ABB ACS800-67, System Description And Start-Up Manual

Page: 40 / 120

40 System description
Phasing checks executed at start-up
During the encoder calibration and voltage synchronization, the software ensures that the
grid, encoder, stator and rotor phasings are correct. The U-phase (and V- and W-phase) of
the grid is connect to the U-phase of the stator via main circuit breaker.
The following checks are automatically executed at start-up in the order in which they are
listed:

Grid phasing
Grid flux is a measured quantity. The angle of the flux is calculated. The angle is derivated
and filtered. As a result, angular speed of the grid flux is received. If the speed is negative,
the grid phasing is incorrect.

Encoder phasing
The generator actual speed is received from the encoder speed feedback. If the direction
is negative, the encoder phasing is wrong.
Note: This check is executed only if RUN command has been issued.

Stator phasing
During normal operation, the grid flux and the stator flux rotate clockwise at the grid
frequency. If the sum of the rotor flux speed and slip does not rotate at the frequency of the
stator flux, the stator phasing is incorrect.
Note: The rotation speed of the rotor flux is independent of whether the rotor phasing is
correct or not.

Rotor phasing
The dot product between the two flux vectors is approxi1 when the rotor phasing
is correct and approximately -1 when the rotor phasing is incorrect.
Stator
Grid
Main circuit breaker
U V W U W V
NUIM-6x
Commissioning phasing requirement