The Alcator C-MOD power system

The-14 magnets or the Alcator C-MOD device require over 500 MJ to be delivered in a few seconds. Peak powers approaching 300 MW will be delivered from the upgraded 225-MVA alternator used to power the Alcator C device. Most magnets have dedicated power conversion systems in order to maximize flexibility and to allow for operation with a single-null divertor. Details of the power system design are presented. The Toroidal Field (TF) conversion system features 260 kA output coupled with an auto-tap changing design to increase power factor. The 50-kA Ohmic Heating (OH) system utilizes a single DC interrupter to switch 3 OH magnets and 3 OH converters. The vertical position control system uses a combination of fast, chopper-type supplies and conventional line-commutated converters to combine fast response with low cost. The radial position control system utilizes a reconfigured Alcator C-era OH supply in combination with surplus DC traction motors outfitted with flywheels. 12 refs., 9 figs