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Technical Paper
2014-09-16
Christine Ross, Michael Armstrong, Mark Blackwelder, Catherine Jones, Patrick Norman, Steven Fletcher
Abstract The Turboelectric Distributed Propulsion (TeDP) concept uses gas turbine engines as prime movers for generators whose electrical power is used to drive motors and propulsors. For this NASA N3-X study, the motors, generators, and DC transmission lines are superconducting, and the power electronics and circuit breakers are cryogenic to maximize efficiency and increase power density of all associated components. Some of the protection challenges of a superconducting DC network are discussed such as low natural damping, superconducting and quenched states, and fast fault response time. For a given TeDP electrical system architecture with fixed power ratings, solid-state circuit breakers combined with superconducting fault-current limiters are examined with current-source control to limit and interrupt the fault current. To estimate the protection system weight and losses, scalable models of cryogenic bidirectional current-source converters, cryogenic bidirectional IGBT solid-state circuit breakers (CBs), and resistive-type superconducting fault current limiters (SFCLs) are developed to assess how the weight and losses of these components vary as a function of nominal voltage and current and fault current ratings.
Technical Paper
2014-09-16
Karen Davies, Patrick Norman, Catherine Jones, Stuart Galloway, Graeme Burt
Abstract 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. The impact of system quench and associated rise in network resistance as well as network parameters such as network voltage and pre-fault current, on the resulting fault profile are also examined using a range of sensitivity studies.
Technical Paper
2014-09-16
Ralf D. Pechstedt
Abstract Recently, there has been an increasing interest in Fiber Optic Sensors (FOS) for aircraft applications. Many of the FOS are based on different transducer mechanisms and hence, employ sensor-specific readout systems. However, for ease of maintenance and cost saving purposes, a ‘universal interrogator’ that can be used with at least a large sub-group of sensors is the preferred option for deployment in aircraft. Oxsensis has been developing sensors for harsh environments with focus on land based gas-turbine monitoring and combustion control and more recently is also looking at applying its technology to other areas such as Aerospace and Oil & Gas. In this paper we report on recent progress on the development of a number of FOS and how these could find application in aircraft with a ‘universal interrogator’ concept in mind.
Technical Paper
2014-09-16
Marco Amrhein, Jason Wells, Eric Walters, Seana McNeal, Brett Jordan, Peter Lamm
Abstract Transient operating conditions in electrical systems not only have significant impact on the operating behavior of individual components but indirectly affect system and component reliability and life. Specifically, transient loads can cause additional loss in the electrical conduction path consisting of windings, power electronic devices, distribution wires, etc., particularly when loads introduce high peak vs. average power ratios. The additional loss increases the operating temperatures and thermal cycling in the components, which is known to reduce their life and reliability. Further, mechanical stress caused by dynamic loading, which includes load torque cycling and high peak torque loading, increases material fatigue and thus reduces expected service life, particularly on rotating components (shaft, bearings). This article investigates the aforementioned stress mechanisms and provides analysis techniques and metrics to quantify the impact of transient operating conditions onto system and component reliability and life.
Technical Paper
2014-09-16
Serhiy Bozhko, Seang Shen Yeoh, Fei Gao, Tao Yang, Christopher Hill
Abstract The paper reports the control design for an aircraft electric starter-generator system based-on high-speed permanent magnet machine operated in a flux-weakening mode and controlled by an active front-end rectifier. The proposed system utilizes advances of modern power electronics allowing the use of novel machine types and the introduction of controlled power electronics into the main path of energy flow. The paper focuses on control design for such system and includes development of flux weakening control of high-speed permanent magnet machine and droop control of the system output dc-link current. The achieved analytical design results and the expected system performance are confirmed by time-domain simulations.
Technical Paper
2014-09-16
Martin Bradish, Obed Sands, Ted Wright, Casey Bakula, Daniel Oldham, William Ivancic, Michael Lewis, Joseph Klebau, Nicholas Tollis, Andrew Jalics
Abstract This paper summarizes the Power, Avionics and Software (PAS) 1.0 subsystem integration testing and test results that occurred in August and September of 2013. This paper covers the capabilities of each PAS assembly to meet integration test objectives for non-safety critical, non-flight, non-human-rated hardware and software development. This test report is the outcome of the first integration of the PAS subsystem and is meant to provide data for subsequent designs, development and testing of the future PAS subsystems. The two main objectives were to assess the ability of the PAS assemblies' to exchange messages and to perform audio tests of both inbound and outbound channels. This paper describes each test performed, defines the test, the data, and provides conclusions and recommendations.
