ABB RET670 Commissioning Manual page 123

1MRK 504 154-UUS B
I I
≤
t ovrl p
,
EQUATION14042 V1 EN-US
Reference is made to the numerical values of the example, explained in the "Setting guidelines" of
Application Manual . A test current equal to 2.5 time the base current of the generator is
the
chosen; this choice is related to the selected test voltage that is applied while testing the point SE
and RE.
I 2 5 .
= ×
t
EQUATION14043 V1 EN-US
The parameter
percent of the parameter
value of the reactance is
ReachZ
X
=
RZ 1
EQUATION14044 V1 EN-US
The calculation of the test voltage, that is related to
has imaginary part X
RRZ 1
=
EQUATION14045 V1 EN-US
The magnitude of the impedance Z
=
Z
RZ 1
EQUATION14046 V1 EN-US
Hence the reference voltage of the test of the boundary between zone 1 and zone 2 is
V Z
=
t RZ , 1
EQUATION14047 V1 EN-US
If the test voltage is lower than V
test voltage is higher than V
Considering the resistances and reactances which are related to the settings (
ForwardX ) and ( ReverseR , ReverseX ):
ForwardR
R
=
FwdR
EQUATION14048 V1 EN-US
ForwardX
X
=
FwdX
EQUATION14049 V1 EN-US
Commissioning manual
I
9000
rp
I 4 36000
= × = × =
ovrl
I 1
rs
I 2 5 8367 20918 . A
= × =
Base
ReachZ1 defines the boundary between zone 1 and zone 2; it is expressed in
ForwardX . If the setting of ReachZ1 = 12% , then corresponding primary
1 ForwardX
ZBase
× ×
100 100
and real part R
RZ1
Re achZ 1 ForwardR
ZBase
× ×
100 100
+ = +
2 2 2
R X 0.009 0.068
RZ 1 RZ 1
I 0 069 20918 1435 .
× = × =
RZ 1 t
t,RZ1
8 19 .
ZBase
× = ×
100 100
59 33 .
ZBase
× =
100 100
A
12 59 33 .
0 9522 0 .
= × ×
100 100
ReachZ1 , is based on the impedance Z
:
RZ1
12 8 19 .
0 9522 0 0 .
= × ×
100 100
is:
RZ1
= W
2
0.069
V
(or in opposition), then the test is related to the zone 1; if the
t,RZ1
, then the test is related to the zone 2.
0 9522 0 078 . .
= Ω
0 9522 0 565 . .
× = Ω
Testing functionality by secondary injection
.0 0 68Ω
=
. 0 0 9Ω
=
ForwardR ,
Section 10
(Equation 2)
(Equation 3)
(Equation 4)
that
RZ1
(Equation 5)
(Equation 6)
(Equation 7)
(Equation 8)
(Equation 9)
117