Eike Richter

Two-channel switched reluctance starter/generator results

Measured data and simulation results for a two-channel experimental switched-reluctance-motor (SRM)-based aircraft engine starter/generator system are presented. The two channels of the system provide power to two separate and independent loads. The results presented document the performance capability of this system with both channels operating simultaneously. Both measured and predicted system performance are presented and compared. In addition, operating characteristics that are unique to this SRM-based system are described. Of particular interest are the interactions between the two separate channels when one channel experiences a load transient and the other channel does not. The source of channel interactions is described, and measured data is provided. The issue of clearing load faults is also addressed. Design results for adding this capability to the experimental system are described.

The Ferrite Permanent Magnet AC Motor---A Technical and Economical Assessment

The design and analysis study for the conceptual design of an economical high-efficiency ac motor based on permanent magnets is summarized. Material considerations, design trade-off options as well as transient and steady-state performance under normal and abnormal conditions have been considered. The baseline comparison is the high-efficiency induction motor. The permanent magnet (PM) motor must fit into the same frame size and surpass the induction motor on a life cost basis that includes 2.5 years of operation at a 50 percent duty cycle. The study results indicate that a motor with ferrite magnets meets the objectives of the program in ratings of up to 25 hp. A 7.5-hp motor design is carried through the conceptual design stage.

POWER DENSITY CONSIDERATIONS FOR PERMANENT MAGNET MACHINES

Abstract Electrical motors and generators used on mobile platforms--including aircraft and ship and land vehicles--are required to exhibit as high a power density as practically possible. With the advent of high-energy permanent magnets, it appears possible to build permanent magnet machines which can compete with electrically excited machines in terms of power density. This paper presents a discussion of the power density limitations as they apply to synchronous-type permanent magnet machines using rare earth cobalt permanent magnets. It also presents guidelines for future material development necessary to improve the power density of this class of machines.