Many of the reports created at assembly lines, where all components of an aircraft are installed, frequently indicate that errors threaten safety. The proposed methodology in this study evaluates error prediction and risk mitigation to prevent failures and their consequences. The results linked to a typical electrical harness manufacture of a military aircraft estimated reductions of 93% in time and 90% in error during the creation of engineering manufacturing processes using AI techniques. However, traditional risk assessments methods struggle to identify and mitigate errors effectively. Thus, developing an advanced methodology to ensure systems safety is needed. This paper addresses how innovative AI technology solutions can overcome these challenges, mitigate error risks, and enhance safety in aerospace. Technologies, such as artificial intelligence, predictive algorithms, machine learning, and automation, can play a key role in enhancing safety. The aim of this study is to develop a model that considers the factors that can potentially contribute to error creation, through an artificial intelligence (AI) approach. The specific AI techniques used such as support vector machine, random forest, logistic regression, K-nearest neighbor, and XGBoost (Python 3.8.5) show good performance for use in error mitigation. We have compared the modeled values obtained in this study with the experimental ones. The results confirm that the best metrics are obtained by using support vector machine and logistic regression. The smallest deviation between the measured and modeled values for these AI methods do not exceed 5%. Furthermore, using advancements in machine learning methods can enhance error mitigation in aerospace. The use of AutoML can play a key role in automatically finding an appropriate model which provides the best performance metrics and therefore the most reliable forecast for data prediction and error mitigation.

Common mode chokes are widely employed to reduce common mode emissions of three phase systems. This work presents an advanced technique for analyzing and characterizing common mode chokes with three or four windings. The central idea of the method is a modal analysis of the choke, where the modes are based on the modes of the noise signal transmitted by the three-phase line. These modes are defined following the criterion of its suitability from the perspective of electromagnetic interference control. This modal analysis is used to propose a circuit model of the choke that accounts for the impact of high-frequency parasitic effects and, at the same time, allows for a straight forward parameter identification. This parameter identification is achieved by using a characterization technique that makes use of measurements of the response of the common mode choke in simple connections, whose suitability is justified thanks to the ability of the modal analysis to provide analytical and easy-to-interpret expressions of these connections. This makes also possible to predict and quantify mode conversions caused by the device in the three-phases line. The accuracy of the obtained circuit model within a wide frequency range has been demonstrated by comparing measurements with calculated responses for several three- and four-wires common mode chokes.

This work analyzes the impact of asymmetries in common-mode chokes, critical components for suppressing electromagnetic interference in electronic circuits. The study introduces a novel characterization method specifically designed to account for the effects of geometric imperfections or variations in core material properties. The proposed method builds upon a well-established symmetrical model for CMCs, incorporating modifications that facilitate the estimation of mode conversion. This phenomenon arises when asymmetries cause common-mode noise to convert into differential-mode noise, ultimately hindering EMI suppression efforts. The key advantage of the proposed approach lies in its ability to enhance the capabilities of the symmetrical model without compromising accuracy or significantly increasing its complexity. To validate the method’s effectiveness, it has been applied to a commercially available choke. The model successfully reproduces the characterization measurements outlined in the CISPR-17 standard, thus demonstrating its reliability and applicability in practice.

The current trend towards the increase of switching frequencies in modern power converters is aimed at achieving higher power densities. This poses a great challenge to comply with stringent EMC normative, especially in automotive and aeronautical industries. They are clearly antagonist requirements since filtering and shielding techniques are usually required to fulfill those standards, but generally to the detriment of power density. For this reason, this work checks and compares the effectiveness of some cost-effective EMI filter improvement techniques that may provide modest attenuation enhancement of conducted emissions with a negligible power density cost in a real-case scenario, where the noise source is a laboratory prototype of a DC-DC power converter.

