Lenze 8400 motec - Manual (Page 157)

Lenze · 8400 motec · Reference manual · DMS 4.1 EN · 08/2013 · TD05 157
5 Motor control (MCTRL)
5.10 Parameterisable additional functions
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

How to optimise the torque feedforward control:
1. Run a typical speed profile and record the inputs and outputs of the speed controller with
the data logger.
• For this, the data rate of the 8400 motec diagnostic interface is insufficient. Thus, use the
fieldbus for the communication between the 8400 motec and the »Engineer«.
• Motor control variables to be recorded:
nSpeedSetValue_a (speed setpoint)
nMotorSpeedAct_a (actual speed value)
nOutputSpeedCtrl_a (speed controller output)
2. Estimate the moment of inertia and set it in C00273 in relation to the motor end (i.e. with
account being taken of the gearbox factors).
3. Repeat the data logger recording (see step 1).
Now the data logger should show that part of the required torque is generated by the
feedforward control and the speed controller output signal (nOutputSpeedCtrl_a) is
correspondingly smaller. The resulting following error decreases.
4. Change the setting in C00273 and repeat the data logger recording until the intended
response to setpoint changes is reached.
• The optimisation could aim at the speed controller being completely relieved (see signal
characteristics in Fig. [5-13] ).
5. Save the parameter set (device command: C00002/11 ).