The ratio
between the secondary current injection and the primary measured current value should
stay the same regardless the coil/plunger position.
In addition, the measurement the zero sequence voltage should reflect the real value on
the primary side and not just the voltage the PAW. score 10
represents the worst case and should not used!
.
RS
UNE_3
U0d
IS
ICI_3
UNE_2
PAW
Figure 162: Possible measurement points the P-coil with PAW
The below list possible combinations and their score:
Combination the
measurement
points:
Usual measurement accuracy Score*)
ICI_3 UNE_2
UNE3
IS
ICI3 UNE2 ±10% 5
ICI3 UNE3 ±3% 3
ICI3 U0d ±3% 3
*) score represents the best solution record the measured values.
PAW Power auxiliary winding
W Winding
P-coil with PAW
In this case, the P-coil functions transformer. The accuracy the results strongly de-
pends constant conversion ratio between the PAW and the main winding.Page 232 Commissioning the HPCI
We take care it
