Multi-Area Frequency Restoration Reserve Sizing

Frequency Restoration Reserves are traditionally sized using deterministic methods. The constant growth in non-dispatchable renewable energy, however, is increasing the importance of probabilistic methods for reserve sizing. In addition, as the geographical scope of reserve sizing expands, overall power imbalance stochasticity is reduced. In this article, we propose a probabilistic method for shared cross-border frequency restoration reserve commitment and sizing, based on the concept of system generation margin and employing mathematical optimization. The aim is to reduce overall reserve volumes and costs. The cross-border interconnection capacities among countries are taken into account, and the shared uncertainty across interconnections is addressed via a novel robust approach. The method is tested on the cross-border system of south-east Europe that includes 9 countries. 5 different operational scenarios are used and a detailed calculation of the uncertainty distributions in each country is employed. Results show that cross-border shared sizing can significantly reduce overall reserve volumes and costs in a secure way.©2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Investigation of the H₂O sensing mechanism of DC operated chemiresistors based on graphene oxide and thermally reduced graphene oxide

Graphene oxide (GO) is a promising material for H 2O vapour sensing. However, the H 2O sensing mechanisms are still under investigation especially in the case of thermally reduced GO. To this purpose, planar devices were fabricated by spin-coating graphene oxide on glass substrates. Ultra high response to H 2O was recorded but poor repeatability and stability over time were also noted. Three different degrees of thermal reduction were applied to improve material stability. An inverse change of resistance was observed for reduced graphene oxide compared to pure graphene oxide upon interaction with H 2O. The sensing mechanisms that govern GO and reduced GO behavior were studied based on DC measurements. In the case of GO, strong ionic conductivity was proposed whereas in the case of reduced GO mixed electronic/ionic with the leading mechanism affected by H 2O percentage in air, degree of material reduction, and sensor working temperature. Finally, it was found that by promoting one sensing mechanism over the other, improved operating humidity range of the sensor can be achieved. </p

Overview of the Satellite Networked Open Ground Stations (SatNOGS) Project

The SatNOGS, or Satellite Network Open Ground Stations, project promotes and supports free and open space applications. It seeks to address the problem of connecting many satellite users/observers to many ground station operators. Modern Open Source software, web, and hardware techniques are used in implementing the Network, Database, Client, and Ground Station sub-projects. Modularity in all the systems promotes the dual-use of ground stations by not interfering with local operation while utilizing the great amount of time a civilian, non-commercial ground station would otherwise sit idle

An Updated Overview of the Satellite Networked Open Ground Stations (SatNOGS) Project

An overview of the SatNOGS project, a network of satellite ground stations around the world, optimized for modularity, built from readily available and affordable tools and resources. The rate of Low Earth Orbit (LEO) satellite launches increases with the participation of old and new entities. In this growing environment, SatNOGS provides a scalable and modular solution to track, identify, receive telemetry from, monitor, and assist operators in command/control of satellites. The SatNOGS global community, dedicated to its free and open-source values, develops hardware ground station designs (antennas, rotators, electronics), software for SDR-based communications, satellite scheduling and mission monitoring platforms. SatNOGS continuously develops and improves its infrastructure to allow observers to use this networked ground segment and remotely operate SatNOGS ground stations around the world. It also provides an easy way to store, access and view increasingly received satellites data, by supporting VHF, UHF, L and S bands