Predesign Considerations for the DC Link Voltage Level of the CENTRELINE Fuselage Fan Drive Unit

Abstract

Electric propulsion (EP) systems offer considerably more degrees of freedom (DOFs) within the design process of aircraft compared to conventional aircraft engines. This requires large, computationally expensive design space explorations (DSE) with coupled models of the single components to incorporate interdependencies during optimization. The purpose of this paper is to exemplarily study these interdependencies of system key performance parameters (KPIs), e.g., system mass and efficiency, for a varying DC link voltage level of the power transmission system considering the example of the propulsion system of the CENTRELINE project, including an electric motor, a DC/AC inverter, and the DC power transmission cables. Each component is described by a physically derived, analytical model linking specific subdomains, e.g., electromagnetics, structural mechanics and thermal analysis, which are used for a coupled system model. This approach strongly enhances model accuracy and simultaneously keeps the computational effort at a low level. The results of the DSE reveal that the system KPIs improve for higher DC link voltage despite slightly inferior performance of motor and inverter as the mass of the DC power transmission cable has a major share for a an aircraft of the size as in the CENTRELINE project. Modeling of further components and implementation of optimization strategies will be part of future work.

Comparative Analysis and Optimization of Technical and Weight Parameters of Turbo-Electric Propulsion Systems

“…These comparisons revealed an accuracy of 2% to 5% for our analytical models depending on component and power level. As the modeling is similar to some of our previous work, text parts from [8,15] were re-used for the following description. Figure 3.…”

A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft

“…Such a design has potential for 10-15% power electronics size reduction over DC system, as shown by NASA convergent aeronautics solutions (CAS) study [177]. A DC power transmission system was considered in the CENTRELINE project to assess the weight and efficiency sensitivity in the electrical system both at the component level and system level with ae voltage variation between a range from 1000 V over to 5000 V [186]. The study illustrated that a high voltage level could be beneficial from overall mass and efficiency point of view.…”

Special Issue “9th EASN International Conference on Innovation in Aviation & Space”

“…The serviceability limits defined by the authors could enable helicopter users to significantly reduce operating costs by extending the remaining useful life (RUL) of the engines operated in a desert environment. Finally, in the study of Biser et al [8], the possibilities of coupled, analytical models for sizing electric propulsion systems were demonstrated by considering the example of a propulsion system developed in the frame of a relevant EU-funded project. The approach proposed by the authors was found to favor model accuracy and low computational effort.…”