I have this problem that I need a 120hz power supply whit 220 Volts for my project. Does any one have any suggestion about haw to doing it or help me whit some schematics like a converter that I can use?!! My main Voltage source is 220v in 60hz.
How much current / power do you need?
Head over to your closest industrial electrical supplier and ask about Variable Frequency Drives (VFDs). These will do what you want at probably lower cost than you can build it for.