The configuration effect of UHV substation on VFTO and its inhibitory effect analysis

The very fast transient overvoltage (VFTO) is changed under different configurations, the voltage waveform graph and amplitude-frequency characteristic curve are acquired on Dommel transmission line theory, The influence of disconnector (DS) closing sequence and potential transformer (PT) position on VFTO is computed by simulation. And the inhibitory effect of different suppression equipment on VFTO is also given. The results show that the VFTO dominant frequency and the corresponding amplitude can be reduced by reasonable choice of DS closing sequence and PT installation site. Compared to the closing resistor, ferrite has advantages in suppressing VFTO. The VFTO peak increases first then decreases with the increase of the length of the ferrite.