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Commissioning current injection
13.1 Impact the P-coil's design the results of
current injection
air-gap
d
higher
lower Imin
Imax
moveable
core
spindle
moveable
core
fixed core
primary
winding
PAW
MW
Figure 132: Basic design continuously adjustable P-coil
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.
.5.
In addition, the measurement the zero sequence voltage should reflect the real value on
the primary side and not just the voltage the PAW. The ratio
between the secondary current injection and the primary measured current value should
stay the same regardless the coil/plunger position
