Decision-Making Support Method for the Preventive Substitution of Surge Arresters on Distribution Systems

In the protection systems of power distribution networks, surge arresters are critical for protecting the grid against overvoltages caused by lightning. This equipment is subject to high voltages and currents during its operation, which degrades its expected lifetime. In general, the replacement of surge arresters is based on corrective maintenance procedures, which exposes the electrical system to failures since the protective characteristics of the arresters have already degraded. In this context, we seek to develop a new method for estimating the life span of surge arresters and a set of criteria for their preventive replacement. The method consists of assessing the correlation between fault occurrences in a distribution system with the occurrence of lightning in the concession area of a power utility company. In addition, the method assesses the correlation between the fault and lightning occurrences and data related to the degradation of such devices obtained by experimental and field tests in new surge arresters to estimate their life span and to implement a decision-making support system for their preventive substitution.