The simplest solution would be transformer to boost the voltage to 380, plug and play. Somebody who knows what they are doing could check your machine to see if it is really necessary or if it can be run on the lower voltage as is. Any idea what the 220/75v transformer is used for? The drive will not mind the frequency difference but usually drives will not output voltage higher than input so you may lack top speed on the spindle if you only feed it 220v.