Siemens SINAMICS S120 Function Manual page 96

Operating Modes
Servo control
Notes regarding methods of pole position identification
The relevant method can be selected using parameter P1980. The following meth-
ods can be used for identifying the pole position:
S Saturation based, 1st + 2nd harmonics (p1980 = 0)
S Saturation based, 1st harmonic (p1980 = 1)
S Saturation based, two step (p1980 = 4)
S Movement based (p1980 = 10)
The following general conditions apply for the saturation-based methods:
S These methods can be used for both braked and non-braked motors.
S They can only be used if the speed setpoint = 0 or from standstill.
S The specified currents (p0325, p0329) must be strong enough to generate a
significant measuring signal.
S The pole position of ironless motors cannot be determined using the
saturation-based methods.
S The method based on the 2nd harmonic (p1980 = 0, 4) must not be used for
1FN3 motors.
S The two-step method (p1980 = 4) must not be used for 1FK7 motors. The value
in p0329, which is set automatically, must not be reduced.
The following general conditions apply for the movement-based method:
S The motor must move freely and must not be affected by any external forces
(no vertical axes)
S This method can only be used if the speed setpoint = 0 or from standstill.
S If a motor brake is installed, it must be open (p1215 = 2).
S The specified current (p1993) must be sufficient to move the motor.
Warning
!
Before the pole position identification function is used, the control direction of the
speed control loop must be set correctly (p0410.0).
For linear motors, refer to the Commissioning Manual.
In the case of rotating motors, the actual speed value (r0061) and the speed
setpoint (r1438) must have the same sign in "operation without encoder" mode
and with a low positive speed setpoint (10 r.p.m).
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© Siemens AG, 2005. All rights reserved
SINAMICS S120 Function Manual, 06/05 Edition