Circuit design

The student will design, construct and test a low-voltage three-phase power supply (Health and Safety will form an important part of this project: Although the unit may be single-phase mains-powered, beyond the input transformer no part of the circuit can exceed at any point: 50V and 20A and 400W maximum). The output should be variable from about 0 – 25V per phase, with about 5A per phase available. I would like only some help with the circuit if you could just design a circuit that I can plug in a source ac or dc on a software i.e. multisim, which is fully simulated. The results of the simulation at the end of the circuit an oscilloscope that shows the three phases as demanded in the question using electronics i.e. op amps, capacitors... etc.