The BPX electrical power system

The design of the BPX (Burning Plasma Experiment) power system has evolved over a period of several years and has included studies of several alternative approaches. The reapplication of the existing TFTR (Tokamak Fusion Test Reactor) power and energy facilities has been basic to all approaches. The dynamics of the power requirements for the BPX poloidal coil system suggest that the TFTR facilities would be most suitably applied to that requirement. The chief concern related to that match has been the adequacy of the 4.5-GJ energy rating of the TFTR flywheel units. The toroidal field power requirements are the greatest of the BPX subsystems and, fortunately, are sufficiently free of dynamics to allow the consideration of different approaches to providing pulse power and energy. Additional design challenges were presented by the multiplicity of plasma control scenarios incorporated in the BPX physics planning and the power response demanded of the plasma position control system. The plasma control scenarios include upper, lower, and symmetrical poloidal diverter operation as well as limiter operation. The plasma position control coils (internal to the TF bore) have a collective peak power demand of 640 MVA, require four quadrant drive, and require 1 ms voltage response