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Massimo Brignone - IEEE Xplore Author Profile

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This paper presents a new method to solve the inverse problem of reconstructing the lightning return-stroke current from measurements of the radiated magnetic field. Although the lightning channel is still assumed to be straight, vertical and at a known distance from the sensors measuring the fields, no model or channel-base measurement of the current is required, so that, unlike previous approach...Show More
This contribution discusses the impact of using parameters and statistical distributions derived from Lightning Location System (LLS) data on assessing the Lightning Performance (LP) of an overhead distribution line. Both negative and positive return strokes are considered in the analysis, and multiple-stroke flashes are simulated using the probability distributions for the flash multiplicity and ...Show More
This contribution proposes a new approach to locate lightning striking points by using the voltage waveform recorded by sensors placed on transmission lines. The method takes advantage of the use of Neural Networks (NN); the time domain voltage waveforms are transferred in the frequency domain with a Discrete Fourier Transform. Then, to reduce the dimensionality of the problem, it is performed a p...Show More
The electric fields radiated by a lightning discharge may represent an important source of damage for electric and electronic equipment. Often, an analysis of such fields in the frequency domain is necessary and their frequency-domain expressions have always been evaluated by considering an infinite time-window and omitting the zero-frequency term coming from the static component of the fields. Th...Show More
By relying on suitable propagation models, lightning electromagnetic fields can be computed from the knowledge of the channel-base current (CBC) and of the attenuation function. While the CBC is measured by means of instrumented towers, a parametric attenuation function is usually assumed a priori and then compared with the measured fields in order to find optimal values for the CBC parameters. Un...Show More
The spreading diffusion of renewable energy leads to an increase in the transmission of electrical power using HVDC, which is more appropriate than HVAC to manage large quantities of less predictable power. Therefore, the number of main return electrodes, necessary to manage potential failures, will increase as well, making it more difficult to identify their suitable locations. This contribution ...Show More
In this article, a machine-learning-based model for the regression of cloud-to-ground lightning location and peak current from time-domain waveforms of lightning-induced voltage measurements on overhead transmission lines is presented. A principal component analysis (PCA) procedure is applied for extracting significant features and decreasing the dimension of the input vector. Then, a shallow neur...Show More
The electromagnetic lightning field is usually computed by considering a model consisting in a vertical and rectilinear channel, as well as a Transmission-Line (TL) type propagation characterized by an attenuation function, which expresses how the current decreases while it travels upward along the lightning channel. When dealing with realistic channels, affected by tortuosity, the current attenua...Show More
The behavior of the return-stroke current along the lightning channel is extremely important for the evaluation of the electromagnetic fields radiated at various distances, since such fields may cause disturbances or faults on electric and electronic equipment. It is commonly known that lightning current attenuates while propagating along the channel and several models have been adopted in an atte...Show More
Lightning strikes attachment to Wind Turbines (WTs) is not uncommon. The current discharge along the WT components can cause variations in the electromagnetic field radiation, affecting the surrounding power and electronic systems. In this contribution, a WT transient response to direct lightning strikes is studied with a full-Maxwell approach, involving a complete model for the WT. Simulations ar...Show More
To face the complexity introduced by the ever-increasing participation of new energy sources, storage systems and controllable loads to electricity markets, Distributed Energy Systems must optimize the power exchange. Usually, Energy Management System (EMS) are used to manage Micro-Grids (MGs) operations, but computational timings may become prohibitive, due to high number of constraints and links...Show More
Lightning events can cause several damages to electronic and electric infrastructure. One of the most important variables is the channel-base current (CBC) waveform, usually measured by means of proper instruments installed on tall towers where the striking probability is higher. However, the presence of the tower itself and the low number of registered events represent a critical issue in the pos...Show More
The most common lightning channel model consists in a vertical thin-wire radiator, even though it is known that lightning path is affected by tortuosity. This physical characteristic of lightning has remarkable effects on the generated electromagnetic fields and, consequently, on the voltage induced on transmission and distribution lines, which may lead to insulator flashover. This contribution pr...Show More
Lightning may be the cause of outages and faults on electrical infrastructures. In overhead distribution lines, voltages overcoming the critical flashover value of the line may be induced by indirect lightning strikes, and this fact may cause serious damages to insulators. Consequently, the assessment of induced voltages is an important aspect in the design phase of transmission and distribution l...Show More
Today, many important submarine HVDC links are being designed and commissioned all around the world. The use of Sea Return Electrodes is the cheapest option to manage many possible faults. However, over the last years, many areas of seas were exploited, and they are now concessions for exploration and production of oil&gas. Pipelines connecting extraction pits to the shore were installed, and offs...Show More
Lightning-related phenomena are one of the most dangerous factors affecting the overhead distribution systems. Said that, protective measures to reduce lightning damages are an important issue to guarantee distribution line reliability. The most widely employed protective measures against lightning are: shield wires, surge arresters, and increasing the line insulation level, usually by increasing ...Show More
This contribution discusses the combined impact of the uncertainties related to the forecasts of the power production from Renewable Energy Sources, the Electrical Load and the Thermal Load on the operation costs of a microgrid. To quantify the possible variation of the cost determined by an Energy Management System, a stochastic approach has been adopted. The perturbation of the forecasted data i...Show More
Lightning electromagnetic (EM) fields are typically computed by assuming the current propagation within a straight vertical channel of negligible cross section. However, it is well known that the lightning path is tortuous and this can significantly affect the radiated fields and the lightning-induced voltages on power lines. Lupò et al. (2000) proposed an analytical method evaluating the EM field...Show More
The Fourier transform (FT) of the electric field (EF) radiated by a lightning return stroke is shown to include a distributional term at zero frequency, which prevents numerical algorithms, such as fast FT, from working properly. Inspired by the finite duration of any field measurement in real applications, we introduce a time-windowing strategy, whereby the integration time-interval of the FT bec...Show More
Wind turbines (WTs) can beseriously damaged by lightning strikes and they can be struck by a significant number of flashes. This should be taken into account when the WT lightning protection system is designed. Moreover, WTs represent a path for the lightning current that can modify the well-known effects of the lightning discharge in terms of radiated electromagnetic fields, which are a source of...Show More
Lightning ElectroMagnetic (EM) fields represent the most cumbersome part of the lightning-induced voltages computation process. Their evaluation is usually performed through a numerical routine or with simplified analytical expressions, which are valid only assuming an infinite ground conductivity and specified channel base current waveform. This paper first briefly recalls a recently proposed ana...Show More
Dealing with realistic networks, the solution of lightning electromagnetic field coupling to transmission lines is generally obtained through a Finite-Difference Time-Domain (FDTD) algorithm interfaced with an electromagnetic simulator. As well known, the stability of the FDTD scheme is determined by the Courant stability condition. In this contribution, it is shown that a second stability conditi...Show More
Dealing with lightning performance computation, researchers usually consider only negative downward first return strokes and the relevant channel-base peak current distribution. The aim of this article is to account for the lightning flash mechanism, which means to include also downward negative subsequent strokes and downward positive strokes, taking into account available distributions of the nu...Show More
This article proposes a method for the derivation of a formula that links the maximum lightning-induced-overvoltage occurring on an overhead distribution line with the variables that characterize the lightning return stroke, such as the peak current, front duration, and stroke location. The coefficients of such formulas are obtained thanks to a limited number of lightning field-to-line coupling si...Show More
This article provides the implementation procedure, the validation, and some considerations on the computational efforts of the analytical expressions developed for the lightning electromagnetic fields presented in the companion paper. The validation is presented with different configurations in terms of channel-base current, ground conductivity, and distance to the lightning channel, comparing th...Show More