The project’s objective is to study and research innovative solutions for components and materials to enhance the safety and resilience of the electrical system, also through the use of new diagnostic methodologies necessary to meet the new demands of the grid and the changing environmental stresses it faces.
The project specifically aims to address the issues of safety and resilience of the electrical system by identifying different ways to mitigate the effects that environmental phenomena can have on the grid.
These topics are of particular importance in the 2017 National Energy Strategy (SEN2017), the European Strategic Energy Technology Plan (SETPLAN), and the more recent National Integrated Energy and Climate Plan (PNIEC). Additionally, ARERA has established a technical working group with TSO and DSO to enhance the resilience of electrical infrastructure in response to increasingly frequent severe weather events.
In particular, the following topics were addressed in the activities completed during 2021:
• Meteorological phenomena with snow and ice overloads on overhead power lines: The activity included the development of new coatings and the study of devices to mitigate the phenomenon. The characterization and performance verification of the coatings were carried out in the laboratory and through field installations (on operational lines or experimental plants). Additionally, the modeling and experimentation of the mechanical properties of wet snow were addressed with the development of new testing methodologies.
• Contaminant accumulation on insulators: The activities involved harmonizing experimental data collected on insulators with modeling data using data fusion techniques, which, for the first time, enabled the definition of a severity map of air insulation contamination levels in Italy considering both methods. Furthermore, improvements were made to the forecasting and alert system for critical conditions, the study of new coatings to increase insulator durability, the development of innovative monitoring systems, and the execution of tests in both laboratory and field settings.
• Heatwaves and lack of rainfall: This topic involved the development of diagnostic and monitoring systems for the condition of medium voltage (MV) cable networks, as well as the development of a system to predict critical conditions related to failures on underground distribution lines in urban areas. The activity also included the implementation of a prototype tool (demonstrator) for acquiring raw data (non-proprietary) on partial discharges, processed with advanced analysis techniques.
• Resilience and fragility of electrical substations concerning earthquakes and floods: Continuing from the second year of the three-year research program, experimental studies on local seismic amplification were conducted in other areas of interest to the Electrical System (ES), along with the experimental definition of fragility curves for non-structural elements of the ES. Additionally, the user manual for the Seismological Application developed by RSE was drafted, useful for the seismological characterization of areas of interest for the national electrical system.
• Superconducting components and devices for AC and DC networks: Characterization measurements in both AC and DC were performed on new 2G SAT tapes and windings, and numerical simulations were conducted to analyze the use of new tapes in SFCL for the power grid. Measurements of stresses and strains in superconducting tapes using strain gauges at cryogenic temperatures and simulations using multiphysics packages continued. Benchmarking activities between the SC cable simulation code developed by RSE and the 4C code also continued. Additionally, a methodology for optimizing the configuration of SAT cables was developed to support the assessment of potential technical-economic advantages over conventional resistive cables.
• Modeling of partial discharges in polymer matrices: Activities included developing an algorithm for simulating PD in real geometries and chemically modeling the phenomenon, laying the groundwork for identifying and describing a carbon cycle within cavities subject to PD. Regarding experimental activities, it was demonstrated that the Viktor sensor could be used to detect defects in high-voltage insulators and distinguish between external surface conduction and internal defect detection. Experimental analyses of the aging of resin-insulated transformers also continued.
• Innovative diagnostics and sensors for ester oil-insulated transformers: The effects of the interaction of virgin ester oil on the dielectric response of the solid insulation system and the optical response for detecting furfural in different types of paper and ester were positively analyzed. Neural networks were applied for the first time to the analysis of vibration data from transformers for fault classification, both in a binary case (tight or loose transformer windings) and in a multi-class case (reconstruction of the transformer degradation profile).