Search Results

Aiming at the global energy optimization of aircraft, the More Electric Aircraft (MEA) concept becomes more interesting for the aeronautical industry. The MEA concept is based on utilizing electric power to drive aircraft subsystems that historically have been driven by a combination of hydraulic, electric, pneumatic and mechanical power transfer systems. The development of the future MEA systems is a challenging task: the system integration is becoming a central topic. In all phases of the system development process, the respective subsystems within the MEA will be treated in a highly integrated manner to achieve optimum efficiency and performance at aircraft and systems level. Concerning the electric network in the future MEA, advanced design and analysis methods based on mathematical models are required to face the potential issues accompanying the MEA. For this purpose, the use of advanced modelling and simulation technologies is a key success factor.

In upcoming and future airplanes, more nonlinear electrical loads and loads behaving nonlinearly will be connected to the power distribution network. This induces advanced demands on the network to keep the power quality. The generator design also has to face the new demands and constraints. Trade offs between performance, weight, and latterly power quality have to be made and design choices have to be backed up by qualitative and quantitative measures. In a prior study a design tool chain was elaborated for an externally excited synchronous generator. In the first part of this paper this study is concluded. An outlook is given on the generator size demanded in relation to the portion of nonlinear loads in the network, in case the industrial standards are kept unchanged. The power quality criteria can be gained by time-domain simulation. This simulation can be computationally extensive, especially in case of a large ramp up time to the operating point.

Advanced modeling and simulation techniques are becoming more important in today's industrial design processes and for aircraft energy systems in specific. They enable early and integrated design as well as validation of finalized system and component designs. This paper describes the main methods and tools that can be applied for different phases of the energy design process. For demonstration, the object-oriented modeling language Modelica was chosen, since it enables convenient modeling of multi-physical systems. Based on this standard, common modeling guidelines, a modeling library template, and common interfaces have been provided. A common modeling infrastructure is proposed with considerations on additional libraries needed for local tasks in the energy design process. The developed methods and tools have been tested by means of some predefined use cases, which are performed in cooperation with diverse aircraft industrial partners.