E-REDES solution for real-time overvoltage monitoring in LV grid | pilot results

E-REDES has been implementing initiatives to proactively identify anomalies in the low-voltage (LV) network, seeking more efficient asset management, to reduce supply interruptions, customer compensations and improve the customer experience. Considering that approximately 75% of customer premises' damages in Portugal are caused by grid-neutral losses, the need to detect neutral ruptures in advance and mitigate their effects was raised. In this context, a new functionality was specified for the LV smart meters to detect these situations and simultaneously disconnect customers' installations to prevent potential damage to their electrical appliances. The neutral loss detection feature is based on real-time voltage monitoring. When an overvoltage is detected, the customer's installation is disconnected from the grid by opening the smart meter's switch (internal relays) and, if it remains, the smart meter does not allow the switch manual reconnection by the customer. Only when the voltage returns to the established limits, during a defined monitoring period, the smart meter’s switch is allowed to be closed, either by an automatic reconnection trigger or manual closure. Considering the high increase of distributed generation, this feature can also interrupt installations in an overvoltage scen ario not associated with neutral loss, such as over-production. Different voltage limits are used, with a lower setting for injection, avoiding grid disturbances propagation and ensuring selectivity. This paper aims to present the approach, key findings and the pilot project results that focus on this new LV network management functionality relying on overvoltage real-time monitoring and actuation using the smart grid infrastructure.