Technical Paper
2014-09-16
Rudolf Neydorf, Sergey Novikov, Nikita Kudinov
Abstract Airship designers research application versions of systems with several ballonets for adjustment of airship roll and/or pitch as a whole. This requires effective automatic status management of each separate ballonet. But multi-ballonet system control issue encounters the absence of industrially measurable variables of each separate ballonet status. Thus status control issue of the system becomes uncertain. The fact requires the issue studying and shaping new scientific and technical solutions. This publication represents research results implying that fairly simple implementation and effective result can be achieved by application of fuzzy control concept. Its application is built on generating the representative quantity of fuzzy production rules. They are based on present set evaluation of known parameters and measured variables. This results in fuzzy but meaningful image of ballonet system status and airship as a whole. Thus achieving fairly good control over multi-ballonet system.
Technical Paper
2014-09-16
Jon Hagar
Abstract System testing can, in part, be defined as the application of concepts as an attempt to demonstrate that the implementation does not meet its intended use. Unfortunately, some industry verification test efforts only show that a system meets requirements which while necessary, are not sufficient to fully address a product's system-software testing. Managers, engineers, and testers may not be familiar with the wide variety of test concepts, approaches, and standards available for system-software testing-many of which can save projects money and effort in the long run. Newer software test standards and advanced techniques can offer a wealth of knowledge and improvement opportunities for software products. This paper offers a review of emerging software test concepts and standards in which teams will find potential value toward their improvement efforts including: Math-based techniques which apply combinatorial, statistical, Design of Experiments (DOE), or domain-based concepts Attack-based testing which focuses on common industry error taxonomies Independent model-based testing using tools and standards New standards-driven testing to address verification and validation (V&V), testing, and documentation.
Technical Paper
2014-09-16
James Borg Bartolo, Chris Gerada
Abstract A 45kW, switched reluctance type, starter-generator, having a 1:4 constant power speed range has been designed as a possible candidate for a regional jet application. In the first section of this paper, a review of the major starter-generator topologies considered for the aerospace application is provided, highlighting the advantages of choosing the Switched reluctance topology for such a safety critical application. Following this, the required torque speed characteristic of the machine, along with the imposed physical constraints, in terms of cooling and outer dimensions, are also detailed. Section III provides a description of the Electromagnetic design, and challenges encountered in meeting both the low speed, peak torque node, at 8000rpm, and the high speed, high power node, at 32000rpm. The induced mechanical stresses in the rotor at such high speeds have also been evaluated and used as a material selection criterion for such a design as presented in section III. Section IV, describes the thermal model developed to estimate the radial temperature distribution within the machine, taking into account end winding phenomena and cooling fluid constraints.
Technical Paper
2014-09-16
Puvan Arumugam, Chris Gerada, Serhiy Bozhko, He Zhang, Weeramundage Fernando, Antonino La Rocca, Stephen Pickering
Abstract This paper describes a high-speed electrical machine for an aircraft starter-generator. A surface mounted permanent magnet machine is designed to have minimal rotor losses and a novel cooling system for the stator. An inner stator sleeve is adopted to allow for a flooded stator whilst minimizing rotor windage losses. Different slot-pole combinations are compared in view of attaining an optimal combination that provides minimum losses whilst satisfying the electromagnetic, mechanical and thermal constraints.
Technical Paper
2014-09-16
Richard Mourn
Abstract The paper provides an introduction into IEEE-1394, AS5643 and related documents. It then explores the I/O Technology Suitability Study criteria used to originally select IEEE-1394b (Beta) as the Vehicle System Data Bus for the F-35 Joint Strike Fighter and update each criterion with new information based on more than a decade of experience and use in not only the F-35 but several other programs. Based on the suitability study criteria, the reader gains insight into how and why programs like the F-35, which implements dozens of AS5643/IEEE-1394 devices per plane, utilize AS5643/IEEE-1394 for its vehicle system network. This unprecedented use of a high speed (491.52Mb/s) serial interface on an aircraft proves the capability of AS5643/1394, and opens the door for higher bandwidth communication between the Control Computer and remote nodes. While I/O bandwidth is important, system level deterministic behavior is required for most vehicle system networks and AS5643 coupled with 1394 provides the required deterministic behavior.
