Field excitation and discharge switching for air-core compulsators

The Center for Electromechanics at The University of Texas (USA) has designed and built three generations of air-core compulsators for railgun power supply application. These systems rely on compact power electronics to provide rapid self-excitation of the field windings and control of the main current discharge. All three systems built so far have been single-phase armature machines. The parameters for these systems range from 20 to 42 kA field excitation at 125 to 400 Hz rectification and 2.5 to 12 kV. The main discharge peak current ranges from 0.3 to 3 MA. The design and performance of past switching systems is reviewed and the prospects for further mass and volume reductions is presented.