Aircraft Electrical System Research Articles

X-RMTV: An Integrated Approach for Requirement Modeling, Traceability Management, and Verification in MBSE

Formal requirements modeling and traceability management are essential for effectively implementing Model-Based Systems Engineering (MBSE). However, few studies have explored the integration of requirement modeling, traceability management, and verification within MBSE-based systems engineering methodologies. Moreover, the predominant modeling language for MBSE, SysML, lacks sufficient capabilities for requirement description and traceability management and for depicting physical attributes and executable capabilities, making it challenging to verify functional and non-functional requirements collaboratively. This paper proposes an integrated approach for requirement modeling, traceability management, and verification, building on the previously proposed integrated modeling and the simulation language called X language. Our contributions primarily include defining the ReqXL specification for MBSE-oriented requirement modeling based on X language, proposing an algorithm for automatically generating requirement traces, and an integrated framework for requirements modeling, traceability management, and verification was developed by combining the X language with ReqXL. These functionalities were customized on the self-developed integrated modeling and simulation platform, XLab, which is specifically tailored for the X language. Furthermore, we showcase the efficacy and promise of our approach through a case study involving the design of an aircraft electrical system.

Comparative study on the impact of different E-J relations on the performance of resistive superconducting fault current limiters under high and low impedance faults in cryo-electric aircraft

To achieve the goal of zero emission in aviation, it is critical to advance electric aircraft technologies, especially in short to medium range flights. Superconducting fault current limiters (SFCLs) have shown promising potential in electric aircraft system as a protection solution to limit the peak of fault current. Many research works focused on the SFCL performance under low impedance faults, where the fault current is much higher than the nominal current and the SFCL will transit to normal (metal) state quickly. However, there are limited reports on investigating the SFCL reacting to high impedance faults for electric aircraft system, where the SFCL does not abruptly transit to normal state. In this paper, we built an electric-thermal coupled model in MATLAB which simulates the behaviour of a resistive type SFCL both under low and high impedance faults. We investigated three mathematical relations of local electric field E and local current density J representing the transition from superconducting state to normal state, both under high and low impedance fault. The three mathematical relations are classic E-J power-law, modified E-J power-law and two- stage E-J power law. The electric-thermal model of the SFCL incorporating all these three types of mathematical relations, respectively, have been used to calculate the SFCL responses under high and low impedance faults, and compared with each other, as well as testing results. The limited fault current, voltage drop, resistance and temperature variations in the SFCL are observed and analysed. The results have shown that the proposed SFCL model is able to accurately characterise a resistive type SFCL under both high impedance and low impedance fault.

Research on Step-Down Aviation Three-Phase Power Factor Correction based on Machine Learning and Optimization Algorithm

Objectives: The study looks at power quality issues, such as phase imbalance, voltage sags, and power factor issues, in aircraft systems. It highlights how immediate power factor correction steps are required to avoid equipment longevity problems and boost system efficiency, which will ultimately improve the performance of the entire aviation system. Methodology: Using a variety of data sources, real-time data gathering, and machine learning approaches, this study focuses on data collecting and real-time monitoring in aviation systems. Predictive modeling, testing methods for data preparation and analysis, and optimization algorithms for capacitor bank size and placement are all included. Considerations for privacy and security are covered. Result: Salp Swarm Optimization and the Dragonfly Algorithm are used in the study to assess the ideal capacitor sizes and positions, which results in better voltage profiles and lower active power losses. Aviation systems benefit from improved power factor correction through the application of integrated machine learning and optimization, which promotes sustainability and energy efficiency. Conclusion: The study demonstrated the significance of power factor correction in aviation by successfully addressing power quality issues in aircraft electrical systems through the use of optimization algorithms for capacitor sizing and location.

Modelling Inductive Sensors for Arc Fault Detection in Aviation.

