Sensitive Directional Residual Overcurrent And Power Protection Sdepsde (67N); Identification; Application - Hitachi Relion 670 Series Applications Manual

1MRK511407-UUS Rev. N
In a transmission network a normal value of RCA is about 80°.
VPolMin: Minimum polarization (reference) voltage % of VBase.
I>Dir: Operate residual current level for directional comparison scheme. The setting is given in % of
IBase. The pickup forward or pickup reverse signals can be used in a communication scheme. The
appropriate signal must be configured to the communication scheme block.
8.4 Sensitive directional residual overcurrent and power
protection SDEPSDE (67N)
8.4.1

Identification

Function description
Sensitive directional residual over
current and power protection
8.4.2

Application

In networks with high impedance grounding, the phase-to-ground fault current is significantly smaller than
the short circuit currents. Another difficulty for ground fault protection is that the magnitude of the phase-
to-ground fault current is almost independent of the fault location in the network.
Directional residual current can be used to detect and give selective trip of phase-to-ground faults in high
impedance grounded networks. The protection uses the residual current component 3I
is the angle between the residual current and the residual voltage (-3V
characteristic angle. Alternatively, the function can be set to strict 3I
Directional residual power can also be used to detect and give selective trip of phase-to-ground faults in
high impedance grounded networks. The protection uses the residual power component 3I
φ, where φ is the angle between the residual current and the reference residual voltage, compensated
with a characteristic angle.
A normal non-directional residual current function can also be used with definite or inverse time delay.
A backup neutral point voltage function is also available for non-directional residual overvoltage
protection.
In an isolated network, that is, the network is only coupled to ground via the capacitances between the
phase conductors and ground, the residual current always has -90º phase shift compared to the residual
voltage (3V
In resistance grounded networks or in Petersen coil grounded, with a parallel resistor, the active residual
current component (in phase with the residual voltage) should be used for the ground fault detection. In
such networks, the characteristic angle is chosen to 0º.
As the magnitude of the residual current is independent of the fault location, the selectivity of the ground
fault protection is achieved by time selectivity.
Phasor measurement unit RES670
Application manual
IEC 61850
identification
SDEPSDE
). The characteristic angle is chosen to -90º in such a network.
0
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IEC 60617 ANSI/IEEE C37.2
identification device number
- 67N
), compensated with a
0
level with a check of angle φ.
0
Section 8
Current protection
SEMOD171436-1 v4
SEMOD172025-2 v4
SEMOD171959-4 v12
· cos φ, where φ
0
· 3V · cos
0 0
131