Research and Development of High Performance Current Collectors for Homopolar Generators

Over the past five years three homopolar generators (HPGs) have been operated in our laboratory under a variety of experimental conditions. Two of the machines were routinely used as pulsed power supplies, the third machine is an experimental facility for the development of HPG components. Because of the Center for Electromechanics at The University of Texas at Austin (CEM-UT) recent move into a new facility, all three of the machines have been disassembled and inspected offering a wealth of information on the performance of high-slip-speed, high current- density current collectors. Wear rates of sintered, copper-graphite brushes running on steel slip rings as a function of current density and slip speed will be presented along with effects of slip-ring surface finish, using the brushes as a switch to close the electrical circuit and direction of current transfer. Funding for this research has been provided by the U. S. Army Research and Development Command (ARDC), Defense Advanced Research Projects Agency (DARPA), National Science Foundation (NSF), and the Texas Atomic Energy Research Foundation (TAERF).