Modern aircraft are being equipped with high-voltage and direct current (HVDC) architectures to address the increase in electrical power. Unfortunately, the rise of voltage in low pressure environments brings about a problem with unexpected ionisation phenomena such as arcing. Series arcs in HVDC cannot be detected with conventional means, and finding methods to avoid the potentially catastrophic hazards of these events becomes critical to assure further development of more electric and all electric aviation. Inductive sensors are one of the most promising detectors in terms of sensitivity, cost, weight and adaptability to the circuit wiring in aircraft electric systems. In particular, the solutions based on the detection of the high-frequency (HF) pulses created by the arc have been found to be good candidates in practical applications. This paper proposes a method for designing series arc fault inductive sensors able to capture the aforementioned HF pulses. The methodology relies on modelling the parameters of the sensor based on the physics that intervenes in the HF pulses interaction with the sensor itself. To this end, a comparative analysis with different topologies is carried out. For every approach, the key parameters influencing the HF pulses detection are studied theoretically, modelled with a finite elements method and tested in the laboratory in terms of frequency response. The final validation tests were conducted using the prototypes in real cases of detection of DC series arcs.

Analisis Keandalan Main Battery Peshawar CRJ-1000 Di Maskapai Garuda Indonesia

The main battery on the CRJ-1000 aircraft is an important component in the aircraft's electrical system. The main battery functions as the main source of electric power when the aircraft is turned off or when the aircraft engine is not operating. If there is a failure in the aircraft's battery it can cause disruption to other systems so that the aircraft cannot fly or Aircraft on Ground (AOG). In Garuda Indonesia's CRJ-1000 aircraft battery, there were several findings where the battery failed before reaching the scheduled removal time. This study aims to analyze the reliability of the CRJ-1000 main battery on the Garuda Indonesia airline. The analytical method is carried out by collecting historical data on main battery failures and calculating the Mean Time Between Failure (MTBF) and Availability values for a certain period. In addition, an analysis was also carried out on maintenance procedures and replacement of the main battery carried out by Garuda Indonesia airline technicians. The results of the analysis show that the MTBF of the CRJ-1000 main battery on Garuda Indonesia airlines has a fairly good value, but there is a need for improvement in maintenance procedures and replacement of the main battery to increase availability. The recommendations proposed are evaluating the main battery maintenance and replacement procedures, as well as increasing the availability of main battery spare parts which can speed up repair times in failure situations.

Neuron-like thermal silica bridge between boron nitride nanosheets with hard-soft composite structure to enhance thermal conductivity and anti-icing properties on CFRP

Carbon fiber reinforced polymer (CFRP) composites are popular as novel aeronautical material for its high strength and low density. However, CFRP is unfit for aircraft electric deicing system due to its low thermal conductivity and hydrophilicity, which leads to more serious icing phenomenon and inhibition of de-icing effect. Inspired by neuron structure, the thermal silica bridge in BNNS@SiO2 composite coatings were designed to improve the in-plane thermal conductive from 1.647 to 6.702 W/mK by sol–gel method and spraying technology. Hard SiO2 particles and soft boron nitride nanosheets (BNNS) constitute hard-soft composite structure with hydrophobicity, anti-icing properties (4.09 times icing delay time) and abrasion resistance (kept 98.7% after 180 abrasion cycles). Under the combined action of thermal conductivity and hydrophobicity, the 53.8% energy saving of de-icing system was realized under the heating power of 3 W. Meanwhile, the thermal conductive/hydrophobic composite coating both possessed insulation and flame retardant.

The Use of Radar Absorbing Materials to Reduce Crosstalk in the Aircraft Electrical System Circuits

The Use of Radar Absorbing Materials to Reduce Crosstalk in the Aircraft Electrical System Circuits

A Megawatt-Scale Si/SiC Hybrid Multilevel Inverter for Electric Aircraft Propulsion Applications

This paper presents the design and development of a megawatt-scale medium-voltage (MV) hybrid inverter prototype to validate its feasibility and potentials for the electric propulsion on the next-generation electric aircraft system with an onboard MV dc distribution, e.g., 3 kV dc bus in this work. The proposed hybrid converter consists of a three-level active-neutral-point-clamped (ANPC) stage using 3.3 kV silicon IGBTs cascaded with an H-bridge stage using cost-effective 1.2 kV SiC MOSFETs in each phase. Comprehensive design and evaluation of the full-scale prototype are elaborated, including the low-inductance busbar design, converter architecture optimization and system integration. In addition, a low computational cost space vector modulation with common-mode voltage (CMV) reduction feature is proposed to fully exploit the benefits of SiC MOSFET in this hybrid topology. Extensive simulation and experimental results are provided to demonstrate the performance of each power stage and the full converter assembly in both the steady-state operation and variable frequency operations. Compared with the widely adopted IGBT based ANPC converter in MV applications, the proposed 7-L hybrid inverter system features higher power efficiency, reduced harmonics, higher dc voltage utilization, reduced CMV and lower dv/dt, while remains cost effective compared to the solution using MV SiC MOSFETs.

