Rotor topologies for a switched-reluctance machine for the ‘more-electric’ aircraft engine

The switched reluctance machine (SRM) design is different from the design of most of other machines. SRM has many design parameters that have non-linear relationships with the performance indices (i.e., average torque, efficiency, and so forth). Hence, it is difficult to design SRM using straight forward equations with iterative methods, which is common for other machines. Optimization techniques are used to overcome this challenge by searching for the best variables values within the search area. In this paper, the optimization of SRM design is achieved using multi-objective Jaya algorithm (MO-Jaya). In the Jaya algorithm, solutions are moved closer to the best solution and away from the worst solution. Hence, a good intensification of the search process is achieved. Moreover, the randomly changed parameters achieve good search diversity. In this paper, it is suggested to also randomly change best and worst solutions. Hence, better diversity is achieved, as indicated from results. The optimization with the MO-Jaya algorithm was made for 8/6 and 6/4 SRM. Objectives used are the average torque, efficiency, and iron weight. The results of MO-Jaya are compared with the results of the non-dominated sorting genetic algorithm (NSGA-II) for the same conditions and constraints. The optimization program is made in Lua programming language and executed by FEMM4.2 software. The results show the success of the approach to achieve better objective values, a broad search, and to introduce a variety of optimal solutions.

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Considerations of the All Electric (Accessory) Engine Concept

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1243/pime_proc_1995_209_301_02 ◽

1995 ◽

Vol 209 (4) ◽

pp. 273-280 ◽

Cited By ~ 10

Author(s):

R I Jones

Keyword(s):

System Component ◽

Electrical Machine ◽

Main Shaft ◽

Switched Reluctance Machine ◽

Switched Reluctance ◽

Design Considerations ◽

Reluctance Machine ◽

Starter Generator ◽

Engine Concept ◽

Engine Type

The concept of the all electric (accessory) engine (AEE) involves the use of an electrical machine integrated on an engine main shaft acting as a starter generator, providing power to both engine and airframe systems. Through removal of the various constraints caused by the present mechanical accessory drives, this concept apparently provides a number of advantages. However, the concept of an AEE has been around for some years and yet has not been adopted to-date. A brief review of electrical machine types previously considered as internally mounted starter/generators highlights basic problems of the concept. The reasons for favouring the Switched Reluctance Machine for this application are then explained and some present and planned developments on this basis outlined. An approximate sizing of starter/generators to replace shaft off-takes alone and bleed in additions in a civil turbofan application is presented, showing more detailed design considerations. Other system component aspects and concerns are also covered before addressing the effects on the ease of adopting the AEE concept of likely future changes to civil engines. Major differences relative to the civil case are indicated for other engine type applications. Conclusions are then drawn on the likely future of the AEE concept.

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