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A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. I. INTRODUCTIONHE more-electric aircraft (MEA) concept is one of the major trends in modern aerospace engineering aiming for reduction of the overall aircraft weight, operation cost and environmental impact. Electrical systems are employed to replace existing hydraulic, pneumatic and mechanical actuators. As a consequence, the onboard installed electrical power increases significantly and this results in challenges in the design of the aircraft electrical power systems (EPS). The tendency is to replace traditional AC distribution with highvoltage DC distribution. This can increase efficiency, reduce weight and remove the need for reactive power compensation devices [1], [2].In literature, the primary power distribution in aircrafts has been traditionally based on the single-generator-per-bus paradigm with switched distribution providing the connectivity and system integrity. Instead, the proposed "single-bus" concept uses the micro-grid approach in which all the generators and loads are connected to a single distribution bus. This single bus configuration has been widely used in other applications such as residential microgrids [3]. Such a system has the potential to considerably reduce the EPS weight since bus mass is reduced and load and generator fault isolation function can be integrated in power converters; in addition the controlled power sharing between generators has the potential to reduce generator capacity and operate at maximum efficiency levels.As the parallel operation of multiple generators is a promising solution for the MEA EPS, appropriate power sharing among the different power sources needs to be carefully considered. From the communication point of view, overall control of DC systems can be divided into three categories: distributed control, centralized control and decentralized control [4].

Gao, Fei and Bozhko, Serhiy (2016) A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk 1 Abstract-The impedance based stability assessment method has been widely used to assess the stability of interconnected systems in different application areas. This paper deals with the source/load impedance analysis of the droop-controlled multiple sources multiple loads system which is a promising candidate in the future more-electric aircraft (MEA). This paper develops a mathematical model of the PMSG-based variable frequency generation system, derives the output impedance of the source subsystem including converter dynamics and shows the effect of parameters variation on source impedance and load impedance. A dynamic droop controller is proposed to provide the active damping to the system. In addition, the impedance analysis is extended to a generalized single bus-based multiple sources multiple loads system in which power losses are also investigated. The aforementioned analytical result is confirmed by experimental results.

A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk

This paper presents a new electricity power generation architecture for the engine system of more electric aircraft (MEA). A starter/generator (SG) is connected to highpressure (HP) spool, and a generator is attached to low-pressure (LP) spool. Their outputs supply a common DC bus. A back-toback (B2B) converter is connected between the AC sides of two generators. There are two main contributions of the proposed idea. First, some power can be transferred from LP shaft to HP shaft via the B2B converter, which will benefit to reduce the fuel consumption and increase compressor surge margin of the engine. Second, the HP starter/generator could operate in a high speed without flux weakening, hence the magnitude of stator current will largely decrease when output same active power, leading to the reduction of overall power losses. Modeling and control method design are illustrated. The effectiveness of proposed power generation architecture, engine performance improvement and power loss reduction are verified.