This paper presents a formal mathematical framework for the use of the morphological matrix in a computerized conceptual design framework. Within the presented framework, the matrix is quantified so that each solution principle is associated with a set of characteristics such as weight, cost, performance, etc. Selection of individual solutions is modeled with decision variables and an optimization problem is formulated. The applications are the conceptual design of subsystems for an Unmanned Aerial Vehicle and an aircraft fuel transfer system. Both the system models and the mathematical framework are implemented in MS Excel.

A computerized optimization framework for the morphological matrix applied to aircraft conceptual design

The development of all electric aircraft (AEC) has provided new opportunities in the field of electronic devices and power electronics. One of the most interesting areas is focused on the protection devices field and the management of the loads by means of the solid state power controllers (SSPC). This is mainly due to the great increase of these devices in the electrical power distribution system architectures used in the new airplanes such as A380 and B787. This paper presents a survey of conventional and future trends of protection devices in onboard platforms. Moreover a virtual test bench is developed in order to analyze the potential problems that could appear by using SSPC in new onboard platforms. In addition an experimental validation with commercial SSPC and its model are presented.

Protection Devices for Aircraft Electrical Power Distribution Systems: State of the Art

The development of all electric aircraft has provided new opportunities in the area of electronic devices and power electronics One of the most interesting fields is related to the protection devices area and the loads management by means of the Solid State Power Controllers (SSPC) This is mainly due to the noticeable increase of these devices in the architectures of electrical power distribution system used in the new airplanes such as A380 and B787 This paper presents a survey of conventional and future trends of protections in on-board platforms In addition, a virtual test bench is developed in order to analyze the potential problems that could appear by using SSPC technology in the new onboard platforms

Protection devices for aircraft electrical power distribution systems: a survey

This article presents a novel high-temperature superconductive (HTS) power flow controller and current limiter (PFCCL), which limits fault currents and manages power flow in the intended transmission line. The proposed device includes series HTS reactors, HTS controlling dc coil, recovery resistive coil, and power electronic switches, which protects the microgrid from the upstream ac grid, short-circuit faults, and it controls the power flow between a microgrid and the upstream grid. Performance of the proposed PFCCL is mathematically analyzed, utilizing MATLAB and Maxwell software, and then validated by laboratory scaled-down experimental setup. It is shown that the simulation results are in fair agreement with the developed experimental laboratory setup results.

A Multifunction High-Temperature Superconductive Power Flow Controller and Fault Current Limiter

In the scope of this thesis, a methodology for modeling of entire system architectures of commercial transport aircraft is presented. The author’s approach facilitates technology assessment of innovative system technology on aircraft-level in conceptual and early preliminary aircraft design. It closes the existing gap of sound systems modeling in early aircraft design synthesis. The proposed methodology uses a strictly function-driven approach for sizing of the single aircraft systems according to the dedicated aircraft-level functions. System weight and maximum as well as mission dependent power off-takes are estimated. The principle of energy balance is used to derive the power demand of the single systems. A modular and flexible approach has been chosen that allows for fast variation of the system architecture. Thus, investigation of large design spaces is possible. For integration and assessment of innovative systems technology, a probabilistic framework is introduced that incorporates remaining uncertainties. The proposed system model has been integrated into the Institute’s of Aeronautics and Astronautics (ILR) Multidisciplinary Integrated Conceptual Aircraft Design and Optimization (MICADO) environment. Thus, repercussions of system integration, e.g. on aircraft efficiency or performance, can be captured in a highly integrated environment. The proposed systems model is a valuable tool for sound assessment of innovative system technology on overall aircraft-level already in conceptual aircraft design. The proposed systems model has been validated against two commercial transport aircraft. Additionally, comprehensive sensitivity studies show dependencies and identify the main design drivers of the single systems. Two case studies show the added-value of integration of the proposed systems model into early aircraft design synthesis. The first case study concentrates on evaluation of the impact of engine power off-takes on aircraft performance and efficiency. The second design study focuses on integration of innovative technology into the overall system architecture and on application of the proposed probabilistic framework for considering the remaining uncertainties in design and technology assessment.

Integration of aircraft systems into conceptual design synthesis

In future more electric aircraft (MEA) applications increased requirements of power levels stress the importance of low losses in converters and switching elements. In this work the losses of transistor switches are analysed and compared with the losses in magnetic amplifiers (Magamp) where amorphous alloy properties allows design of competitive devices. More Electric Aircraft technology can take advantage of this to accomplish compact, robust and reliable systems with low losses. Magamps are already used in the power supply of the Electronic Flight Control System in the Swedish "Gripen" fighter-aircraft. This paper presents a comparison between Magamp technology and an alternative Insulated Gate Bi-polar Transistor (IGBT) design. The study is concentrated on the power losses in a proposed 10 kW converter with ± 270 VDC (540 VDC) regulated output, where the fundamental difference between the switching elements is that the magnetic switch handles AC and the IGBT handles DC. To allow comparison, the copper and magnetic losses in the magnetic switch of the magnetic amplifier are considered as equivalent to the switching and conduction losses in the IGBT. The comparison is based on the sum of losses in power converters comprising six switching elements.

Evaluation of switching losses in magnetic amplifiers as an alternative to IGBT switching technologies

A modeling approach of a magnetic amplifier

This paper illustrates a collaborative approach for distributed model development and simulation applied to aircraft systems design in the so-called “More Electric Aircraft” (MEA) study. A computational framework and a distributed model were created as a joint effort between Linkoping University, Saab Aerosystems, and the Royal Institute of Technology in Sweden. Parts of the model were developed at different locations and integrated to a complete system. The principle for the models, the proposed methodology and the developed computational framework are described in the paper.

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Tools and Methodology for Collaborative Systems Design Applied on More Electric Aircraft

A trend of increased Electric Power in Aircraft stresses the need of robust, low weight systems with low losses New hard and soft magnetic materials have made it feasible to work with high speed and high frequency Applications of new soft magnetic materials and hard magnetic materials like NeFeB magnets have enabled high density power generation systems A new concept comprising a high speed PM-generator system and a magnetic amplifier control is presented Magnetic amplifiers are used in the power supply of the Electronic Flight Control System in the Swedish "Gripen" fighter-aircraft This technology is attractive in More Electric Aircraft (MEA) systems due to the possibility to achieve a compact, robust and a highly reliable system with low losses Applications of new soft magnetic materials, such as amorphous magnetic alloys, have enabled the use of magnetic amplifier (magamp) technology in the design of competitive electric power converters This paper presents a studied design on a 20-40 kW generator system including a +/- 270V controlled output, performed by magnetic amplifier technology This work addresses the power generator, and the power converter High speed PM-generators are offering high power density The impact of operating a generation system with higher frequency and an increasing number of poles as well as the advantages with new soft magnetic materials is studied The iron losses and the copper losses are analyzed for the generator, and the power converter

Lars Austrin

Papers

Evaluation of switching losses in magnetic amplifiers as an alternative to IGBT switching technologies

A modeling approach of a magnetic amplifier

Tools and Methodology for Collaborative Systems Design Applied on More Electric Aircraft

A new high power density generation system

Concept Optimization of Aircraft Systems Using Scaling Models