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The solid state power controller (SSPC) is one of the most important power electronic components of the aircraft electrical power distribution (EPS) systems. This paper presents an architecture of the DC SSPC and provides the mitigation techniques for transient voltage overshoot during its turn-off. The high source side inductance carries breaking current (9xnominal current) just before turnoff and induces large voltage transient across the semiconductor devices. Therefore, the stored inductive energy needs to be dissipated in order to prevent semiconductor switches from over-voltage/thermal breakdown. Three different transient voltage suppression (TVS) devices to reduce voltage stress across switches are included in the paper for detail study. The comprehensive comparison of the TVS devices is presented. In addition, the thermal impact of the TVS devices on the semiconductor switches is also analyzed.

High power density for aerospace motor drives is a key factor in the successful realization of the More Electric Aircraft (MEA) concept. An integrated system design approach offers optimization opportunities, which could lead to further improvements in power density. However this requires multi-disciplinary modelling and the handling of a complex optimization problem that is discrete and nonlinear in nature. This paper proposes a multi-level approach towards applying random heuristic optimization to the integrated motor design problem. Integrated optimizations are performed independently and sequentially at different levels assigned according to the 4-level modelling paradigm for electric systems. This paper also details a motor drive sizing procedure, which poses as the optimization problem to solve here. Finally, results comparing the proposed multi-level approach with a more traditional single-level approach is presented for a 2.5 kW actuator motor drive design.

The paper will deal with the problem of establishing a desirable power sharing in multi-feed electric power system for future more-electric aircraft (MEA) platforms. The MEA 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 loads. Hence the onboard installed electrical power increases significantly and this results in challenges in the design of electrical power systems (EPS). One of the key paradigms for future MEA EPS architectures assumes high-voltage dc distribution with multiple sources, possibly of different physical nature, feeding the same bus(es). In our study we investigate control approaches to guarantee that the total electric load is shared between the sources in a desirable manner. A novel communication channel based secondary control method is proposed in this paper.

In this paper, the load sharing principles in dc-distribution electric power systems (EPS) for future more-electric aircraft (MEA) are investigated. The study is conducted using a potential MEA EPS architecture with multiple sources feeding into the main dc bus. Corresponding reduced-order EPS models are established. The influence of the cable impedance on the load sharing accuracy is analyzed and sharing error is quantized in mathematical equations. In addition, source/load impedance of the droop-controlled system has been derived leading to the discussion of the stability issues in multi-feed dc EPS under different droop control strategies. The influence of load sharing ratio on the EPS stability margins has been investigated. The theoretical findings were supported by time-domain simulations in Matlab/SimPower.

This paper considers the electromechanical interconnection between the electrical power system of the More Electric Aircraft (MEA) and the shaft connecting the engine to the generator. In order to investigate the coupling between these two systems the effect of an electric load impact on the mechanical system of the MEA will be analysed. In the MEA, many functions traditionally powered by pneumatic, hydraulic and mechanical systems will be replaced by the electrical systems. Thus the electrical power rating will be considerably higher than that of a traditional aircraft. With the increase of electrical power, the impact of electrical load on the mechanical system, especially the engine shaft, will become significant. This paper focuses on the study of the interaction between the electrical and mechanical system.

This paper summarizes recent activities undertaken in the University of Nottingham towards development of simulation tools for accelerated simulation studies of complex aircraft electric power systems. The more-electric aircraft (MEA) is a major trend in aircraft electric power system (EPS) engineering that results in a significantly increased number of power electronic driven loads onboard. Development and assessment of EPS architectures, ensuring system integrity, stability and quality performance under normal and abnormal scenarios requires extensive simulation activity. Increased power electronics can make the simulation of a total EPS impractical due to large computation time or even numerical non-convergence due to the model complexity. Hence there is a demand for accurate but time-efficient modeling techniques for MEA EPS simulations.

This paper describes the design, construction and testing of a dual-output power converter concept where the large components, such as the DC link capacitor and heat-sink, are shared between two actuators which are used sequentially in the deployment of aircraft landing gear. This mutual component approach combines the advantages of dual-use power converters with the flexibility of one power converter per application. Practical results of the converter operating are presented for a range of test conditions in order to validate the simulation study.

One of the most recent trends in the aerospace industry is the increased use of electrical power in place of hydraulic, pneumatic and mechanical power. This paper presents an analytical and experimental feasibility study regarding the application of an electro-mechanical actuator (EMA) for the aileron of an aircraft using a real flight profile as a reference. The analysis is focused on the input power flow of the actuator converter, showing that the total amount of energy that would be regenerated into the aircraft power network is small and that the use of a bi-directional power flow converter has the advantage of reducing the size of the braking circuit. The investigation is carried out assuming a two stage matrix converter as the candidate power conversion topology. However many of the conclusions are equally applicable to other conversion topologies that are capable of bidirectional power flow.

This paper considers a wide range of options for the allowing regeneration onto the aircraft bus for possible inclusion in future aircraft power quality specifications. For many loads, such as actuators, the size and weight of power converters could be significantly reduced if the requirement to avoid regeneration was removed from the specifications.

This paper develops fast reduced-order models for generic aircraft electromechanical actuators (EMA). The models derivation is described in detail. It is shown that constant power load representation has its own dynamics that depend both on the principal machine parameters and upon the pulse-width modulation algorithm used. The accuracy specification cannot be met unless these dynamics are considered. The mechanism to take these dynamics into account by reduced-order models is proposed. Simulation results demonstrate the accuracy within the specified frequency bandwidth and the significant improvement in the computational time. The reported models can be used in a wide range of aircraft power system simulations.