Safety risk assessment of aircraft EWIS based on the improved combined weight and cloud model

Purpose This study aims to conduct the aircraft electrical wiring interconnection system (EWIS) safety risk assessment process abundantly and hierarchically and establish the assessment index system considering the weights and interrelationships of different levels of indices. Design/methodology/approach Due to the failure of EWIS being multifactorial, hidden and diverse, this paper divides the factors influencing the failure of EWIS into 3 primary indices, 13 secondary indices and 38 tertiary indices. Taking open circuit failure (OCF) and short circuit failure (SCF) as examples, calculate the weights of assessment indices based on the triangular fuzzy number analytic hierarchy process (TFNAHP) and triangular fuzzy number decision-making trial and evaluation laboratory (TFNDEMATEL). The cloud model (CM) divides the risk levels and obtains the safety risk assessment results. The comparative analyses of different weight calculation methods, different failure modes and different aircraft EWIS zones verify the effectiveness and practicability of the proposed method. Findings The results show that the proposed method aligns more with the actual situation than other methods. Also, the results identify key focus objects in EWIS safety risk assessment, such as the surrounding environmental factors among the primary indices having the most significant influence on OCF and SCF, the risk level of SCF being higher than that of OCF, etc. Originality/value This paper proposes a safety risk assessment index system for aircraft EWIS based on the cable parameters, surrounding environmental factors, installation and protection methods. The weight assignment is added to the assessment index system, and the safety risk assessment model is constructed by combining TFNAHP, TFNDEMATEL and CM.

A novel pulse multiplication circuit for reducing harmonic distortion of 12 pulse rectifiers in aircraft electrical power systems

AbstractTo improve the performance and reduce the total harmonic distortion (THD) of the autotransformer 12‐pulse rectifier, a novel pulse multiplication circuit (PMC) based on two tapped inter‐phase reactors (TIPRs) is proposed to improve performance and reduce the THD of the autotransformer 12‐pulse rectifier. The proposed rectifier includes a phase‐shifting autotransformer based on a polygon connection, two 6‐pulse diode bridge rectifiers (DBRs), and a PMC. The novel PMC consists of two TIPRs (TIPR1 and TIPR2), an auxiliary single‐phase diode bridge (including four diodes D1 to D4), and two auxiliary diodes D21 and D22, which are connected directly to the output terminal of the DBRs (DBR1 and DBR2). The simulation and experimental results confirm the high capability of the proposed PMC to reduce the harmonic distortion of the input current, so that by using the proposed PMC, the input current is almost sinusoidal and the THD of the input current is less than 3%. Also, the results show that the proposed 12‐pulse rectifier meets the standard requirements of aircraft electrical systems (DO‐160G) without the need for any input and output filters.

Hybrid Multilevel Converter With Silicon and Silicon Carbide Devices: Impact to Aviation Industry and Beyond

This paper introduces the patented hybrid multilevel converters with Silicon (Si) and Silicon Carbide (SiC) devices (US10191531B2) and its impact to industry and academia. The patent invents a novel concept by combining high frequency switched SiC devices and fundamental frequency switched Si devices, therefore balances the cost and performance. The patent has been implemented in the world's first megawatt-class and multi-kilovolt hybrid electric aircraft system. Additionally, there are many world-wide following up works in extended topologies, control and modulation methods.

Trim Tab Flight Stabilisation System Performance Assessment under Degraded Actuator Speeds

One of the areas involved in changing current aircraft into more electric ones is decreasing energy consumption by the aircraft’s automatic flight control. Therefore, some aircraft types have tested the possibility of controlling the flight in automatic mode or stabilising the flight with trimmers. Previous research on cost-effective and less electrical-energy-consuming automatic stabilisation systems for an aircraft resulted in constructing a laboratory model of the system. Such a feature is beneficial for initiatives like Future Sky, electric aircraft and aircraft stabilisation system retrofits. The system was developed using model-based design and next tuned and tested in model, pilot and hardware-in-the-loop simulations. The implementation of this system does not modify the pilot’s primary manual controls. Instead, the electrical trim system is used for automatic stabilisation or manual trimming, depending on the chosen operation mode. The paper presents the development process of the laboratory model of the system and its simulation under degraded actuator speeds. The results were the basis for its control performance assessment. First, the control performance measure was defined. Then the simulation scenarios that compare system behaviour in stabilisation mode after aerodynamic disturbance with three different trim tab actuator speeds were described. The performance measure is highly degraded by the slower actuator speeds, although altitude and heading are finally stabilised in all cases. Moreover, the performance of stabilisation in a lateral channel is less affected by the slowest actuator than in a longitudinal channel.

