R. B. Rodrigues

Lightning Data Observed With Lightning Location System in Portugal

This paper presents an investigation into cloud-to-ground lightning activity over the continental territory of Portugal with data collected by the National Lightning Location System. The lightning location system in Portugal is first presented. Analyses about geographical, seasonal, and polarity distribution of cloud-to-ground lightning activity and cumulative probability of peak current are carried out. An overall ground flash density map is constructed from the database, which contains the information of more than five years and almost four million records. This map is compared with the thunderstorm days map, produced by the Portuguese Institute of Meteorology, and with the orographic map of Portugal. Finally, conclusions are duly drawn.

An investigation over the lightning location system in Portugal for wind turbine protection development

This paper presents a characterization of the wind energy in Portugal in what regards: the installed power capacity, the capacity under construction, and the geographical location of wind turbines. The Portuguese lightning location system (LLS) is described, and new experimental and analytical results are presented. Analysis about geographical and time distribution of cloud-to-ground (CG) strikes and accumulative probability of peak current are carried out. Also, new ground flash density (GFD) maps are presented. Hence, the paper improves the knowledge about the lightning activity in Portugal, allowing the enhancement of risk analysis studies.

Electromagnetic transients due to lightning strikes on wind turbines: A case study

The lightning discharge is one of the two natural sources of electromagnetic interference. Electric and magnetic fields generated by lightning represent a serious hazard to various systems, particularly those containing sensitive electronics. As wind power generation undergoes rapid growth, lightning damages involving wind turbines have come to be regarded with more attention. This paper is concerned with lightning surge propagation in wind turbines. We present a case study, based on a wind turbine with an interconnecting transformer, for the analysis of lightning surges. Computer simulations obtained by using the EMTP-RV code are presented, and conclusions are duly drawn.

Electromagnetic transients study due to lightning strikes on two interconnected wind turbines

As wind power generation undergoes rapid growth, lightning damages involving wind turbines have come to be regarded with more attention. Electric and magnetic fields generated by lightning represent a serious hazard to wind turbines. A new case study is presented with two interconnected wind turbines, considering that lightning strikes directly the blade of one wind turbine. Computer simulations obtained by using EMTP-RV are presented and conclusions are duly drawn.

Analysis of the Thunderstorm Activity in Portugal for its Application in the Lightning Protection of Wind Turbines

This paper presents a brief characterization of wind power in Portugal, considering the installed power capacity, the capacity under construction, and the location of wind farms. It also describes the Portuguese Lightning Location System, and presents the results of the occurrence of cloud-to-ground strikes both temporally and geographically distributed and the accumulative probability of the peak current. Based on these results, new ground flash density maps were drawn. Thus, this paper allows the characterization of discharges occurring in Portugal, helping to improve risk analysis and the protection systems adopted.

Direct lightning surge analysis in wind turbines using electromagnetic transients computer program

This paper is concerned with direct lightning surge analysis in wind turbines. Portugal has one of the most ambitious goals in terms of wind power, and in 2006 was the second country in Europe with the highest wind power growth. Nevertheless, there are still very few studies in Portugal regarding lightning protection of wind turbines using the electromagnetic transients computer program, namely the most recent and restructured version EMTP-RV. A case study is presented in this paper, based on a wind turbine with an interconnecting transformer, for the analysis of direct lightning surges. Computer simulations obtained by using EMTP-RV software are presented. These computer simulations can be easily customized for parameters characterizing wind turbines or other countries. Finally, conclusions are duly drawn.

Wind turbine power electronics and electrical machines: On lightning protection simulation

This paper presents an overview of wind energy in Portugal and briefly describes the Portuguese Lightning Location System. Some aspects of lightning activity in Portugal are discussed. The method for risk assessment due to lightning flashes to earth is performed by the computer program LPS 2008 developed in Visual Basic by the authors. LPS 2008 is based on well established standards and on the Rolling Sphere Method. LPS 2008 draws in 3D the most vulnerable points to lightning of a structure. A case study is presented to illustrate the protection measures resulting from this methodology, reducing damages due to lightning effects in power electronics and electrical machines to acceptable levels.