ABB RELION REX640 Technical Manual page 623

1MRS759142 C
REX640
Technical Manual
GUID-1B4F8735-D81E-4FC8-9A50-B5499CE5D463 V1 EN
Figure 341: Low voltage test arrangement. The three-phase low voltage source
can be the station service transformer.
The Tapped winding control setting parameter has to be set to "Not in use" to make
sure that the monitored current values are not scaled by the automatic adaptation to the
tap changer position. When only the angle values are required, the setting of Tapped
winding is not needed since angle values are not affected by the tap changer position
adaptation.
When injecting the currents in the high voltage winding, the angle values
I_ANGL_A1_B1, I_ANGL_B1_C1, I_ANGL_C1_A1, I_ANGL_A2_B2,
I_ANGL_B2_C2 and I_ANGL_C2_A2 have to show +120 deg. Otherwise the phase
order can be wrong or the polarity of a current transformer differs from the polarities
of the other current transformers on the same side.
If the angle values I_ANGL_A1_B1, I_ANGL_B1_C1 and I_ANGL_C1_A1 show
-120 deg, the phase order is wrong on the high voltage side. If the angle values
I_ANGL_A2_B2, I_ANGL_B2_C2 and I_ANGL_C2_A2 show -120 deg, the
phase order is wrong on the low voltage side. If the angle values I_ANGL_A1_B1,
I_ANGL_B1_C1 and I_ANGL_C1_A1 do not show the same value of +120, the
polarity of one current transformer can be wrong. For instance, if the polarity of the
current transformer measuring IL2 is wrong, I_ANGL_A1_B1 shows -60 deg,
I_ANGL_B1_C1 shows -60 deg and I_ANGL_C1_A1 shows +120 deg.
When the phase order and the angle values are correct, the angle values
I_ANGL_A1_A2, I_ANGL_B1_B2 and I_ANGL_C1_C2 usually show ±180 deg.
There can be several reasons if the angle values are not ±180 deg. If the values are 0
deg, the value given for CT connection type is probably wrong. If the angle values are
something else, the value for Clock number can be wrong. Another reason is that the
combination of Winding 1 type and Winding 2 type does not match Clock number. This
means that the resulting connection group is not supported.
Example
If Winding 1 type is set to "Y", Winding 2 type is set to "y" and Clock number is set to
"Clk num 1", the resulting connection group "Yy1" is not a supported combination.
Similarly if Winding 1 type is set to "Y", Winding 2 type is set to "d" and Clock number
Section 4
Protection functions
617