Lightning Electromagnetic Field Coupling to Overhead Lines: Theory, Numerical Simulations, and Experimental Validation (original) (raw)
Related papers
2021 35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)
Recent power quality studies have been focused on the source-identification of voltage disturbances at distribution network busses. This paper describes a method aimed at correlating indirect-lightning events with power systems relay operations, associated with voltage dips. The proposed method, based on the coordinated use of the Italian lightning location system CESI-SIRF, the Italian monitoring system of protection manoeuvres CESI-SAM, and the availability of an advanced simulation tool for the accurate simulation of lightning-induced voltages on complex power networks, namely the LIOV-EMTP code, is applied to the real case of an Italian distribution system. The LIOV-EMTP code is also employed along with a statistical procedure based on the Monte Carlo method to carry out a statistical analysis aimed at assessing the lightning performance of a typical Italian distribution line.
Effect of nearby lightning on overhead electric lines: a comparison of simulation methods
IEEE International Caracas Conference on Devices, Circuits and Systems, 1998
A survey of the methods proposed in the literature to evaluate the effect of nearby lightning strokes on electric power transmission/distribution circuits is performed, describing the assumptions taken as well as the mathematical tools applied at each of the simulation stages of the physical phenomena. A comparison is made between the approaches proposed by Master & Uman [1984] and Chowdhury
Lightning – Induced Overvoltages on Overhead Lines : Modelling and Experimental Validation
2007
The evaluation of induced overvoltages from indirect lightning has been for more years one of the most important problems in designing and coordinating the protection of overhead power lines. In this paper, we present the frequently coupling model used in the power lightning literature for the calculation of lightning induced overvoltages, the Agrawal approach. The algorithm applies to single conductor line above a perfectly conducting ground. The computation results are first validated by experimental results obtained using a reduced scale line model illuminated by the EMP simulator of the Swiss Federal Institute of Technology in Lausanne (SEMIRAMIS), and then are compared with the computation results obtained by the LIOV code (beta version).
Transient Voltages in Transmission Lines Caused by Direct Lightning Strikes
IEEE Transactions on Power Delivery, 2005
This work presents some results concerning the computational simulation of electromagnetic transients in transmission lines caused by direct strikes of lightning. The research has been carried out by application of a hybrid electromagnetic code developed by the authors' research group. The presented results comprise mostly overvoltage waves developed across insulator strings or at ground wires due to the injection of impulsive current at the top of towers and at the shielding wires along span. The effect of adjacent towers on the developed overvoltage is evaluated. Sensitivity analyses are developed considering a range of values for soil resistivity, variable configurations of tower-footing and different injected current waveshapes. Some remarkable conclusions concern the grounding effective length for mitigation of overvoltage across the insulator strings, the relevance of midspan strikes and the importance of accurate representation of lightning current waveshape in the evaluation of lightning performance of lines.
Effects of nearby buildings on lightning induced voltages on overhead power distribution lines
Electric Power Systems Research, 2013
For the case of urban overhead lines, the presence of nearby buildings is expected to affect the overvoltages induced by nearby cloud-to-ground lightning return strokes. So far, this effect has been seldom taken into account in the literature on the subject. The paper presents a 3D FEM model that calculates the lightning electromagnetic pulse (LEMP) taking into account the presence of a building placed in proximity of the LEMP-coupled overhead line. As a first approximation, all the metallic elements are assumed as perfect conductors, as well as the ground plane. The calculated fields are then introduced in the Agrawal et al. coupling model for the calculation of the induced voltages. The results of a sensitivity analysis carried by varying the model and dimensions of the building, its distance to the line and the position of the lightning stroke location are presented and discussed.
Procceedings of the International Conference on Power Systems Transients (IPST-2005), 2005
Abstract—Lightning-induced voltages are important sources of power quality problems: indeed, they can cause short interruptions and voltages sags on distribution systems. The analysis of these disturbances induced on distribution networks by lightning electromagnetic pulses (LEMP) radiated by nearby lightning, requires the availability of accurate models and relevant computer programs of LEMP-illuminated lines. These should be able to reproduce the real and complex configuration of distribution systems including the presence of ...
Lightning-induced voltages on overhead lines
IEEE Transactions on Electromagnetic Compatibility, 1993
The paper discusses a modeling procedure that permits calculation of lightning-induced voltages on overhead lines starting from the channel-base current. The procedure makes use of 1) a lightning return-stroke model proposed by the authors for the calculation of the lightning electromagnetic field; and 2) a coupling model already presented in the literature based on the transmission line theory for field-to-overhead line coupling calculations. Both models are discussed and tested with experimental results. The hypothesis of perfect conducting ground, generally adopted in studies on the subject, is discussed in order to better assess its validity limits. The procedure is applied for the analysis of the voltages induced on an overhead line by a nearby lightning return stroke with a striking point equidistant from the line terminations. The analysis shows that the vertical and horizontal components of the electric field are both to be taken into account in the coupling mechanism. The peak value and the maximum time derivative of the channel-base current are shown to affect both the peak value and the maximum front steepness of the induced voltages while, for the examined case, the returnstroke velocity affects practically only the front steepness of the induced voltages. A comparison with other models proposed for the same purpose is presented. Peak value and maximum front steepness of the induced voltages calculated using other lightning return-stroke models differ; these differences are of the same order of magnitude as those that would result from different sets of characteristic parameters of the lightning discharge. It is also shown that a different coupling model used in the power-lightning literature by several other authors may result in a less accurate estimation of the induced voltages.
Journal of Electrostatics, 2004
The evaluation and the analysis of the lightning electromagnetic pulse (LEMP) response of distribution networks require the availability of accurate models of LEMP-illuminated lines and their implementation into software tools able to calculate lightning-induced electromagnetic transients in distribution systems having complex configuration. This paper deals indeed with a computer code, LIOV (lightning induced overvoltage code), and with two interfaces recently realized between it and (a) the DCG/EPRI EMTP96 on the one hand and (b) the SimPowerSystems program in the Matlab-Simulink environment on the other hand. The aim of these interfaces is to extend the simulation capabilities of the LIOV code, which computes lightning-induced voltages on a single multiconductor transmission line above lossy ground, to the case of distribution systems characterized by complex yet realistic configurations. Models/code validation by means of a comparison with experimental results is also presented. r
IEEE Transactions on Power Delivery, 2010
In this paper, the effect of the tilt angle of return stroke channel and the stratified lossy ground on the lightning-induced voltages on the overhead lines are studied using the modified transmission-line model with linear current decay with height (MTLL). The results show that the lightning-induced voltages from oblique discharge channel are larger than those from the vertical discharge channel, and the peak values of the induced voltages will increase with increasing the tilt angle. When the ground is horizontally stratified, the peak of the induced voltages will increase with increasing the conductivity of the lower layer at different distances. When the upper ground conductivity increases, the voltage peak values will decrease if the overhead line is nearby the lightning strike point and increase if the overhead line is far from the lightning strike point. Moreover, the induced voltages are mainly affected by the conductivity of the lower layer soil when the conductivity of the upper layer ground is smaller than that of the lower layer ground at far distances. When the ground is vertically stratified, the induced voltages are mainly affected by the conductivity of the ground near the strike point when the overhead line and the strike point are located above the same medium; if the overhead line and the strike point are located above different mediums, both of the conductivities of the vertically stratified ground will influence the peak of the induced voltages and the conductivity of the ground which is far from the strike point has much more impact on induced voltages.