Need a power supply with 30 to 32A capacity.
smooth voltage needed, which can be varied.
Auto Cut off if it reaches beyond a set ampere and voltage rating ( that i can do with microcontroller).
What kind of a power supply are you looking forward to build?
A linear or a switching power supply?
0-30V at 32A...You will be roughly dissipating 1000 Watts at full load!
If you design the circuit around LM317...Then you may get a voltage range of 1.2V-37V (According to the datasheet) since LM317 uses a internal reference voltage of around 1.25V for regulation.
For the series pass transistor circuitry, you can refer to this page.