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Author: n.sene
Type: Publication
Date: 2015-04-02

Indirect-Lightning Performance of Overhead Distribution Networks With Complex Topology

Description:
The paper deals with the evaluation of the indirect-lightning performance of overhead distribution networks. The novelty of this contribution is that it takes into account the inherent complexity of d... see moreistribution networks. These networks are indeed characterized by a plurality of lines (main feeder and laterals) and also by the presence of typical power components (e.g., transformers and surge arresters); they consequently differ considerably from the straight line configuration generally adopted in this type of studies.
To accomplish such an evaluation we have extended the general procedure already presented in a previous paper based on the use of the LIOV code along with the Monte Carlo method. The extended procedure combines the advantage of the LIOV-EMTP computer code—that allows the calculation of lightning-induced voltages in complex distribution networks—with a heuristic technique specifically developed and integrated in the Monte Carlo routine in order to reduce the computational effort. The application of the proposed procedure to a set of distribution overhead networks characterized by different topologies, but all of the same length, shows that, in general, the usual single straight-line approach may result into a misestimation of the indirect-lightning performance. The paper also analyzes and discusses the influence of both the line terminations, and the position of the line poles.

Authors: Alberto Borghetti, Senior Member, IEEE, Carlo Alberto Nucci, Fellow, IEEE, and Mario Paolone, Member, IEEE

IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 24, NO. 4, OCTOBER 2009

Tag(s): LIOV-EMTP, lightning-induced overvoltages, lightning performance, power quality, distribution systems, overhead power lines.

Author: n.sene
Type: Publication
Date: 2015-04-01

Lightning-Induced Overvoltages Transferred Through Distribution Power Transformers

Description:
This paper deals with the calculation of lightning induced overvoltages on medium-voltage (MV) and low-voltage (LV) distribution networks taking into account the presence of MV–LV distribution trans... see moreformers and, in particular, the surge transfer through them. The influence of the high-frequency model adopted for the representation of the power transformer on the calculation results is analyzed, with regards to two different models, both identified and validated by means of laboratory measurements: namely, a simple π of capacitances, and the more complex one introduced by Morched, Marti, and Ottevangers in 1993. Accurate simulation results provide information on the adequacy of both models for the calculations of interest. Additional results, useful to evaluate the expected level of power quality and the benefits achievable by a proper installation of protection devices, are presented making reference to a realistic and complex configuration of an overhead distribution system

Authors: Alberto Borghetti, Atef Morched, Fabio Napolitano, Carlo Alberto Nucci, Mario Paolone,

IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 24, NO. 1, JANUARY 2009

Tag(s): Lightning, distribution transformers, overvolatges

Author: n.sene
Type: Publication
Date: 2015-04-01

Continuous-Wavelet Transform for Fault Location in Distribution Power Networks: Definition of Mother Wavelets Inferred From Fault Originated Transients

Description:
The paper presents a fault location procedure for distribution networks based on the wavelet analysis of the fault-generated traveling waves. In particular, the proposed procedure implements the conti... see morenuous wavelet analysis applied to the voltage waveforms recorded during the fault in correspondence of a network bus. In order to improve the wavelet analysis, an algorithm is proposed to build specific mother wavelets inferred from the fault-originated transient waveforms. The performance of the proposed algorithm are analyzed for the case of the IEEE 34-bus test distribution network and compared with those achieved by using the more traditional Morlet mother wavelet.

Authors: Alberto Borghetti, Senior Member, IEEE, Mauro Bosetti, Mauro Di Silvestro, Carlo Alberto Nucci, Fellow, IEEE, and Mario Paolone, Member, IEEE

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 23, NO. 2, MAY 2008

Tag(s): Continuous wavelet transform, distribution network, EMTP simulations, fault location, mother wavelet, power quality.