Operational experience with two types of 2 MW HVDC power supplies on LEDA

The high voltage DC power supplies are predicted to be the most expensive component of the accelerator at the Accelerator Production of Tritium (APT) plant. Two different types of candidate HV power supplies are being tested on the Low Energy Demonstration Accelerator (LEDA) at Los Alamos National Laboratory. The first type uses SCRs in a twelve pulse topology with a spark gap crowbar. The second type uses IGBTs in a Solid State Modulator topology without a crowbar. While both topologies have been proven in existing high voltage applications, both systems contain new features to improve performance and reliability that have advanced the state of the art in HVDC power supply design. LEDA is being used to demonstrate the benefits of these features for the APT plant and evaluate their impact on power supply reliability, serviceability and cost. We present detailed measurements of total power supply efficiency and the effect each topology has on the power factor and harmonic input currents drawn from the local power distribution system in addition to operational performance with other accelerator systems.