An Integrated Approach for Power Quality Monitoring in Transmission and Distribution Systems: The Italian Scenario

This paper presents an integrated approach to power quality monitoring across Italian transmission and distribution systems. The proposed methodology combines datasets from the Italian transmission system operator, Terna, and from the QuEEN monitoring system developed by RSE, which collects power quality information in terms of voltage events and variations on medium voltage busbars in primary substations. The integration enables a unified SQL-based database architecture that supports advanced statistical analysis and cross-layer event correlation. Two case studies are presented considering a 14-years observation period: i) the evaluation of the selectivity of the protection systems carried out by analyzing the number of load disconnections per failure; ii) the investigation of the correlation between high voltage outages and medium voltage interruptions recorded by QuEEN measurement units. Results highlight a gradual decreasing trend in system selectivity and a significant match between high and medium voltage events, highlighting the benefits brought by an integrated monitoring for reliability assessment and predictive maintenance.