5motor control (mctrl) – Lenze 8400 StateLine User Manual

Page 169

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Lenze · 8400 StateLine · Reference manual · DMS 12.0 EN · 06/2014 · TD05/TD14

169

5

Motor control (MCTRL)

5.7

Sensorless vector control (SLVC)

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Speed controller reset time Ti
Apart from setting the P component,

C00071/1

provides the possibility to take influence on the I

component of the PI controller.

Tip!
Value range recommended by Lenze for the setting of the reset time:
Ti = 20 ms … 150 ms

5.7.4.3

Optimising dynamic performance and field weakening behaviour

In the Lenze setting, the torque controller has been preset in such a way that robust and stable

operation with a moderate dynamic response is enabled over the entire speed range. Retrospective

optimisation of the controller parameters is not necessary.

A greater dynamic performance of the sensorless vector control can be achieved by reducing time

constant Ti of the speed controller (

C00074/2

).

A greater dynamic performance of the field weakening function can be achieved by setting a time

constant ≤ 15 ms. This means for actual speeds above rated speed a better torque-speed-

characteristic in the field weakening range:

[5-11] Speed / torque characteristic diagram in the field weakening range

• For Ti > 15 ms (see ), the actual speed value slightly drops in the field weakening range if the

load torque increases in the motor mode.

• For Ti ≤ 15 ms (see ), the speed remains stable in the field weakening range if the torque is

within the M/n characteristic field highlighted in grey.

Tip!
For applications with high dynamic performance and speed/torque accuracy requirements

in the field weakening range, we recommend a time constant Ti ≤ 15 ms.
In this case, the maximum torque should be limited via the nTorqueMotLimit_a and

nTorqueGenLimit_a process input signals to 1.5 x M

N

to ensure stable operation in the field

weakening range.

Parameter

Info

Lenze setting

Value Unit

C00073/2

SLVC: Vp torque controller

1.25

C00074/2

SLVC: Ti torque controller

30 ms

Torque controller time constant Ti > 15 ms

Torque controller time constant Ti ≤ 15 ms

1

0

n

N

n

N

M

N

M

N

M

M

n

n

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