Preventing a decrease of the switching frequency, 5motor control (mctrl) – Lenze 8400 TopLine User Manual
Page 257
Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
257
5
Motor control (MCTRL)
5.10
Parameterisable additional functions
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Settable switching frequencies
= "2: 8 kHz var.drive-opt." is the optimal value for standard
applications.
Preventing a decrease of the switching frequency
The value must not fall below the permissible switching frequency if the motor is not approved for
the setting switching frequency or if a sinusoidal filter is connected between the output of the
inverter and the motor that is not approved for the setting switching frequency.
In order to prevent a decrease of the switching frequency, the following settings have to be made:
1. The temporary switching frequency reduction has to be activated by the setting
= "0: Off".
2. The switching frequency has to be set in
so that the value is not fallen below the
permissible switching frequency.
3. If a sinusoidal filter is available, only a drive-optimised switching frequency ("drive-opt.") is
permissible.
Example: A sinusoidal filter is connected between the output of the inverter and the motor which
only is to be operated with a minimum switching frequency of 8 kHz.
In this case, only the following settings in
are permissible:
Selection in
1 4 kHz var./drive-optimised
21 8 kHz var./drive-opt./4 kHz min
2 8 kHz var./drive-optimised
22 16 kHz var./drive-opt./4 kHz min
3 16 kHz var./drive-optimised
23 16 kHz var./drive-opt./8 kHz min
5 2 kHz constant/drive-optimised
31 8 kHz var./min. Pv/4 kHz min
6 4 kHz constant/drive-optimised
32 16 kHz var./min. Pv/4 kHz min
7 8 kHz constant/drive-optimised
33 16 kHz var./min. Pv/8 kHz min
8 16 kHz constant/drive-optimised
Abbreviations used:
• "var.": Adaptation of the switching frequency
depending on the current
• "drive-opt.": drive-optimised modulation ("sine/delta
modulation")
• "fixed": fixed switching frequencies
• "min. Pv": additional reduction of power loss
11 4 kHz var./min. Pv
12 8 kHz var./min. Pv
13 16 kHz var./min. Pv
15 2 kHz constant/min. Pv
16 4 kHz constant/min. Pv
17 8 kHz constant/min. Pv
18 16 kHz constant/min. Pv
Selection in
7 8 kHz constant/drive-optimised
8 16 kHz constant/drive-optimised
23 16 kHz var./drive-opt./8 kHz min