Lightning Indirect Effects Research Articles

Analyzing the Indirect Effects of Lightning on Unmanned Aerial Vehicle Navigation Receivers

To investigate the interference effects of lightning on unmanned aerial vehicle (UAV) navigation receivers, an analytical approach for the evaluation of indirect lightning effects is suggested. The blocking mechanism of lightning pulses on the receiver is analyzed using the vector method. A behavioral-level simulation model of the receiver’s radio frequency (RF) front-end is constructed, and a lightning pulse injection simulation is performed based on the advanced design system (ADS). The simulation results indicate that lightning pulses induce blocking interference on the RF front-end of the navigation receiver, reducing its sensitivity and dynamic range. This interference is attributed to gain compression and degradation of the noise figure in the low-noise amplifier (LNA). To further validate the simulation results, a pin injection test is carried out to examine the influence of lightning pulses with different peak voltages on receiver sensitivity. The test results indicate a notable reduction in the receiver sensitivity when the lightning pulse peak reaches 250 V. The sensitivity trends across various test panels are consistent, and the damage thresholds are similar. These findings confirm the accuracy of the simulation results.

Analysis of Cable Shielding and Influencing Factors for Indirect Effects of Lightning on Aircraft

Analysis of Cable Shielding and Influencing Factors for Indirect Effects of Lightning on Aircraft

Analysis of Indirect Lightning Effects on Low-Noise Amplifier and Protection Design

In order to analyze the interference mechanisms of indirect lightning effects on a low-noise amplifier (LNA), a circuit model of the LNA was constructed based on the advanced design system 2020 (ADS 2020) software. Lightning pulse injection simulations were conducted to explore the influence of lightning pulses on the performance of the LNA. A pin injection test was performed to investigate the interference and damage threshold of the LNA. A protective circuit incorporating the transient voltage suppressor (TVS) and Darlington structure was designed through simulation, employing the ADS 2020 for the LNA. The research findings reveal that the interference threshold for the LNA is 60 V, while the damage threshold is determined to be 100 V. The protective circuit demonstrates a measured insertion loss of 0.1 dB, a response time of 1.5 ns, and a peak output voltage of 20 V. The research results indicate that the protective circuit can effectively reduce the impact of lightning’s indirect effects on the LNA. In the future, we will continue the design work of the protective circuit and proceed with physical fabrication and experimental validation.

Lightning induced disturbances in the power network considering losses, frequency effect and non-linearities

The malfunctions and even the material damage caused by lightning stroke are generally significant in electrical networks.. To help design equipment that can withstand lightning disturbances (e.g. electrical insulation, surge arresters, etc.), while compromising with the economic problem, researchers and engineers use numerical simulation. In this paper, we propose a new modeling to study the direct or indirect impact of lightning stroke on an electrical network of power transmission overhead lines or overhead or underground power cables. This modeling is carried out directly in the time domain and takes into account the losses, the frequency dependence and the presence of components with non-linear behavior (example: surge arresters). The new formalism that we propose uses the transmission line equations, the numerical method of Finite Differences Time Domain (FDTD) and the approximation technique called vector fitting. To stimulate the direct or indirect effects of lightning, our modeling is carried out with only the 1D spatial discretization (1D meshing) of the conductive parts, and provides access simoulenatlously to transient voltages and currents at any point of the network. Also consideration to surge arresters is rendered easy in our modeling.

Tower Models for Power Systems Transients: A Review

Fast-front transients play an important role in the insulation design of any power system. When a stroke hits the shield wire or the tower of high-voltage overhead power lines, flashover may occur either along the span or across tower insulators, depending on the relevant voltages and insulation strength. As a result, backflashover may take place from the tower structure to the phase conductor whenever a huge impulse current flows along the tower towards considerably high footing impedances. For these reasons, tower modeling for transients studies is an important step in the insulation design, and also for lower voltage applications, where indirect lightning effects may play a predominant role. However, after decades of research on tower modeling, starting from the 1930s with the first model proposed by Jordan, no consensus has been reached neither on a widely accepted tower model nor on the quantitative effect of the tower models on insulation design. Moreover, the fundamental mechanisms at the base of the transient response of towers and the definition of some fundamental parameters have not been totally clarified yet. The aim of this review is to present the available tower models developed through the years in the power community, focussing mainly on lumped/distributed circuit models, and to help the reader to obtain a deeper understanding of them.

