboard. Subsequently, the basics of electrical design of power transformer insulation are described. In particular, the peculiarities of DC-stresses on the insulation and the requirements with regard to development tests of insulation components and systems are detailed. Robust and well-clamped windings are essential in order to withstand the internal oscillating forces which are caused by short-circuit events in the grid. The impact of the selection of materials, of the drying and oil impregnation processes is explained by results from laboratory investigations with small disk winding models. Finally, a multitude of hints is given that contribute improving the reliability and prolonging service time of power transformers.
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Notes
Transformerboard: Markenname der Firma Weidmann.
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Krause, C. Isolierstoffe aus Zellulose für die elektrische Isolierung von Leistungstransformatoren. Elektrotech. Inftech. 129, 332–341 (2012). https://doi.org/10.1007/s00502-012-0030-3
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DOI: https://doi.org/10.1007/s00502-012-0030-3