A model for an inductive VT was selected and
implemented in EMTP-ATP. This has allowed the influence
of the VT on a practical switching waveform to be examined.
It was found that the instantaneous change in voltage applied
to the VT primary winding during switching resulted in an
oscillation at 2.6 kHz being introduced to the waveform on
the VT secondary. This oscillation corresponds to the
resonant frequency of the VT. At 2.6 kHz, the VT frequency
response peaked in magnitude, providing a high gain.
Similarly, at a slightly higher frequency of 2.82 kHz, the VT
frequency response reaches a minimum. Transients at around
2.82 kHz will be attenuated by the VT.