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Turbine-engine-driven distributed electrical aircraft power systems [also referred to as turboelectric distributed propulsion (TeDP)] are proposed for providing thrust for future aircraft with superconducting components operating at 77 K, in order for performance and emission targets to be met. The proposal of such systems presents a radical change from current state-of-the-art aeroelectrical power systems. Central to the development of such power systems are architecture design trades which must consider system functionality and performance, system robustness, and fault ridethrough capability, in addition to the balance between mass and efficiency. This paper presents a quantitative comparison of the three potential candidate architectures for TeDP electrical networks. This analysis provides the foundations for establishing the feasibility of these different architectures subject to design and operational constraints. The findings of this paper conclude that a purely ac synchronous network performs best in terms of mass and efficiency, but similar levels of functionality and controllability to an architecture with electrical decoupling via dc cannot readily be achieved. If power electronic converters with cryocoolers are found to be necessary for functionality and controllability purposes, then studies show that a significant increase in the efficiency of solid-state switching components is necessary to achieve specified aircraft performance targets. [ABSTRACT FROM AUTHOR]

Purpose -- The purpose of this paper is to highlight and discuss the unique safety and protection requirements for the electrical microgrid system in a turboelectric distributed propulsion aircraft. Design/methodology/approach -- The NASA N3-X concept aircraft requirements were considered. The TeDP system was decomposed into three subsystems: turbogenerator, distribution system and propulsors. Unique considerations for each of these subsystems were identified. Findings -- The fail-safe requirements for a TeDP system require a divergence from the standard safety case used for conventional propulsion systems. Advantages in flight control and single-engine-out scenarios can be realized using TeDP. Additionally, a targeted use of energy storage and reconfigurability may enable seamless response to propulsion systems failures. Practical implications -- The concepts discussed in this paper will assist to guide the early conceptual and preliminary design and evaluation of TeDP architectures. Originality/value -- The safety case for TeDP architectures is currently immature. The work presented here acts to frame some of the major issues when designing, evaluating and verifying TeDP conceptual architectures. [ABSTRACT FROM AUTHOR]

Purpose -- This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components. Design/methodology/approach -- The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions. Findings -- Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems. Practical implications -- The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems. Originality/value -- The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP. [ABSTRACT FROM AUTHOR]