Analysis of Electro-Mechanical Actuator Systems in More Electric Aircraft Applications

Conventional hydraulic actuators in aircraft are demanding regarding maintenance which implies high operation costs. In recent years the focus therefore has been set on electro-hydrostatic and electro-mechanical actuators. The aim of this work is to analyze and evaluate the possibility of introducing electro-mechanical actuators (EMAs) in more electric aircraft applications. The major goal is to optimize the weight of such actuator systems including the electro-machine (electric motor) gear mechanism and power converter, without loss of reliability. Other optimisation criteria on such solutions are low losses and good thermal properties. A quasi-static model approach of EMAs is used here in order to decrease the simulation time. It is possible because the low (mechanical) and high (electrical) frequency components are separated in the model, see [1]. The inverters and converters are described as fictive DC-DC transformers with corresponding efficiencies, see [2]. By introducing an object oriented approach the model is flexible and re-usable and can be used as a framework in the future build-up of models of entire MEA aircrafts, see [3]. Power density, cost and weight of the actuator systems are some of the important key factors for comparing purpose and as a platform for the dimensioning of the aircraft. The next issue becomes the scalability of the model and the key factors, because of the diversity of the actuators used in different parts of the MEA aircraft. Therefore the ambition is set to build up a database of different scalable actuator solutions which among others returns these key factors as output.