Efficient Networks Siemens Sinamics S120 - Manual (Page 91)

Servo control
3.11 Sensorless operation (without an encoder)
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
91
Series reactor
When high-speed special motors are used, or other low leakage induction motors, a series
reactor may be required to ensure stable operation of the current controller.
The series reactor can be integrated via p0353.
Commissioning/optimization
1. Estimate the motor current p1612 on the basis of the mechanical conditions (I = M/kt).
2. Set Kn (p1470) and Tn (p1472) above I/f operation (> p1755). The load moment of inertia
should be set to zero here (p1498 = 0), since this deactivates part of the torque pre-
control.
3. Determine the load moment of inertia in the speed range above I/f operation (> p1755) by
setting p1498 via a ramp response (e.g. ramp time 100 ms) and assessing the current
(r0077) and model speed (r0063).
Function diagrams (see SINAMICS S List Manual)
● 5050 Kp_n-/Tn_n adaptation
● 5060 Torque setpoint, control type switchover
● 5210 Speed controller
Overview of key parameters (see SINAMICS S List Manual)
● p0341 motor moment of inertia
● p0342 Ratio between the total moment of inertia and that of the motor
● p0353 Motor series inductance
● p0600 Motor temperature sensor for monitoring
● p0640 current limit
● p0642 Sensorless current reduction
● p1300 Open-loop/closed-loop control operating mode
● p1400.11 Speed control configuration; sensorless operation actual speed value start
value
● p1404 Sensorless operation changeover speed
● r1407.1 CO/BO: Status word speed controller; sensorless operation active
● p1470 Speed controller sensorless operation P-gain
● p1472 Speed controller sensorless operation integral-action time
● p1498 Load moment of inertia
● p1517 Accelerating torque smoothing time constant
● p1612 Current setpoint, open-loop control, sensorless
● p1755 Motor model without encoder, changeover speed
● p1756 Motor model changeover speed hysteresis