Parasitic capacitances typically undermine the filtering performance of common mode chokes at high frequencies. This work demonstrates that these parasitic capacitances can be reduced by using a wise winding strategy that depends on the physical properties of the core material. Due to its practical interest, we specifically focus on single-layer common mode chokes wounded on NiZn or MnZn ferrite cores. Based on a physical model that enables the identification of parameters influencing the electrical coupling between the turns of the coils of the choke, the hypothesis proposed is that the optimal winding configuration depends on the core material, differing for NiZn and MnZn cores. To verify this hypothesis and to assess improvements actually achieved by optimum winding strategies, an accurate high-frequency model of the common mode choke along with an efficient characterization technique are used to numerically estimate the parasitics of common-mode chokes with different core materials and winding configurations. In addition, the filtering performance of these common mode chokes have been measured and compared.

Cybersecurity plays a relevant role in the new digital age within the aerospace industry. Predictive algorithms are necessary to interconnect complex systems within the cyberspace. In this context, where security protocols do not apply, challenges to maintain data privacy and security arise for the organizations. Thus, the need for cybersecurity is required. The four main categories to classify threats are interruption, fabrication, modification, and interception. They all share a common thing, which is to soften the three pillars that cybersecurity needs to guarantee. These pillars are confidentiality, availability, and integrity of data (CIA). Data injection can contribute to this event by the creation of false indicators, which can lead to error creation during the manufacturing engineering processes. In this paper, the impact of data injection on the existing dataset used in manufacturing processes is described. The design model synchronizes the following mechanisms developed within machine learning techniques, which are the risk matrix indicator to assess the probability of producing an error, the dendrogram to cluster the dataset in groups with similarities, the logistic regression to predict the potential outcomes, and the confusion matrix to analyze the performance of the algorithm. The results presented in this study, which were carried out using a real dataset related to the electrical harnesses installed in a C295 military aircraft, estimate that injection of false data indicators increases the probability of creating an error by 24.22% based on the predicted outcomes required for the generation of the manufacturing processes. Overall, implementing cybersecurity measures and advanced methodologies to detect and prevent cyberattacks is necessary.

This article presents a method for characterization of common-mode chokes aimed at constructing accurate virtual prototypes of electromagnetic interference filters. This method is based on a general modal analysis that identifies the natural modes of a symmetric four-port network in a power line. Natural modes excited in the setups defined in the CISPR-17 norm to characterize filtering devices are determined. From this analysis, two simple measurement setups particularly suitable for characterizing common-mode chokes are identified, and a decision-making algorithm is presented to determine the parameters of a configurable circuit model of the common-mode choke. This circuit model is especially devised so that each one of its different circuit blocks can be associated with a single modal response of the common-mode choke. This, along with the use of physical criteria to define the basic schematic of each circuit block, ensures the simplicity, accuracy, and generality of the final circuit model. Characterization of many commercial common-mode chokes with different core materials and winding configurations has been carried out to demonstrate that this circuit model is able to accurately account for the actual response of different types of common-mode chokes in a wide frequency range.

In this work, we analyze the impact of the permittivity of the material of the core and of the configuration of the winding on the parasitic capacitance that typically undermines the performance of ring-core inductors at high frequencies. Inductors with NiZn and MnZn ferrite cores and with both loose and tight windings have been constructed, measured and compared. Also, a high-frequency circuit model of the inductors has been employed along with a simple characterization technique to obtain equivalent circuits of the ring-core inductors. This has allowed us to quantify the impact of the different core choices and winding strategies on the performance of the inductors up to frequencies of at least 30 MHz. Our results demonstrate that the parasitic capacitance of single-layer ring core inductors can be reduced by using winding strategies that are different for NiZn and MnZn cores. We conclude that the different responses of inductors made with different core materials is due to the differences in the permittivity of the ferrite materials of the core.

Safety investigations about electrical wiring harness caused by failures in electrical systems establish that origin of these accidents are related to electrical installation. Predictive techniques which mitigate and reduce risk of the occurrence of errors to enhance safety shall be considered. The development of machine learning has evolved towards the creation of innovative predictive algorithms which show high performance in data analysis and making predictions in the context of artificial intelligence. The Monte Carlo approach is used to validate the model performance. In this paper, Monte Carlo simulation was used to evaluate the level of the uncertainty of the selected parameters over 1000 runs. This study analyzes the reliability of the predictive algorithm in order to be implemented as an automatic error predictor in aerospace. The results obtained are within the expected range suggesting that the model used is accurate and reliable.

