Evaluation of electric actuation for fighter aircraft

Abstract: The tendency of recent years towards electrification of aircraft components and subsys-tems has opened the door for a wider usability of electro-mechanical actuators (EMAs) inthat context. EMAs are already in use in aircraft industries but mainly in civil aviation forsecondary control systems and non-critical applications. Therefore it is evident that thereexists a need for further research in the sector of utilization of EMAs for other areas withinthe aircraft manufacturing industry before they can be effectively applied. In this thesisan analysis of the power and thermal behaviour of EMAs has been done to evaluate theirapplicability in primary control systems for fighter aircrafts as compared to conventionallyused hydraulic systems. Furthermore, a method for scaling of such actuators in an initialdesign stage where few parameters are known has been developed and validated. One ofthe most substantial drawbacks against choosing EMAs for these purposes is the disadvan-tageous thermal transfer capability of electrical machines in high power applications. Aninvestigation has therefore also been made on calculation of power losses of electrical mo-tors and inverters. The results have been compared against a servo hydraulic actuator. Ascalable simulation model derived from motor data statistics has been developed in orderto simulate power losses and the thermal behaviour of these actuators. The model takesvery few parameters as input as an aircraft designer working in the preliminary stages ofthe design process often have limited knowledge of the final product, but at the same timeneed a fairly accurate view of how the actuators ought to be scaled with regard to weight,power and thermal transfer. The model shows promising results when verified against anactual electro-mechanical actuator on Iron Bird test rig. Finally, this work aims to furtherthe development of an Iron Bird situated on Linköping University, through an integrationbetween three thesis projects where the final product shall be an Hardware In The Loop(HWIL) simulation with several actuators involved.