ABB Relion 670 Series Technical Reference Manual page 354

Section 6
Impedance protection
348
D
Rv
LdAngle
D
D
Rv
j
ANSI05000175 V2 EN
Figure 184: Operating characteristic for ZMRPSB (68) function (setting parameters
in italic)
The impedance measurement within ZMRPSB (68) function is performed by solving
equation 72 and equation
applicable for phases B and C).
æ ö
V
A
£
Re Rset
ç ÷
I
è ø
A
EQUATION1557 V1 EN
æ ö
V
A
£
Im Xset
ç ÷
I
è ø
A
EQUATION1558 V1 EN
The R and X are R and X boundaries.
set set
jX
X1OutFw
X1InFw
R1FInRv
D
Rv
Rv
RLdInRv RLdInFw
RLdOutRv
D
Rv
73 (Typical equations are for phase A, similar equations are
1MRK505222-UUS C
R1LIn
ZL
D
Fw
R1FInFw
j
D
Fw
D
Fw
D
Fw
D
Fw
RLdOutFw
X1InRv
X1OutRv
ANSI05000175-2-en.vsd
Technical reference manual
j
D
Fw
LdAngle
R
(Equation 72)
(Equation 73)