SBIR-STTR Award

Compact source of electric power is needed on unmanned combat air vehicles (UCAV) for directed energy weapon (DEW) systems. Electrodynamics proposes integration of high speed induction generator electromagnetics and controls hardware rated at 200 kW, 62000 RPM into a viable system for these applications. The generator produces controlled AC power at a frequency of about 2.1 kHz., which will be stepped up to 30000 plus volts using a high frequency transformer-rectifier-filter unit. The technology integration will be in thermal and mechanical areas. Also the electrical interface issues relating to delivery of high voltage DC power to the HPM weapons are addressed. Innovative approaches proposed are: use of low friction, oil-free air foil bearings for the generator, effective cooling techniques using air or fuel to remove heat, generator packaging in lightweight housing, use of Metglass for stator core to lower iron losses and help thermal management, compact transformer-rectifier-filter design for high voltage output, control of HVDC bus from low potential generator control loop, engine start function, and other protective functions. A team of experts is assembled to carry out the R&D activity. Phase I program will result in hardware designs and drawings for Phase II fabrication and test demonstration

Electric power needs for modern aircraft are increasing due to addition of electric power loads. At the same time, the thermal capacity of the jet fuel for heat removal from the equipment is limited. More and more, the demand is for electric power system that is efficient, power dense and robust. This proposal offers the solution using a high speed induction generator and controller that can be directly coupled to a high speed turbine to provide electric power in the range of 150 to 300 kW for aircraft utility, avionics, or weapon system. Directed energy weapons in particular need a power source that is in the proposed range of 150 kW to 300 kW. Efficiency issues are addressed by minimizing the fixed losses such as iron loss, windage loss, and the bearing friction loss. This results in high efficiency over a wide range of power output. Effective insulation system is designed to be robust and provide an average life of 30000 hours. Heat removal system is designed to lower insulation temperatures through conduction of heat without use of coolants in the generator cavity. This eliminates the high churning losses. Bearing damping system is incorporated to provide robust and nearly vibration free construction. Control algorithm is included for optimized performance at all operating temperatures and under all load conditions including steady state and transient conditions. During Phase II a complete motor generator set will be built to demonstrate the operation of the generator and controller at the speed of 60000 RPM. An interdisciplinary team of experts is organized to address electromagnetic, control, simulation, rotor dynamics, and thermal management issues.

Keywords:
Electric Generator, High Speed Generator, Induction Generator, Generator Control System