Magnetic coupling between components in compact electromagnetic interference filters is one of the main effects that undermine their ability to reduce conducted emissions of power converters at frequencies above several hundreds of kilohertz or a few megahertz. This article analyzes and compares the performance of two different shielding strategies based upon the use of copper bands (high-conductivity material) and flexible ferrite sheets (high-permeability material) to improve the attenuation provided by electromagnetic interference filters. We make use of electromagnetic simulations, measurements, and modeling with a circuit model of the filter to identify the causes of the limited shielding performance of high-conductivity materials and to quantify the reductions in the mutual inductances between the components of the filter that can be obtained by using a smart arrangement of the shielding structures that is able to overcome these limitations while preserving the compactness of the filter. We also describe a design strategy for electromagnetic interference filters which maximizes the benefits of the proposed shielding techniques. Measurements on several filter prototypes demonstrate that the shielding techniques proposed here can provide 20-30 dBs increase in the attenuation provided at high frequencies by the electromagnetic interference filter for differential mode noise.

In this work, we analyze the impact of output filter design techniques aimed to reduce conducted emissions at the output of a DCDC power converter. A thorough analysis, based on high-frequency circuit models of the converter, is performed to assess expected improvements offered by different design strategies. This analysis is then confronted with measurements of conducted emissions at the output of a 300 W 48 V to 12 V Phase Shift Full Bridge (PSFB) prototype. Those experimental results demonstrate that a symmetric arrangement of the output LC filter and a direct bonding of the return output terminal of the converter to chassis are effective to reduce common mode conducted emissions at the output. Those results also demonstrate that the symmetry of the output LC filter can reduce conducted emissions in differential mode at high frequencies, where common mode to differential mode conversion is the predominant contribution to differential mode noise. However, direct bonding to chassis of the return output terminal may be ineffective at high frequencies due to the parasitic inductance associated with this connection. Main conclusions drawn for this analysis are applicable in general for isolated converters with a high voltage step between high and low voltage sides. Since the techniques of reduction of conducted emissions studied here do not increase the number of filter components, they are especially suitable for applications where high power density is an important requirement, e.g., aerospace or automotive applications.

DC-DC isolated converters allowing a bidirectional flow of energy between High-Voltage DC and Low-Voltage DC networks have been proposed to be integrated in future on board power distribution systems. These converters must meet the specially stringent efficiency and power density requirements that are typical of the aeronautic industry. This makes it specially challenging to determine which converter topology is best suited for each particular application. This work presents a thorough review of several topologies of bidirectional DC-DC power converters that are considered good candidates to meet certain important aeronautic requirements, as those related with high efficiency and high power density. We perform simulations on virtual prototypes, constructed by using detailed component models, and optimized following design criteria that are in accordance with those typically imposed by aeronautic requirements. This comparative analysis is aimed to clearly identify the advantages and drawbacks of each topology, and to relate them with the required voltage and power levels. As an outcome, we point out the topologies that, for the required power level at the chosen switching frequencies, yield higher efficiency in the whole range of required operation points and that are expected to allow more important weight reductions.

Many papers related to this topic can be found in the bibliography; however, just a modest percentage of the introduced techniques are developed to a Technology Readiness Level (TRL) sufficiently high to be implementable in industrial applications. This paper is focused precisely on the review of this specific topic. The investigation on the state of the art has been carried out as a systematic review, a very rigorous and reliable standardised scientific methodology, and tries to collect the articles which are closer to a possible implementation. This selection has been carefully done with the definition of a series of rules, drawn to represent the adequate level of readiness of fault detection techniques which the various articles propose.

