ABB ACS850 series, Manual

Page: 67 / 370

Program features 67
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User-definable U/f curve
The user can define a custom U/f curve (output voltage as a function of frequency).
The curve can be used in special applications where linear and quadratic U/f ratios
are not adequate (e.g. when motor break-away torque needs to be boosted).
Note: The U/f curve can be used in scalar control only, i.e, when 99.05 Motor ctrl
mode setting is Scalar .
Note: Each user-defined point must have a higher frequency and higher voltage than
the previous point.
WARNING! High voltage at low frequencies may result in poor performance
or motor damage due to overheating.
Settings
Parameter group 38 Flux ref (page 217 ).
„
Autophasing
Autophasing is an automatic measurement routine to determine the angular position
of the magnetic flux of a permanent magnet synchronous motor or the magnetic axis
of a synchronous reluctance motor. The motor control requires the absolute position
of the rotor flux in order to control motor torque accurately.
f (Hz)
Custom U/f ratio Voltage (V)
Par. 38.13
Par. 38.12
Par. 38.11
Par. 38.10
Par. 38.09
Par. 38.04 Par. 38.05 Par. 38.06 Par. 38.07 Par. 38.08