The aim of this paper is to give scientific background and essential assumptions to be introduced into the design of lightning and surge protection in photovoltaic installations (PVIs), with particular emphasis on the aspects of standardization to be covered. For this purpose, the relevant protective measures given in the standards for conventional low-voltage power distribution systems (CLVPDSs) are adapted in part. This revision is required because the peculiar characteristics of PVIs are different from those of CLVPDSs. The resulting protection approach that determines the advisable protective measures by a risk management has been applied to an actual grid-connected PVI (GCPVI), Univer Project. The extra cost of this protection in this PVI (approximately 3.6% of the system cost) is of secondary importance because of the increase of safety and availability. Furthermore, in order to fulfill with this protection, the surge withstand capability (SWC) of PV modules has been investigated as well.

This paper assesses the protection against electric shock in a photovoltaic generator (PVG), the DC side of a PV installation. Within this context, we discuss the applicability of the protection requirements of the International Electrotechnical Commission 60364, the international standard that provides guidelines for wiring in low-voltage (LV) electrical installations. The unique operational characteristics of a PVG, which differ from those of a conventional AC LV system, made it necessary to revise and adapt these requirements. With a view to discovering the effectiveness of electric shock protection in ungrounded PVGs, we carried out both a theoretical and practical study in a real PVG in order to analyze its electrical behavior. As part of our study, the feasibility of applying an ldquoactiverdquo means of protection was experimentally tested in this same PVG.