Application of the transfer function to recognition of resonance overvoltages in transformer windings

作者：Florkowski Marek^*; Furgal Jakub

来源：Measurement Science and Technology, 2010, 21(12): 125702.

DOI：10.1088/0957-0233/21/12/125702

• overvoltage
• internal resonance
• power system
• transformer
• winding
• transfer function

Power transformer insulation systems are subjected to many stresses during normal operation due to lightning and switching. If the spectrum of incoming surge voltage matches the winding one, a corresponding resonance will be excited. Therefore external transients occurring in power systems might trigger internal overvoltages of a large maximum value in transformer windings. Overvoltages having such a character have been the main cause of many power transformer failures. This paper presents a novel approach to the identification of sensitive zones in the transformer windings based on measurements of overvoltages inside the windings and the frequency dependences of admittance of the power transformer. The frequency characteristics of the transformer winding may determine those regions in the frequency spectrum. The presented methodology might be used both for design optimization and diagnostics of power transformers.

• 出版日期2010-12