Hitachi Relion 670 Series Applications Manual page 152

Section 8
Current protection
8.2 Two-step directional phase overcurrent protection
D2PTOC
8.2.1 Function revision history
Document
revision
A
B
C
D
E
F
G
H
J
K
M
N
8.2.2 Identification
Function description
Directional phase overcurrent
protection, two steps
8.2.3 Application
The two-step directional phase overcurrent protection D2PTOC is used in several applications in the
power system. Some applications are:
• Short circuit protection of feeders.
• Back-up short circuit protection of transmission lines.
• Back-up short circuit protection of power transformers.
In many applications several steps with different current pickup levels and time delays are needed.
D2PTOC can have one or two, individually settable steps. The following options are possible:
Non-directional / Directional function: In most applications the non-directional functionality is used.
This is mostly the case when no fault current can be fed from the protected object itself. In order to
achieve both selectivity and fast fault clearance, the directional function can be necessary.
146
Product History
revision
2.2.1 -
2.2.1 -
2.2.2 -
2.2.3 -
2.2.3 -
2.2.4 -
2.2.4 -
2.2.4 -
2.2.4 -
2.2.5 • The harmonic restraint function changed to freeze the definite and IDMT timers.
• The previously called setting tDef1 is changed to t1 for more clear understanding.
2.2.6 -
2.2.6 Changed minimum set value for k-factor multiplier for IDMT curves.
IEC 61850
identification
D2PTOC
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GUID-71346D64-9EF5-4E35-879B-C4C12945F330 v2
IEC 60617 ANSI/IEEE C37.2
identification device number
51_67
IEC15000155 V3 EN-US
Railway application RER670
1MRK506375-UEN Rev. N
SEMOD129998-1 v8
M14885-1 v6
M15335-3 v9
Application manual