Large flywheel generator diode convertor for the JET Tokamak

Two large vertical shaft generators with integrated flywheel energy storage and output diode rectifiers will deliver DC pulses of current up to 100 kA and energy up to 2600 MJ to the toroidal and poloidal field coils of the JET Tokamak. Although a straight development from the pump storage hydro-generator, the pulsed operation of the generators (100,000 pulses), the large energy stored in the integrated flywheel (3.75 GJ) and the rapid response required from the voltage feedback loop called for careful investigation and development tests during the design phase. Two years after the release of the Contract, a review is made here of some of the most important points of the design, now completed, as well as of the status of the manufacture. This paper is the result of a joint collaboration between the Manufacturer (GEC) and the Jet team. (author)