Stephen R. Jones

Detailed design of a 30-kW switched reluctance starter/generator system for a gas turbine engine application

A switched reluctance starter/generator (SR S/G) system has been developed for an aircraft engine application. The system is rated at 30 kW, 270 VDC, 52 kRPM maximum operating speed. The system also provides 17 hp to start the 1400 hp engine. The system consists of an SR machine directly coupled to the gas turbine engine, an inverter converter unit (ICU), and an electronic controller. The system is designed to meet requirements such as power quality per MIL-STD-704E, 30% (9 kW) step loads, 75% constant power loads, operation over a wide speed range, and a -51 degrees C to +125 degrees C environment. The emphasis in the present work is on the design and implementation of the system. The SR S/G system is currently undergoing design assurance tests. Test results are given to validate the system design and performance. System efficiency is about 80% when generating 30 kW. >

Performance evaluation of a switched reluctance starter/generator system under constant power and capacitive type loads

The US Armys objectives for future multipurpose vehicles calls for using electric power for vehicle functions currently driven by hydraulic, pneumatic or mechanical means. The use of electrical power and power electronics components and systems are expected to enhance reliability, fault tolerance, power density, and performance. An electrical starter/generator system is one of the key technologies to make the concept of a more electric vehicle a reality. This paper focuses on the performance evaluation of a 30 kW, 270 V DC, 52000 r.p.m. switched reluctance starter/generator system for a 1400 HP gas turbine engine under constant power and capacitive type loads. In contrast, most of the literature on switched reluctance systems deals with motor drives or starter/generator systems operating with constant resistive type loads. The system model is discussed and simulation and test results are compared to show model accuracy. The test data is presented to show that the system meets the power quality requirements in steady state, as well as load switching modes of operation.<<ETX>>

Performance of a high-speed switched reluctance starter/generator system using electronic position sensing

A switched reluctance machine-based system, whether a motor drive or a starter/generator, requires the rotor position to be determined to commutate at the correct instants. This paper compares the performance of a high-speed switched reluctance starter/generator (SR S/G) system when operating with a resolver to the performance when operating resolverless, or sensorless, using an electronic position sensing subsystem for rotor position estimation. A brief overview of the SR S/G system is given, followed by the approach for sensorless system operation. Test results are given, and system efficiency is compared, for both approaches when operating both as a starter and as a generator. Minimal difference is seen in system efficiency, with peaks at over 75 percent for start-mode and at over 79 percent for generate mode, for both resolver-based and sensorless operation.

Design and implementation of a five horsepower switched reluctance, fuel-lube, pump motor drive for a gas turbine engine

A new switched reluctance (SR) fuel/lube (F/L) pump system has been developed for a gas turbine engine application. The system is rated at 5 HP, 270 VDC, 12500 RPM maximum operating speed, and consists of a SR machine mounted on the F/L pump shaft, an inverter, and an electronic controller. This paper focuses on the design, implementation, and performance of the system. The system can use one of two methods for rotor position sensing, either a resolver or electronic position sensing (EPS). The F/L pump system has undergone extensive performance testing with the resolver. Currently, testing is underway using electronic position sensing. Test results are given to validate the system design and compare the performance using both approaches to position sensing. System efficiency is about 82 percent at full load.<<ETX>>