Lenze 9400 - Manual (Page 206)

5 Motor interface
5.8 Parameterisable additional functions
206
Lenze · Servo-Inverter 9400 HighLine · Reference manual · DMS 10.0 EN · 11/2013 · TD05/06
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5.8.2 Field weakening for synchronous machines
This function is available from software version V2.0!
If required, the field weakening mode can be switched on in C00093 for synchronous machines.
[5-28] Voltage/speed characteristic with switched-on field weakening
[5-29] Calculation of the maximally reachable speed with switched-on field weakening
[5-30] Speed/torque characteristics of a synchronous servo motor with field weakening

Note!
Function only possible for servo control!
 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 Œ 
U
motor
n
max
n
rated_mot
800V
2 U
rated_mot
⋅
-------------------------------------- ⋅ =
 Standstill torque
 Rated torque
 Characteristic for continuous operation
 Limit characteristic at mains voltage of 400 V without field weakening
 Limit characteristic with field weakening
0
10
20
30
40
50
60
M [Nm]
Œ

0 1500 3000 4500
Ž
0
1
n [rpm]