ABB Relion 670 series - Page 357

Signals ZOUT_n (outer boundary) and ZIN_n (inner boundary) in figure 185 are
related to the operation of the impedance measuring elements in each phase separately
(n represents the corresponding A, B and C). They are internal signals, calculated by
ZMRPSB (68) function.
The tP1 timer in figure
185 serve as detection of initial power swings, which are
usually not as fast as the later swings are. The tP2 timer become activated for the
detection of the consecutive swings, if the measured impedance exit the operate area
and returns within the time delay, set on the tW waiting timer. The upper part of
figure
185 (internal input signal ZOUT_A, ZIN_A, AND-gates and tP-timers) are
duplicated for phase B and C. All tP1 and tP2 timers in the figure have the same settings.
ANSI05000113-2-en.vsd
AND
ZINA
AND
DET-A
OR
AND
AND
ZOUTA
-loop
ZOUTB
ZOUTC
OR
detected
OR
-loop
0-tP1
0
0-tP2
0
0
0-tW
ANSI05000113 V2 EN
Figure 185: Detection of power swing in phase A
ANSI01000057-2-en.vsd
DET-A
DET-B
DET-C
DET1of3 - int.
DET2of3 - int.
AND
AND
AND
OR
OR
ANSI01000057 V2 EN
Figure 186: Detection of power swing for 1-of-3 and 2-of-3 operating mode
1MRK505222-UUS C Section 6
Impedance protection
351
Technical reference manual