Effect on Inner Electrical Field Distributions of EHV Converter Transformer by Insulation Material Characteristics

Abstract:

In order to analyze inner electrical field distributions of EHV converter transformers windings end at valve side, a simulation circuit model of oil-paper combination insulations is established in this paper. Then ANSYS10.0 finite element method (FEM) is used to calculate the electrical field distributions under four different excited volatges, containing DC voltage, AC voltage, superimposed DC-AC voltage and polarity reversal (PR) voltage respectively. Simulation results show that when only under DC voltage, resistive electrical field distributions highly convergen on insulating cardboard whose resistivity is correspondingly big. While only under AC voltage, capactive electrical filed distributions highly centeralize on insulating oil whose dielectic capacity is correspondingly small. And under superimposed DC-AC voltage, its unformity lies in DC voltage or AC voltage function alone. While under transient polarity reversal volatge, its distrbutions present like tooth and electrical strength of insulating oil is bigger than that of insulating paper.

• Periodical: Applied Mechanics and Materials (Volume 320)
• Pages: 241-247
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.320.241
• Online since: May 2013
• Authors: Ping Zhang, Xin Peng Nie, Jun Ping Meng, You Hua Wang
• Keywords: Converter Transformer, HVDC Power Transmission, Insulation Charactersitics, Oil-Paper Combination Insulation Model, Polarity Reversal Voltage

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