[muhammadnour]

I want to buy inverter driver for a 60000RPM 1.2KW 3PH 220V spindle and I recently knew about VVFD drivers which is variable voltage frequency driver vs the usual VFD which only use variable voltage to driver the motor.


The VVFD controls the the voltage and the frequency of the motor which can lead to a better start up performance by decreasing the startup voltage which lead to decrease the startup current of the motor.


I do not know if this is good for high speed spindles or not
Does anyone have used this type of inverters before to control Chinese spindles?

[joeavaerage]

Hi,
all VFDs control frequency AND voltage. They have to. Imagine applying 5Hz 230VAC on a motor winding......the current would be huge blowing both the motor and the VFD!!.
If you reduce the frequency you must also reduce the voltage otherwise the current will go through the roof.. This is called V/F control. More recent developments, called vector control,
refine the basic V/F strategy, but the same principle applies....the voltage and frequency must vary together.

Craig