Testing of Conductive Carbon Fiber Reinforced Polymer Composites Using Current Impulses Simulating Lightning Effects

Carbon fiber reinforced polymer (CFRP) composites are lightweight and an increasingly used material with good mechanical properties. In the aviation industry, they are also required to have specific electrical properties that guarantee resistance to the direct and indirect lightning effects. The paper is focused on the description of a test stand and development of a method used to determine the electrical characteristics of conductive CFRP laminate samples with the use of high current impulses of lightning nature. Samples of three laminates (square format with side 30 × 30 cm) with a different composition were tested on the constructed stand, confirming the possibility of characterizing this type of laminate sample in terms of electrical conductivity and resistance to the effects of lightning current. It was possible to observe the impulse current flow (with a peak value up to 15 kA and a rise time above 6 µs) from the high voltage electrode placed in the center of the sample in all directions towards the edge. The optical fiber measuring system was used to record the voltage and current time waveforms. The energy stored in the impulse current generator was sufficient to simulate the mechanical damage, such as burnout and delamination, that accompanies the direct lightning strike to structural elements made of CFRP. The influence of the matrix composition used for laminate fabrication on the test results describing the electrical properties of the tested CFRP samples was noted. The experimental setup allows the testing of specimens with a maximum width and length of 50 × 50 cm and any thickness with a peak current of up to 50 kA.

Protection From Indirect Lightning Effects for Power Converters in Avionic Environment: Modeling and Experimental Validation

This article focuses on a protection system from lightning indirect effects applicable to power converters for avionic applications. The case study considered in this article is a dc-dc pulsewidth modulation buck-boost converter protected by a metal oxide varistor and a series inductive blocking element. The converter is investigated when operated in normal operating conditions, under lightning indirect strokes without protection, and under lightning indirect strokes with protection. A numerical model of the system based on a finite-difference time-domain scheme is proposed. Validation of the system is performed through a comparison with experimental measurements and alternative numerical modeling techniques, showing the effectiveness of the blocking system and the accuracy of the proposed model.

Multi-Stroke Lightning Interaction with Wiring Harness: Experimental Tests and Modelling

This paper presents the obtained results of experimental tests and modelling of lightning disturbances that were propagated in a model of aircraft cable bundle and caused by multiple lightning return-strokes interactions. The work is a continuation of previous research, which was concerned mainly with the interaction of lightning discharge with a single return-stroke. The section of the cable harness arranged above the metal plate was investigated. In one of its wires, a multiple-stroke current representing indirect lightning effects was injected from an impulse current generator dedicated to avionics immunity tests. Overvoltages induced at the ends of other wires surrounded by a braided shield, as well as the influence of line parameters and shield grounding condition on the shape and level of observed transients, were examined. The computer simulation results match the measurement data with satisfactory accuracy, and therefore, the presented model can be used to estimate indirect lightning effects in the wiring harness of avionics.

PAV 케이블 하네스에 대한 낙뢰 간접 영향성 인증 기법에 관한 연구

PAV 케이블 하네스에 대한 낙뢰 간접 영향성 인증 기법에 관한 연구

Direct Current Injection Test Devices on Metal Cylinder: Experiment and Numerical Simulation

In order to study the lightning indirect effects on the metal cylinder, the direct current injection test devices on the metal cylinder were studied in this paper based on experiment and simulation. The return conductor configuration was designed. A giant magneto resistive (GMR) sensor was calibrated to measure the intensity of the magnetic field inside and outside the metal cylinder. The impulse current injection test system similar to coaxial transmission line was established and the injection experiment was carried out. In order to verify the experimental results, a numerical simulation using the CST Microwave Studio was given. The magnetic field intensity inside and outside the metal cylinder is discussed by comparing the experimental and computational results. Moreover, the space distribution of the magnetic field is also simulated. The results show the feasibility of the test devices. The conclusions provide a foundation for further lightning indirect effect test on cylindrical ordnance.

