Quantifying the benefits of Room Temperature Vulcanising rubber coatings for HV insulators against pollution in power system resilience assessment studies

Load disruptions caused by environmental threats implicate high societal costs. Transmission System Operators (TSOs) are thus pushed to predict potentially critical scenarios and apply suitable countermeasures. Pollution mechanisms are a significant environmental cause for component outages, in particular insulators. Resilience-oriented cost-benefit analyses call for the availability of models to simulate the vulnerability of insulators to pollution and the effects of countermeasures, as well as of tools to compute resilience indicators. The paper proposes an analytical model for the vulnerability of Extra-High Voltage (EHV) / High Voltage (HV) insulators with Room Temperature Vulcanizing (RTV) rubber coatings to pollutant deposits under wet conditions, with a focus on the time dependent performances of the coatings used to improve insulators response to the threat. The proposed modeling allows to quantify the benefits brought to power system resilience by this countermeasure. In particular, the models are integrated in the resilience assessment and enhancement tool RELIEF by RSE for long-term planning studies. The application of the tool to a realistic study case, referring to a portion of the Italian EHV/HV grid, demonstrates the effectiveness of the proposed model in evaluating the technical benefits of the countermeasure in terms of increase in the outage return periods of the components.