System Performance and Characteristics of High-Speed HTS Generators

Pairing of a high-speed, high-temperature superconducting, homopolar inductor alternator (HTSHIA) with a gas turbine engine as prime mover results in a power dense generator-set well suited to applications requiring large step load accepts and rejects. Though the HTSHIA's low synchronous reactance allows it to respond to large step loads, typical gas turbine engines require seconds to ramp from idle to full power. A mismatch between load and turbine power during a step transient will result in generator speed droop. If the speed droops too severely either the generator or gas turbine engine may no longer be able to maintain rated power. This paper presents a generator set and control approach which exploits the HTSHIA's flywheel properties (high speed and relatively high rotor inertia) to power large, repeated step loads. The gas turbine engine, generator, power conditioning system (PCS), load, and control were modeled to evaluate the system performance, develop control, and to allow system level trades to be made.