LIGHTNING PROTECTION OF LOW-VOLTAGE NETWORKS

The improvement of the reliability and power quality levels of electric systems is a matter of increasing concern because today’s equipment are much more susceptible to power quality issues than was equipment used in the past. Distribution networks are often located in areas with high ground flash densities, being therefore subject to lightning-caused power interruptions. As a significant number of line faults and equipment damages, as well as malfunction of customer electronic systems, is lightning-associated, many studies have been carried out, especially on medium voltage (MV) lines, aiming at obtaining a better understanding of the characteristics of the lightning overvoltages. More recently, special attention has been drawn to the transients on low voltage (LV) networks. Due to their much lower withstand capabilities in comparison with those of MV lines, LV networks are more prone to lightning electromagnetic interferences