Technical Paper
2014-09-16
Arthur V. Radun
Abstract There is a continuing need to simulate power electronic circuits that include magnetic components. It is necessary to determine the interaction of the magnetic component with the rest of the power electronic system so that a dynamic circuit model of the magnetic components including material saturation and iron losses is required. Also, the magnetic component model must be valid when the magnetic component's excitation is not sinusoidal. A dynamic magnetic circuit model derived from Maxwell's equations along with useful theorems for building circuit models from the structure of the magnetic device is reviewed. The developed circuit models are general including magnetic saturation and iron losses. Simulation results for a DC/DC converter employing a conventional gapped inductor and a gapped coupled inductor are presented.
Technical Paper
2014-09-16
Michael Usrey, Kevin Harsh, Alexander Brand, R. Steve McKown, Alireza Behbahani
Abstract Air Force Research Laboratory (AFRL) is pursuing development of advanced, distributed, intelligent, adaptive engine controls and engine health monitoring systems. The goals this pursuit are enhancing engine performance, safety, affordability, operability, and reliability while reducing obsolescence risk. The development of smart, high-bandwidth, high-temperature-operable, wide-range, pressure/temperature multi-sensors, which addresses these goals, is discussed. The resulting sensors and packaging can be manufactured at low cost and operate in corrosive environments, while measuring temperatures up to 2,552 °F (1,400 °C) with simultaneous pressure measurements up to 1,000 psi (68 atm). Such a sensor suite provides unprecedented monitoring of propulsion, energy generation, and industrial systems. The multi-sensor approach reduces control system weight and wiring complexity, design time, and cost, while increasing accuracy and fault tolerance. In situ pressure sensors reduce size and weight while eliminating failures associated with hypo-tube fouling.
Technical Paper
2014-09-16
Yamina Boughari, Ruxandra Botez, Georges Ghazi, Florian Theel
Abstract The main goal of this flight control system is to achieve good performance with acceptable flying quality within the specified flight envelope while ensuring robustness for model variations, such as mass variation due to fuel burn. The Cessna Citation X aircraft linear model is presented for different flight conditions to cover the aircraft's flight envelope, on which a robust controller is designed using the H-infinity method optimized by two heuristic algorithms. The optimal controller was used to achieve satisfactory dynamic characteristics for the longitudinal and lateral stability control augmentation systems with respect to this aircraft's flying quality requirements. The weighting functions of the H-infinity method were optimised by using both genetic and differential evolution algorithms. The evolutionary algorithms gave very good results. This is the first time these algorithms have been used in this form to optimize H-infinity controllers on a business aircraft, respecting both flying quality requirements and robustness criteria as objective functions and avoiding the use of other computationally complicated algorithms.
Technical Paper
2014-09-16
Mario Luca Fravolini, Matthew Rhudy, Srikanth Gururajan, Silvia Cascianelli, Marcello Napolitano
Abstract A measurement device that is extremely important for Unmanned Aerial Vehicle (UAV) guidance and control purposes is the airspeed sensor. As the parameters of feedback control laws are conventionally scheduled as a function of airspeed, an incorrect reading (e.g. due to a sensor fault) of the Pitot-static tube could induce an incorrect feedback control action, potentially leading to the loss of control of the UAV. The objective of this study is to establish the accuracy and reliability of the two airspeed estimation techniques for eventual use as the basis for real-time fault detection of anomalies occurring on the Pitot-static tube sensor. The first approach is based on an Extended Kalman Filter (EKF) and the second approach is based on Least Squares (LS) modeling. The EKF technique utilizes nonlinear kinematic relations between GPS, Inertial Measurement Unit and Air Data System signals and has the advantage of independence from knowledge of the aircraft model. The LS method is based on explicit knowledge of the aircraft model and has the advantage of on-line computation of the airspeed estimate, with minimal computational effort.
Technical Paper
2014-09-16
Srikanth Gururajan, Mario Luca Fravolini, Matthew Rhudy, Antonio Moschitta, Marcello Napolitano
Abstract Recent catastrophic air crashes have shown that physical redundancy is not a foolproof option for failures on Air Data Systems (ADS) on an aircraft providing airspeed measurements. Since all the redundant sensors are subjected to the same environmental conditions in flight, a failure on one sensor could occur on the other sensors under certain conditions such as extreme weather; this class of failure is known in the literature as “common mode” failure. In this paper, different approaches to the problem of detection, identification and accommodation of failures on the Air Data System (ADS) of an aircraft are evaluated. This task can be divided into component tasks of equal criticality as Sensor Failure Detection and Identification (SFDI) and Sensor Failure Accommodation (SFA). Data from flight test experiments conducted using the WVU YF-22 unmanned research aircraft are used. Analytical redundancy is provided through a least squares modeling based approach and an extended Kalman filter approach to handle the Sensor Failure Accommodation (SFA) task.
