Technology Selection for Optimal Power Distribution Efficiency in a Turboelectric Propulsion System 2012-01-2180

Turboelectric propulsion is a technology that can potentially reduce aircraft noise, increase fuel efficiency, and decrease harmful emissions. In a turbo-electric system, the propulsor (fans) is no longer connected to the turbine through a mechanical connection. Instead, a superconducting generator connected to a gas turbine produces electrical power which is delivered to distributed fans. This configuration can potentially decrease fuel burn by 10% [1]. One of the primary challenges in implementing turboelectric electric propulsion is designing the power distribution system to transmit power from the generator to the fans. The power distribution system is required to transmit 40 MW of power from the generator to the electrical loads on the aircraft. A conventional aircraft distribution cannot efficiently or reliably transmit this large amount of power; therefore, new power distribution technologies must be considered. Two critical components in the power distribution system that must be redesigned are the cables and power converters.

Sizing algorithms for a conventional copper cable and a superconducting cable have been developed to determine the best method of power transmission. In order to create the sizing models, cable structure and materials were selected for both cable types. The sizing models determine the dimensions and weight of the cables as a function of system nominal voltage and cable length. A range of values were used for the design variables to produce sizing data; then, the data was regressed to create simple equations that can be used to estimate cable size. A turboelectric propulsion system required the use of inverters and rectifiers. Converter structures and control schemes will be explored and the optimal alternatives for this application will be modeled. The final goal of this research is to estimate the weight of the cables and performance of the converters to determine the optimal combination of power distribution technologies for a turboelectric propulsion system.