ABB Relion 670 Series RES670, Technical Manual

Page: 157 / 888

ZMRPSB (68) function can operate in two operating modes:
• The 1 out of 3 operating mode is based on detection of power swing in any of the three
phases. Figure 37 presents a composition of an internal detection signal DET-A in
this particular phase.
• The 2 out of 3 operating mode is based on detection of power swing in at least two out
of three phases. Figure 38 presents a composition of the detection signals DET1of3
and DET2of3.
Signals ZOUT_n (outer boundary) and ZIN_n (inner boundary) in figure 37 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 37 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 37 (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 37: Detection of power swing in phase A
1MRK 511 365-UUS A
Section 7
Impedance protection
Phasor measurement unit RES670 2.1 ANSI 151
Technical manual