High-Temperature, High-Efficiency Electrical Starter/Generator

The U.S. Navy SBIR topic addresses the need for improved electrical power generation systems (EPGS) for aerospace applications that are comprised of an electrical starter/generator (ES/G) and a generator control unit (GCU).  The primary objective of the effort is to develop a 200 kW continuous, 500 kW peak EPGS that improves over existing technology in terms of power capability, temperature / coolant capability, power density, efficiency, and heat load.The proposed EPGS solution consists of a surface-mount permanent magnet synchronous machine (the ES/G) coupled to a dc/ac inverter (the GCU) that connects to a 270 Vdc power distribution system.  The concept ES/G developed in the Phase I effort consists of a lightweight rotor assembly, high-performance lamination and winding materials, and a mechanical disconnect system to decouple the rotor from the main shaft. It addresses high power density, low loss, and safe operation during potential faults while achieving the desired power and torque capability with a high-temperature coolant.  The GCU utilizes several dc/ac inverter modules based on high-performance wide bandgap semiconductors to provide a compact, lightweight, and modular implementation.  Further, it integrates solid-state relay technology to provide current conditioning under a variety of fault scenarios.  Combined, the ES/G and GCU provide a high-performance high-power density EPGS package.