User`s manual

apfiff09 marine vacon • 183
24-
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7.10 Drive Control
P2.10.1 Switching frequency ID601
Motor noise can be minimised using a high switching frequency. Note, however, that
increasing the switching frequency increases losses of the frequency converter. Lower
frequencies are used when the motor cable is long and the motor is small.
The range of this parameter depends on the size of the frequency converter:
Type
Min. [kHz]
Max. [kHz]
Default [kHz]
0003 0061 NX_5
0003 0061 NX_2
1.0
16,0
3,6
0072 0520 NX_5
1.0
10.0
3.6
0041 0062 NX_6
0144 0208 NX_6
1.0
6.0
1.5
Table 7-2. Size-dependent switching frequencies
Note!
The actual switching frequency might be reduced down to 1,5kHz by thermal
management functions. This has to be considered when using sine wave filters or other
output filters with a low resonance frequency.
Note!
If the switching frequency is changed it is necessary to redo the identification run.
DriveSynch operation
When using DriveSynch the maximum switching frequency is limited to 3,6 kHz.
P2.10.2 Modulator Type ID1516
Select modulator type. Some operations require use of a software modulator.
0 = ASIC modulator
A classical third harmonic injection. The spectrum is slightly better compared to the
Software 1 modulator.
NOTE: An ASIC modulator cannot be used when using DriveSynch or PMS motor with an
incremental type encoder.
1 = Software Modulator 1
Symmetric vector modulator with symmetrical zero vectors.
Current distortion is less than with software modulator 2 if boosting is used.
NOTE: Recommended for DriveSynch (Set by default when DS activated) and needed
when using PMS motor with an incremental encoder.
2 = Software modulator 2
One phase at a time in IGBT switches is not modulated during a 60-degree period of the
frequency cycle. The unmodulated phase is connected to either positive or negative DC-
bus.
This modulator type reduces switching losses up to two-thirds and all switches become
evenly loaded.
BusClamp modulation is useful if the voltage is >80% of the maximum voltage, in other
words, when the drive is operating near full speed. Then again, the motor ripple at low
speeds is the double compared to selection 1.