High Frequency Transfer Characterization of a Three Phase Transformer Using Two-port Vector Network Analyzer

Abstract

This paper proposes a novel methodology to obtain the high frequency transfer characteristics of a three phase power transformer using two-port Vector Network Analyzer (VNA), which has been widely used in the high frequency RF electronic circuit. For a 50kVA rated three phase power transformer, fifteen measurements using two-port VNA were conducted to assemble a six by six S-parameters of the transformer, and then it is used in the circuit simulator to predict the secondary side output voltage and current due to an arbitrary pulse input in the primary side of the transformer. The measurement repeatability and reliability were confirmed by using the redundancy of the diagonal S-parameters of the matrix and from the winding turn ratio calculated from the measured S-parameters as well. Finally, the sinusoidal and pulse signal responses in the secondary side, which are calculated using the proposed methodology are described.