Thanks, And controller is limited in output power? or it depends on self and switch parts? I am going to make 1khw 1000V smps but some of controllers have schematic about 200W and all of them are 400V output!!!
The 400 Volts is chosen to be just above the peak level of the highest common AC line voltage.But it is set by a resistor divider, so you can change it to whatever voltage you want. You will need to choose a mosfet with a D-S voltage higher than the DC output voltage.
As far as the power limit of the controller, it only needs to drive the gate of the mosfet. If you need more gate current, you can buffer the output with a bigger gate driver IC.