ABB REG670 - Page 294

OperationZ1, OperationZ2: With the settingsOperationZ1 and OperationZ2 each
zone can be set On or Off.
For the two zones the impedance settings are made as shown in figure 151.
R
X
Z1 or Z2
-XoffsetZ1 or -XoffsetZ2
Z1diameter or Z2diameter
IEC06000460_2_en.vsd
IEC06000460 V2 EN
Figure 151: Impedance settings for the fast (Z1) and slow (Z2) zone
The impedances are given in pu of the base impedance calculated according to
equation 171.
IBase
UBase
Z
Base
3
=
EQUATION1776 V1 EN (Equation 171)
XoffsetZ1
and XoffsetZ2, offset of impedance circle top along the X axis, are given
negative value if X < 0.
XoffsetZ1: It is recommended to set XoffsetZ1= - X
d
'/2 and Z1diameter = 100% of
ZBase.
Section 8 1MRK 502 071-UEN -
Impedance protection
288 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual