Toshiba GR200 Series Instruction Manual page 390

Line differential protection ied

Hide thumbs Also See for GR200 Series:

Table of Contents

VT failure detection (VTF)

If a failure occurs on the secondary circuit in the voltage transformer (VT), the operation in

relays cannot be obtained properly because the relays do not measure voltages correctly.

Therefore, the VT failure detection (VTF) function is provided to block operating the relays

upon occurrence of the VT failure. Accordingly, if a VT failure is detected by the VTF function,

an alarm signal is issued for the relays upon occurrence of the VT failure. Accordingly, an

alarm signal is issued if a VT failure is detected by the VTF function; a detection signal by the

VTF function blocks operating the relay for the voltage monitor

After the disappearance of the VT failure, the VTF function can take account of the VT

secondary circuit being in healthy condition in the three-phase; the operation of the VTF

function is reset

the VTF alarm is automatically removed and then the user can find resetting the VTF alarm.

Note: The VTF function can block the operation in several relays, but it does not block

the operation in other relays. To know the blocking, refer sections of the respective

protection functions.

Note: The user can programmable the operation using the setting and the PLC signals.

─────────────────────────────────────────────────────────────────

Several IED models do not have VTF detection features. To determine whether the

features are implemented in the IED or not, locate the IED ordering number; and check the

order number at "G&T position" referring to the comparison table below. For more information,

Appendix: Ordering

Table 2.30-1 Comparative table in respective ordering numbers

VTF detection (VTF)

✓: Applicable

. Thus, the blocked relays are allowed to operate again. Incidentally, issuing

NA: Not applicable

6F2S1914 (0.49)

Ordering No. at "G&T"

GRL200 (Soft 033 & 037)

Chapters

Table of Contents