The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper analyses the lightning induced voltages in large loops, considering the propagation of the scattered voltages along the loop. The loop is modeled as a transmission line having two possible configurations: two wires above ground and one wire above ground. The inducing electric field components are introduced gradually, in order to identify the effect of each one of them. It is shown that...
This paper presents the front time and time-to-half values of lightning induced voltages obtained from deterministic and probabilistic simulations. The lightning induced-voltages are calculated at the center of an overhead line above lossy ground, considering typical parameters for first negative strokes. The waveshape parameters are influenced by the distance from the stroke striking point to the...
This paper presents the development of a simple but accurate formula to obtain the coating thickness of galvanized steel wires from the impedance of a solenoid containing a sample of the wire. The basic assumption behind the formula is that the skin depth of eddy currents in the coating is much larger than the coating thickness, which can be obtained by a proper frequency selection. The results of...
This paper presents the effect of considering propagation delays and displacement currents in the calculation of currents and voltages induced into loops due to nearby lightning flashes. Results from numerical calculation, based on a more complete electromagnetic formulation (Method of Moments — MoM) are compared with results from a quasi-stationary approach. It is shown that the voltages induced...
This paper presents a time-domain method for the calculation of the electric field at the surface of earth due to lightning, when the earth structure is made of two parallel horizontal layers of finitely conducting earth. The method is based on the assessment of the electric field at the surface considering the earth as homogeneous and with the electrical parameters of the first layer. The contribution...
This paper presents the results of a computer model to calculate the current through the power conductors of an installation struck by lightning. The model is validated by comparing its results with measurements carried out in an experimental installation struck by rocket-triggered lightning. In the following, the model is used in order to assess the current in the power conductors considering the...
This paper presents the protection procedures applied to an electronic equipment installed in the vicinity of a conductor carrying the partial or total lightning current. The paper assesses the level of overvoltages that might be induced within the equipment and the attenuation that may be achieved by the use of a metallic enclosure. Complementary procedures are also described, such as the treatment...
The installation of surge protective devices (SPD) can provide adequate lightning protection for equipment inside a structure. To this end, the main SPD characteristics are the SPD protection factor and its protection level. This paper shows that a coordinated SPD system, characterized by both the nominal discharge current and the impulse current, can have different protection factors for each equipment...
This paper presents the calculation results of lightning induced voltages on overhead lines using two different formulations for the horizontal electric field at the earth surface. The first one is a time-domain equation equivalent to the surface impedance contained in the Cooray-Rubinstein formula, while the second one is an improved equation that provides more accurate results in the vicinity of...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.