Lenze 8400 User Manual

5 Motor control (MCTRL)
5.7 Sensorless vector control (SLVC)
206
Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23
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5.7.4.7 Optimising field feedforward control and torque feedforward control
At the start of an acceleration process and at the end of a deceleration process, the field current
(nReaktCurrentId_a) may oscillate.
• Especially when accelerating via small acceleration ramps, these oscillations become obvious by
the speed being unable to follow the setpoint or speed drops during acceleration.
• Oscillating can be reduced by increasing the gain of the field current controller in C00985
. A
small increase of the cross current controller gain in C00986
can further improve the starting
performance for small acceleration ramps.
In the field weakening range, the cross current (nEffCurrentIq_a) may oscillate when an acceleration
process starts or a deceleration process ends.
• In case of some motors, this cross current oscillation (nEffCurrentIq_a) can also occur in the
motor setting range/field weakening range transitions which may also cause an overcurrent
interruption.
• These oscillations can be reduced by again increasing the cross current controller gain slightly
in C00986
.
 Note!
The setting of C00985 and C00986 reduces the torque setting range.

Lenze 8400 Specifications

General

Category	DC Drives
Series	8400
Protection class	IP20
Control Type	Vector control
Communication	CANopen, PROFIBUS, Ethernet
Protection Features	Overcurrent, overvoltage, undervoltage, overtemperature
Input Voltage	AC 230/400/480 V