Lenze 8400 User Manual

5 Motor control (MCTRL)
5.8 Sensorless control for synchronous motors (SLPSM)
228
Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23
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5.8.6 Field weakening for synchronous motors
This function extension is available from version 11.00.00!
[5-17] Voltage/speed characteristic with switched-on field weakening
[5-18] Calculation of the maximally reachable speed with switched-on field weakening
 Note!
In the Lenze setting, the field weakening for synchronous motors is activated in
C00079/4
.
• If a high energy efficiency is required, keep the field weakening switched off or restrict
the field weakening operation via C00938
.
 Stop!
In the field weakening operation, a current is injected into the synchronous motor even
in idle state which can rise to maximum current (C00022
).
Ensure that this no-load current does not cause the motor to be heated impermissibly!
• We recommend using a temperature feedback via PTC or thermal contact. Motor
temperature monitoring (PTC) ( 302)
 Armature control range
 Field weakening range
• When field weakening is switched on, the motor
magnetising current is increased from 0 A to the maximally
effective magnetising current via an internal control loop
when the voltage limit is reached.
• As a result, a higher speed can be reached at the same
motor voltage or DC-bus voltage.
n


U
motor
n
max
n
nenn_mot
800V
2U
nenn_mot
⋅
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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