Application of Magnetic Energy Recovery Switch (MERS) to power supply systems of nuclear fusion device

Abstract

Electric power circuits applied with Magnetic Energy Recovery Switch (MERS) are proposed to be used for power supply systems of nuclear fusion device. MERS basically consists of four self-commutated power electronics elements as switching unit and one capacitor. MERS can be operated with on-off switching of four power electronics elements by controlling their gate signals to output its electric power in DC or AC. As poloidal ield coil power supply, it is required that the coil current is slightly high DC one and controlled to sustain plasma current and/or configuration. When MERS assist the conventional AC/DC converter of poloidal field coil power supply, it is expected that the voltage rating of AC/DC converter would be reduced and the controllability of coil current would be also improved. As RWM (Resistive Wall Mode) suppressing coil power supply, it is required that the coil current should be pulsatile one in wide frequency range and controlled more rapidly to stabilize the plasma instability. When MERS is applied to RWM suppressing coil power supply, it will be promised that the controllability of coil current is improved with resonant operation of MERS and RWM suppressing coil itself.