Wave process in scale-down model of UHVDC converter transformer winding under the lightning impulse voltage

Abstract

An experimental scale-down model of UHVDC converter transformer is designed and manufactured to study the wave process in the winding under impulse voltage. Nine outgoing lines are set up on the different winding coil of the scale-down model. The voltage waveforms of different outgoing lines are obtained by lightning impulse test. The simulation model of scale-down transformer is established to calculate the distributed parameter matrices by the finite element method. The equivalent circuit of transformer winding is proposed to calculate the node voltage waveforms and the potential gradient distribution. The comparative analysis of test and simulation results shows that the oscillating voltage occurs in the winding and the simulation results can reflect the wave process characteristics.