Robust Lightning Indirect Effect Protection in Avionic Diagnostics: Combining Inductive Blocking Devices With Metal Oxide Varistors

The combination of iron core inductors and metal oxide varistors has been modeled and experimentally characterized to propose a robust protection system for indirect lightning effects in avionic environment. In particular, a numerical procedure to design transient limiters with high current rating, low clamping voltage, and low degradation rate is presented and described in detail. The protection systems are modeled using a circuital approach based on the diffusion equation, which is implemented in a finite difference time domain scheme. Two different modeling approaches to represent the nonlinearity and the hysteretic behavior of an iron core inductor are presented and discussed. Simulation results are verified by pin injection tests following the specific standards for avionic diagnostics.

Lightning Indirect Effects on Helicopter: Numerical Simulation and Experiment Validation

When lightning strikes an aircraft, the electromagnetic (EM) field penetrates inside the aircraft, and induces currents and voltages on the onboard cables, resulting in the risk of equipment failure, which is a serious safety hazard to the flight safety. With the wide use of low-conductivity composite materials in aircraft manufacturing, the EM shielding effectiveness of the aircraft is weakened. As for the helicopter, the proportion of windows and doors is relatively larger than the fixed-wing aircraft, thus the EM shielding effectiveness is much weaker. Proper lightning protection design must be validated to eliminate the risk of electrical and electronic equipment failure. This paper describes the lightning indirect effects related to the modeling and simulation process of the composite UH-60 helicopter. The external and internal EM field environment together with the induced currents and voltages on cables are discussed. Moreover, in order to validate the simulation, an iron helicopter model was tested and the comparison between simulated and measured waveforms was carried out.

Modeling of Inductive Blocking Devices for the Mitigation of Indirect Lightning Effects

In this paper we propose a computational procedure to evaluate the performances of inductive blocking devices used for the mitigation of indirect lightning effects on electrical and electronic equipment, with special relation to the avionic environment. The non linear behavior of the blocking devices is simulated using a FEM scheme in time domain. Computations and experimental results are compared and discussed.

The influence of lightning induced voltage on the distribution power line polymer insulators.

Protection of medium voltage (MV) overhead lines against the indirect effects of lightning is an important issue in Malaysia and other tropical countries. Protection of these lines against the indirect effects of lightning is a major concern and can be improved by several ways. The choice of insulator to be used for instance, between the glass, ceramic or polymer, can help to improve the line performance from the perspective of increasing the breakdown strength. In this paper, the electrical performance of a 10 kV polymer insulator under different conditions for impulse, weather and insulator angle with respect to a cross-arm were studied (both experimental and modelling) and the results were discussed accordingly. Results show that the weather and insulator angle (with respect to the cross-arm) are surprisingly influenced the values of breakdown voltage and leakage current for both negative and positive impulses. Therefore, in order to select a proper protection system for MV lines against lightning induced voltage, consideration of the local information concerning the weather and also the insulator angles with respect to the cross-arm are very useful for line stability and performance.

Simulation research on the return conductor configuration of aircraft lightning indirect effect test

Simulation research on the return conductor configuration of aircraft lightning indirect effect test

