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In recent years, the More-Electric Aircraft (MEA) concept has undergone significant development and refinement, striving towards the attainment of reductions in noise and CO2 emissions, increased power transmission efficiency and improved reliability under a range of flight scenarios. The More-Electric Engine (MEE) is increasingly being seen as a key complementary system to the MEA. With this concept, conventional engine auxiliary systems (i.e. fuel pumps, oil pumps, actuators) will be replaced by electrically-driven equivalents, providing even greater scope for the combined aircraft and engine electrical power system optimisation and management. This concept, coupled with extraction of electrical power from multiple engine spools also has the potential to deliver significant fuel burn savings. To date, single or dual channel electrical power generation and distribution systems have been used in engines and aircrafts.

The continued electrification of aircraft is required such that ambitious decarbonisation targets can be met. A significant challenge presented with this trend is the increased reliance on electrical systems to perform flight-critical operations in a manner that has not been seen in previous generations of aircraft. The power electronic converter is a key enabling technology in aircraft electrification. Its prevalence is such that the failure rate of flight critical-loads is closely linked with that of the associated power electronic converters. As such, there is a clear need to better understand the impact of improvements in both the reliability and failure estimation of novel power electronic converters at a systems level in future aerospace applications. Accordingly, this paper presents key highlights from literature on power converter research, summarising advances in reliability-enhancing features and more accurate Physics-of-Failure modelling methods.

Turbo-electric distributed propulsion (TeDP) for aircraft allows for the complete redesign of the airframe so that greater overall fuel burn and emissions benefits can be achieved. Whilst conventional electrical power systems may be used for smaller aircraft, large aircraft (~300 pax) are likely to require the use of superconducting electrical power systems to enable the required whole system power density and efficiency levels to be achieved. The TeDP concept requires an effective electrical fault management and protection system. However, the fault response of a superconducting TeDP power system and its components has not been well studied to date, limiting the effective capture of associated protection requirements. For example, with superconducting systems it is possible that a hotspot is formed on one of the components, such as a cable. This can result in one subsection, rather than all, of a cable quenching.

Turboelectric Distributed Propulsion (TeDP) is actively being investigated as a means of providing thrust in future generations of aircraft. In response to the lack of published work regarding the system-level fault behaviour of a fully superconducting network, this paper presents key points from a two stage Failure Modes and Effects Analysis (FMEA) of a representative TeDP network. The first stage FMEA examines the qualitative behaviour of various network failure modes and considers the subsequent effects on the operation of the remainder of the network, enabling the identification of key variables influencing the fault response of the network. For the second stage FMEA, the paper focuses on the characterisation of the rate at which electrical faults develop within a TeDP network.

A number of concepts have been proposed to meet future aircraft performance goals. One such concept under consideration is Turboelectric Distributed Propulsion (TeDP) featuring a large number of superconducting motors powered by two superconducting generators placed on each wingtip and connected through a DC distribution network. A key aspect in any design concept is the ability to prove that the system will exhibit a satisfactory reliability for all intended operating conditions. A common tool to support the calculation of failure rates and reliability is Fault Tree Analysis (FTA), and this will be utilized within this paper. The paper undertakes an architectural level FTA on a NASA proposed TeDP architecture to identify any significant factors contributing to the failure rate of key functionalities within the network.

In addition to providing thrust, the engines on conventional civil jet airliners generate power for on-board systems and ancillary loads in the form of pneumatic, hydraulic and electrical power. Reduced fuel-burn and efficiency targets have driven the move towards More Electric Aircraft (MEA) technology which seeks to replace hydraulic and pneumatic loads with electrical equivalents. This technological shift, in conjunction with a growing electrical power load per passenger in general, has greatly increased the electrical power demands of aircraft in recent years - over 1 MVA for the Boeing 787 for example. With increasing fuel prices, there is a growing need to optimise efficiency of power extraction from the aircraft engines for the electrical system and loads. In particular, the utilisation of multi-shaft power off-takes, interconnected generation and power sharing between shafts is thought to offer potentially significant engine operability and fuel efficiency benefits.