Protection Functions
210 PRS-7367
3.44 Transformer Fuse failure supervision TF VTS
3.44.1 Overview
The main and important function of Fuse failure supervision (VTS) is to continuously supervised
the protected electrical network by the help of instrument transformer (VT) and to ensure the
stability of accurate operation. If any kind of trouble situation happened in the following circuits
between instrument transformer (VT) and intelligence electronic device (IED), cause many
un-legal operation of protection function are follows:
ï‚· Overcurrent protection with voltage controlled element
ï‚· Synchronization and many other protections
The operation principle criteria of fuse failure supervision VT’s based on the following points:
ï‚· Negative-sequence voltage is greater than 8V
ï‚· Each phase voltage is less than 30V
In addition, the VTS can be configured on the high-voltage side, middle-voltage side or low-voltage
side of the transformer as a backup protection for each side.
3.44.1.1 Function Block