Decarbonised Future Regional Airport Infrastructure

Sustainability and, especially, emission reductions are significant challenges for airports currently being addressed. The Clean Sky 2 project GENESIS addresses the environmental sustainability of hybrid-electric 50-passenger aircraft systems in a life cycle perspective to support the development of a technology roadmap for the transition to sustainable and competitive electric aircraft systems. This article originates from the GENESIS research and describes various options for ground power supply at a regional airport. Potential solutions for airport infrastructure with a short (2030), medium (2040) and long (2050) time horizon are proposed. This analysis includes estimating the future energy demand per day, month and year. In addition, the current flight plan based on conventional aircraft is adapted to the needs of a 50-PAX regional aircraft. Thus, this article provides an overview of the energy demand of a regional airport, divided into individual time horizons.

Special issue on all‐electric and hybrid‐electric flight

Special issue on all‐electric and hybrid‐electric flight

Design Exploration for Sustainable Regional Hybrid-Electric Aircraft: A Study Based on Technology Forecasts

The environmental impact of aviation in terms of noise and pollutant emissions has gained public attention in the last few years. In addition, the foreseen financial benefits of an increased energy efficiency have motivated the transport industry to invest in propulsion alternatives. This work is collocated within the Clean Sky 2 project GENESIS, focused on the environmental sustainability of 50-passenger hybrid-electric aircraft from a life-cycle-based perspective to support the development of a technology roadmap for transitioning towards sustainable and competitive electric aircraft systems. While several studies have already focused on the definition of possible aircraft designs combining several propulsion systems, the novelty of the present work is to consider technology forecasts and more comprehensive indicators in the design phase. These include the performance and emissions on a 200 nmi typical mission, which reflects the most economically attractive range for aircraft in the regional class. The work proposes a complete exploration of three major technology streams for energy storage: batteries, fuel cells, and turbine internal combustion engine generators, also including possible combinations of those technologies. The exploration was carried out through the execution of several designs of experiments aiming at the identification of the most promising solutions in terms of aircraft configuration for three different time horizons: short-term, 2025–2035; medium-term, 2035–2045; and long-term, 2045–2050+. As a result, in the short-term scenario, fuel energy consumption is estimated to be reduced by around 24% with respect to conventional aircraft with the same entry-into-service year thanks to the use of hybrid propulsive systems with lithium batteries. Fuel saving increases to 45% in the medium-term horizon due to the improvement in the energy density of storage systems. By the year 2050, when hydrogen fuel cells are estimated to be mature enough to completely replace kerosene-based engines, the forthcoming hybrid-electric aircraft promise no NOx and CO2 direct emissions, while being approximately 50% heavier than conventional ones.

The Possibility of Using Superconducting Magnetic Energy Storage/Battery Hybrid Energy Storage Systems Instead of Generators as Backup Power Sources for Electric Aircraft

The annual growth rate of aircraft passengers is estimated to be 6.5%, and the CO2 emissions from current large-scale aviation transportation technology will continue to rise dramatically. Both NASA and ACARE have set goals to enhance efficiency and reduce the fuel burn, pollution, and noise levels of commercial aircraft. However, such radical improvements require radical solutions. With the current traditional aircraft designs based on gas turbines or piston engines, these goals are infeasible. Small-scale aircraft have successfully proven emission reductions using energy storage systems, such as Alice aircraft. This paper involves an investigation of the possibility of using superconducting magnetic energy storage (SMES)/battery hybrid energy storage systems (HESSs) instead of generators as backup power sources to improve system efficiency and reduce emissions. Two different power system architectures of electric aircraft (EA) were compared in terms of reliability and stability in a one-generator failure scenario. As weight is crucial in EA designs, the weights of the two systems were compared, including the generators and energy storage systems. The two EA systems were built in Simulink/MATLAB to compare their reliability and stability. With the currently available technologies, based on the energy density of 250 Wh/kg for lithium-ion batteries and a power density of 8.8 kW/kg for generators, the use of the generators as backup sources proved more efficient than the use of HESS. The break-even point was observed at 750 Wh/kg for battery energy density. Any value more than the 750 Wh/kg energy density makes HESS lighter and more efficient than generators.

