DESIGN CONSIDERATIONS FOR HIGH SPEED DIRECT DRIVE TURBINE GENERATORS

摘要

The University of Texas at Austin Center for Electromechanics (UT-CEM) conducted development and testing of a 3 MW high speed generator and turbine drive system for a hybrid vehicle propulsion system as a part of the Advanced Locomotive Propulsion System (ALPS) Program [1]. Several critical design issues were identified that apply to high speed wound field synchronous generators and turbine drive systems. The focus of the paper is directed to the more aggressive designs that, like ALPS, are intended to maximize the power density of the turbine/generator package. Design issues addressed by the paper include: 1. Thermal management for the armature and field windings; 2. Structural support and insulation of the rotating field winding; 3. Design of the brushless exciter and rotating diode array; 4. Design of the rotor bearings, seals, and dampers; 5. System dynamic response to sudden load changes. The results of trade studies for selection of the generator technology (wound field, permanent magnet, high temperature superconducting) will also be presented to identify key size/weight and cost drivers in the design process. Lessons learned during the fabrication, assembly, and testing of the ALPS generator will be discussed in this paper, in particular, issues concerning the high pressure stator air cooling system, improvements to the field winding insulation, and field coil installation techniques will be addressed. A companion paper will present the results of testing the high-speed generator and turbine drive system to a 1.5 MW power level at NAVSEA (Philadelphia, PA) and UT-CEM with a fixed resistive load.