Lenze ECSCSxxx - Manual (Page 159)

Commissioning
Optimising the drive behaviour after start
Adjustment of field controller and field weakening controller
6
l
159 EDBCSXS064 EN 4.0
6.16.2.2 Field weakening controller adjustment
ƒ The field weakening controller determines the speed performance of the
asynchronous motor in the field weakening range.
ƒ The field weakening controller can only be set correctly when the system
constellation has been completed and is under load.
)
Note!
An excessive value of I
max
(C0022) can cause a malfunction of the drive in the
field weakening range of the asynchronous motor. For this reason, the current
is limited in terms of speed in the field weakening range. The limitation has a
1/n characteristic and is derived from the motor parameters.
The limitation can be adjusted with the stator leakage inductance (C0085):
ƒ Low values cause a limitation at higher speeds.
ƒ Higher values cause a limitation at lower speeds.
Setting sequence
1. Set gain V
p
: C0577 = 0.01 ... 0.99
– V
p
must not be "0" (deactivates the field weakening controller)!
2. Set integral−action time T
n
: C0578 = 1 ... 40 ms
3. Select a speed setpoint so that the motor is operated in the field weakening range.
4. Observe the speed curve
– If the speed takes an irregular course, the field weakening controller must be
readjusted.
– The field weakening controller must be provided with a distinct integral action.
I
Tip!
Parameter setting with a distinct I component can improve the drive
behaviour when changing to the field weakening range.
For this purpose, set the gain (V
p
) in C0577 to at least 0.01.
The following applies:
ƒ P component = V
p
= C0577
ƒ I component = V
I
= C0577/C0578
If the P component (V
p
) is reduced via C0577, adapt the reset time C0578
accordingly to keep the I component (V
I
).