In one word, no. A VFD cannot be used as a replacement for a voltage transformer. If a motor requires 400Vac, then a 400Vac source is required as an input to the 400Vac VFD. The same goes for other voltage classes,

The only exception to this rule is with phase number. If the motor requires a 3ph voltage source, then a VFD can use a 1ph voltage source (of the same voltage), and convert it to 3ph for the motor, but in this case, the VFD is to be downgraded. (for 3ph inverters, not 1ph inverters)

Note: this phase conversion is exclusively the case for 200Vac 1ph \ 3ph systems. (i.e. not all of the inverter series’ have the 200Vac 1ph version available.

Note: Some inverter series’ come with a 200Vac 1ph inverter model – and in such cases – downgrading of the VFD will not be required.