Micom P634 - Definite-Time Overcurrent Protection (Function Groups DTOC1 to DTOC4); Enabling or Disabling DTOC Protection

3.23 Definite-Time Overcurrent Protection (Function Groups
DTOC1 to DTOC4)
In the P634, a three-stage definite-time overcurrent protection function (DTOC
protection) is available for up to 4 transformer ends. The measured values to be
monitored by the respective DTOC functions are selected using a setting
parameter.
These values can also be quantities formed by summation of the current values
from two user-selected transformer ends.
Phase current values as well as negative-sequence and residual current
measured values are monitored.
The function group DTOC1 will serve as an example to illustrate the operation of
the DTOC protection functions. The same will apply to function groups DTOC2,
DTOC3 and DTOC4.
64Z5070A
DTOC1:
Select. meas. input
[ 019 103 ]
0
1
2
4
3
0: End a
1: End b
2: End c
4: End d
3: Current summation
40
IA,y
IB,y
IC,y
IN,y
IA,a
IB,a
IC,a
IN,a
IA,b
IB,b
IC,b
IN,b
IA,c
IB,c
IC,c
IN,c
IA,d
IB,d
IC,d
IN,d
ΣIA
ΣIB
ΣIC
ΣIN
Fig. 3-106: Selection of measured values for DTOC protection.
3.23.1 Enabling or Disabling DTOC Protection
DTOC protection can be enabled or disabled using setting parameters. Moreover,
enabling can be carried out separately for each parameter set.
P634
3 Operation
3-152 P634/EN M/R-42-A // P634‑311‑653