МАТЕМАТИЧЕСКИЕ МОДЕЛИ ОБЪЕКТОВ КОНТРОЛЯ И ДИАГНОСТИКИ ДЛЯ ОПРЕДЕЛЕНИЯ ТЕХНИЧЕСКОГО СОСТОЯНИЯ СИСТЕМ ЭЛЕКТРОСНАБЖЕНИЯ ЛЕТАТЕЛЬНЫХ АППАРАТОВ

The article studies the features and methods used to monitor and diagnose the technical condition of onboard electrical systems by using as an example analytical, tabular and logical models. The advantages and disadvantages of these models are highlighted. Based on the analysis results, applying a complex monitoring and diagnostic system is advisable to establish up to date intellectualization of onboard electrical systems, specifically aircraft electrical power supply systems and formation of a single information space.

Digital Twins in the Theory and Practices of Aircraft Electrical Power Systems

The article addresses the problem of applying new digital technologies at the aircraft electrical equipment life cycle stages. The features pertinent to the development and application of digital twins in aircraft electrical equipment systems are presented. A unified approach to development of mathematical models for digital twins, called an energy processes mathematical prototyping method, is suggested. This method is based on taking into account the energy potentials and flows occurring inside the system, as well as incoming and outgoing energy flows. It is shown that for particular tasks arising at the products and systems life cycle stages, it is possible to use projections of the full model on the observed and controlled parameters corresponding to these tasks. Such projections are called "digital portraits". In addition, a set of properties of a particular object or system due to which it can perform informational interaction with other objects (systems), and which ones follow from the digital twin full model, is proposed to be called "digital passports".

A Power-Electronics Free Protection Device for Superconducting Electrical Propulsion Aircraft

Research into developing cryogenic protection devices for superconducting electrical systems is lacking. One of the few investigations was of cryogenic switches in the form of a solid-state circuit breaker (CB). It was reported that these breakers would take up nearly 40% of the superconducting electrical system mass and losses. This article designs a cryogenic switch, free of power electronics, whose conduction loss is only 4.1% of a comparable solid-state CB’s total loss. Protection considerations of a 1-kV/40-MW cryogenic system are referred to validate its application in a superconducting electrical powertrain. The designed cryogenic switch’s dc and ac interrupting ability were verified by experiments to interrupt 750-V/1500-A dc and 1-kV/6.3-kA ac, very close to the dc and ac limits of the proposed 40-MW Center for High Efficiency Electric Aircraft (CHEETA) system. For fault conditions, a noninductive pancake resistive superconducting fault current limiter unit was designed to help with the unacceptable fault current. The 750-V/10-kA prospective current was suppressed to 1.4 kA in 588 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> and interrupted by the switch in 12 ms. Cooperation of the cryogenic switch and superconducting fault current limiter shows potential in dealing with fault currents in future electric aircraft.

Optimised temperature fluctuation control strategy for lifetime improvement in aircraft electrical power distribution system

As a power electronic converter with bidirectional energy transmission, the Dual Active Bridge (DAB) has a broad application prospect in the electrical power distribution system of hybrid-electric flight. For the DAB application in the electrical power distribution system, high efficiency and high reliability are envisaged due to the mission-critical nature of the application. A new pulse width modulation optimization control strategy is proposed, which is based on the feedback temperature fluctuations of the GaN (Gallium Nitride) power transistors, to improve the lifetime of the whole circuit. The complete topology and simulations of the DAB converter are carried out in PLECS. Detailed simulation results manifest the precise lifetime of the GaN power transistors and verify the accuracy of the new optimization control strategy. Meanwhile, Insulated Gate Bipolar Translator is set as a control group to compare the lifetime of conventional silicon-based power devices with the GaN power transistor. Hardware In Loop platform test is built to further validate the proposed method.