Technical Paper
2014-09-16
Viacheslav Pshikhopov, Mikhail Medvedev, Victor Krukhmalev, Roman Fedorenko, Boris Gurenko
Abstract The paper describes methods for control of docking of two moving stratospheric airships. One of them (cruiser) implements cruising flight at the defined altitude with defined velocity. The other one (feeder) fulfills the mission of chasing the cruiser with following docking operations. Mathematical model of exact airships are used in the work. Instances of structural and algorithmic implementation are based on position-trajectory controller. Simulation of docking control was accomplished with proposed methods.
Technical Paper
2014-09-16
Niloofar Rashidi Mehrabadi, Bo Wen, Rolando Burgos, Dushan Boroyevich, Chris Roy
Abstract The development of the concepts, terminology and methodology of verification and validation is based on practical issues, not the philosophy of science. Different communities have tried to improve the existing terminology to one which is more comprehensible in their own field of study. All definitions follow the same concept, but they have been defined in a way to be most applicable to a specific field of study. This paper proposes the Verification, Validation, and Uncertainty Quantification (VV&UQ) framework applicable to power electronic systems. Although the steps are similar to the VV&UQ frameworks' steps from other societies, this framework is more efficient as a result of the new arrangement of the steps which makes this procedure more comprehensible. This new arrangement gives this procedure the capability of improving the model in the most efficient way. Since the main goal of the VV&UQ process is to quantitatively assess the confidence in modeling and simulation, the second part of this paper focuses on uncertainty quantification.
Technical Paper
2014-09-16
Nicholas Ernest, Kelly Cohen, Corey Schumacher, David Casbeer
Abstract Looking forward to an autonomous Unmanned Combat Aerial Vehicle (UCAV) for future applications, it becomes apparent that on-board intelligent controllers will be necessary for these advanced systems. LETHA (Learning Enhanced Tactical Handling Algorithm) was created to develop intelligent managers for these advanced unmanned craft through the novel means of a genetic cascading fuzzy system. In this approach, a genetic algorithm creates rule bases and optimizes membership functions for multiple fuzzy logic systems, whose inputs and outputs feed into one another alongside crisp data. A simulation space referred to as HADES (Hoplological Autonomous Defend and Engage Simulation) was created in which LETHA can train the UCAVs intelligent controllers. Equipped with advanced sensors, a limited supply of Self-Defense Missiles (SDM), and a recharging Laser Weapon System (LWS), these UCAVs can navigate a pre-defined route through the mission space, counter enemy threats, and destroy mission-critical targets.
Technical Paper
2014-09-16
Jay Wilhelm, Joseph Close, Wade Huebsch
A Hybrid Projectile (HP) is a ballistically launched round that transforms into an Unmanned Aerial Vehicle (UAV) at a designated point during flight. Aerodynamic control surfaces and associated control laws were sought that would extend the projectile's range using body lift and include guidance for a selected point of impact. Several challenges were encountered during the modification of an existing projectile, in this case a 40mm round, to achieve range extension and controllability. The control surfaces must be designed to allow for de-spin, controllability, and natural static stability. Also, a control system with laws and guidance relationships between heading, pitch or glide rate, and the associated aerodynamic surface movements needed to be developed. The designed aerodynamic surfaces, external ballistics, and control methods developed were modeled in a projectile flight simulator built in MATLAB. The base model was an M781 practice round and the aerodynamic coefficients and mass data were found in literature.
Technical Paper
2014-09-16
Aurelie Beaugency, Marc Gatti, Didier Regis
Abstract Since 2000, avionics is facing several changes, mostly driven by technological improvements in the electronics industry and innovation requirements from aircraft manufacturers. First, it has progressively lost its technological leadership over innovation processes. Second, the explosion of the electronics consumer industry has contributed to shorten even more its technology life cycles, and promoted the use of COTS. Third, the increasing complexity of avionics systems, which integrate more and more functions, have encouraged new players to enter the market. The aim of this article is to analyze how technological changes can affect the competitiveness of avionics firms. We refer to criticality levels as a determinant of the market competitiveness. Certification processes and costs could stop new comers to bring innovations from the consumer electronics industry and protects traditional players. The study will compare three avionics systems regarding their patent dynamics since 1980: flight controls, Integrated Modular avionics and Head-Up Displays.
