Program features 79 Switching frequencyThe drive has two switching frequencies: reference switching frequency andminimum switching frequency. The drive tries to keep the highest allowed switchingfrequency (= reference switching frequency) if thermally possible, and then adjustsdynamically between the reference and minimum switching frequencies dependingon the drive temperature. When the drive reaches the minimum switching frequency(= lowest allowed switching frequency), it starts to limit output current as the heatingup continues.For derating, see chapter Technical data, section Switching frequency derating in theHardware manual of the drive.Example 1: If you need to fix the switching frequency to a certain value as with someexternal filters, set both the reference and the minimum switching frequency to thisvalue and the drive will retain this switching frequency.Example 2: If the reference switching frequency is set to 12 kHz and the minimumswitching frequency is set to the smallest available value, the drive maintains thehighest possible switching frequency to reduce motor noise and only when the driveheats it will decrease the switching frequency. This is useful, for example, inapplications where low noise is necessary but higher noise can be tolerated when thefull output current is needed.SettingsParameter 97.01 Switching frequency reference and 97.02 Minimum switchingfrequency (page 280).
