Lenze 8400 TopLine - Manual (Page 250)

5 Motor control (MCTRL)
5.9 Servo control (SC)
250
Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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5.9.4.8 Optimising the behaviour of the asynchronous motor in the field weakening range
The behaviour of the asynchronous motor in the field weakening range is influenced by:
• the field controller
• the field weakening controller
• the field feedforward control unit
• adaptive adaptation of the P component of the field and speed controllers
• An additional limitation of the I component of the controller when the voltage limit is reached

Note!
By default, these control parts are called every 1 ms. However, the 1-ms cycle is not
always sufficient to achieve an optimum jerk-free transition to the field weakening
range.
From version 14.00.00 , the control parts can be called for an optimum jerk-free
transition to the field weakening range in a 500- μ s cycle. For this purpose, bit 5 has to be
set to "1" int in C02864/1 .
• With this setting, C00015 and C00576 do not have any influence anymore on the field
feedforward control.
• We recommend this setting for new applications.
• In existing applications, this setting may require an increase of the reset times of the
field weakening controller ( C00578 ) and the field controller ( C00078 ) by the factor 2
in order to achieve a stable operation.
In general, these settings are pre-optimised so that further optimisation is not required.
Optimisation for special motors (e.g. mid-frequency motors) or for standard
asynchronous motors whose power is not adapted can be carried out according to the
algorithms shown in the following sections.