Technical Paper
2014-09-16
Yves C.J. Lemmens, Tuur Benoit, Rob De Roo, Jon Verbeke
Vives College University and Kulab (KU Leuven University campus Ostend) in Belgium are undertaking an aeronautical research program about the development of a new Unmanned Aerial Vehicle (UAV). Since the UAV is completely electrically powered, the analysis of the energy management of the integrated electrical system was critical to the development of the UAV. LMS, A Siemens Business, is involved in the project to support the development of a multi-physics simulation model for electro-thermal analysis of the aircraft. This paper reports on the subsequent investigation of integrating the detailed electrical system model for a Pilot-in-the-Loop simulation. In order to perform this simulation, the model of the electrical system was converted into a real-time simulation model. The aim was to perform more realistic flight simulations to evaluate the performance of the aircraft before its first flight by taking into account the electrical system's behavior. Furthermore, the behavior of the electrical system can be directly assessed during and after the Pilot-in-the-Loop tests.
Technical Paper
2014-09-16
Michelle Bash, Michael Boyd, Chad Miller
Abstract This paper presents the details of an engine emulation system utilized within a Hardware-in-the-Loop (HIL) test environment for aircraft power systems. The paper focuses on the software and hardware interfaces that enable the coupling of the engine model and the generator hardware. In particular, the rotor dynamics model that provides the critical link between the modeled dynamics of the engine and the measured dynamics of the generator is described in detail. Careful consideration for the measured torque is included since the measurement contains inertial effects as well as torsional resonances. In addition, the rotor model is equipped with the ability to apply power and speed scaling between the engine and generator. This scaling approach provides significant flexibility that can be useful when hardware resources are limited such that a direct engine-generator match is not possible or when one wants to evaluate turboshaft engine dynamics for a variety of applications and power levels.
Technical Paper
2014-09-16
Michael Ellis, William Anderson, Jared Montgomery
Under a program funded by the Air Force Research Laboratory (AFRL), Advanced Cooling Technologies, Inc. (ACT) has developed a series of passive thermal management techniques for cooling avionics. Many avionics packages are often exposed to environment temperatures much higher than the maximum allowable temperatures of the electronics. This condition prevents the rejection of waste heat generated by these electronics to the surrounding environment and results in significant ambient heat gain. As a result, heat must be transported to a remote sink. However, sink selection aboard modern aircraft is limited at best. Often, the only viable sink is aircraft fuel and, depending on mission profile, the fuel temperature can become too high to effectively cool avionics. As a result, the electronic components must operate at higher than intended temperatures during portions of the mission profile, which reduces component lifetime and significantly increases the probability of failure. To address this issue, ACT developed two passive thermal management approaches for avionics packages: heat pipe assemblies to reduce the internal temperature gradient and a Loop Heat Pipe (LHP) to transport thermal energy to alternative sinks.
Technical Paper
2014-09-16
Andrew Slippey, Michael Ellis, Bruce Conway, Hyo Chang Yun
Abstract Carbon fiber reinforced polymer (CFRP) composite material is an attractive structural material in applications where mass is critical. The carbon fiber matrix provides strength comparable to steel with only 25% of the density. The CFRP sheet can often also be made thinner than metal with similar mechanical properties, further increasing the mass savings. However, thermal challenges have arisen with the increased use of composites. In the area of electronics enclosures, traditional metal structures conduct and spread heat over large surfaces, but composites act as insulation. Heat generated by components causes internal temperatures to rise and has detrimental impact on the performance and reliability of the electronics. A method is proposed and tested that utilizes constant conductance heat pipes (CCHPs) that penetrate through the CFRP walls. The CCHPs are capable of transporting significant heat energy through a limited cross-section with a minimal temperature penalty. CCHPs are passive, two-phase, thermal transport devices which have extremely high effective thermal conductivities on the order of thousands of W/m-K.
