Siemens siprotec 7SA6, Manual

Page: 241 / 876

Functions
6-51
7SA6 Manual
C53000-G1176-C156-2
current transformers600 A/5 A
voltage transformers110 kV/0.1 kV
The resulting minimum load impedance is therefore:
When applying the settings with a personal computer and DIGSI
®
4 these values may
be entered as primary values. The conversion to secondary values is
when applying a security margin of 10 % the following is set:
primary:
R load (Ø-E)
=
97.98 Ω
or
secondary:
R load (Ø-E)
=
10.69 Ω
.
The spread angle of the load trapezoid
ϕ
load (Ø-E)
(address
1242
) and
ϕ
load (Ø-
Ø) (address
1244
) must be greater (approx. 5°) than the maximum arising load angle
(corresponding to the minimum power factor cos
ϕ
).
Calculation example:
minimum power factor
cos
ϕ
min
= 0.63
ϕ
max
= 51°
Setting ϕ
load (Ø-E)
=
ϕ
max
+ 5° =
56
°.
6.2.3.3 Settings
Note: The indicated secondary current values and values of impedance for setting
ranges and default settings refer to I
N
= 1 A. For the nominal current 5 A the current
values are to be multiplied by 5. The values of impedance are divided by 5.
Addresses which have an „A“ attached to its end can only be changed with DIGSI
®
4
in “Additional Settings“.
R
Load prim
U
min
3
I
L max
⋅
-------------------------
0.9 110 kV
⋅
3 525 A
⋅
--------------------------
108.87
Ω
= = =
R
Load sec
N
CT
N
VT
---------- R
Load prim
⋅
600 A/5 A
110 kV/0.1 kV
-------------------------------------- 108.87
Ω ⋅
11.88
Ω
= = =
Addr. Setting Title Setting Options Default Setting Comments
1201 FCT Distance ON
OFF ON Distance protection is
1202 Minimum Iph> 0.10..4.00 A 0.10 A Phase Current threshold for
dist. meas.
1215 Paral.Line Comp NO
YES YES Mutual coupling parall.line
compensation
1232 SOTF zone with Pickup (non-directional)
with Zone Z1B
Inactive Inactive Instantaneous trip after Swit-
chOnToFault
1241 R load (Ø-E) 0.100..250.000 Ohm;
∞ ∞
Ohm R load, minimum Load Impe-
dance (ph-e)