ABB RET 543 - Page 52

Fig. 7 Protection, control, measurement and supervision functions of an Dyn-connected power trans-
former, implemented with RET 543 transformer terminal and an REF 543 feeder terminal. The
neutral point of the low-voltage network is earthed via a high impedance. REF 610 is used as a
backup relay on the high-voltage side. This sceme can be applied also for parallel connected
transformers.
Dyn-trafo_impEarthedLVn
MF
MF
RET/3I
REF/4I
RET/3I
REF/3I
RET/1I
REF/1I
RET/RTD
RET/1U
REF/3U
3DI> 87T
RET 54_
3I
U
TCS
R
513I>
50
51N
50N
I >
0
683I >
3 49T
513I>
50
HV
LV
HV
62BFCBFP
HV
2
I > 46
HV
0
DI > 87TN
LV
51N
50N
I >
0
LV
I
0
3I
I
0
T
O
T
w
oo
90
CBFP
LV
62BF
U
U
3U
3I
51N
0
I >
REF 54_
CBFP 62BF
50N
3I>
50
51
3U<
3U>
27
59
R
TCS
I
0
P
Q
50N
62BF
REF 610
CBFP
I >
0
51N
3I> 51
50
LO 86
TCS
3I I
0
000
HV
R
000
p>
Q
Q
2f
000
000
Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
52