This work presents a technique to measure the attenuation of differential mode noise provided by common mode chokes. The proposed setup is a simpler alternative to the balanced setup commonly employed to that end, and its main advantage is that it avoids the use of auxiliary circuits (baluns). We make use of a modal analysis of a high-frequency circuit model of the common mode choke to identify the natural modes actually excited both in the standard balanced setup and in the simpler alternative setup proposed here. This analysis demonstrates that both setups are equivalent at low frequencies and makes it possible to identify the key differences between them at high frequencies. To analyze the scope and interest of the proposed measurement technique we have measured several commercial common mode chokes and we have thoroughly studied the sensitivity of the measurements taken with the proposed setup to electric and magnetic couplings. We have found that the proposed setup can be useful for quick assessment of the attenuation provided by a common mode choke for differential mode noise in a frequency range that encompasses the frequencies where most electromagnetic compatibility regulations impose limits to the conducted emissions of electronic equipment.

This paper analyzes and compares available measurement techniques that can be used to assess the effect of parasitics on the impedance of capacitors and inductors within the frequency range, where most electromagnetic compatibility regulations impose limits to conducted emissions of power converters. Direct measurement of impedance is compared with measurement of the transmission coefficient of the component. For impedance measurement, a criterion is identified to determine whether cables and test fixtures used to connect the component to the measuring device will have an impact on the measurements. It is shown that this criterion is more restrictive than the well known requirement of electrically short cable. We also show that, by contrast with direct impedance measurement, the measurement of the magnitude of the transmission coefficient is not affected by the cables in the frequency range of interest. Therefore, to carry out compensation previous measurements are not required. This permits us to quickly evaluate the effect of parasitics on the impedance of inductors and capacitors and also allows us to readily construct a circuit model for the component, which can be used to improve accuracy in the prediction of conducted emissions of power converters by simulation. Experimental validation is presented for practical capacitors and inductors.

This work analyzes the effect of conducting bands placed close to a common mode choke on the attenuation provided by an electromagnetic interference filter where the common mode choke is mounted. The main aim was to determine whether the response of the common mode choke can be modified and to clearly identify and quantify the physical mechanism responsible for the changes found in the attenuation of the common mode choke and the electromagnetic interference filter. The impact of grounded and ungrounded conducting surfaces was studied for the two more typical configurations of common mode chokes: vertically and horizontally mounted. This study has allowed us to devise an optimum shield for a common mode choke that can significantly improve the attenuation to both common mode and differential mode noise of an electromagnetic interference filter at high frequencies, where parasitic effects usually undermine the performance of the filter. Key features of the technique described here are that it can be applied easily and that it does not result in an increase of the weight, volume, or cost of the filter.

In recent years, Brushless DC (BLDC) motors have been gaining popularity as a solution for providing mechanical power, starting from low cost mobility solutions like the electric bikes, to high performance and high reliability aeronautical Electro-Mechanical Actuator (EMA). In this framework, the availability of fault detection tools suited to these types of machines appears necessary. There is already a vast literature on this topic, but only a small percentage of the proposed techniques have been developed to a sufficiently high Technology Readiness Level (TRL) to be implementable in industrial applications. The investigation on the state of the art carried out during the first phase of the present work, tried to collect the techniques which are closest to possible implementation. To fill a gap identified in the current techniques, a partial demagnetisation detection method is proposed in this paper. This technique takes advantage of the asymmetries generated in the current by the missing magnetic flux to detect the failure. Simulations and laboratory experiments have been carried out to validate the idea, showing the potential and the easy implementation of the method. The results have been examined in detail and satisfactory conclusions have been drawn.

This work presents a quick and simple method to characterize planar transformers at high frequencies. This method only requires two measurements which can be performed with a spectrum analyzer with tracking generator. By performing a circuit analysis of a high-frequency circuit model of the planar transformer regarded as a four-ports device we obtain analytical expressions of the transmission coefficients of the planar transformer excited in open-circuit, common mode and differential mode setups in a wide frequency range. This allows us to develop an efficient method to determine the high-frequency parameters of the circuit model from the result of these simple measurements. Different commercial planar transformers have been measured and the predicted performance of the model has been compared with measured responses. We have verified that in all the cases the measured transmission coefficient exhibits the behavior predicted by the theoretical analysis.