Lenze 8400 TopLine - Manual (Page 318)

6 Encoder/feedback system
6.1 Encoder selection
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Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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Up to and including version 02.xx.xx the following applies:
• For motor control types without speed feedback ( C00495 = "0: No encoder") a speed-
proportional unit is taken for calculating the nMotorSpeedAct_v speed signal. This derivation,
however, is very imprecise so that in case of applications with synchronous motors without
speed feedback it is not possible to calculate the current position from the current
nMotorSpeedAct_v speed signal.
• If no position encoder is available ( C00490 = "0: No encoder"), the dnMotorPosAct_p position
signal is always derived from the nSpeedSetValue_a speed setpoint. This derivation, however, is
very imprecise since in this case, speed limitations (e.g. by overcurrent limitations) are not
considered.
From version 12.00.00 the following applies:
• For applications with synchronous motors without speed feedback, an nMotorSpeedAct_verror-
free speed signal is available. This is calculated from the electrical voltage output angle of the
controller considering the number of pole pairs of the nMotorSpeedAct_v speed signal.
• From version 13.00.00 , the electrical voltage output angle is shown at the
nVoltageAngleAct_a output of the LS_MotorInterface SB (scaling: 16384 ≡ 360°). This
process signal can for instance be used in applications where a change-over from inverter to
mains operation is to be carried out (synchronisation of the controller output voltage to the
mains voltage).
• When synchronous or reluctance motors without feedback are used in the motor control types
V/f characteristic control (VFCplus) and Sensorless control for synchronous motors (SLPSM) , the
nMotorSpeedAct_v speed signal can be used to create an error-free position signal via a control
if the nMotorSpeedAct_v signal is read out by the control in a 1 ms cycle.
• If no position encoder is available ( C00490 = "0: No encoder"), the dnMotorPosAct_p position
signal is continued to be derived from the nSpeedSetValue_a speed setpoint. The extended
selection text "0: No encoder:nSpeedSetValue_a" in C00490 refers to this behaviour.
• The new selection "10: No encoder: C495 or nMotorSpeedSetAct_v" in C00490 is used to
calculate the dnMotorPosAct_p position signal either from the set speed feedback (when
C00495 > 0) or from the nMotorSpeedAct_v speed signal (when C00495 = 0).
• For all motor control types without speed feedback, this selection serves to improve the
creation of the dnMotorPosAct_p position signal.
• When synchronous or reluctance motors without feedback are used, the dnMotorPosAct_p
position signal can be created correctly.
• In case of the motor control types with speed feedback, the dnMotorPosAct_p position signal
is directly created from the speed feedback signal.