Magnet coil power supply by a self-excited induction generator with a flywheel for a small tokamak, PHiX

Abstract Tokamak devices with non-superconducting magnets require a large amount of pulsed power consumption when the power grids are not robust enough. In this case, these devices are equipped with some energy buffers to avoid the influence on the grids. In this paper, we deal with the flywheel energy storage system employing an induction motor/generator. We used self-excitation phenomena of the induction motor/generator to discharge energy from a flywheel. Furthermore, we adopted an additional self-exciting capacitor connected to the induction motor/generator during the discharging phase. As an experimental result, we achieved 117 kW of peak power and 0.25 s of flattop period using a 55-kW rated induction motor/generator.