Does anyone out there have any experience of the application of Vtm (Voltage-controlled time-multiplier) protection on a high Voltage distribution system?
I believe the system is based on overcurrent relays which are arranged to reduce their time multipler settings as the system Voltage falls...
I work for a UK distribution network operator.
We fit Neutral Voltage Displacement protection on our 33/11kV delta-star transformers in order to detect and clear earth-faults backfed from the 11kV busbars.
Traditionally, the NVD protection signal has been derived from a star-connected set of...
