Siemens SINAMICS S120 Function Manual page 266

Function modules
7.7 Extended torque control (kT estimator, Servo)
The k
the drive converter always has small errors, caused by voltage drives across the power
semiconductors etc. The lower the speed and therefore the output voltage, the greater the
negative influence on the estimation as a result of low voltage errors. This is the reason that
the estimation is de-activated below a specific speed. The estimated value is smoothed
using time constant p1795. The correction value for the torque constant is displayed in
r1797. By identifying the torque constant k
torque accuracy can be improved also below the speed threshold (p1752).
The k
Function diagrams (see SINAMICS S120/S150 List Manual)
● 7008 kT estimator
Overview of important parameters (see SINAMICS S120/S150 List Manual)
● r0108.1 Function module - extended torque control active
● p1780.3 Selects motor model PEM k
● p1780.8 Compensation of the voltage emulation error in the drive converter
Motor/drive converter identification
● p0352 Cable resistance
● p1909 Motor data identification control word
● p1910 Activates motor data identification routine, stationary (standstill)
kT estimator
● p1752 Motor model, changeover speed operation with encoder
● p1795 Motor model PEM k
● r1797 Motor model PEM k
Compensation of the voltage emulation error of the drive converter
● p1952 Voltage emulation error, final value
● p1953 Voltage emulation error, current offset
266
estimator is only activated above a specific speed (p1752). The terminal voltage of
T
estimator is activated using p1780.3 and the voltage compensation using p1780.8.
T
using the rotating motor identification routine, the
T
adaptation
T
adaptation smoothing time
T
adaptation correction value
T
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Drive functions