Low voltage, high current DC power supply with self commutated converter using power-MOSFET

The DC power supply for a nuclear fusion experimental system based on the low aspect ratio spherical torus requires a low voltage and high current output to power a toroidal field coil consisting of a single turn center conductor. To meet such requirements, the self-commutated converter using a power-MOSFET, which is more efficient than the conventional thyristor or diode converter, is proposed. The converter has the advantage of fast switching speed, low on-state resistance and voltage gate signal. The operating characteristics of a power-MOSFET and the switching unit using four MOSFET elements are also discussed.