ABB Relion 670 Series Technical Reference Manual page 369

1MRK505222-UUS C
Technical reference manual
• the minimum current exceeds 0.10 I
setting).
• the maximum voltage falls below 0.92 VBase
• the voltage Ucosφ (the voltage in phase with the generator current) has an angular
velocity of 0.2...8 Hz and
• the corresponding direction is not blocked.
IEC07000004 V1 EN
Figure 193: Different generator quantities as function of the angle between the
equivalent generators
An alarm is given when movement of the rotor is detected and the rotor angle exceeds
the angle set for 'WarnAngle'.
Slipping is detected when:
• a change of rotor angle of min. 50 ms is recognized
• the slip line is crossed between Z
When the impedance crosses the slip line between Z
1 and between Z and Z
C
signal EXTZONE1 is high (external device detects the direction of the centre of slipping).
(I is IBase parameter set under general
N N
and Z .
A B
in zone 2. The entire distance ZA-ZB becomes zone 1 when
A
Section 6
Impedance protection
en07000004.vsd
and Z it counts as being in zone
B C
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