3.6.2 Switching frequency and temperature
The drive controller cooling is designed by way that the heat sink overtemperature
threshold is not exceeded at rated conditions. A switching frequency higher than the rat-
ed switching frequency also produces higher losses and thus a higher heat sink heating.
If the heat sink temperature reaches a critical threshold (T
dr) the switching frequency
can be reduced automatically step by step, in order to prevent that the drive controller
switchesoduetooverheatingoftheheatsink.Iftheheatsinktemperaturefallsbelow
Tur, the switching frequency is increased to the setpoint again. At temperature Tem the
switching frequency is immediately reduced to rated switching frequency. "Derating“
must be activated, for this function to work.
Voltage class 400 V 230 V
Device size 07 09 10 07 09
Mains phases 3 1
Rated switching frequency
1)
fSN / kHz 8 8
Max. switching frequency
1)
fS_max / kHz 16 16
Max. heat sink temperature
T
HS / °C 90 80
Temperature for derating the switching frequency
2)
Tdr / °C 80 70
Temperature for uprating the switching frequency
2)
Tur / °C 70 60
Temperature for switching to rated switching
frequency
2)
Tem / °C 85 75
Table 29: Switching frequency and temperature
1)
The output frequency is to be limited in such a way that it does not exceed 1/10 of the switching frequency.
2)
On reaching the temperature Tdr the switching frequency is step down. The switching frequency is in-
creased again on cooling down to temperature Tur.
If derating is not requested in individual cases, the function can be deactivated via software.
46
GENERAL DATA
To Next Page
Loading...
Need help?
General
