ABB Relion 670 series - Page 377

7.10.6 Monitored data
PID-3526-MONITOREDDATA v3
Table 161: PSPPPAM (78) Monitored data
Name Type Values (Range) Unit Description
SFREQ REAL - Hz Slip frequency
SLIPZOHM REAL - Ohm Slip impedance in ohms
SLIPZPER REAL - % Slip impedance in percent of ZBase
VCOS REAL - kV UCosPhi voltage
VCOSPER REAL - % VCosPhi voltage in percent of VBase
7.10.7 Operation principle
SEMOD155755-4 v4
If the generator is faster than the power system, the rotor movement in the impedance and
voltage diagram is from right to left and generating is signaled. If the generator is slower than the
power system, the rotor movement is from left to right and motoring is signaled (the power
system drives the generator as if it were a motor).
The movements in the impedance plane can be seen in Figure
196. The transient behavior is
described by the transient EMF's E
A
and E
B
, and by X'
d
, X
T
and the transient system impedance Z
S
.
1MRK 502 066-UUS B Section 7
Impedance protection
371
Technical manual