항공기 탑재 컴퓨터용 간접낙뢰 보호장치 개발 및 검증

본 논문에서는 간접낙뢰로 인한 항공기 탑재 컴퓨터의 손상을 보호하기 위한 간접낙뢰 보호장치의 설계 내용 및 시험 과정을 소개한다. 낙뢰로부터 유도된 서지 전압은 항공기 전기 전자장비의 기능 장애나 손상을 가져오는데 이것을 낙뢰의 간접영향이라 한다. 이러한 항공기의 낙뢰 간접영향으로부터 항공전자 장비를 보호하기 위해서는 항공기에 가해진 낙뢰로 인한 영향성을 분석하고 이에 따른 보호 설계를 각각의 장비에 적용한다. 본 논문에서는 보호대상 장비의 간접낙뢰로 인한 손상을 방지하기 위하여 수행한 RTCA DO-160G Section22의 카테고리 분석과 선정을 통한 간접낙뢰 수준 결정, 선정된 레벨에 따른 보호회로 설계 방법을 소개한다. 또한 설계된 보호회로의 유효성 확인을 위해 수행한 낙뢰 간접영향 검증시험 결과를 보인다. This paper introduces the design details and test procedures of the lightning induced transient protection device for protecting the damage caused by indirect lightning strike on the computer mounted on the aircraft. Lightning induced surge voltage is bring a malfunction or damage to the aircraft electrical and electronic equipment, that is referred to indirect effects of lightning. In order to protect the electronic equipment on aircraft from the indirect effects of lightning, that is achieved by analyzing the effect on aircraft from lightning and protect design for each devices. In this paper, we introduce an indirect lightning strike level decisions, the protection circuit design method according to the chosen level through the RTCA DO-160G Section 22 category analysis and selection was performed in order to protect the damage caused by indirect lightning strikes in the protected equipment. In addition, we show the indirect lightning effects verification test performed to validate the designed protection circuits.

The Role of Electromagnetic Compatibility Qualification Considerations in Airborne System Integration Programs

There are many misconceptions that surround Equipment Electromagnetic Compatibility (EMC) qualification testing and installation assessment. The objective of this paper is to raise awareness of some of the issues that applicable to the subject, and offer a perspective of what qualification means to a certification program both technically and programmatically. The paper seeks to analyze common situations that occur during system integration programs and provides an indication of the level of detail to be considered in EMC design assessments. For the purposes of this paper the term EMC is considered to cover all aspects of electromagnetic compatibility, including, High Intensity Radiated Fields (HIRF), Indirect Effects of Lightning (IEL) and Electromagnetic Pulse (EMP).

Accelerating the numerical computation of indirect lightning effects by means of vector fitting

Abstract. In the context of numerical computation of indirect lightning effects it is customary to use volume-discretizing methods in time domain, such as the Finite Difference Time Domain (FDTD) method, the Finite Integration Technique (FIT), or the Transmission Line Matrix (TLM) method. If standard lightning electromagnetic pulses (LEMPs) of tenths of microseconds duration are used as excitations, these methods require long computation times, as implied by the Courant criterion. It is proposed to use shorter pulse forms and to compare the transfer functions obtained by different pulse durations by means of macromodels that are obtained from the vector fitting method. Numerical computation of lightning related transfer functions of a canonical structure indicate that the duration of the exciting pulse can typically be shortened by at least one order of magnitude if compared to a standard pulse.

Protection of wind energy systems against the indirect effects of lightning

This paper is concerned with the protection of wind energy systems against the indirect effects of lightning. As wind energy is gaining increasing importance throughout the world, lightning damages involving wind energy systems have come to be regarded with more attention. Nevertheless, there are still very few studies in Portugal regarding lightning protection of wind energy systems using models of the Electro-Magnetic Transients Program (EMTP). Hence, a new case study is presented in this paper, based on a wind turbine with an interconnecting transformer, considering that lightning strikes the soil near the tower at a distance such that galvanic coupling occurs through the grounding electrode. Computer simulations obtained by using EMTP-RV are presented and conclusions are duly drawn.

Application of wavelet‐based denoising techniques to remote sensing very low frequency signals

In this paper, we apply wavelet‐based denoising techniques to experimental remote sensing very low frequency (VLF) signals obtained from the Holographic Array for Ionospheric/Lightning research system and the Elazig VLF receiver system. The wavelet‐based denoising techniques are tested by soft, hard, hyperbolic and nonnegative garrote wavelet thresholding with the threshold selection rule based on Stein's unbiased estimate of risk, the fixed form threshold, the mixed threshold selection rule and the minimax‐performance threshold selection rule. The aim of this study is to find out the direct (early/fast) and indirect (lightning‐induced electron precipitation) effects of lightning in noisy VLF transmitter signals without discomposing the nature of signal. The appropriate results are obtained by fixed form threshold selection rule with soft thresholding using Symlet wavelet family.