VAMP Ltd
Generator protection relay
Technical description
VAMP 210
VM210.EN004
Vamp 24h support phone: +358 (0)20 753 3264
39
3.2.
Directly connected generator with
unearthed generator neutral
L1
L2
L3
L1
L2
L3
G
~
U<
U<<
U>
U>>
X<
X<<
f>
f<
f<<
I ,U >
0
0
I ,U >>
0
0
P>
P>>
I >
0
I >>
0
3I>
3I>>
I >
2
F
>
X3
2
3
4
5
6
7
1
2
18
1
17
3
4
5
6
7
8
9
10
11
12
13
14
17
18
X1
X3
X4
X5
IL1
IL2
IL3
I
01
I
02
U
12
U
23
U
0
12
13
14
15
9
11
10
10
11
12
13
16
14
17
15
18
X3
X2
5
6
7
8
A1
T2
T1
A5
A4
A3
A2
IF
vamp210appl_2
+48 V DC
Digital
inputs
Blocking and
output matrix
Protection function
VAMP 210
Figure 3.2-1 Generator connected directly to the distribution busbar.
Unearthed generator neutral.
The neutral point of the generator winding is unearthed. The
busbar system is earthed via a separate earthing transformer.
In this case the earth-fault protection principle is straight-
forward. It is simply based on the measurement of the earth-
fault current (I
01
) between the generator and the distribution
busbars.