Siemens SINAMICS S120 Function Manual page 120

Servo control
3.11 Sensorless operation (without an encoder)
Commissioning/optimization
1. Estimate the motor current p1612 on the basis of the mechanical conditions (I = M/kt).
2. Optimize Kn (p1470) and Tn (p1472) above I/f operation (> p1755). The load moment of
precontrol.
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 S120/S150 List Manual)
• 5050
• 5060
• 5210
Overview of important parameters (see SINAMICS S120/S150 List Manual)
• p0341[0...n] Motor moment of inertia
• p0342[0...n] Ratio between the total and motor moment of inertia
• p0353[0...n] Motor series inductance
• p0600[0...n] Motor temperature sensor for monitoring
• p0640[0...n] Current limit
• p0642[0...n] Encoderless operation current reduction
• p1300[0...n] Open-loop/closed-loop control operating mode
• p1400.11
• p1404[0...n] Encoderless operation changeover speed
• r1407.1
• p1470[0...n] Speed controller encoderless operation P gain
• p1472[0...n] Speed controller sensorless operation integral time
• p1498[0...n] Load moment of inertia
• p1517[0...n] Acceleration torque smoothing time constant
• p1612[0...n] Current setpoint, open-loop control, encoderless
• p1755[0...n] Motor model changeover speed encoderless operation
• p1756
118
inertia should be set to zero here (p1498 = 0), since this deactivates part of the torque
Servo control - Speed controller adaptation (Kp_n/Tn_n adaptation)
Servo control - Torque setpoint, switchover control mode
Servo control - Speed controller without encoder
Speed control configuration; encoderless operation actual velocity start
value
CO/BO: Status word speed controller; encoderless operation active
Motor model changeover speed hysteresis
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Drive functions