The proposed service is composed of two solutions, each addressing a specific department of the owners of High Voltage (HV) power infrastructures:
- The department dedicated to the maintenance of the power infrastructure
- The department in charge of the network operations and energy dispatching.
The first solution provides the maintenance department with a monitoring system, in charge of continuously monitoring pylons’ status, providing alarms in case of anomalies, without the need of site inspections. The service allows the users to enhance the current inspection procedures, characterized by 2 to 3 site inspections per year, which are not able to:
- immediately detect sudden damages/anomalies before they grow up causing power system failure;
- Promptly identify rapidly evolving problems (sliding, ice sleeves growth, etc.).
The second solution provides information about line transmission capacities, to support the energy dispatch operations in critical conditions potentially leading to line overloading. Such criticalities may occur during power lines outages or in proximity of Renewable Energy Sources due to unpredictable production peaks. These peaks are threats for the owners of HV infrastructures that need to guarantee power flux within safety limitations. The proposed solution intends to overcome the current conservative approach based on static estimations of network capacity, acquiring local and adjusted parameters in order to evaluate the “true” network capacity and to safely transmit power.
Users and their needs
The potential customers are owners of High Voltage power infrastructures: these companies are in charge of dispatching the electrical energy keeping the network balanced between energy production and demand.
The involved user is the Italian Transmission System Operator (TERNA).
After consultations, TERNA expressed the needs to:
- receive alerts/alarms in case an anomaly arises (i.e., pylon displacement over user-defined threshold, structural parameters beyond user-defined threshold).
- In absence of anomalies, receive weekly report on current status;
- assess the dynamic capacity of their lines to avoid overloading
The first two needs are related to the knowledge of the integrity status of the pylons in a timely manner, more frequent with respect to the current situation.
The last need is related to the relevance of getting updated information about the operating conditions of the lines to improve the transmission of energy.
Service/ system concept
The solution provides the following information:
- Pylons’ natural frequencies.
- Displacement of the pylons using two techniques: Synthetic Aperture Radar Interferometry and Differential GNSS.
- Environmental condition (air temperature, wind speed and direction and Solar irradiation) over the entire network.
- Conductor Temperature.
- Estimates of the current capacities of the overhead lines.
The natural frequencies are parameters correlated to damages in the infrastructure: this means that a change in their values are correlated to modifications of the mechanical condition of the pylons, possibly due to damages (e.g. presence of snow on the line).
The knowledge of the actual environmental condition and the conductor temperature allows energy dispatcher to perform a more precise evaluation of the maximum amount of transmittable power.
Such information is acquired by a network of sensors that are installed on some critical structures. These data are transmitted to the user control centre, and then integrated with space data coming from Earth Observation data providers and Weather service providers.
Space Added Value
The proposed solution exploits the following space assets:
- Navigation is used for the assessment of the pylons displacements in conditions where terrain is subject to landslides and slow movements. With the installation on pylons of GNSS receivers, the system can continuously monitor pylons’ displacement with respect to a reference position (initial position of the GNSS receiver’s); this system allows the critical structure to be continuously and remotely monitored, filling the gap between traditional ground inspections.
- Earth Observation: Two type of Earth observation data are considered:
- Synthetic Aperture Radar images (Medium and High Resolution, from both COSMOSky-Med and Sentinel-1 satellites) are collected and processed using Interferometry techniques based on Permanent Scatterers; this process allows to periodically monitor pylons’ displacements over large areas. The advantage of using EO images is that it enables to observe many structures within a single image. Such solution is used in conjunction with local GNSS sensors.
- Weather data are used to support the energy dispatching service. Information regarding the current environmental condition (in conjunction with local sensors for specific areas) can be used to estimate the current capacities of the overhead lines.
The CDR of the GridWatch has been held the 28th of June; from that date on, the consortium has the task to procure all the necessary components and produce the Pilot device, based on the final architecture; once completed the Pilot device production, the execution of the testing plan arranged will assess the compliances of the final architecture with definitive list of System Requirements. Moreover, commercial interactions with additional potential users are planned to assess the possible interest of other companies in the products in phase of development.