Manual Optimization; Optimization Of Closed-Loop Armature Current Control - Siemens SINAMICS DCM Operating Instructions Manual

8.8

Manual optimization

Manual optimization is best performed using the STARTER commissioning tool.
For this purpose, STARTER provides the functions
● function generator and
● trace.
8.8.1

Optimization of closed-loop armature current control

Determining the armature circuit parameters (3 options)
1.
2.
3.
SINAMICS DCM DC Converter
Operating Instructions, 1.2012, C98130-A7066-A1-05-7619
Determining the armature-circuit parameters according to the motor list
Take the armature circuit resistance (p50110) and armature circuit inductance
(p50111) from the motor manufacturers data.
Disadvantage: The data is very imprecise and/or the actual values deviate
significantly.
Feeder cable resistances are not taken in the armature-circuit resistance. Additional
smoothing reactors and feeder cable inductances are not taken into account in the
armature-circuit inductance.
Roughly estimating the armature-circuit parameters from the rated data for the motor
and line supply
The basis of this formula is that for the rated armature current, there is a drop of 10%
of the rated armature voltage across the armature circuit resistance Ra.
This formula is based on the empirical value: The transition point from discontinuous to
continuous current is approximately 30% of the rated motor armature current.
Determining the armature circuit parameters by measuring the current/voltage
 Establish closed-loop current controlled operation
-p50084=2: Select closed-loop current controlled operation
-p50153=0: Precontrol disabled
-p50082=0: Switch-off the field to prevent motor from moving and, where
necessary, lock the rotor of the DC motor if retentiveness is too high.
-p50354=5 %: Threshold for overspeed protection
-Enter 0 for the main setpoint.
-If "OPERATION ENABLE" has been applied and the "SHUTDOWN"
command is entered, an armature current of approximately 0% will now flow.
p50110 = Armature-circuit resistance [Ω]
p50101 = Rated motor armature voltage [V]
p50100 = Rated motor armature current [A]
p50111 = Armature circuit inductance [mH]
r50071 = Rated unit supply voltage, armature [V]
p50100 = Rated motor armature current [A]
Commissioning
8.8 Manual optimization
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