A Three-Phase Hybrid DC-AC Inverter System Utilizing Hysteresis Control

This is a NAVAL POSTGRADUATE SCHOOL MONTEREY CA report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A335424. The abstract provided by the Pentagon follows: The naval vessels of the future will require lighter more compact and more versatile power electronics systems. With the advent of the DC Zonal Electrical Distribution System more innovative approaches to the conversion of the dc bus power to ac power for motor drives will enhance the efficiency and warfighting capability of tomorrow's ships. This thesis explored the concept of a hybrid dc-ac power converter that combines a hysteresis controlled inverter with a six-step bulk inverter. A six-step bulk inverter was built from discrete components and tested in simulation and hardware. The two inverters were connected in parallel to provide a high-fidelity current source for a three- phase load. The addition of the hysteresis inverter to the bulk inverter added a closed current loop for more robust control and improved the quality of the output load current.