A very high speed switched reluctance generator
The thesis investigates a high speed switched reluctance (SR) generator suitable for applications such as aerospace and turbo-charged ground vehicles. The generator is two-phase with 16-8 stator-rotor poles. The stator is 70 mm OD by 25 mm core length made of soft ferrite. The rotor comprises 30 pm laminations of amorphous alloy chosen for its mechanical strength. The rotor of the generator was mounted on the protruding shaft of an air turbine and extensive tests were performed at a variety of speeds and supply voltages. The generator is shown to be capable of delivering around 280 Watts to a resistive load at 60,000 rpm, and 60 volts, with an estimated efficiency of around 77%. The thesis describes in detail the electromagnetic and mechanical construction of the generator and presents a comprehensive survey of operating waveforms and performance measurements. The design utilises a simple magnetic model for the SR generator based on a quasi-linear flux-current characteristics which are shown to provide a very useful tool for performance prediction.