Technical Paper
2014-09-16
Riko Bornholdt, Frank Thielecke
Abstract Due to a shift of the major aviation concerns to focus on enhancements of the successful programs instead of pushing their successors, the need for new methodologies for aircraft system architecture design emerges. Challenging the existing requirements and reconsidering the functions and their allocation could help to dissolve the system specific development paradigm and lead to beneficial architecture concepts. To help understand the mechanisms and boundary conditions of developing fault-tolerant systems, the first part of the paper gives an overview of the successive process of architecture design. The significant architectural design decisions and the concurrent safety assessment process are discussed. One crucial step in the design space exploration of future aircraft system architectures is the allocation of the consumers to the available power sources. Within the paper a methodology for the optimization of the power allocation for flight control systems is proposed. With this methodology the evaluation of a large amount of architecture permutations on the basis of a preliminary system safety assessment regarding multiple top failure events is possible in a short time period.
Technical Paper
2014-09-16
Teresa Donateo, Maria Grazia De Giorgi, Antonio Ficarella, Elisabetta Argentieri, Elena Rizzo
Abstract The present study aims at the implementation of a Matlab/Simulink environment to assess the performance (thrust, specific fuel consumption, aircraft/engine mass, cost, etc.) and environmental impact (greenhouse and pollutant emissions) of conventional and more electric aircrafts. In particular, the benefits of adopting more electric solutions for either aircrafts at given missions specifications can be evaluated. The software, named PLA.N.E.S, includes a design workflow for the input of aircraft specification, kind of architecture (e.g. series or parallel) and for the definition of each component including energy converter (piston engine, turboprop, turbojet, fuel cell, etc.), energy storage system (batteries, super-capacitors), auxiliaries and secondary power systems. It is also possible to setup different energy management strategies for the optimal control of the energy flows among engine, secondary equipment and storage systems during the mission. The tool is designed to be integrated with a multi-objective optimization environment.
Technical Paper
2014-09-16
Neno Novakovic
Abstract Since the early 1970s, when microprocessors became commercially available, they quickly became a common part of all aircraft control and indication systems. With an ever-increasing number of microprocessor-based airborne applications, safety regulations and software standards like RTCA DO-178 evolved, demanding rigorous requirements and processes for software development, testing, life cycle, and certification. Over the years, as development of aerospace software applications increased, engineering costs of development and product certification costs exponentially increased, having a significant impact on the market. Landing Gear Actuation system is one of many aircraft systems whose control functions are based on microprocessors and software application. Considering that Landing Gear Actuation control algorithm can be defined in a form of the State Machine, this article intends to demonstrate that such controller can be realized as wired logic hardware, without software implementation.
Technical Paper
2014-09-16
Evan Racine, Zachary Lammers, Street Barnett, John Murphy, Quinn Leland
Abstract The purpose of this study is to set up a laboratory test apparatus to analyze aircraft flight control EMAS' electrical and thermal energy flow under transient and dynamic flight profiles. A hydraulic load frame was used to exert load to the EMA. The actuator was placed within an environmental chamber which simulates ambient temperature as function of altitude. The simulated movement or stroke was carried out by the EMA. The under test EMA's dynamic load, stroke, and ambient temperature were synchronized through a real time Labview DAQ system. Motor drive voltage, current, regenerative current, and motor drive and motor winding temperature were recorded for energy analysis. The EMA under test was subjected to both transient and holding load laid out in a test matrix. It was found that the transient missions of EMAS presented the most electric demand on the aircraft electric power supply system while holding presented the most severe thermal stress on the EMAS, where the EMAS operated at 0% efficiency and all the electric power converted to heat.
Technical Paper
2014-09-16
Christopher Ian Hill, Chris Gerada, Paolo Giangrande, Serhiy Bozhko
Abstract This paper presents the initial development of a Modelica Library for Electro-Mechanical Actuator system analysis. At present two main system components are described, these are the Power Electronic Converter and Electric Machine, although further components will be added. These models provide the user with the ability to simulate Electric Machine and Power Electronic Converter systems including physical effects, losses and fault conditions. Established modelling programs such as Saber and MATLAB SimPowerSytems are often unable to provide all the aspects required to accurately simulate real systems in an easy to use, flexible manner. Therefore this paper shows how Modelica has been used to create versatile models able to simulate many practical aspects such as Power Electronic Converter losses and Power Electronic Converter faults, Electric Machine losses and Electric Machine faults. Examples are included in order to demonstrate the use of these models within a variety of systems including an Electro-Mechanical Actuator.
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